🏷

Classifications

Harrison's Part

Occupational Disease

◆

Subtypes

3

Simple (Uncomplicated) Coal Workers' Pneumoconiosis

The early form, defined radiographically by small rounded opacities (ILO profusion categories 1-3) reflecting coal macules and micronodules, without conglomerate masses. Frequently asymptomatic and detected only on surveillance radiography, which is what makes periodic screening the key intervention window.

Show evidence (1 reference)

PMID:41411198 SUPPORT Human Clinical

"Early pneumoconiosis can be asymptomatic, but advanced disease often leads to disability and premature death."

Establishes the asymptomatic early stage that distinguishes simple CWP from the complicated form, and why it is found by screening rather than by symptoms.

Complicated CWP / Progressive Massive Fibrosis (PMF)

Defined by conglomerate fibrotic masses one centimetre or larger (ILO large opacity categories A, B, C) formed by coalescence of nodular lesions. Carries a substantially worse prognosis than simple CWP and is characteristically relentless — it can progress after dust exposure ends. Its prevalence in long-tenured central Appalachian miners has risen roughly tenfold from a late 1990s nadir.

Show evidence (2 references)

PMID:35353671 SUPPORT Human Clinical

"the prevalence of PMF has increased from 0.33% to 3.2% in miners with 25 years or more of tenure"

Quantifies the resurgence of the complicated form among long-tenured central Appalachian miners. Note this sentence sits in the cited paper's introduction and carries its own citations; the primary surveillance reports are the source of record for the figure itself.

PMID:31302880 SUPPORT Other

"respiratory morbidity including ongoing fibrosis and functional impairment can occur after exposure ceases"

Sources the claim that this subtype keeps progressing once dust exposure has ended, which is what separates its prognosis from simple CWP.

Rapidly Progressive Pneumoconiosis (RPP)

An accelerated presentation in which radiographic profusion advances unusually fast, often in younger miners with shorter tenure. Lung pathology in these cases shows features of accelerated silicosis and mixed-dust lesions with abundant birefringent silica and silicates rather than the classic coal-predominant macule, so this subtype is better understood as a silica-driven variant of coal mine dust lung disease than as fast simple CWP.

Show evidence (2 references)

PMID:26513613 SUPPORT Human Clinical

"Thirteen cases were reviewed, many of which had features of accelerated silicosis and mixed dust lesions."

Documents that rapidly progressive cases carry accelerated-silicosis and mixed-dust histology rather than the classic coal macule pattern.

PMID:26513613 SUPPORT Human Clinical

"Our findings suggest that rapidly progressive pneumoconiosis in these miners was associated with exposure to coal mine dust containing high concentrations of respirable silica and silicates."

Attributes the rapidly progressive subtype to the silica and silicate fraction of the dust, the basis for treating it as a distinct subtype.

?

Discussions and Knowledge Gaps

1

Does epithelial-mesenchymal transition in alveolar epithelial cells actually contribute myofibroblasts to human coal workers' pneumoconiosis, or is the EMT branch curated here an artifact of the model system it was demonstrated in?

HUMAN MODEL MISMATCH OPEN emt_human_fidelity

Attached to

pathophysiology#Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition pathophysiology#Fibroblast Activation and Myofibroblast Differentiation

The entire EMT branch rests on one study, PMID:36581638. Its in vitro arm used A549 — a lung adenocarcinoma line standing in for alveolar type II cells — and BEAS-2B, a bronchial line; its in vivo arm gave C57BL/6 mice coal dust *nanoparticles*, a fraction of, not a substitute for, the respirable coal mine dust miners inhale. No human CWP tissue evidence supports the branch. Two things make this a mismatch rather than a plain gap. The node binds CL:0002063 pulmonary alveolar type 2 cell and asserts type-II EMT in human disease on the strength of a carcinoma line's behaviour. And EMT as a source of myofibroblasts in human lung fibrosis is contested in its own right, not settled background — lineage-tracing work in other fibrotic lung disease has repeatedly failed to confirm it. The mechanism is well evidenced in the model; whether it operates in a miner's lung is the open question.

Proposed experiments

Lineage-traced fate mapping of alveolar type II cells in a coal mine dust model

emt_lineage_trace_coal_dust

Expose alveolar-type-II-lineage-labelled reporter mice to authentic respirable coal mine dust rather than to a nanoparticle fraction, and score whether labelled cells appear within fibrotic lesions carrying myofibroblast markers. Substituting real mine dust for the nanoparticle preparation is the point of the experiment, not an incidental detail.

Would support

pathophysiology#Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition

Would refute

pathophysiology#Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition

Supporting outcome

Lineage-labelled alveolar type II descendants are found inside coal macules and fibrotic foci co-expressing alpha-SMA, in proportion to lesion burden.

Refuting outcome

Labelled cells remain confined to the epithelium with no alpha-SMA-positive descendants in lesions, placing the myofibroblast pool entirely with resident mesenchymal cells.

EMT marker localization in human CWP lung tissue

emt_marker_human_cwp_tissue

Apply dual-marker immunohistochemistry for epithelial and mesenchymal markers to archived human coal miner lung specimens — the National Coal Workers' Autopsy Study material this entry already cites for PMF typing — scoring cells at the macule and PMF margins for a transitional phenotype.

Would support

pathophysiology#Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition

Would refute

pathophysiology#Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition

Supporting outcome

Cells co-expressing epithelial and mesenchymal markers are enriched at lesion margins in miner lung relative to unexposed controls.

Refuting outcome

No transitional phenotype is detectable at lesion margins, leaving the EMT branch unsupported in human tissue.

Recorded rather than resolved by deleting the branch: the model evidence is real and the branch is the only route by which epithelial injury reaches the fibroblast pool in this entry. The point is that its translational status is unestablished, not that it is wrong.

⚙

Pathophysiology

15

Respirable Coal Mine Dust Deposition and Retention

Respirable coal mine dust — a heterogeneous mixture of carbonaceous coal particles, crystalline silica, and other silicate minerals — is small enough to escape upper-airway defences and deposit in the terminal bronchioles and alveoli, beyond the reach of mucociliary clearance. Cumulative retained dust burden, not any single exposure, is the driving quantity.

respiratory bronchiole UBERON:0002188 pulmonary alveolus UBERON:0002299

Downstream

Alveolar Macrophage Phagocytosis of Retained Dust

Silica-Enriched Dust Burden

Show evidence (2 references)

PMID:41411198 SUPPORT Human Clinical

"Coal workers' pneumoconiosis (CWP) is a preventable, progressive occupational lung disease caused by inhaling respirable coal mine dust, a complex mixture commonly containing coal, crystalline silica, and other silicate minerals."

Establishes inhaled respirable coal mine dust as the necessary cause and names the three mineral fractions of the deposited material.

PMID:35831008 SUPPORT Other

"the lesions and macules comprise inhaled coal dust particles engulfed in alveolar macrophages and surrounded by inflammatory cells"

Establishes that the retained particles are coal dust specifically, sitting inside alveolar macrophages in the lesion — the deposition-and-retention step this node represents, rather than a general statement about ambient particulate matter.

Silica-Enriched Dust Burden

The crystalline silica and silicate fraction of the retained dust, which in contemporary thin-seam mining is markedly higher than historically because accessing thin coal seams requires cutting silica-bearing rock strata. Silica is far more cytotoxic and fibrogenic per particle than carbonaceous coal, so a silica-enriched burden shifts the disease toward the accelerated and silica-type severe forms rather than merely producing more of the same lesion.

Downstream

Alveolar Macrophage Phagocytosis of Retained Dust

Nodule Coalescence into Progressive Massive Fibrosis

Show evidence (3 references)

PMID:35353671 SUPPORT Human Clinical

"In situ mineralogic analysis showed that the percentage (26.1% vs. 17.8%; P < 0.01) and concentration (47.3 × 108 vs. 25.8 × 108 particles/cm3; P = 0.036) of silica particles were significantly greater in specimens from contemporary miners compared with their historical counterparts."

Directly measures the silica fraction of retained lung dust and shows it has risen in contemporary miners, which is the mineralogic basis for this node.

PMID:26513613 SUPPORT Human Clinical

"Polarized light microscopy revealed large amounts of birefringent mineral dust particles consistent with silica and silicates; carbonaceous coal dust was less prominent."

Shows silica and silicates dominating over carbonaceous coal in the retained dust of severe contemporary cases, supporting a distinct silica-enriched burden rather than simply more coal.

PMID:35831008 SUPPORT Other

"In contrast to coal dust, silica dust is considered more toxic and potent in eliciting oxidative stress and cellular inflammation in the lungs"

Sources the comparative-potency half of this node's claim, which the mineralogy evidence above does not address: the mineralogy says how much silica is present, this says why that matters per particle.

Alveolar Macrophage Phagocytosis of Retained Dust

Alveolar macrophages recognize and internalize the deposited particles in an attempt to clear them. Coal and silica particles are poorly biodegradable, so the macrophage cannot resolve the load and instead becomes the persistently activated cell around which the lesion is built.

alveolar macrophage CL:0000583

phagocytosis GO:0006909 ↑ INCREASED

Downstream

Reactive Oxygen Species Generation and Oxidative Injury

Dust-Laden Macrophage Death

Show evidence (2 references)

PMID:26024344 SUPPORT Other

"Human and laboratory studies have suggested oxidant injury, and increased recruitment and activity of macrophages play important roles in dust-induced lung injury."

Places increased macrophage recruitment and activity, alongside oxidant injury, at the centre of coal-dust lung injury.

PMID:35831008 SUPPORT Other

"the lesions and macules comprise inhaled coal dust particles engulfed in alveolar macrophages and surrounded by inflammatory cells"

States the phagocytic uptake this node annotates: coal dust particles engulfed by alveolar macrophages, and the lesion built around them.

Reactive Oxygen Species Generation and Oxidative Injury

Dust-laden macrophages and the reactive particle surfaces generate reactive oxygen species that overwhelm local antioxidant defences. Reactive oxygen species are the shared upstream signal feeding both the inflammasome branch and the epithelial injury branch of the cascade.

alveolar macrophage CL:0000583

reactive oxygen species metabolic process GO:0072593 ↑ INCREASED

Downstream

Macrophage Mitochondrial Dysfunction and Defective Mitophagy

NF-kappaB and NLRP3 Inflammasome Activation

Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition

Show evidence (3 references)

PMID:15364596 SUPPORT Model Organism

"TBARS were increased 60 days after coal dust exposure and protein carbonyl groups increased at all times after coal dust exposure (48 h, 7 days, 30 days, and 60 days)."

Direct in vivo measurement of lipid peroxidation and protein oxidation in coal-dust-exposed lung, which is the oxidative injury this node asserts rather than an inference from a signalling pathway in one cell type.

PMID:36581638 SUPPORT In Vitro

"activation of the IGF1/IGF1R axis induced generation of reactive oxygen species (ROS) to promote epithelial-mesenchymal transition (EMT) in alveolar epithelial cells (AECs) to accelerate PF"

Supports the edge from reactive oxygen species to epithelial-mesenchymal transition in alveolar epithelial cells, one of the two branches this node feeds. Note this branch is epithelial; the macrophage-derived and particle-surface oxidant claim rests on the in vivo item above.

PMID:36581638 SUPPORT Model Organism

"ROS induced inflammation and EMT by the activation of the NF-kB/NLRP3 axis to accelerate PF"

Supports the other branch: reactive oxygen species acting through the NF-kappaB/NLRP3 axis to drive inflammation.

Macrophage Mitochondrial Dysfunction and Defective Mitophagy

Coal-silica dust collapses mitochondrial membrane potential and impairs oxidative phosphorylation in macrophages, while suppressing PINK1/Parkin signalling so the damaged mitochondria are not cleared. The failure of mitochondrial quality control amplifies the oxidant load and feeds both macrophage death and the inflammatory output, rather than being a passive consequence of them.

alveolar macrophage CL:0000583

mitophagy GO:0000423 ↓ DECREASED

Animal models

Coal-silica mixed dust mouse model with kinetin mitophagy rescue Mouse recapitulates Reproduces the mitochondrial collapse and mitophagy failure in macrophages after mixed coal-silica dust exposure.

Downstream

Dust-Laden Macrophage Death

Sustained Inflammatory Cell Recruitment and Amplification

Show evidence (2 references)

PMID:41894156 SUPPORT Model Organism

"CSD exposure triggered ROS accumulation, mitochondrial membrane potential collapse, and impaired oxidative phosphorylation, leading to reduced adenosine triphosphate synthesis."

Measures the mitochondrial dysfunction this node asserts, in a coal-silica mixed dust exposure rather than in a generic particulate model.

PMID:41894156 SUPPORT Model Organism

"CSD suppressed PINK1/Parkin signaling and diminished LC3B mitochondrial recruitment, resulting in defective mitophagy"

Sources the defective-mitophagy half of the node and names the pathway through which clearance fails.

Dust-Laden Macrophage Death

Poorly biodegradable particles — the silica fraction especially — are cytotoxic to the macrophages that ingested them, and pro-apoptotic signalling rises in the alveolar compartment after coal dust exposure. Particles freed by dying cells are available for re-uptake by newly recruited macrophages, a loop that keeps the lesion building without further inhaled dust. How much of the early injury this cell death actually accounts for is contested; see the refuting evidence below.

alveolar macrophage CL:0000583

apoptotic process GO:0006915 ↑ INCREASED

Downstream

Alveolar and Small-Airway Tissue Injury

Show evidence (2 references)

PMID:16966090 SUPPORT INDIRECT Model Organism

"In rats exposed to BNF, CD exposure increased alveolar expression of the proapoptotic mediator Bax but decreased CYP1A1 induction relative to BNF exposure alone."

Indirect on two counts, both material. The pro-apoptotic response is measured under co-exposure to beta-naphthoflavone rather than to coal dust alone, and the assay localizes to alveolar cells generally rather than to macrophages specifically. Quoted in full so the conditional survives.

PMID:16966090 REFUTE Model Organism

"Combined BNF and CD exposure increased Bax expression and apoptosis in the lung, but Bax and apoptosis were not the major determinants of early lung injury in this model."

The same study's own conclusion argues against apoptosis being the main driver of early injury. Curated as a REFUTE item rather than omitted, because the supporting quote above comes from the same paper and reading one without the other would overstate the node.

Alveolar and Small-Airway Tissue Injury

The cumulative tissue-level result of retained dust, macrophage death and oxidant exposure: structural and functional damage concentrated in the alveoli and the small conducting airways, which is where the dust sits and where the reparative program is then triggered.

wound healing GO:0042060 ↕ DYSREGULATED

respiratory bronchiole UBERON:0002188

Animal models

Coal dust particle instillation mouse model with vitamin D rescue Mouse recapitulates Reproduces alveolar structural destruction and activation of inflammatory and cell-death pathways after sustained coal dust exposure.

Downstream

Sustained Inflammatory Cell Recruitment and Amplification

Show evidence (2 references)

PMID:26024344 SUPPORT Other

"Inhalation of coal mine dust results in a spectrum of symptoms, dysfunction, and pathological changes in the respiratory tract that collectively have been labeled coal mine dust lung disease."

Sources the tissue-injury claim this node makes, and the coal mine dust lung disease framing under which the injury is classified.

PMID:26024344 SUPPORT Other

"Pathologic changes associated with mineral dust deposition in the small airways may be of particular importance in contemporary miners with rapidly progressive respiratory impairment."

Localizes the injury to the small airways, the anatomical claim this node makes, and ties it to the contemporary rapidly progressive presentation.

NF-kappaB and NLRP3 Inflammasome Activation

Reactive oxygen species and retained particles activate NF-kappaB signalling and assembly of the NLRP3 inflammasome in macrophages and epithelial cells, activating caspase-1 and releasing mature IL-1beta and IL-18. This converts a particle-handling problem into a sustained cytokine signal.

alveolar macrophage CL:0000583

NLRP3 inflammasome complex assembly GO:0044546 ↑ INCREASED positive regulation of canonical NF-kappaB signal transduction GO:0043123 ↑ INCREASED

Downstream

Sustained Inflammatory Cell Recruitment and Amplification

Show evidence (2 references)

PMID:36581638 SUPPORT Model Organism

"the protein levels of p-NF-κB(Ser536)/NF-κB, NLRP3 and Cleaved Caspase1(Asp297)/Caspase1 in the lung tissues, as well as the contents of IL-1β and CXCL2 in the bronchoalveolar lavage fluid, were significantly increased in CD-NPs-induced pre-fibrosis model mice"

The study's own in vivo measurement of every component this node asserts — NF-kappaB phosphorylation, NLRP3, cleaved caspase-1 and the IL-1beta output — in coal-dust-exposed mouse lung.

PMID:36581638 SUPPORT In Vitro

"p-NF-κB(Ser536)/NF-κB was significantly increased in the CD-NPs-induced pre-fibrotic cell model and could be inhibited by PPP for 24 h"

The cell-model counterpart, with pharmacological inhibition establishing that the NF-kappaB activation is coal-dust-driven rather than incidental.

Sustained Inflammatory Cell Recruitment and Amplification

IL-1beta, IL-18, TNF-alpha and chemokines recruit neutrophils and further macrophages to the peribronchiolar region. Because the retained dust is never cleared, the recruitment does not resolve, and the small airways carry the signature chronic inflammatory change of coal miners' lungs.

neutrophil CL:0000775 alveolar macrophage CL:0000583

chronic inflammatory response GO:0002544 ↑ INCREASED leukocyte migration GO:0050900 ↑ INCREASED

respiratory bronchiole UBERON:0002188

Downstream

Fibroblast Activation and Myofibroblast Differentiation

Chronic cough

Show evidence (2 references)

PMID:26024344 SUPPORT Other

"Inflammatory changes in the small airways have long been recognized as the signature lung pathology among coal miners."

Establishes sustained small-airway inflammation as the defining, and anatomically localized, pathology of coal miners' lungs.

PMID:36581638 SUPPORT Model Organism

"the contents of IL-1β and CXCL2 in the bronchoalveolar lavage fluid, were significantly increased in CD-NPs-induced pre-fibrosis model mice"

Measures the neutrophil chemokine CXCL2 and IL-1beta in coal-dust-exposed mouse airway fluid, the recruitment signal this node claims rather than a background statement about inflammasomes generally.

Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition

Injured alveolar epithelial cells undergo epithelial-mesenchymal transition, losing epithelial identity and acquiring a mesenchymal, matrix-producing phenotype. This is a second route into the fibroblast pool, parallel to activation of resident fibroblasts by the inflammatory milieu.

alveolar type II epithelial cell CL:0002063

epithelial to mesenchymal transition GO:0001837 ↑ INCREASED

Downstream

Fibroblast Activation and Myofibroblast Differentiation

Show evidence (2 references)

PMID:36581638 SUPPORT In Vitro

"The above data indicated that inhibition of NLRP3 reversed EMT induced by CD-NPs."

The study's own loss-of-function result: blocking NLRP3 abolishes the coal-dust-induced transition, establishing this node as downstream of the inflammasome rather than merely coincident with it.

PMID:36581638 SUPPORT Model Organism

"CD-NPs induced PF by promoting inflammation and EMT via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."

The study's overall conclusion, placing epithelial-mesenchymal transition downstream of coal dust and upstream of pulmonary fibrosis. Demonstrated with coal dust nanoparticles in cell and mouse systems; that nanoparticle fraction is a component of, not a substitute for, the respirable coal mine dust miners inhale.

Fibroblast Activation and Myofibroblast Differentiation

Resident lung fibroblasts, together with cells arriving via epithelial-mesenchymal transition, differentiate into alpha-smooth-muscle-actin positive myofibroblasts under TGF-beta and inflammatory cytokine signalling. This is the central effector step: from here the lesion is matrix, not inflammation.

lung fibroblast CL:0002553 myofibroblast CL:0000186

transforming growth factor beta receptor signaling pathway GO:0007179 ↑ INCREASED

Animal models

Coal dust particle instillation mouse model with vitamin D rescue Mouse partially recapitulates Reproduces profibrotic signalling and an M2 macrophage population that tracks fibrosis, with vitamin D reducing both.

Downstream

Peribronchiolar Collagen Deposition and Coal Macule Formation

Show evidence (2 references)

PMID:36581638 SUPPORT In Vitro

"the protein levels of COL-1, COL-3, and α-SMA were highest in the CD-NPs-induced cell model"

Directly measures the alpha-SMA-positive myofibroblast phenotype and its collagen output after coal dust exposure — the node's central claim, from the study's own results rather than its background.

PMID:35831008 SUPPORT Other

"activate fibroblasts, which increase the production of extracellular matrix proteins, leading to collagen deposition and eventual scarring of lung tissue"

Sources the inflammation-to-fibroblast-activation step this node sits at, from a review of coal and silica dust lung disease specifically rather than from generic pulmonary-fibrosis background. The same passage names TGF-beta among the mediators produced, which is the signalling annotated here.

Peribronchiolar Collagen Deposition and Coal Macule Formation

Myofibroblasts deposit collagen and reticulin around the dust-laden macrophage collection at the respiratory bronchiole, producing the coal macule — the histopathologic hallmark lesion of CWP. Macules aggregate into micronodules and nodules that become visible as small rounded opacities on chest radiography, defining simple CWP.

extracellular matrix organization GO:0030198 ↑ INCREASED collagen biosynthetic process GO:0032964 ↑ INCREASED

respiratory bronchiole UBERON:0002188

Downstream

Focal Centrilobular Emphysema

Nodule Coalescence into Progressive Massive Fibrosis

Pulmonary nodule

Show evidence (1 reference)

PMID:26024344 SUPPORT Other

"The coal macule is an inflammatory lesion associated with deposited dust, and occurs in the region of the most distal conducting airways and proximal respiratory bronchioles."

Defines the hallmark lesion and fixes its anatomical location at the respiratory bronchiole, which is the location bound on this node.

Focal Centrilobular Emphysema

Destruction of alveolar walls immediately around the coal macule produces focal centrilobular emphysema. This is the obstructive component of coal mine dust lung disease and runs alongside the restrictive fibrotic component rather than replacing it, which is why advanced disease is characteristically a mixed defect.

Downstream

Impaired Gas Exchange and Mixed Ventilatory Defect

Emphysema

Show evidence (3 references)

PMID:35831008 SUPPORT Other

"coal macules or lesions <10 mm in diameter occurring mostly in the upper lung lobes due to the accumulation of dust particles and dust-laden macrophages are usually associated with focal centrilobular emphysema"

Sources the morphologic claim this node actually makes — focal centrilobular emphysema arising around the macule — and with it the incoming edge from coal macule formation.

PMID:24186945 SUPPORT INDIRECT Human Clinical

"Coal mine dust exposure increased risk for mortality from pneumoconiosis and COPD."

Indirect: establishes an obstructive disease burden attributable to coal mine dust at the population level, from which the emphysematous substrate follows, rather than reporting the morphology itself.

PMID:24186945 SUPPORT Human Clinical

"Our findings support previous studies showing that exposure to coal mine dust and respirable silica leads to increased mortality from malignant and non-malignant respiratory diseases even in the absence of smoking."

Shows the excess respiratory mortality persists in the absence of smoking, so the obstructive component is dust-driven rather than a confounded smoking effect.

Nodule Coalescence into Progressive Massive Fibrosis

Nodular lesions coalesce into conglomerate fibrotic masses one centimetre or larger, destroying regional lung architecture. PMF is the disabling complicated form and is characteristically self-sustaining: it can continue to progress after dust exposure has ended. The silica-enriched dust burden of contemporary mining shifts the histologic type of these masses toward silica-type PMF.

lung UBERON:0002048

Animal models

Coal-silica mixed dust mouse model with kinetin mitophagy rescue Mouse partially recapitulates Produces pulmonary fibrosis after mixed-dust exposure, but on a months-long murine timescale.

Downstream

Impaired Gas Exchange and Mixed Ventilatory Defect

Pulmonary fibrosis

Show evidence (5 references)

PMID:37295943 SUPPORT Human Clinical

"Of 322 cases found to have PMF, study pathologists characterised 138 (43%) as coal-type, 129 (40%) as mixed-type and 55 (17%) as silica-type PMF."

Establishes the histologic typing of PMF masses in autopsy material and the relative frequency of each type.

PMID:37295943 SUPPORT Human Clinical

"Our findings demonstrate a shift in PMF types among US coal miners, from a predominance of coal- and mixed-type PMF to a more commonly encountered silica-type PMF."

Supports the edge from the silica-enriched dust burden node to this one: more silica in the dust changes the type of mass that forms.

PMID:35353671 SUPPORT Human Clinical

"We found a significantly higher proportion of silica-type PMF (57% vs. 18%; P < 0.001) among contemporary miners compared with their historical counterparts."

Independent case series quantifying the same contemporary shift toward silica-type PMF.

+ 2 more references

Impaired Gas Exchange and Mixed Ventilatory Defect

Fibrotic mass lesions restrict lung expansion while focal emphysema and small airway disease obstruct airflow, producing the mixed restrictive-obstructive physiology and ventilation-perfusion mismatch of advanced CWP. Progressive hypoxemia follows, and chronic hypoxic vasoconstriction with vascular destruction raises pulmonary artery pressure toward cor pulmonale.

Downstream

Exertional dyspnea

Restrictive ventilatory defect

Airway obstruction

Hypoxemia

Elevated pulmonary artery pressure

Show evidence (2 references)

PMID:37284491 SUPPORT Human Clinical

"The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups."

Shows measured pulmonary function declining stepwise from healthy controls through dust-exposed workers to CWP patients, grounding the functional impairment claim in a graded human series.

PMID:41411198 SUPPORT Human Clinical

"Early pneumoconiosis can be asymptomatic, but advanced disease often leads to disability and premature death."

Supports the progression from a silent early lesion to disabling functional impairment that this node represents.

✶

Histopathology

2

Coal macule

Black pigment deposited around the walls of respiratory bronchioles and alveolar ducts, comprising dust-laden macrophages with reticulin and collagen. The earliest lesion of CWP and, with the coal nodule, what pathologically defines the simple form.

Show evidence (2 references)

PMID:36972614 SUPPORT Other

"The coal macule is the earliest lesion to form and consists of black pigment deposited around walls of respiratory bronchioles and alveolar ducts."

Defines the lesion and fixes its anatomical location at the respiratory bronchiole, matching the pathophysiology node that builds it.

PMID:36972614 SUPPORT Other

"Simple CWP is pathologically defined by the presence of coal macules and nodules."

Makes the macule the defining histologic criterion for the simple subtype curated in has_subtypes.

Mineral dust alveolar proteinosis

Accumulation of surfactant-like material in alveoli, a marker of very heavy dust burden. Substantially more common in contemporary US miners than in their historical counterparts, tracking the same silica-enriched exposure shift as silica-type PMF.

Show evidence (1 reference)

PMID:35353671 SUPPORT Human Clinical

"Mineral dust alveolar proteinosis was also more common in contemporary miners compared with their historical counterparts (70% vs. 37%; P < 0.01)."

Quantifies the finding and its historical shift in autopsy material from US coal miners with progressive massive fibrosis.

⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

●

Phenotypes

10

Cardiovascular 2

Elevated pulmonary artery pressure HP:0004890

Sequelae: Cor pulmonale

Show evidence (1 reference)

PMID:39620857 SUPPORT Human Clinical

"CWP group was noted to have higher mean pulmonary artery pressures"

Direct measurement of elevated mean pulmonary artery pressure in CWP patients relative to other lung transplant recipients.

Cor pulmonale HP:0001648

Show evidence (1 reference)

PMID:39620857 SUPPORT INDIRECT Human Clinical

"CWP group was noted to have higher mean pulmonary artery pressures"

Indirect: the paper measures the pulmonary hypertension that causes cor pulmonale rather than right ventricular failure itself, so the cor pulmonale claim follows by the standard inference from sustained elevated pulmonary artery pressure and is not asserted by the quote.

Respiratory 8

Pulmonary nodule HP:0033608

Show evidence (2 references)

PMID:31302880 SUPPORT Other

"Extended exposure to the dust that is generated in the process of extracting coal can cause interstitial fibrosis of the lungs that can be visualized by chest radiography."

Sources the radiographic detectability of the dust-induced parenchymal lesion on which this phenotype and the whole surveillance program rest.

PMID:36972614 SUPPORT Other

"Pathologic studies have shown that rounded opacities on chest imaging correspond to coal macules and coal nodules, and irregular opacities to interstitial fibrosis."

Ties the radiographic nodule to the coal macule and nodule specifically, the lesion this phenotype names.

Pulmonary fibrosis HP:0002206

Show evidence (1 reference)

PMID:27626436 SUPPORT Human Clinical

"pneumoconiosis (CWP) is a lethal fibrotic lung disease caused by inhalation and deposition of inorganic coal mine dust in the lung"

Characterizes CWP as a fibrotic lung disease, the substrate of this phenotype.

Exertional dyspnea FREQUENT HP:0002875

Show evidence (2 references)

PMID:35831008 SUPPORT Other

"This is associated with increased collagen deposition and fibrosis around the airways and within the parenchyma, exertional breathlessness, haemoptysis and lung scarring."

Names exertional breathlessness directly as a manifestation of the dust-driven fibrosis, which the mortality statistics used elsewhere in this entry do not.

PMID:35831008 SUPPORT Other

"Patients with PMF often experience increasing breathlessness and severe deterioration in lung function"

Sources the progression of breathlessness specifically in the complicated form, matching this phenotype's description.

Chronic cough HP:0034315

Show evidence (2 references)

PMID:26024344 SUPPORT Other

"There is increasing evidence supporting an important association of abnormalities in the small peripheral airways with the development of respiratory symptoms"

Links the small-airway pathology of CWP to respiratory symptoms, the mechanistic basis for cough in this disease.

PMID:35831008 SUPPORT Other

"as the disease manifests, patients exhibit symptoms of coughing, sneezing, increased sputum production, breathlessness and breathing difficulties"

Names cough and increased sputum production directly among the symptoms of manifest CWP, which the mechanistic quote above does not.

Emphysema Centrilobular emphysema HP:0032966

Show evidence (2 references)

PMID:35831008 SUPPORT Other

"coal macules or lesions <10 mm in diameter occurring mostly in the upper lung lobes due to the accumulation of dust particles and dust-laden macrophages are usually associated with focal centrilobular emphysema"

Names the centrilobular distribution and its association with the coal macule, which is why this phenotype binds the centrilobular child term rather than the generic Emphysema parent.

PMID:24186945 SUPPORT INDIRECT Human Clinical

"Our findings support previous studies showing that exposure to coal mine dust and respirable silica leads to increased mortality from malignant and non-malignant respiratory diseases even in the absence of smoking."

Indirect: establishes dust-attributable non-malignant respiratory disease independent of smoking, from which the dust rather than smoking origin of the emphysema follows. It reports mortality, not morphology.

Restrictive ventilatory defect HP:0002091

Show evidence (2 references)

PMID:11952275 SUPPORT Human Clinical

"The major pattern of impairment for miners with PMF was obstructive, but there was an increasing trend for restrictive impairment for higher radiological categories."

Distinguishes the restrictive from the obstructive pattern and ties the restrictive component to advancing radiographic category, which the biomarker correlation cited elsewhere cannot do.

PMID:35032040 SUPPORT Human Clinical

"Lung function abnormalities were seen in 9.0% with primarily restrictive patterns."

Surveillance spirometry showing the restrictive pattern predominating in a screened miner population.

Airway obstruction HP:0006536

Show evidence (1 reference)

PMID:31302880 SUPPORT Other

"since coal mine dust can cause chronic obstructive pulmonary disease (COPD), which is not reliably detected by chest radiography"

States that coal mine dust causes obstructive disease and that radiography misses it, the rationale for adding spirometry to surveillance.

Hypoxemia HP:0012418

Show evidence (1 reference)

PMID:39620857 SUPPORT Human Clinical

"CWP group was noted to have higher mean pulmonary artery pressures, LAS, need for prolonged intubation and extracorporeal membrane oxygenation (ECMO) at 72 h"

Documents severe gas-exchange failure in end-stage CWP, to the point of requiring extracorporeal support around transplantation.

🧬

Genetic Associations

3

TNF (Host susceptibility modifier. The TNF-alpha promoter polymorphisms -308 and -238 are associated with CWP risk in meta-analysis of candidate-gene case-control studies, chiefly in Chinese coal-miner cohorts. These are common regulatory variants that amplify the TNF-alpha-driven inflammatory response to retained dust; they modify risk and are neither necessary nor sufficient without the exposure.)

Gene: TNF hgnc:11892 relationship_type: SUSCEPTIBILITY variant_origin: GERMLINE

Show evidence (2 references)

PMID:39578762 SUPPORT Human Clinical

"The analysis revealed that allele A of TNFα-308, allele A of TNFα-238, and allele C of IL-1RA + 2018 were identified as risk factors for the development of diseases."

Meta-analytic association of both TNF-alpha promoter alleles with disease risk across the pooled candidate-gene literature.

PMID:39578762 SUPPORT Human Clinical

"Despite similar exposure levels, individuals exhibit varying responses."

States the observation that motivates a host-susceptibility layer at all: equal dust exposure does not produce equal disease.

TGFB1 (Host susceptibility modifier acting on the central profibrotic pathway. In a case-control study of 508 CWP patients and 526 exposed-miner controls, the rs1800470 CC genotype was associated with reduced CWP risk and the rs11466345 GG genotype with increased risk. TGF-beta1 is the same signal the Fibroblast Activation node is annotated with, so this locus modifies the rate of a mechanism the entry already models rather than adding a new one.)

Gene: TGFB1 hgnc:11766 relationship_type: SUSCEPTIBILITY variant_origin: GERMLINE

Show evidence (2 references)

PMID:23554640 SUPPORT Human Clinical

"Multivariate logistic regression analysis revealed that SNP2 (rs1800470) CC genotype was associated with decreased risk of CWP (OR = 0.50, 95% CI = 0.32-0.78)"

Reports the protective genotype association with an effect estimate in a CWP-specific exposed-control design.

PMID:23554640 SUPPORT Human Clinical

"the SNP5 (rs11466345) GG genotype was associated with an increased risk of CWP (OR = 2.5, 95%CI = 1.36-4.57)"

Reports the risk-increasing genotype at the same locus, showing the modifier acts in both directions.

H19 (Protective susceptibility modifier. The H19 long noncoding RNA variant rs2067051 CT/TT genotypes were associated with decreased CWP risk in 703 cases and 705 exposed controls from Chinese coal mines. One of the few reported protective loci in this disease.)

Gene: H19 hgnc:4713 relationship_type: SUSCEPTIBILITY variant_origin: GERMLINE

Show evidence (1 reference)

PMID:27626436 SUPPORT Human Clinical

"We found that individuals with the H19 rs2067051 CT/TT genotypes showed a decreased risk of CWP compared with those with the CC genotype (adjusted OR = 0.64, 95%CI = 0.49-0.83, p = 0.001)."

Reports the protective genotype association and effect estimate in a CWP case-control study with dust-exposed controls.

💊

Medical Actions

6

Exposure Cessation and Dust Reduction

Action: occupational exposure cessation Ontology label: Therapeutic Procedure NCIT:C49236

Platform: Behavioral / lifestyle

Removal from further dust exposure — through the Part 90 transfer right, engineering controls, or leaving the work — is the only intervention that changes the disease trajectory in early CWP. It halts accrual of new dust burden; it does not clear retained dust, and it does not reliably stop PMF, which can progress after exposure ends.

Mechanism Target:

Respirable Coal Mine Dust Deposition and Retention — Ending exposure stops further deposition and retention of respirable dust, capping the cumulative burden that drives every downstream step.

Show evidence (2 references)

PMID:36972614 SUPPORT Other

"Most pneumoconioses are irreversible and incurable, but disease progression can be mitigated by removal from or reduction in further exposure."

States both halves of this treatment's claim: the disease is not reversible, and exposure reduction is what mitigates progression.

PMID:41411198 SUPPORT Human Clinical

"Disease progression can occur after cessation of exposure"

Sources the limit on this treatment stated in its description: stopping exposure caps the dust burden but does not reliably stop established disease from advancing.

Supportive Respiratory Care

Action: Supportive Care NCIT:C15747

Platform: Other

Vaccination against influenza and pneumococcus, prompt treatment of respiratory infection, mycobacterial surveillance given impaired local lung defences, and smoking cessation. Standard of care and the backbone of management at every stage, since no disease-modifying drug exists.

Show evidence (1 reference)

PMID:36972614 SUPPORT Other

"Many pneumoconioses are irreversible and develop due to excessive cumulative respirable dust inhalation."

Establishes the irreversibility that makes supportive rather than curative management the standard of care.

Pulmonary Rehabilitation

Action: Pulmonary Rehabilitation NCIT:C157966

Platform: Behavioral / lifestyle

Structured exercise and education to maintain functional capacity and activities of daily living in miners with established functional impairment.

Mechanism Target:

Impaired Gas Exchange and Mixed Ventilatory Defect — Targets the functional consequences of impaired gas exchange and mixed ventilatory defect rather than the fibrotic lesion itself.

Show evidence (1 reference)

PMID:37284491 SUPPORT INDIRECT Human Clinical

"Because the disease is progressive and incurable, early diagnosis or early prevention is especially important to control this disease."

Indirect: the quote establishes that CWP is progressive and incurable — the reason management is functional rather than curative — but does not itself evaluate pulmonary rehabilitation.

Long-Term Oxygen Therapy

Action: Oxygen Therapy NCIT:C94624

Platform: Other

Supplemental oxygen for chronic hypoxemia in advanced disease, and to mitigate the hypoxic pulmonary vasoconstriction that drives pulmonary hypertension and cor pulmonale.

Mechanism Target:

Impaired Gas Exchange and Mixed Ventilatory Defect — Compensates for the failed gas exchange surface; it does not alter the fibrotic or emphysematous lesion producing it.

Show evidence (1 reference)

PMID:39620857 SUPPORT INDIRECT Human Clinical

"CWP group was noted to have higher mean pulmonary artery pressures, LAS, need for prolonged intubation and extracorporeal membrane oxygenation (ECMO) at 72 h"

Indirect: documents the severity of oxygenation failure in advanced CWP that indicates oxygen support, rather than evaluating long-term oxygen therapy as an intervention.

Lung Transplantation

Action: Organ Transplantation NCIT:C15289

Platform: Surgery

The only definitive intervention for end-stage CWP with progressive respiratory failure. Post-transplant graft and patient survival in CWP recipients are comparable to other indications, so the disease is not itself a contraindication, though CWP candidates arrive with higher pulmonary artery pressures and higher allocation scores and have a more demanding perioperative course.

Mechanism Target:

Nodule Coalescence into Progressive Massive Fibrosis — Replaces the fibrotic organ outright. It is the only listed treatment that removes the conglomerate lesion rather than managing its consequences.

Show evidence (3 references)

PMID:39620857 SUPPORT Human Clinical

"Overall graft survival (Log-rank p = 0.889) and patient survival (Log-rank p = 0.910) were not significantly different between the two groups."

Registry comparison showing CWP transplant recipients do as well as recipients transplanted for other indications.

PMID:39620857 SUPPORT Human Clinical

"Between May 2005 and June 2021, 158 patients underwent LT for CWP."

Establishes the cohort size behind the survival comparison, so the equivalence claim is not read off a handful of cases.

PMID:22360577 SUPPORT Human Clinical

"There was no increased risk of perioperative or postoperative complications."

Independent single-centre series reaching the same conclusion on perioperative safety.

Antifibrotic Therapy

Action: Pharmacotherapy NCIT:C15986

Agent: pirfenidone CHEBI:32016

Platform: Small molecule

Pirfenidone, an antifibrotic established in idiopathic pulmonary fibrosis, has been trialled in CWP with pulmonary fibrosis on the reasoning that the fibroblast-activation step is shared. Investigational, not standard of care — no antifibrotic is approved for CWP. Nintedanib is discussed in the same context in the literature but is not listed as a therapeutic_agent here because no CWP trial or study was found to cite for it.

Mechanism Target:

Fibroblast Activation and Myofibroblast Differentiation — Both agents act on the fibroblast activation and matrix-deposition step that this entry models as the central effector of the lesion.

Show evidence (1 reference)

clinicaltrials:NCT04461587 SUPPORT Other

"Examination of pirfenidone (Esbriet®) therapy in coal workers' pneumoconiosis (black lung) with pulmonary fibrosis (scarring of the lung)."

Registration record establishing that pirfenidone has been formally trialled in CWP with pulmonary fibrosis. A trial record documents that the question was asked; it is not evidence the therapy works.

🌍

Environmental Factors

2

Occupational inhalation of respirable coal mine dust

Hazard type: CHEMICAL

Route: INHALATION

Duration: CHRONIC

GHS hazard class: STOT REPEATED EXPOSURE

Exposome domain: SPECIFIC EXTERNAL

No iarc_carcinogen_group is recorded. IARC evaluated coal dust in Monographs volume 68 and placed it in Group 3 (not classifiable as to carcinogenicity to humans); the schema's IARCCarcinogenGroupEnum was checked and does admit GROUP_3, so this omission is a judgement rather than a schema limit — the Group 3 listing is for coal dust as an agent, while the exposure curated here is coal *mine* dust, a mixture whose silica fraction carries its own classification. Crystalline silica's Group 1 listing belongs to the Silicosis entry's exposure, not to this one. The cohort association between coal mine dust and lung cancer mortality is instead curated as evidence, on the mortality items below.

Cumulative inhalation of respirable coal mine dust during underground or surface coal mining is the necessary cause of CWP. Classic risk work is underground extraction, with roof bolting and continuous-miner operation among the dustiest tasks; contemporary thin-seam mining raises the silica fraction of the dust because accessing the seam requires cutting silica-bearing rock.

Show evidence (4 references)

PMID:41411198 SUPPORT Human Clinical

"Among workers employed in the mining industry, the highest PMR was among underground mining machine operators (164.6)."

Identifies underground mining machine operation as the highest-risk task by proportionate mortality, grounding the occupational specificity of the exposure.

PMID:31302880 SUPPORT Other

"Contributing factors may include mining of thin coal seams or cutting rock to access coal, which may expose miners to coal mine dust with a higher content of silica and silicates than in the past."

Sources the thin-seam mechanism by which contemporary coal mine dust carries more silica than historical dust.

PMID:24186945 SUPPORT Human Clinical

"We saw a significant relationship between coal mine dust exposure and lung cancer mortality (HR=1.70; 95% CI 1.02 to 2.83) but not with respirable silica (HR=1.05; 95% CI 0.90 to 1.23)."

The lung-cancer association this exposure's notes refer to, with the effect attaching to coal mine dust rather than to its respirable silica fraction. Curated as evidence on the exposure rather than as a hazard classification.

+ 1 more reference

Mechanism Target:

TRIGGERS Respirable Coal Mine Dust Deposition and Retention — Coal extraction liberates dust in the respirable size range, which is the fraction that reaches the terminal bronchioles and alveoli to be deposited and retained.

Show evidence (1 reference)

PMID:41411198 SUPPORT Human Clinical

"Coal workers' pneumoconiosis (CWP) is a preventable, progressive occupational lung disease caused by inhaling respirable coal mine dust, a complex mixture commonly containing coal, crystalline silica, and other silicate minerals."

Ties the occupational activity directly to inhalation of the respirable dust that the deposition node represents.

EXACERBATES Silica-Enriched Dust Burden — Cutting silica-bearing rock strata to reach thin coal seams raises the crystalline-silica content of the generated dust, which is what shifts the retained burden toward the more fibrogenic silica-enriched form.

Show evidence (1 reference)

PMID:31302880 SUPPORT Other

"Contributing factors may include mining of thin coal seams or cutting rock to access coal, which may expose miners to coal mine dust with a higher content of silica and silicates than in the past."

States the specific mining practice that raises the silica fraction of the dust, which is the edge this link asserts.

Cigarette smoking

Smoking does not cause CWP and is not required for it — the excess respiratory mortality of coal miners is present in never-smokers. It is curated here because it compounds the obstructive component and overall respiratory morbidity, and smoking cessation is a core management step.

Show evidence (1 reference)

PMID:24186945 SUPPORT Human Clinical

"Our findings support previous studies showing that exposure to coal mine dust and respirable silica leads to increased mortality from malignant and non-malignant respiratory diseases even in the absence of smoking."

Establishes that the dust effect is independent of smoking, which is the reason smoking is curated here as a compounding factor rather than a cause.

Mechanism Target:

MODULATES Impaired Gas Exchange and Mixed Ventilatory Defect — Smoking worsens measured lung function in miners who already have progressive massive fibrosis, on top of the dust-driven impairment, without being required for it. MODULATES rather than EXACERBATES because the cohort evidence puts the excess respiratory mortality in never-smokers, so the interaction is additive burden rather than a demonstrated amplification of the dust mechanism.

Show evidence (2 references)

PMID:11952275 SUPPORT Human Clinical

"Smoking miners had even lower FEV1/FVC and DLCO than did their non-smoking counterparts."

Measures worse airflow obstruction and diffusing capacity in smoking miners with progressive massive fibrosis, the additive functional effect this link asserts.

PMID:11952275 SUPPORT Human Clinical

"The loss of lung function cannot be accounted for by different smoking habits."

The same study's conclusion that smoking does not explain the impairment, which is why this link is MODULATES and not a causal edge.

🔬

Biochemical Markers

4

Serum Krebs von den Lungen-6 (KL-6) (INCREASED)

Pathograph Readouts

Readout Of Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition Positive Diagnostic

KL-6 is shed by injured and regenerating alveolar type II cells, so rising serum concentration reports the alveolar epithelial injury node rather than the fibrotic mass burden directly.

Show evidence (1 reference)

PMID:37284491 SUPPORT Human Clinical

"Compared with HCs, patients with higher OPN, KL-6, Syndecan-4 and Gremlin-1 had higher risk for CWP."

Establishes the positive direction of the marker with respect to disease, the claim this readout link makes.

Show evidence (1 reference)

PMID:37284491 SUPPORT Human Clinical

"The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups."

Shows the stepwise rise in serum KL-6 across exposure and disease groups, alongside falling pulmonary function.

Serum osteopontin (INCREASED)

Pathograph Readouts

Readout Of Sustained Inflammatory Cell Recruitment and Amplification Positive Diagnostic

Osteopontin is a macrophage-associated matricellular protein, so serum concentration tracks the sustained inflammatory recruitment node rather than a specific matrix compartment.

Show evidence (1 reference)

PMID:37284491 SUPPORT Human Clinical

"The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups."

Shows serum osteopontin rising stepwise with exposure and disease status, the graded positive relationship this readout asserts.

Show evidence (1 reference)

PMID:37284491 SUPPORT Human Clinical

"The combination of OPN, KL-6, and Syndecan-4 can improve the diagnostic sensitivity and specificity of CWP patients differentiated from HCs or DEWs."

Reports the panel's incremental diagnostic value over single markers, the basis for curating these together.

Serum syndecan-4 (INCREASED)

Pathograph Readouts

Readout Of Peribronchiolar Collagen Deposition and Coal Macule Formation Positive Diagnostic

Syndecan-4 is a cell-surface heparan sulfate proteoglycan involved in matrix assembly, so serum concentration is read here against the matrix deposition node rather than against the inflammatory compartment.

Show evidence (1 reference)

PMID:37284491 SUPPORT Human Clinical

"The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups."

Shows the graded positive relationship across healthy controls, dust-exposed workers and CWP patients that this readout asserts.

Show evidence (1 reference)

PMID:37284491 SUPPORT Human Clinical

"The combination of OPN, KL-6, and Syndecan-4 can improve the diagnostic sensitivity and specificity of CWP patients differentiated from HCs or DEWs."

Establishes syndecan-4 as the third member of the panel whose combination outperforms any single marker.

Serum gremlin-1 (INCREASED)

Pathograph Readouts

Readout Of Fibroblast Activation and Myofibroblast Differentiation Positive Diagnostic

Gremlin-1 is a BMP antagonist that de-represses TGF-beta-driven fibrogenesis, so it is read against the mesenchymal activation node.

Show evidence (1 reference)

PMID:37284491 SUPPORT Human Clinical

"The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups."

Shows gremlin-1 rising stepwise with exposure and disease status, the graded relationship this readout asserts.

Show evidence (1 reference)

PMID:37284491 SUPPORT Human Clinical

"Compared with HCs, patients with higher OPN, KL-6, Syndecan-4 and Gremlin-1 had higher risk for CWP."

Associates higher gremlin-1 with CWP risk in the case-control series.

🔬

Diagnosis

1

Occupational exposure history with ILO-classified chest radiography

CWP is diagnosed clinically, not histologically: a compatible coal mine dust exposure history plus a characteristic chest radiograph classified under the ILO International Classification of Radiographs of Pneumoconioses, read by a NIOSH-certified B Reader. Profusion of small opacities is graded 0-3 with size categories p/q/r, and large opacities A/B/C define the complicated form. Tissue sampling is reserved for atypical presentations or a separate indication such as suspected malignancy. Certification matters measurably — non-certified readers over-read both presence and severity.

Chest Radiography NCIT:C38103

Radiography does not distinguish between the coal-dust-induced interstitial lung diseases, so a surveillance "case of CWP" is an opacity-based definition rather than a claim about which lesion is present. Genetic testing has no diagnostic role; the susceptibility loci curated in `genetic:` are research findings.

Show evidence (4 references)

PMID:36972614 SUPPORT Other

"Diagnosis of silicosis, coal workers’ pneumoconiosis, or asbestosis may be made based on a suggestive occupational history and typical chest imaging without the need for tissue sampling."

States the two-part diagnostic basis this entry uses and that biopsy is not required.

PMID:36972614 SUPPORT Other

"A chest radiograph classified using the International Labor Office (ILO) system has been the mainstay for medical surveillance of pneumoconioses in dusty trades."

Sources the ILO classification as the standard instrument, which the subtype definitions in this entry are stated in terms of.

PMID:31302880 SUPPORT Other

"Certified B Readers are physicians who have successfully passed the certification examination, demonstrating competence with the ILO system."

Sources the B Reader certification that the surveillance program depends on for consistent classification.

+ 1 more reference

🩻

Imaging Findings

2

Rounded small opacities on chest radiography

Small rounded opacities, graded p (up to 1.5 mm), q (1.5-3 mm) and r (3-10 mm) by the ILO system, corresponding pathologically to coal macules and nodules. Irregular opacities in the same films correspond instead to interstitial fibrosis, so opacity shape carries lesion information.

Xray Diagnostic

Pulmonary nodule HP:0033608

Show evidence (1 reference)

PMID:36972614 SUPPORT Other

"A chest radiograph classified using the International Labor Office (ILO) system has been the mainstay for medical surveillance of pneumoconioses in dusty trades. ... Coal mine dust lung disease (CMDLD), or black lung, is a group of lung conditions caused by exposure to coal mine dust, including..."

Restores the plain-radiograph/ILO context and coal-workers' pneumoconiosis diagnostic setting before the opacity-to-pathology mapping. The selected passage does not give p/q/r millimeter boundaries.

Nodules on high-resolution CT not visible on plain radiography

HRCT detects parenchymal nodules in miners whose plain films are classified ILO category 0/0, so radiographic surveillance under-calls early disease. This is a sensitivity gap in the diagnostic standard rather than a competing diagnostic criterion.

Ct

Show evidence (1 reference)

PMID:8404184 SUPPORT Human Clinical

"By HRCT, nodules were identified in 12 miners; 4 of 9 were classified as category 0/0 CWP"

Directly measures the under-detection: nodules on HRCT in miners the ILO film classification called normal.

📊

Prevalence

3

US underground coal miners with 25 or more years of tenure

Point Prevalence 10000.0 per 100,000 >1 in 1,000

Radiographic CWP (ILO profusion 1/0 or greater, or a large opacity) in the NIOSH Coal Workers' Health Surveillance Program, 1970-2017. Reported as "exceeds 10%", so the normalized rate is a floor rather than a point estimate.

Show evidence (1 reference)

PMID:30024799 SUPPORT Human Clinical

"Following a low point in the late 1990s, the national prevalence of CWP in miners with 25 years or more of tenure now exceeds 10%."

Source for the national long-tenure prevalence figure and for the fact that it is rising from a late-1990s nadir.

Central Appalachian (Kentucky, Virginia, West Virginia) long-tenured coal miners

Point Prevalence 20600.0 per 100,000 >1 in 1,000

20.6% of long-tenured central Appalachian miners, roughly double the national figure for the same tenure band. This regional concentration is the core epidemiologic signal of the CWP resurgence.

Show evidence (1 reference)

PMID:30024799 SUPPORT Human Clinical

"In central Appalachia (Kentucky, Virginia, West Virginia), 20.6% of long-tenured miners have CWP."

Direct source for the central Appalachian prevalence figure and the states it covers.

Central Appalachian coal miners with 25 or more years of tenure (PMF)

Point Prevalence 3200.0 per 100,000 >1 in 1,000

Progressive massive fibrosis specifically, risen from 0.33% to 3.2% in long-tenured central Appalachian miners — an order-of-magnitude increase in the disabling form.

Show evidence (1 reference)

PMID:35353671 SUPPORT Human Clinical

"the prevalence of PMF has increased from 0.33% to 3.2% in miners with 25 years or more of tenure"

Source for both the current PMF prevalence and the magnitude of its increase in this population.

🔀

Differential Diagnoses

1

Conditions with similar clinical presentations that must be differentiated from Coal Workers Pneumoconiosis:

Caplan Syndrome Not Yet Curated MONDO:0005690

Overlapping Features Rheumatoid pneumoconiosis: well-defined peripheral pulmonary nodules with necrobiotic centres retaining mineral dust, arising in a dust-exposed worker who also has rheumatoid arthritis. First described in Welsh coal miners, and a genuine consideration in any miner presenting with nodules.

Distinguishing Features

Coexisting rheumatoid arthritis, which ordinary CWP does not require
Peripheral, well-defined nodules rather than the upper-zone rounded opacities of simple CWP
Necrobiotic nodule centre retaining mineral dust
Nodules may appear before, at, or years after the arthritis is diagnosed

Show evidence (2 references)

PMID:34027516 SUPPORT Human Clinical

"Classically, they form peripheral well-defined pulmonary nodules with characteristic silica retained in the necrobiotic center."

Describes the nodule morphology and retained mineral dust that separate Caplan syndrome from ordinary rheumatoid lung nodules and from the coal macule.

PMID:34027516 SUPPORT Human Clinical

"Caplan's syndrome also known as rheumatoid pneumoconiosis is a disease entity that is seen in patients with rheumatoid arthritis (RA) exposed to chronic silica and inorganic dust"

States the exposure range — chronic silica and inorganic dust generally, not coal specifically — which is the nosological point behind curating this as a differential rather than a coal-dust subtype.

🔬

Clinical Trials

1

NCT04461587 PHASE_II COMPLETED

Phase II study of pirfenidone in coal workers' pneumoconiosis with pulmonary fibrosis and radiographic and functional impairment, examining reduction in disease progression, exacerbation rates, and inflammatory biomarkers.

Target Phenotypes: Pulmonary fibrosis HP:0002206

Show evidence (1 reference)

clinicaltrials:NCT04461587 SUPPORT Other

"Examination of pirfenidone (Esbriet®) therapy in coal workers' pneumoconiosis (black lung) with pulmonary fibrosis (scarring of the lung)."

ClinicalTrials.gov record establishing the trial's population, intervention, and target condition.

🐁

Animal Models

2

Coal-silica mixed dust mouse model with kinetin mitophagy rescue

Coal-silica mixed dust exposure in mice, with pharmacological mitophagy activation (kinetin) as a rescue arm and PINK1 knockdown to test pathway dependence. The genetic arms are what make this more than an exposure model: abolishing the rescue by knocking down PINK1 establishes the mechanism rather than just the association.

Species

Mouse

Genotype

Wild-type, with PINK1 overexpression and PINK1 knockdown arms

Publication

PMID:41894156

Pathograph links

Macrophage Mitochondrial Dysfunction and Defective Mitophagy recapitulates fidelity: moderate Reproduces the mitochondrial collapse and mitophagy failure in macrophages after mixed coal-silica dust exposure.

Limitations: Mouse macrophages, and a coal-silica mixture whose ratio need not match any particular mine's respirable dust. No human coal miner tissue confirmation of the PINK1/Parkin defect exists.

Readouts

Mitochondrial membrane potential and oxidative phosphorylation

Direction: DECREASED

Interpretation: Direct functional correlate of the mitochondrial dysfunction node.

Show evidence (1 reference)

PMID:41894156 SUPPORT Model Organism

"CSD exposure triggered ROS accumulation, mitochondrial membrane potential collapse, and impaired oxidative phosphorylation, leading to reduced adenosine triphosphate synthesis."

Reports the measurement behind this readout and its direction.

PINK1/Parkin-mediated mitophagy after kinetin treatment

Direction: RESTORED

Interpretation: The rescue arm. Restoring mitophagy reverses the downstream inflammation and fibrosis, which is what makes the node causal rather than correlative.

Show evidence (1 reference)

PMID:41894156 SUPPORT Model Organism

"kinetin treatment and PINK1 overexpression restored PINK1/Parkin activation and LC3II-dependent mitophagy, alleviated mitochondrial dysfunction, and suppressed subsequent macrophage inflammation and pulmonary fibrosis."

Documents the restoration and that it suppressed the downstream inflammation and fibrosis, the direction this readout records.

Nodule Coalescence into Progressive Massive Fibrosis partially recapitulates fidelity: low Produces pulmonary fibrosis after mixed-dust exposure, but on a months-long murine timescale.

Limitations: Murine fibrosis after weeks to months of instilled mixed dust is not the conglomerate mass lesion that defines human PMF after decades of inhalation. The model speaks to fibrogenesis, not to mass formation.

Show evidence (1 reference)

PMID:41894156 SUPPORT Model Organism

"Kinetin exerts its antifibrotic effects on CWP by promoting PINK1-mediated mitophagy, improving mitochondrial function, and alleviating macrophage inflammation."

Establishes a fibrotic endpoint in the model that responds to the mechanism-directed intervention.

Coal dust particle instillation mouse model with vitamin D rescue

Long-course coal dust particle exposure (nine months) with single-cell transcriptomic readout and a vitamin D treatment arm. The dust used was characterized as under 5 microns with under 10% silica, so unlike the model above this one isolates the coal-predominant exposure.

Species

Mouse

Genotype

Wild-type

Publication

PMID:35057792

Pathograph links

Alveolar and Small-Airway Tissue Injury recapitulates fidelity: moderate Reproduces alveolar structural destruction and activation of inflammatory and cell-death pathways after sustained coal dust exposure.

Limitations: Nine months in a mouse compresses what takes one to several decades in a miner, and instillation bypasses the aerodynamic deposition that determines where inhaled dust actually lands.

Readouts

Alveolar structure and pulmonary microenvironment integrity

Direction: DECREASED

Interpretation: Structural correlate of the tissue injury node in a coal-predominant exposure.

Show evidence (1 reference)

PMID:35057792 SUPPORT Model Organism

"Alveolar structure and pulmonary microenvironment were destroyed, inflammatory and death (apoptosis, autophagy, and necrosis) pathways were activated, leading to pneumoconiosis in post 9 months coal dust stimulation."

Reports the structural destruction and pathway activation behind this readout, on a stated timescale.

Fibroblast Activation and Myofibroblast Differentiation partially recapitulates fidelity: low Reproduces profibrotic signalling and an M2 macrophage population that tracks fibrosis, with vitamin D reducing both.

Limitations: The fibrogenic readout is transcriptional and macrophage-phenotypic rather than the alpha-SMA-positive myofibroblast this node names, so it supports the surrounding signalling rather than the effector cell itself. Vitamin D benefit here is not clinically validated in humans.

Show evidence (1 reference)

PMID:35057792 SUPPORT Model Organism

"Beclin1, LC3B, LAMP2, TGF-ß, and MLPH were up-regulated induced by CDP, promoting autophagy and pulmonary fibrosis."

Documents upregulated TGF-beta and a profibrotic program, the signalling this node is annotated with, in a coal-predominant mouse exposure.

{ }

Source YAML

click to show

name: Coal Workers Pneumoconiosis
creation_date: "2026-09-03T00:00:00Z"
category: Environmental Lung Disease
parents:
- Pneumoconiosis
- Occupational Lung Disease
disease_term:
  preferred_term: coal workers' pneumoconiosis
  term:
    id: MONDO:0006654
    label: anthracosis
description: >-
  Coal workers' pneumoconiosis (CWP, "black lung") is a preventable, progressive
  occupational interstitial lung disease caused by the inhalation and pulmonary
  retention of respirable coal mine dust — a heterogeneous mixture of coal,
  crystalline silica, and other silicate minerals. Particles reaching the distal
  airways are phagocytosed by alveolar macrophages, whose oxidative and
  inflammasome-driven response builds the coal macule: a pigmented, dust-laden
  macrophage collection with reticulin and collagen centred on the respiratory
  bronchiole, accompanied by focal emphysema. Macules aggregate into
  radiographically visible micronodules and nodules (simple CWP) and, with
  sufficient cumulative or silica-rich dust burden, coalesce into conglomerate
  masses one centimetre or larger — progressive massive fibrosis (PMF, complicated
  CWP), which can continue to progress after exposure ceases and ends in
  restrictive or mixed respiratory failure, pulmonary hypertension, and cor
  pulmonale. Early disease is typically asymptomatic and is detected only by
  radiographic surveillance. After decades of decline following the 1969 US
  Federal Coal Mine Health and Safety Act, CWP has resurged since the late 1990s,
  concentrated in central Appalachia, and contemporary severe cases carry
  markedly more crystalline silica than their historical counterparts — thin-seam
  mining requires cutting silica-bearing rock strata. There is no curative
  therapy; management is supportive, lung transplantation is the only definitive
  intervention for end-stage disease, and prevention through dust control and
  surveillance is paramount.
classifications:
  harrisons_chapter:
  - classification_value: RESPIRATORY
  ilo_disease_category:
  - classification_value: pneumoconiosis_from_fibrogenic_mineral_dust
    notes: >-
      ILO List of Occupational Diseases (revised 2010), item 2.1.1
      "Pneumoconioses caused by fibrogenic mineral dust (silicosis,
      anthraco-silicosis, asbestosis)". Coal mine dust is a mixed fibrogenic
      mineral dust and the item text names anthraco-silicosis explicitly, which
      is the coal-plus-silica pneumoconiosis this entry covers. ILO item 2.1.9
      (COPD from coal dust) is deliberately NOT claimed here: that item names a
      different disease outcome of the same exposure, curated under Chronic
      Obstructive Pulmonary Disease rather than under CWP.
references:
- reference: PMID:41411198
  title: "Coal Workers' Pneumoconiosis-Associated Deaths - United States, 2020-2023."
- reference: PMID:35353671
  title: "Pathology and Mineralogy Demonstrate Respirable Crystalline Silica Is a Major Cause of Severe Pneumoconiosis in U.S. Coal Miners."
- reference: PMID:35831008
  title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
has_subtypes:
- name: Simple CWP
  display_name: Simple (Uncomplicated) Coal Workers' Pneumoconiosis
  description: >-
    The early form, defined radiographically by small rounded opacities
    (ILO profusion categories 1-3) reflecting coal macules and micronodules,
    without conglomerate masses. Frequently asymptomatic and detected only on
    surveillance radiography, which is what makes periodic screening the key
    intervention window.
  evidence:
  - reference: PMID:41411198
    reference_title: "Coal Workers' Pneumoconiosis-Associated Deaths - United States, 2020-2023."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Early pneumoconiosis can be asymptomatic, but advanced disease often leads to disability and premature death."
    explanation: >-
      Establishes the asymptomatic early stage that distinguishes simple CWP
      from the complicated form, and why it is found by screening rather than
      by symptoms.
- name: Complicated CWP
  display_name: Complicated CWP / Progressive Massive Fibrosis (PMF)
  description: >-
    Defined by conglomerate fibrotic masses one centimetre or larger (ILO large
    opacity categories A, B, C) formed by coalescence of nodular lesions. Carries
    a substantially worse prognosis than simple CWP and is characteristically
    relentless — it can progress after dust exposure ends. Its prevalence in
    long-tenured central Appalachian miners has risen roughly tenfold from a late
    1990s nadir.
  evidence:
  - reference: PMID:35353671
    reference_title: "Pathology and Mineralogy Demonstrate Respirable Crystalline Silica Is a Major Cause of Severe Pneumoconiosis in U.S. Coal Miners."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the prevalence of PMF has increased from 0.33% to 3.2% in miners with 25 years or more of tenure"
    explanation: >-
      Quantifies the resurgence of the complicated form among long-tenured
      central Appalachian miners. Note this sentence sits in the cited paper's
      introduction and carries its own citations; the primary surveillance
      reports are the source of record for the figure itself.
  - reference: PMID:31302880
    reference_title: "Current Review of Pneumoconiosis Among US Coal Miners."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "respiratory morbidity including ongoing fibrosis and functional impairment can occur after exposure ceases"
    explanation: >-
      Sources the claim that this subtype keeps progressing once dust exposure
      has ended, which is what separates its prognosis from simple CWP.
- name: Rapidly Progressive Pneumoconiosis
  display_name: Rapidly Progressive Pneumoconiosis (RPP)
  description: >-
    An accelerated presentation in which radiographic profusion advances unusually
    fast, often in younger miners with shorter tenure. Lung pathology in these
    cases shows features of accelerated silicosis and mixed-dust lesions with
    abundant birefringent silica and silicates rather than the classic
    coal-predominant macule, so this subtype is better understood as a
    silica-driven variant of coal mine dust lung disease than as fast simple CWP.
  evidence:
  - reference: PMID:26513613
    reference_title: "Lung Pathology in U.S. Coal Workers with Rapidly Progressive Pneumoconiosis Implicates Silica and Silicates."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Thirteen cases were reviewed, many of which had features of accelerated silicosis and mixed dust lesions."
    explanation: >-
      Documents that rapidly progressive cases carry accelerated-silicosis and
      mixed-dust histology rather than the classic coal macule pattern.
  - reference: PMID:26513613
    reference_title: "Lung Pathology in U.S. Coal Workers with Rapidly Progressive Pneumoconiosis Implicates Silica and Silicates."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our findings suggest that rapidly progressive pneumoconiosis in these miners was associated with exposure to coal mine dust containing high concentrations of respirable silica and silicates."
    explanation: >-
      Attributes the rapidly progressive subtype to the silica and silicate
      fraction of the dust, the basis for treating it as a distinct subtype.
pathophysiology:
- name: Respirable Coal Mine Dust Deposition and Retention
  description: >-
    Respirable coal mine dust — a heterogeneous mixture of carbonaceous coal
    particles, crystalline silica, and other silicate minerals — is small enough
    to escape upper-airway defences and deposit in the terminal bronchioles and
    alveoli, beyond the reach of mucociliary clearance. Cumulative retained dust
    burden, not any single exposure, is the driving quantity.
  role: trigger
  biological_scale: TISSUE
  locations:
  - preferred_term: respiratory bronchiole
    term:
      id: UBERON:0002188
      label: respiratory bronchiole
  - preferred_term: pulmonary alveolus
    term:
      id: UBERON:0002299
      label: alveolus of lung
  downstream:
  - target: Alveolar Macrophage Phagocytosis of Retained Dust
  - target: Silica-Enriched Dust Burden
  evidence:
  - reference: PMID:41411198
    reference_title: "Coal Workers' Pneumoconiosis-Associated Deaths - United States, 2020-2023."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Coal workers' pneumoconiosis (CWP) is a preventable, progressive occupational lung disease caused by inhaling respirable coal mine dust, a complex mixture commonly containing coal, crystalline silica, and other silicate minerals."
    explanation: >-
      Establishes inhaled respirable coal mine dust as the necessary cause and
      names the three mineral fractions of the deposited material.
  - reference: PMID:35831008
    reference_title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "the lesions and macules comprise inhaled coal dust particles engulfed in alveolar macrophages and surrounded by inflammatory cells"
    explanation: >-
      Establishes that the retained particles are coal dust specifically, sitting
      inside alveolar macrophages in the lesion — the deposition-and-retention
      step this node represents, rather than a general statement about ambient
      particulate matter.
- name: Silica-Enriched Dust Burden
  description: >-
    The crystalline silica and silicate fraction of the retained dust, which in
    contemporary thin-seam mining is markedly higher than historically because
    accessing thin coal seams requires cutting silica-bearing rock strata. Silica
    is far more cytotoxic and fibrogenic per particle than carbonaceous coal, so
    a silica-enriched burden shifts the disease toward the accelerated and
    silica-type severe forms rather than merely producing more of the same
    lesion.
  role: driver
  biological_scale: TISSUE
  downstream:
  - target: Alveolar Macrophage Phagocytosis of Retained Dust
  - target: Nodule Coalescence into Progressive Massive Fibrosis
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:37295943
      reference_title: "Historical shift in pathological type of progressive massive fibrosis among coal miners in the USA."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "These results are further evidence of the prominent role of RCS in the pathogenesis of pneumoconiosis among contemporary US coal miners."
      explanation: >-
        Sources the edge from the silica fraction of the retained burden to the
        severe conglomerate disease, which is the causal claim this link makes.
  evidence:
  - reference: PMID:35353671
    reference_title: "Pathology and Mineralogy Demonstrate Respirable Crystalline Silica Is a Major Cause of Severe Pneumoconiosis in U.S. Coal Miners."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In situ mineralogic analysis showed that the percentage (26.1% vs. 17.8%; P < 0.01) and concentration (47.3 × 108 vs. 25.8 × 108 particles/cm3; P = 0.036) of silica particles were significantly greater in specimens from contemporary miners compared with their historical counterparts."
    explanation: >-
      Directly measures the silica fraction of retained lung dust and shows it
      has risen in contemporary miners, which is the mineralogic basis for this
      node.
  - reference: PMID:26513613
    reference_title: "Lung Pathology in U.S. Coal Workers with Rapidly Progressive Pneumoconiosis Implicates Silica and Silicates."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Polarized light microscopy revealed large amounts of birefringent mineral dust particles consistent with silica and silicates; carbonaceous coal dust was less prominent."
    explanation: >-
      Shows silica and silicates dominating over carbonaceous coal in the
      retained dust of severe contemporary cases, supporting a distinct
      silica-enriched burden rather than simply more coal.
  - reference: PMID:35831008
    reference_title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "In contrast to coal dust, silica dust is considered more toxic and potent in eliciting oxidative stress and cellular inflammation in the lungs"
    explanation: >-
      Sources the comparative-potency half of this node's claim, which the
      mineralogy evidence above does not address: the mineralogy says how much
      silica is present, this says why that matters per particle.
- name: Alveolar Macrophage Phagocytosis of Retained Dust
  description: >-
    Alveolar macrophages recognize and internalize the deposited particles in an
    attempt to clear them. Coal and silica particles are poorly biodegradable, so
    the macrophage cannot resolve the load and instead becomes the persistently
    activated cell around which the lesion is built.
  role: driver
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: alveolar macrophage
    term:
      id: CL:0000583
      label: alveolar macrophage
  biological_processes:
  - preferred_term: phagocytosis
    term:
      id: GO:0006909
      label: phagocytosis
    modifier: INCREASED
  downstream:
  - target: Reactive Oxygen Species Generation and Oxidative Injury
  - target: Dust-Laden Macrophage Death
  evidence:
  - reference: PMID:26024344
    reference_title: "Small airways involvement in coal mine dust lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Human and laboratory studies have suggested oxidant injury, and increased recruitment and activity of macrophages play important roles in dust-induced lung injury."
    explanation: >-
      Places increased macrophage recruitment and activity, alongside oxidant
      injury, at the centre of coal-dust lung injury.
  - reference: PMID:35831008
    reference_title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "the lesions and macules comprise inhaled coal dust particles engulfed in alveolar macrophages and surrounded by inflammatory cells"
    explanation: >-
      States the phagocytic uptake this node annotates: coal dust particles
      engulfed by alveolar macrophages, and the lesion built around them.
- name: Reactive Oxygen Species Generation and Oxidative Injury
  description: >-
    Dust-laden macrophages and the reactive particle surfaces generate reactive
    oxygen species that overwhelm local antioxidant defences. Reactive oxygen
    species are the shared upstream signal feeding both the inflammasome branch
    and the epithelial injury branch of the cascade.
  role: driver
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: alveolar macrophage
    term:
      id: CL:0000583
      label: alveolar macrophage
  biological_processes:
  - preferred_term: reactive oxygen species metabolic process
    term:
      id: GO:0072593
      label: reactive oxygen species metabolic process
    modifier: INCREASED
  downstream:
  - target: Macrophage Mitochondrial Dysfunction and Defective Mitophagy
  - target: NF-kappaB and NLRP3 Inflammasome Activation
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:36581638
      reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "ROS can induce the activation of AKT/GSK3β signaling, and inhibition of it can inhibit ROS-induced inflammation and EMT by the NF-kB/NLRP3 axis, thereby inhibiting PF."
      explanation: >-
        Sources this specific edge from the study's own inhibition experiments:
        blocking the pathway between reactive oxygen species and NF-kappaB/NLRP3
        abolishes the downstream inflammation, which is what makes it an edge
        rather than a correlation.
  - target: Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:36581638
      reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "activation of the IGF1/IGF1R axis induced generation of reactive oxygen species (ROS) to promote epithelial-mesenchymal transition (EMT) in alveolar epithelial cells (AECs) to accelerate PF"
      explanation: >-
        Sources this specific edge: reactive oxygen species promoting
        epithelial-mesenchymal transition in alveolar epithelial cells.
  evidence:
  - reference: PMID:15364596
    reference_title: "Lung oxidative response after acute coal dust exposure."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "TBARS were increased 60 days after coal dust exposure and protein carbonyl groups increased at all times after coal dust exposure (48 h, 7 days, 30 days, and 60 days)."
    explanation: >-
      Direct in vivo measurement of lipid peroxidation and protein oxidation in
      coal-dust-exposed lung, which is the oxidative injury this node asserts
      rather than an inference from a signalling pathway in one cell type.
  - reference: PMID:36581638
    reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "activation of the IGF1/IGF1R axis induced generation of reactive oxygen species (ROS) to promote epithelial-mesenchymal transition (EMT) in alveolar epithelial cells (AECs) to accelerate PF"
    explanation: >-
      Supports the edge from reactive oxygen species to epithelial-mesenchymal
      transition in alveolar epithelial cells, one of the two branches this node
      feeds. Note this branch is epithelial; the macrophage-derived and
      particle-surface oxidant claim rests on the in vivo item above.
  - reference: PMID:36581638
    reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "ROS induced inflammation and EMT by the activation of the NF-kB/NLRP3 axis to accelerate PF"
    explanation: >-
      Supports the other branch: reactive oxygen species acting through the
      NF-kappaB/NLRP3 axis to drive inflammation.
- name: Macrophage Mitochondrial Dysfunction and Defective Mitophagy
  description: >-
    Coal-silica dust collapses mitochondrial membrane potential and impairs
    oxidative phosphorylation in macrophages, while suppressing PINK1/Parkin
    signalling so the damaged mitochondria are not cleared. The failure of
    mitochondrial quality control amplifies the oxidant load and feeds both
    macrophage death and the inflammatory output, rather than being a passive
    consequence of them.
  role: driver
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: alveolar macrophage
    term:
      id: CL:0000583
      label: alveolar macrophage
  biological_processes:
  - preferred_term: mitophagy
    term:
      id: GO:0000423
      label: mitophagy
    modifier: DECREASED
  downstream:
  - target: Dust-Laden Macrophage Death
  - target: Sustained Inflammatory Cell Recruitment and Amplification
  evidence:
  - reference: PMID:41894156
    reference_title: "Activation of Mitophagy by Kinetin Mitigates Coal-Silica Mixed Dust-Induced Pulmonary Fibrosis via Modulating Macrophage Mitochondrial Function in Mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "CSD exposure triggered ROS accumulation, mitochondrial membrane potential collapse, and impaired oxidative phosphorylation, leading to reduced adenosine triphosphate synthesis."
    explanation: >-
      Measures the mitochondrial dysfunction this node asserts, in a
      coal-silica mixed dust exposure rather than in a generic particulate
      model.
  - reference: PMID:41894156
    reference_title: "Activation of Mitophagy by Kinetin Mitigates Coal-Silica Mixed Dust-Induced Pulmonary Fibrosis via Modulating Macrophage Mitochondrial Function in Mice."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "CSD suppressed PINK1/Parkin signaling and diminished LC3B mitochondrial recruitment, resulting in defective mitophagy"
    explanation: >-
      Sources the defective-mitophagy half of the node and names the pathway
      through which clearance fails.
  notes: >-
    Demonstrated in mice and cells, not in human coal miner tissue, and the
    branch was added on a reviewer's suggestion after the report flagged its
    translational status as unconfirmed. It is curated because the rescue arm
    below makes it a testable causal claim rather than an observation, but the
    human evidence is not there yet.
- name: Dust-Laden Macrophage Death
  description: >-
    Poorly biodegradable particles — the silica fraction especially — are
    cytotoxic to the macrophages that ingested them, and pro-apoptotic signalling
    rises in the alveolar compartment after coal dust exposure. Particles freed by
    dying cells are available for re-uptake by newly recruited macrophages, a loop
    that keeps the lesion building without further inhaled dust. How much of the
    early injury this cell death actually accounts for is contested; see the
    refuting evidence below.
  role: driver
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: alveolar macrophage
    term:
      id: CL:0000583
      label: alveolar macrophage
  biological_processes:
  - preferred_term: apoptotic process
    term:
      id: GO:0006915
      label: apoptotic process
    modifier: INCREASED
  downstream:
  - target: Alveolar and Small-Airway Tissue Injury
  evidence:
  - reference: PMID:16966090
    reference_title: "Apoptosis and Bax expression are increased by coal dust in the polycyclic aromatic hydrocarbon-exposed lung."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: MODEL_ORGANISM
    snippet: "In rats exposed to BNF, CD exposure increased alveolar expression of the proapoptotic mediator Bax but decreased CYP1A1 induction relative to BNF exposure alone."
    explanation: >-
      Indirect on two counts, both material. The pro-apoptotic response is
      measured under co-exposure to beta-naphthoflavone rather than to coal dust
      alone, and the assay localizes to alveolar cells generally rather than to
      macrophages specifically. Quoted in full so the conditional survives.
  - reference: PMID:16966090
    reference_title: "Apoptosis and Bax expression are increased by coal dust in the polycyclic aromatic hydrocarbon-exposed lung."
    supports: REFUTE
    evidence_source: MODEL_ORGANISM
    snippet: "Combined BNF and CD exposure increased Bax expression and apoptosis in the lung, but Bax and apoptosis were not the major determinants of early lung injury in this model."
    explanation: >-
      The same study's own conclusion argues against apoptosis being the main
      driver of early injury. Curated as a REFUTE item rather than omitted,
      because the supporting quote above comes from the same paper and reading
      one without the other would overstate the node.
- name: Alveolar and Small-Airway Tissue Injury
  description: >-
    The cumulative tissue-level result of retained dust, macrophage death and
    oxidant exposure: structural and functional damage concentrated in the
    alveoli and the small conducting airways, which is where the dust sits and
    where the reparative program is then triggered.
  role: driver
  conforms_to: "fibrotic_response#Tissue Injury"
  biological_scale: TISSUE
  locations:
  - preferred_term: respiratory bronchiole
    term:
      id: UBERON:0002188
      label: respiratory bronchiole
  biological_processes:
  - preferred_term: wound healing
    term:
      id: GO:0042060
      label: wound healing
    modifier: DYSREGULATED
  downstream:
  - target: Sustained Inflammatory Cell Recruitment and Amplification
  evidence:
  - reference: PMID:26024344
    reference_title: "Small airways involvement in coal mine dust lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Inhalation of coal mine dust results in a spectrum of symptoms, dysfunction, and pathological changes in the respiratory tract that collectively have been labeled coal mine dust lung disease."
    explanation: >-
      Sources the tissue-injury claim this node makes, and the coal mine dust
      lung disease framing under which the injury is classified.
  - reference: PMID:26024344
    reference_title: "Small airways involvement in coal mine dust lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Pathologic changes associated with mineral dust deposition in the small airways may be of particular importance in contemporary miners with rapidly progressive respiratory impairment."
    explanation: >-
      Localizes the injury to the small airways, the anatomical claim this node
      makes, and ties it to the contemporary rapidly progressive presentation.
- name: NF-kappaB and NLRP3 Inflammasome Activation
  description: >-
    Reactive oxygen species and retained particles activate NF-kappaB signalling
    and assembly of the NLRP3 inflammasome in macrophages and epithelial cells,
    activating caspase-1 and releasing mature IL-1beta and IL-18. This converts
    a particle-handling problem into a sustained cytokine signal.
  role: driver
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: alveolar macrophage
    term:
      id: CL:0000583
      label: alveolar macrophage
  biological_processes:
  - preferred_term: NLRP3 inflammasome complex assembly
    term:
      id: GO:0044546
      label: NLRP3 inflammasome complex assembly
    modifier: INCREASED
  - preferred_term: positive regulation of canonical NF-kappaB signal transduction
    term:
      id: GO:0043123
      label: positive regulation of canonical NF-kappaB signal transduction
    modifier: INCREASED
  downstream:
  - target: Sustained Inflammatory Cell Recruitment and Amplification
  evidence:
  - reference: PMID:36581638
    reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "the protein levels of p-NF-κB(Ser536)/NF-κB, NLRP3 and Cleaved Caspase1(Asp297)/Caspase1 in the lung tissues, as well as the contents of IL-1β and CXCL2 in the bronchoalveolar lavage fluid, were significantly increased in CD-NPs-induced pre-fibrosis model mice"
    explanation: >-
      The study's own in vivo measurement of every component this node asserts —
      NF-kappaB phosphorylation, NLRP3, cleaved caspase-1 and the IL-1beta
      output — in coal-dust-exposed mouse lung.
  - reference: PMID:36581638
    reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "p-NF-κB(Ser536)/NF-κB was significantly increased in the CD-NPs-induced pre-fibrotic cell model and could be inhibited by PPP for 24 h"
    explanation: >-
      The cell-model counterpart, with pharmacological inhibition establishing
      that the NF-kappaB activation is coal-dust-driven rather than incidental.
- name: Sustained Inflammatory Cell Recruitment and Amplification
  description: >-
    IL-1beta, IL-18, TNF-alpha and chemokines recruit neutrophils and further
    macrophages to the peribronchiolar region. Because the retained dust is never
    cleared, the recruitment does not resolve, and the small airways carry the
    signature chronic inflammatory change of coal miners' lungs.
  role: driver
  conforms_to: "fibrotic_response#Inflammatory Recruitment and Amplification"
  biological_scale: TISSUE
  cell_types:
  - preferred_term: neutrophil
    term:
      id: CL:0000775
      label: neutrophil
  - preferred_term: alveolar macrophage
    term:
      id: CL:0000583
      label: alveolar macrophage
  biological_processes:
  - preferred_term: chronic inflammatory response
    term:
      id: GO:0002544
      label: chronic inflammatory response
    modifier: INCREASED
  - preferred_term: leukocyte migration
    term:
      id: GO:0050900
      label: leukocyte migration
    modifier: INCREASED
  locations:
  - preferred_term: respiratory bronchiole
    term:
      id: UBERON:0002188
      label: respiratory bronchiole
  downstream:
  - target: Fibroblast Activation and Myofibroblast Differentiation
  - target: Chronic cough
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:26024344
      reference_title: "Small airways involvement in coal mine dust lung disease."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "There is increasing evidence supporting an important association of abnormalities in the small peripheral airways with the development of respiratory symptoms"
      explanation: >-
        Sources this specific edge: small-airway abnormality producing
        respiratory symptoms, of which chronic cough is the characteristic one.
  evidence:
  - reference: PMID:26024344
    reference_title: "Small airways involvement in coal mine dust lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Inflammatory changes in the small airways have long been recognized as the signature lung pathology among coal miners."
    explanation: >-
      Establishes sustained small-airway inflammation as the defining, and
      anatomically localized, pathology of coal miners' lungs.
  - reference: PMID:36581638
    reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "the contents of IL-1β and CXCL2 in the bronchoalveolar lavage fluid, were significantly increased in CD-NPs-induced pre-fibrosis model mice"
    explanation: >-
      Measures the neutrophil chemokine CXCL2 and IL-1beta in coal-dust-exposed
      mouse airway fluid, the recruitment signal this node claims rather than a
      background statement about inflammasomes generally.
- name: Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition
  description: >-
    Injured alveolar epithelial cells undergo epithelial-mesenchymal transition,
    losing epithelial identity and acquiring a mesenchymal, matrix-producing
    phenotype. This is a second route into the fibroblast pool, parallel to
    activation of resident fibroblasts by the inflammatory milieu.
  role: driver
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: alveolar type II epithelial cell
    term:
      id: CL:0002063
      label: pulmonary alveolar type 2 cell
  biological_processes:
  - preferred_term: epithelial to mesenchymal transition
    term:
      id: GO:0001837
      label: epithelial to mesenchymal transition
    modifier: INCREASED
  downstream:
  - target: Fibroblast Activation and Myofibroblast Differentiation
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:36581638
      reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "the protein levels of COL-1, COL-3, and α-SMA were highest in the CD-NPs-induced cell model"
      explanation: >-
        Sources this specific edge by its output: coal dust exposure raises
        alpha-SMA (the myofibroblast marker) together with collagen I and III in
        the same model that shows the transition.
  evidence:
  - reference: PMID:36581638
    reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "The above data indicated that inhibition of NLRP3 reversed EMT induced by CD-NPs."
    explanation: >-
      The study's own loss-of-function result: blocking NLRP3 abolishes the
      coal-dust-induced transition, establishing this node as downstream of the
      inflammasome rather than merely coincident with it.
  - reference: PMID:36581638
    reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "CD-NPs induced PF by promoting inflammation and EMT via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
    explanation: >-
      The study's overall conclusion, placing epithelial-mesenchymal transition
      downstream of coal dust and upstream of pulmonary fibrosis. Demonstrated
      with coal dust nanoparticles in cell and mouse systems; that nanoparticle
      fraction is a component of, not a substitute for, the respirable coal mine
      dust miners inhale.
- name: Fibroblast Activation and Myofibroblast Differentiation
  description: >-
    Resident lung fibroblasts, together with cells arriving via
    epithelial-mesenchymal transition, differentiate into alpha-smooth-muscle-actin
    positive myofibroblasts under TGF-beta and inflammatory cytokine signalling.
    This is the central effector step: from here the lesion is matrix, not
    inflammation.
  role: central_effector
  conforms_to: "fibrotic_response#Mesenchymal Cell Activation"
  biological_scale: CELLULAR
  cell_types:
  - preferred_term: lung fibroblast
    term:
      id: CL:0002553
      label: fibroblast of lung
  - preferred_term: myofibroblast
    term:
      id: CL:0000186
      label: myofibroblast cell
  biological_processes:
  - preferred_term: transforming growth factor beta receptor signaling pathway
    term:
      id: GO:0007179
      label: transforming growth factor beta receptor signaling pathway
    modifier: INCREASED
  downstream:
  - target: Peribronchiolar Collagen Deposition and Coal Macule Formation
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:35831008
      reference_title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "activate fibroblasts, which increase the production of extracellular matrix proteins, leading to collagen deposition and eventual scarring of lung tissue"
      explanation: >-
        Sources this specific edge: activated fibroblasts are what raise
        extracellular matrix production and deposit the collagen that builds the
        lesion.
  evidence:
  - reference: PMID:36581638
    reference_title: "Coal dust nanoparticles induced pulmonary fibrosis by promoting inflammation and epithelial-mesenchymal transition via the NF-κB/NLRP3 pathway driven by IGF1/ROS-mediated AKT/GSK3β signals."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "the protein levels of COL-1, COL-3, and α-SMA were highest in the CD-NPs-induced cell model"
    explanation: >-
      Directly measures the alpha-SMA-positive myofibroblast phenotype and its
      collagen output after coal dust exposure — the node's central claim, from
      the study's own results rather than its background.
  - reference: PMID:35831008
    reference_title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "activate fibroblasts, which increase the production of extracellular matrix proteins, leading to collagen deposition and eventual scarring of lung tissue"
    explanation: >-
      Sources the inflammation-to-fibroblast-activation step this node sits at,
      from a review of coal and silica dust lung disease specifically rather
      than from generic pulmonary-fibrosis background. The same passage names
      TGF-beta among the mediators produced, which is the signalling annotated
      here.
- name: Peribronchiolar Collagen Deposition and Coal Macule Formation
  description: >-
    Myofibroblasts deposit collagen and reticulin around the dust-laden
    macrophage collection at the respiratory bronchiole, producing the coal
    macule — the histopathologic hallmark lesion of CWP. Macules aggregate into
    micronodules and nodules that become visible as small rounded opacities on
    chest radiography, defining simple CWP.
  role: consequence
  conforms_to: "fibrotic_response#Excessive ECM Deposition"
  biological_scale: TISSUE
  locations:
  - preferred_term: respiratory bronchiole
    term:
      id: UBERON:0002188
      label: respiratory bronchiole
  biological_processes:
  - preferred_term: extracellular matrix organization
    term:
      id: GO:0030198
      label: extracellular matrix organization
    modifier: INCREASED
  - preferred_term: collagen biosynthetic process
    term:
      id: GO:0032964
      label: collagen biosynthetic process
    modifier: INCREASED
  downstream:
  - target: Focal Centrilobular Emphysema
  - target: Nodule Coalescence into Progressive Massive Fibrosis
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:37295943
      reference_title: "Historical shift in pathological type of progressive massive fibrosis among coal miners in the USA."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Excessive coal mine dust exposure can lead to coal workers' pneumoconiosis (CWP), including its most severe form, progressive massive fibrosis (PMF)."
      explanation: >-
        Places progressive massive fibrosis as the severe end of the same
        dust-driven disease process that produces the macular lesion, which is
        the progression this edge asserts.
  - target: Pulmonary nodule
  evidence:
  - reference: PMID:26024344
    reference_title: "Small airways involvement in coal mine dust lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The coal macule is an inflammatory lesion associated with deposited dust, and occurs in the region of the most distal conducting airways and proximal respiratory bronchioles."
    explanation: >-
      Defines the hallmark lesion and fixes its anatomical location at the
      respiratory bronchiole, which is the location bound on this node.
- name: Focal Centrilobular Emphysema
  description: >-
    Destruction of alveolar walls immediately around the coal macule produces
    focal centrilobular emphysema. This is the obstructive component of coal mine
    dust lung disease and runs alongside the restrictive fibrotic component
    rather than replacing it, which is why advanced disease is characteristically
    a mixed defect.
  role: consequence
  biological_scale: TISSUE
  downstream:
  - target: Impaired Gas Exchange and Mixed Ventilatory Defect
  - target: Emphysema
  evidence:
  - reference: PMID:35831008
    reference_title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "coal macules or lesions <10 mm in diameter occurring mostly in the upper lung lobes due to the accumulation of dust particles and dust-laden macrophages are usually associated with focal centrilobular emphysema"
    explanation: >-
      Sources the morphologic claim this node actually makes — focal
      centrilobular emphysema arising around the macule — and with it the
      incoming edge from coal macule formation.
  - reference: PMID:24186945
    reference_title: "Respiratory disease mortality among US coal miners; results after 37 years of follow-up."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: HUMAN_CLINICAL
    snippet: "Coal mine dust exposure increased risk for mortality from pneumoconiosis and COPD."
    explanation: >-
      Indirect: establishes an obstructive disease burden attributable to coal
      mine dust at the population level, from which the emphysematous substrate
      follows, rather than reporting the morphology itself.
  - reference: PMID:24186945
    reference_title: "Respiratory disease mortality among US coal miners; results after 37 years of follow-up."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our findings support previous studies showing that exposure to coal mine dust and respirable silica leads to increased mortality from malignant and non-malignant respiratory diseases even in the absence of smoking."
    explanation: >-
      Shows the excess respiratory mortality persists in the absence of smoking,
      so the obstructive component is dust-driven rather than a confounded
      smoking effect.
- name: Nodule Coalescence into Progressive Massive Fibrosis
  description: >-
    Nodular lesions coalesce into conglomerate fibrotic masses one centimetre or
    larger, destroying regional lung architecture. PMF is the disabling
    complicated form and is characteristically self-sustaining: it can continue
    to progress after dust exposure has ended. The silica-enriched dust burden of
    contemporary mining shifts the histologic type of these masses toward
    silica-type PMF.
  role: consequence
  conforms_to: "fibrotic_response#Architectural Distortion and Organ Dysfunction"
  biological_scale: TISSUE
  locations:
  - preferred_term: lung
    term:
      id: UBERON:0002048
      label: lung
  downstream:
  - target: Impaired Gas Exchange and Mixed Ventilatory Defect
    causal_link_type: DIRECT
    evidence:
    - reference: PMID:41411198
      reference_title: "Coal Workers' Pneumoconiosis-Associated Deaths - United States, 2020-2023."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Early pneumoconiosis can be asymptomatic, but advanced disease often leads to disability and premature death."
      explanation: >-
        Sources the edge from advanced conglomerate disease to disabling
        functional impairment and death.
  - target: Pulmonary fibrosis
  evidence:
  - reference: PMID:37295943
    reference_title: "Historical shift in pathological type of progressive massive fibrosis among coal miners in the USA."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Of 322 cases found to have PMF, study pathologists characterised 138 (43%) as coal-type, 129 (40%) as mixed-type and 55 (17%) as silica-type PMF."
    explanation: >-
      Establishes the histologic typing of PMF masses in autopsy material and
      the relative frequency of each type.
  - reference: PMID:37295943
    reference_title: "Historical shift in pathological type of progressive massive fibrosis among coal miners in the USA."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our findings demonstrate a shift in PMF types among US coal miners, from a predominance of coal- and mixed-type PMF to a more commonly encountered silica-type PMF."
    explanation: >-
      Supports the edge from the silica-enriched dust burden node to this one:
      more silica in the dust changes the type of mass that forms.
  - reference: PMID:35353671
    reference_title: "Pathology and Mineralogy Demonstrate Respirable Crystalline Silica Is a Major Cause of Severe Pneumoconiosis in U.S. Coal Miners."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We found a significantly higher proportion of silica-type PMF (57% vs. 18%; P < 0.001) among contemporary miners compared with their historical counterparts."
    explanation: >-
      Independent case series quantifying the same contemporary shift toward
      silica-type PMF.
  - reference: PMID:41411198
    reference_title: "Coal Workers' Pneumoconiosis-Associated Deaths - United States, 2020-2023."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Disease progression can occur after cessation of exposure"
    explanation: >-
      Sources the self-sustaining behaviour this node claims, which is the
      property that makes progressive massive fibrosis different from a lesion
      that simply stops accruing when the dust stops.
  - reference: PMID:31302880
    reference_title: "Current Review of Pneumoconiosis Among US Coal Miners."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "respiratory morbidity including ongoing fibrosis and functional impairment can occur after exposure ceases"
    explanation: >-
      Independent statement of the same post-cessation progression, naming
      ongoing fibrosis specifically rather than progression in general.
- name: Impaired Gas Exchange and Mixed Ventilatory Defect
  description: >-
    Fibrotic mass lesions restrict lung expansion while focal emphysema and small
    airway disease obstruct airflow, producing the mixed restrictive-obstructive
    physiology and ventilation-perfusion mismatch of advanced CWP. Progressive
    hypoxemia follows, and chronic hypoxic vasoconstriction with vascular
    destruction raises pulmonary artery pressure toward cor pulmonale.
  role: consequence
  biological_scale: ORGANISM
  downstream:
  - target: Exertional dyspnea
  - target: Restrictive ventilatory defect
  - target: Airway obstruction
  - target: Hypoxemia
  - target: Elevated pulmonary artery pressure
  evidence:
  - reference: PMID:37284491
    reference_title: "Serum Osteopontin, KL-6, and Syndecan-4 as Potential Biomarkers in the Diagnosis of Coal Workers' Pneumoconiosis: A Case-Control Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups."
    explanation: >-
      Shows measured pulmonary function declining stepwise from healthy controls
      through dust-exposed workers to CWP patients, grounding the functional
      impairment claim in a graded human series.
  - reference: PMID:41411198
    reference_title: "Coal Workers' Pneumoconiosis-Associated Deaths - United States, 2020-2023."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Early pneumoconiosis can be asymptomatic, but advanced disease often leads to disability and premature death."
    explanation: >-
      Supports the progression from a silent early lesion to disabling
      functional impairment that this node represents.
phenotypes:
- name: Pulmonary nodule
  category: Respiratory
  description: >-
    Small rounded opacities on chest radiography, graded by the ILO
    classification for profusion and size, corresponding to coal macules and
    micronodules. This is the defining radiographic finding of simple CWP and,
    because early disease is symptomless, usually the first sign of it.
  phenotype_term:
    preferred_term: Pulmonary nodule
    term:
      id: HP:0033608
      label: Pulmonary nodule
  evidence:
  - reference: PMID:31302880
    reference_title: "Current Review of Pneumoconiosis Among US Coal Miners."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Extended exposure to the dust that is generated in the process of extracting coal can cause interstitial fibrosis of the lungs that can be visualized by chest radiography."
    explanation: >-
      Sources the radiographic detectability of the dust-induced parenchymal
      lesion on which this phenotype and the whole surveillance program rest.
  - reference: PMID:36972614
    reference_title: "Pathology and Mineralogy of the Pneumoconioses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Pathologic studies have shown that rounded opacities on chest imaging correspond to coal macules and coal nodules, and irregular opacities to interstitial fibrosis."
    explanation: >-
      Ties the radiographic nodule to the coal macule and nodule specifically,
      the lesion this phenotype names.
- name: Pulmonary fibrosis
  category: Respiratory
  description: >-
    Interstitial fibrosis of the lung, ranging from the reticulin and collagen of
    individual coal macules to the conglomerate masses of progressive massive
    fibrosis.
  phenotype_term:
    preferred_term: Pulmonary fibrosis
    term:
      id: HP:0002206
      label: Pulmonary fibrosis
  evidence:
  - reference: PMID:27626436
    reference_title: "Polymorphisms in Long Noncoding RNA H19 Contribute to the Protective Effects of Coal Workers' Pneumoconiosis in a Chinese Population."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "pneumoconiosis (CWP) is a lethal fibrotic lung disease caused by inhalation and deposition of inorganic coal mine dust in the lung"
    explanation: >-
      Characterizes CWP as a fibrotic lung disease, the substrate of this
      phenotype.
- name: Exertional dyspnea
  category: Respiratory
  description: >-
    Progressive breathlessness on exertion, the dominant symptom of complicated
    disease and the usual reason a miner presents. Absent or minimal in simple
    CWP.
  phenotype_term:
    preferred_term: Exertional dyspnea
    term:
      id: HP:0002875
      label: Exertional dyspnea
  frequency: FREQUENT
  evidence:
  - reference: PMID:35831008
    reference_title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "This is associated with increased collagen deposition and fibrosis around the airways and within the parenchyma, exertional breathlessness, haemoptysis and lung scarring."
    explanation: >-
      Names exertional breathlessness directly as a manifestation of the
      dust-driven fibrosis, which the mortality statistics used elsewhere in
      this entry do not.
  - reference: PMID:35831008
    reference_title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Patients with PMF often experience increasing breathlessness and severe deterioration in lung function"
    explanation: >-
      Sources the progression of breathlessness specifically in the complicated
      form, matching this phenotype's description.
- name: Chronic cough
  category: Respiratory
  description: >-
    Persistent cough, frequently productive, reflecting chronic small-airway
    inflammation from retained dust.
  phenotype_term:
    preferred_term: Chronic cough
    term:
      id: HP:0034315
      label: Chronic cough
  evidence:
  - reference: PMID:26024344
    reference_title: "Small airways involvement in coal mine dust lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "There is increasing evidence supporting an important association of abnormalities in the small peripheral airways with the development of respiratory symptoms"
    explanation: >-
      Links the small-airway pathology of CWP to respiratory symptoms, the
      mechanistic basis for cough in this disease.
  - reference: PMID:35831008
    reference_title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "as the disease manifests, patients exhibit symptoms of coughing, sneezing, increased sputum production, breathlessness and breathing difficulties"
    explanation: >-
      Names cough and increased sputum production directly among the symptoms of
      manifest CWP, which the mechanistic quote above does not.
- name: Emphysema
  category: Respiratory
  description: >-
    Focal centrilobular emphysema surrounding coal macules, plus more diffuse
    dust-related emphysema. Present in never-smoking miners, so it is a
    dust-attributable finding rather than a smoking comorbidity.
  phenotype_term:
    preferred_term: Focal centrilobular emphysema
    term:
      id: HP:0032966
      label: Centrilobular emphysema
  evidence:
  - reference: PMID:35831008
    reference_title: "Understanding the pathogenesis of occupational coal and silica dust-associated lung disease."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "coal macules or lesions <10 mm in diameter occurring mostly in the upper lung lobes due to the accumulation of dust particles and dust-laden macrophages are usually associated with focal centrilobular emphysema"
    explanation: >-
      Names the centrilobular distribution and its association with the coal
      macule, which is why this phenotype binds the centrilobular child term
      rather than the generic Emphysema parent.
  - reference: PMID:24186945
    reference_title: "Respiratory disease mortality among US coal miners; results after 37 years of follow-up."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our findings support previous studies showing that exposure to coal mine dust and respirable silica leads to increased mortality from malignant and non-malignant respiratory diseases even in the absence of smoking."
    explanation: >-
      Indirect: establishes dust-attributable non-malignant respiratory disease
      independent of smoking, from which the dust rather than smoking origin of
      the emphysema follows. It reports mortality, not morphology.
- name: Restrictive ventilatory defect
  category: Respiratory
  description: >-
    Reduced lung volumes from conglomerate fibrosis, typically combined with an
    obstructive component in advanced disease.
  phenotype_term:
    preferred_term: Restrictive ventilatory defect
    term:
      id: HP:0002091
      label: Restrictive ventilatory defect
  evidence:
  - reference: PMID:11952275
    reference_title: "Pulmonary function impairment in pneumoconiotic patients with progressive massive fibrosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The major pattern of impairment for miners with PMF was obstructive, but there was an increasing trend for restrictive impairment for higher radiological categories."
    explanation: >-
      Distinguishes the restrictive from the obstructive pattern and ties the
      restrictive component to advancing radiographic category, which the
      biomarker correlation cited elsewhere cannot do.
  - reference: PMID:35032040
    reference_title: "Respiratory health of American Indian and Alaska Native coal miners participating in the Coal Workers' Health Surveillance Program, 2014-2019."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Lung function abnormalities were seen in 9.0% with primarily restrictive patterns."
    explanation: >-
      Surveillance spirometry showing the restrictive pattern predominating in a
      screened miner population.
- name: Airway obstruction
  category: Respiratory
  description: >-
    Airflow limitation from small-airway disease and focal emphysema. Coal mine
    dust causes chronic obstructive pulmonary disease independently of the
    fibrotic pneumoconiosis, which is why surveillance spirometry was added to
    radiographic screening.
  phenotype_term:
    preferred_term: Airway obstruction
    term:
      id: HP:0006536
      label: Airway obstruction
  evidence:
  - reference: PMID:31302880
    reference_title: "Current Review of Pneumoconiosis Among US Coal Miners."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "since coal mine dust can cause chronic obstructive pulmonary disease (COPD), which is not reliably detected by chest radiography"
    explanation: >-
      States that coal mine dust causes obstructive disease and that radiography
      misses it, the rationale for adding spirometry to surveillance.
- name: Hypoxemia
  category: Respiratory
  description: >-
    Low arterial oxygen from ventilation-perfusion mismatch and destroyed gas
    exchange surface in advanced disease; the usual indication for supplemental
    oxygen.
  phenotype_term:
    preferred_term: Hypoxemia
    term:
      id: HP:0012418
      label: Hypoxemia
  evidence:
  - reference: PMID:39620857
    reference_title: "Outcomes of Lung Transplantation in Coal Workers Pneumoconiosis: Analysis of UNOS Database."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CWP group was noted to have higher mean pulmonary artery pressures, LAS, need for prolonged intubation and extracorporeal membrane oxygenation (ECMO) at 72 h"
    explanation: >-
      Documents severe gas-exchange failure in end-stage CWP, to the point of
      requiring extracorporeal support around transplantation.
- name: Elevated pulmonary artery pressure
  category: Cardiovascular
  description: >-
    Pulmonary hypertension arising from chronic hypoxic vasoconstriction and
    destruction of the pulmonary vascular bed by fibrosis and emphysema. Measured
    to be higher in CWP transplant candidates than in other transplant
    indications.
  phenotype_term:
    preferred_term: Elevated pulmonary artery pressure
    term:
      id: HP:0004890
      label: Elevated pulmonary artery pressure
  sequelae:
  - target: Cor pulmonale
    description: >-
      Sustained pressure overload of the right ventricle progresses to right
      heart failure.
  evidence:
  - reference: PMID:39620857
    reference_title: "Outcomes of Lung Transplantation in Coal Workers Pneumoconiosis: Analysis of UNOS Database."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CWP group was noted to have higher mean pulmonary artery pressures"
    explanation: >-
      Direct measurement of elevated mean pulmonary artery pressure in CWP
      patients relative to other lung transplant recipients.
- name: Cor pulmonale
  category: Cardiovascular
  description: >-
    Right ventricular failure secondary to sustained pulmonary hypertension, the
    terminal cardiovascular consequence of advanced complicated CWP.
  phenotype_term:
    preferred_term: Cor pulmonale
    term:
      id: HP:0001648
      label: Cor pulmonale
  evidence:
  - reference: PMID:39620857
    reference_title: "Outcomes of Lung Transplantation in Coal Workers Pneumoconiosis: Analysis of UNOS Database."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: HUMAN_CLINICAL
    snippet: "CWP group was noted to have higher mean pulmonary artery pressures"
    explanation: >-
      Indirect: the paper measures the pulmonary hypertension that causes cor
      pulmonale rather than right ventricular failure itself, so the cor
      pulmonale claim follows by the standard inference from sustained elevated
      pulmonary artery pressure and is not asserted by the quote.
environmental:
- name: Occupational inhalation of respirable coal mine dust
  description: >-
    Cumulative inhalation of respirable coal mine dust during underground or
    surface coal mining is the necessary cause of CWP. Classic risk work is
    underground extraction, with roof bolting and continuous-miner operation
    among the dustiest tasks; contemporary thin-seam mining raises the silica
    fraction of the dust because accessing the seam requires cutting
    silica-bearing rock.
  exposure_term:
    preferred_term: exposure to respirable coal mine dust
    term:
      id: ECTO:7000005
      label: exposure to coal dust
  exposure_classifications:
    hazard_agent_type:
    - classification_value: CHEMICAL
      notes: >-
        Coal mine dust is a mineral dust, classified as a chemical agent in the
        occupational-hygiene scheme (ILO section 1.1), not as a physical agent.
    exposure_route:
    - classification_value: INHALATION
      notes: >-
        Only the respirable fraction reaching the terminal bronchioles and
        alveoli is pathogenic; the route is what defines the exposure.
    exposure_duration:
    - classification_value: CHRONIC
      notes: >-
        ATSDR chronic duration (365 days and longer). Classic CWP follows one to
        several decades of underground work; the rapidly progressive form
        compresses this but is still a multi-year exposure, not an intermediate
        or acute one.
    ghs_health_hazard_class:
    - classification_value: STOT_REPEATED_EXPOSURE
      notes: >-
        Specific target organ toxicity from repeated exposure — a non-lethal,
        organ-specific effect (lung) accumulating over prolonged exposure rather
        than an acute toxic response.
    exposome_domain:
    - classification_value: SPECIFIC_EXTERNAL
      notes: >-
        An identifiable individual-level occupational agent, in Wild's specific
        external domain rather than the general external environment.
  notes: >-
    No iarc_carcinogen_group is recorded. IARC evaluated coal dust in Monographs
    volume 68 and placed it in Group 3 (not classifiable as to carcinogenicity to
    humans); the schema's IARCCarcinogenGroupEnum was checked and does admit
    GROUP_3, so this omission is a judgement rather than a schema limit — the
    Group 3 listing is for coal dust as an agent, while the exposure curated here
    is coal *mine* dust, a mixture whose silica fraction carries its own
    classification. Crystalline silica's Group 1 listing belongs to the Silicosis
    entry's exposure, not to this one. The cohort association between coal mine
    dust and lung cancer mortality is instead curated as evidence, on the
    mortality items below.
  evidence:
  - reference: PMID:41411198
    reference_title: "Coal Workers' Pneumoconiosis-Associated Deaths - United States, 2020-2023."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Among workers employed in the mining industry, the highest PMR was among underground mining machine operators (164.6)."
    explanation: >-
      Identifies underground mining machine operation as the highest-risk task
      by proportionate mortality, grounding the occupational specificity of the
      exposure.
  - reference: PMID:31302880
    reference_title: "Current Review of Pneumoconiosis Among US Coal Miners."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Contributing factors may include mining of thin coal seams or cutting rock to access coal, which may expose miners to coal mine dust with a higher content of silica and silicates than in the past."
    explanation: >-
      Sources the thin-seam mechanism by which contemporary coal mine dust
      carries more silica than historical dust.
  - reference: PMID:24186945
    reference_title: "Respiratory disease mortality among US coal miners; results after 37 years of follow-up."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We saw a significant relationship between coal mine dust exposure and lung cancer mortality (HR=1.70; 95% CI 1.02 to 2.83) but not with respirable silica (HR=1.05; 95% CI 0.90 to 1.23)."
    explanation: >-
      The lung-cancer association this exposure's notes refer to, with the effect
      attaching to coal mine dust rather than to its respirable silica fraction.
      Curated as evidence on the exposure rather than as a hazard classification.
  - reference: PMID:36635098
    reference_title: "Increased odds of mortality from non-malignant respiratory disease and lung cancer are highest among US coal miners born after 1939."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "US coal miners have excess mortality from NMRD and lung cancer compared with total US and Appalachian populations. Mortality is highest in the most recent birth cohorts, perhaps reflecting increased rates of severe pneumoconiosis."
    explanation: >-
      Independent evidence that both malignant and non-malignant respiratory
      mortality is concentrated in later birth cohorts, consistent with the
      contemporary exposure shift this entry models.
  influences_mechanisms:
  - target: Respirable Coal Mine Dust Deposition and Retention
    environmental_effect: TRIGGERS
    causal_link_type: DIRECT
    description: >-
      Coal extraction liberates dust in the respirable size range, which is the
      fraction that reaches the terminal bronchioles and alveoli to be deposited
      and retained.
    evidence:
    - reference: PMID:41411198
      reference_title: "Coal Workers' Pneumoconiosis-Associated Deaths - United States, 2020-2023."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Coal workers' pneumoconiosis (CWP) is a preventable, progressive occupational lung disease caused by inhaling respirable coal mine dust, a complex mixture commonly containing coal, crystalline silica, and other silicate minerals."
      explanation: >-
        Ties the occupational activity directly to inhalation of the respirable
        dust that the deposition node represents.
  - target: Silica-Enriched Dust Burden
    environmental_effect: EXACERBATES
    causal_link_type: DIRECT
    description: >-
      Cutting silica-bearing rock strata to reach thin coal seams raises the
      crystalline-silica content of the generated dust, which is what shifts the
      retained burden toward the more fibrogenic silica-enriched form.
    evidence:
    - reference: PMID:31302880
      reference_title: "Current Review of Pneumoconiosis Among US Coal Miners."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Contributing factors may include mining of thin coal seams or cutting rock to access coal, which may expose miners to coal mine dust with a higher content of silica and silicates than in the past."
      explanation: >-
        States the specific mining practice that raises the silica fraction of
        the dust, which is the edge this link asserts.
- name: Cigarette smoking
  description: >-
    Smoking does not cause CWP and is not required for it — the excess
    respiratory mortality of coal miners is present in never-smokers. It is
    curated here because it compounds the obstructive component and overall
    respiratory morbidity, and smoking cessation is a core management step.
  exposure_term:
    preferred_term: exposure to cigarette smoking
    term:
      id: ECTO:0100003
      label: exposure to cigarette smoking
  review_notes: >-
    Bound and pathograph-linked as an explicitly non-causal modifier. An earlier
    revision left both the exposure_term and the mechanism link off, reasoning
    that binding a tobacco term would imply smoking is etiologic for CWP. That
    reasoning does not survive contact with the schema: environmental_effect
    exists to separate TRIGGERS from MODULATES, and only TRIGGERS and EXACERBATES
    count as causal for compliance scoring. MODULATES states the intended claim
    machine-readably instead of burying it in prose.
  evidence:
  - reference: PMID:24186945
    reference_title: "Respiratory disease mortality among US coal miners; results after 37 years of follow-up."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our findings support previous studies showing that exposure to coal mine dust and respirable silica leads to increased mortality from malignant and non-malignant respiratory diseases even in the absence of smoking."
    explanation: >-
      Establishes that the dust effect is independent of smoking, which is the
      reason smoking is curated here as a compounding factor rather than a cause.
  influences_mechanisms:
  - target: Impaired Gas Exchange and Mixed Ventilatory Defect
    environmental_effect: MODULATES
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      Smoking worsens measured lung function in miners who already have
      progressive massive fibrosis, on top of the dust-driven impairment, without
      being required for it. MODULATES rather than EXACERBATES because the
      cohort evidence puts the excess respiratory mortality in never-smokers,
      so the interaction is additive burden rather than a demonstrated
      amplification of the dust mechanism.
    evidence:
    - reference: PMID:11952275
      reference_title: "Pulmonary function impairment in pneumoconiotic patients with progressive massive fibrosis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Smoking miners had even lower FEV1/FVC and DLCO than did their non-smoking counterparts."
      explanation: >-
        Measures worse airflow obstruction and diffusing capacity in smoking
        miners with progressive massive fibrosis, the additive functional effect
        this link asserts.
    - reference: PMID:11952275
      reference_title: "Pulmonary function impairment in pneumoconiotic patients with progressive massive fibrosis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The loss of lung function cannot be accounted for by different smoking habits."
      explanation: >-
        The same study's conclusion that smoking does not explain the impairment,
        which is why this link is MODULATES and not a causal edge.
genetic:
- name: TNF
  gene_term:
    preferred_term: TNF
    term:
      id: hgnc:11892
      label: TNF
  association: >-
    Host susceptibility modifier. The TNF-alpha promoter polymorphisms -308 and
    -238 are associated with CWP risk in meta-analysis of candidate-gene
    case-control studies, chiefly in Chinese coal-miner cohorts. These are common
    regulatory variants that amplify the TNF-alpha-driven inflammatory response
    to retained dust; they modify risk and are neither necessary nor sufficient
    without the exposure.
  relationship_type: SUSCEPTIBILITY
  variant_origin: GERMLINE
  evidence:
  - reference: PMID:39578762
    reference_title: "Candidate gene polymorphisms associated with silicosis and coal workers' pneumoconiosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The analysis revealed that allele A of TNFα-308, allele A of TNFα-238, and allele C of IL-1RA + 2018 were identified as risk factors for the development of diseases."
    explanation: >-
      Meta-analytic association of both TNF-alpha promoter alleles with disease
      risk across the pooled candidate-gene literature.
  - reference: PMID:39578762
    reference_title: "Candidate gene polymorphisms associated with silicosis and coal workers' pneumoconiosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Despite similar exposure levels, individuals exhibit varying responses."
    explanation: >-
      States the observation that motivates a host-susceptibility layer at all:
      equal dust exposure does not produce equal disease.
  notes: >-
    The meta-analysis pools silicosis and CWP studies rather than reporting CWP
    separately, so the association is not CWP-specific. It is curated as a
    susceptibility modifier on that basis and not as a CWP-only effect estimate.
- name: TGFB1
  gene_term:
    preferred_term: TGFB1
    term:
      id: hgnc:11766
      label: TGFB1
  association: >-
    Host susceptibility modifier acting on the central profibrotic pathway. In a
    case-control study of 508 CWP patients and 526 exposed-miner controls, the
    rs1800470 CC genotype was associated with reduced CWP risk and the
    rs11466345 GG genotype with increased risk. TGF-beta1 is the same signal the
    Fibroblast Activation node is annotated with, so this locus modifies the rate
    of a mechanism the entry already models rather than adding a new one.
  relationship_type: SUSCEPTIBILITY
  variant_origin: GERMLINE
  evidence:
  - reference: PMID:23554640
    reference_title: "Association of transforming growth factor-β1 gene variants with risk of coal workers' pneumoconiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Multivariate logistic regression analysis revealed that SNP2 (rs1800470) CC genotype was associated with decreased risk of CWP (OR = 0.50, 95% CI = 0.32-0.78)"
    explanation: >-
      Reports the protective genotype association with an effect estimate in a
      CWP-specific exposed-control design.
  - reference: PMID:23554640
    reference_title: "Association of transforming growth factor-β1 gene variants with risk of coal workers' pneumoconiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the SNP5 (rs11466345) GG genotype was associated with an increased risk of CWP (OR = 2.5, 95%CI = 1.36-4.57)"
    explanation: >-
      Reports the risk-increasing genotype at the same locus, showing the
      modifier acts in both directions.
- name: H19
  gene_term:
    preferred_term: H19
    term:
      id: hgnc:4713
      label: H19
  association: >-
    Protective susceptibility modifier. The H19 long noncoding RNA variant
    rs2067051 CT/TT genotypes were associated with decreased CWP risk in 703
    cases and 705 exposed controls from Chinese coal mines. One of the few
    reported protective loci in this disease.
  relationship_type: SUSCEPTIBILITY
  variant_origin: GERMLINE
  evidence:
  - reference: PMID:27626436
    reference_title: "Polymorphisms in Long Noncoding RNA H19 Contribute to the Protective Effects of Coal Workers' Pneumoconiosis in a Chinese Population."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We found that individuals with the H19 rs2067051 CT/TT genotypes showed a decreased risk of CWP compared with those with the CC genotype (adjusted OR = 0.64, 95%CI = 0.49-0.83, p = 0.001)."
    explanation: >-
      Reports the protective genotype association and effect estimate in a
      CWP case-control study with dust-exposed controls.
  notes: >-
    Single-population candidate-gene finding in Han Chinese miners without
    reported independent replication; treat the effect size as provisional. The
    same caveat applies to the wider CWP susceptibility literature, which is
    dominated by Chinese candidate-gene case-control studies and has no
    genome-wide-significant locus.
prevalence:
- population: US underground coal miners with 25 or more years of tenure
  measure_type: POINT_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 10000.0
  notes: >-
    Radiographic CWP (ILO profusion 1/0 or greater, or a large opacity) in the
    NIOSH Coal Workers' Health Surveillance Program, 1970-2017. Reported as
    "exceeds 10%", so the normalized rate is a floor rather than a point
    estimate.
  evidence:
  - reference: PMID:30024799
    reference_title: "Continued Increase in Prevalence of Coal Workers' Pneumoconiosis in the United States, 1970-2017."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Following a low point in the late 1990s, the national prevalence of CWP in miners with 25 years or more of tenure now exceeds 10%."
    explanation: >-
      Source for the national long-tenure prevalence figure and for the fact
      that it is rising from a late-1990s nadir.
- population: Central Appalachian (Kentucky, Virginia, West Virginia) long-tenured coal miners
  measure_type: POINT_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 20600.0
  notes: >-
    20.6% of long-tenured central Appalachian miners, roughly double the national
    figure for the same tenure band. This regional concentration is the core
    epidemiologic signal of the CWP resurgence.
  evidence:
  - reference: PMID:30024799
    reference_title: "Continued Increase in Prevalence of Coal Workers' Pneumoconiosis in the United States, 1970-2017."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In central Appalachia (Kentucky, Virginia, West Virginia), 20.6% of long-tenured miners have CWP."
    explanation: >-
      Direct source for the central Appalachian prevalence figure and the states
      it covers.
- population: Central Appalachian coal miners with 25 or more years of tenure (PMF)
  measure_type: POINT_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 3200.0
  notes: >-
    Progressive massive fibrosis specifically, risen from 0.33% to 3.2% in
    long-tenured central Appalachian miners — an order-of-magnitude increase in
    the disabling form.
  evidence:
  - reference: PMID:35353671
    reference_title: "Pathology and Mineralogy Demonstrate Respirable Crystalline Silica Is a Major Cause of Severe Pneumoconiosis in U.S. Coal Miners."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the prevalence of PMF has increased from 0.33% to 3.2% in miners with 25 years or more of tenure"
    explanation: >-
      Source for both the current PMF prevalence and the magnitude of its
      increase in this population.
biochemical:
- name: Serum Krebs von den Lungen-6 (KL-6)
  presence: INCREASED
  biomarker_term:
    preferred_term: Krebs von den Lungen-6
    term:
      id: NCIT:C154724
      label: Krebs von den Lungen-6 Measurement
  readouts:
  - target: Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >-
      KL-6 is shed by injured and regenerating alveolar type II cells, so rising
      serum concentration reports the alveolar epithelial injury node rather
      than the fibrotic mass burden directly.
    evidence:
    - reference: PMID:37284491
      reference_title: "Serum Osteopontin, KL-6, and Syndecan-4 as Potential Biomarkers in the Diagnosis of Coal Workers' Pneumoconiosis: A Case-Control Study."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Compared with HCs, patients with higher OPN, KL-6, Syndecan-4 and Gremlin-1 had higher risk for CWP."
      explanation: >-
        Establishes the positive direction of the marker with respect to
        disease, the claim this readout link makes.
  notes: >-
    A mucin-like glycoprotein released by injured and regenerating alveolar type
    II cells, elevated in CWP and rising stepwise from healthy controls through
    dust-exposed workers to diagnosed patients. Investigational rather than
    established practice; CWP is still diagnosed by exposure history plus
    radiography.
  evidence:
  - reference: PMID:37284491
    reference_title: "Serum Osteopontin, KL-6, and Syndecan-4 as Potential Biomarkers in the Diagnosis of Coal Workers' Pneumoconiosis: A Case-Control Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups."
    explanation: >-
      Shows the stepwise rise in serum KL-6 across exposure and disease groups,
      alongside falling pulmonary function.
- name: Serum osteopontin
  presence: INCREASED
  biomarker_term:
    preferred_term: osteopontin
    term:
      id: NCIT:C124349
      label: Osteopontin Measurement
  readouts:
  - target: Sustained Inflammatory Cell Recruitment and Amplification
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >-
      Osteopontin is a macrophage-associated matricellular protein, so serum
      concentration tracks the sustained inflammatory recruitment node rather
      than a specific matrix compartment.
    evidence:
    - reference: PMID:37284491
      reference_title: "Serum Osteopontin, KL-6, and Syndecan-4 as Potential Biomarkers in the Diagnosis of Coal Workers' Pneumoconiosis: A Case-Control Study."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups."
      explanation: >-
        Shows serum osteopontin rising stepwise with exposure and disease
        status, the graded positive relationship this readout asserts.
  notes: >-
    A matricellular protein linked to macrophage activation and fibrogenesis,
    elevated in CWP and part of a three-marker panel with KL-6 and syndecan-4
    that improves discrimination of patients from dust-exposed workers.
  evidence:
  - reference: PMID:37284491
    reference_title: "Serum Osteopontin, KL-6, and Syndecan-4 as Potential Biomarkers in the Diagnosis of Coal Workers' Pneumoconiosis: A Case-Control Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The combination of OPN, KL-6, and Syndecan-4 can improve the diagnostic sensitivity and specificity of CWP patients differentiated from HCs or DEWs."
    explanation: >-
      Reports the panel's incremental diagnostic value over single markers, the
      basis for curating these together.
- name: Serum syndecan-4
  presence: INCREASED
  biomarker_term:
    preferred_term: syndecan-4
  readouts:
  - target: Peribronchiolar Collagen Deposition and Coal Macule Formation
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >-
      Syndecan-4 is a cell-surface heparan sulfate proteoglycan involved in
      matrix assembly, so serum concentration is read here against the matrix
      deposition node rather than against the inflammatory compartment.
    evidence:
    - reference: PMID:37284491
      reference_title: "Serum Osteopontin, KL-6, and Syndecan-4 as Potential Biomarkers in the Diagnosis of Coal Workers' Pneumoconiosis: A Case-Control Study."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups."
      explanation: >-
        Shows the graded positive relationship across healthy controls,
        dust-exposed workers and CWP patients that this readout asserts.
  notes: >-
    No ontology term is bound. NCIT has no syndecan-4 measurement concept, and
    binding a broader proteoglycan term would name a different analyte — the
    "no term beats a bad one" rule. Part of the three-marker panel below.
  evidence:
  - reference: PMID:37284491
    reference_title: "Serum Osteopontin, KL-6, and Syndecan-4 as Potential Biomarkers in the Diagnosis of Coal Workers' Pneumoconiosis: A Case-Control Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The combination of OPN, KL-6, and Syndecan-4 can improve the diagnostic sensitivity and specificity of CWP patients differentiated from HCs or DEWs."
    explanation: >-
      Establishes syndecan-4 as the third member of the panel whose combination
      outperforms any single marker.
- name: Serum gremlin-1
  presence: INCREASED
  biomarker_term:
    preferred_term: gremlin-1
  readouts:
  - target: Fibroblast Activation and Myofibroblast Differentiation
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: >-
      Gremlin-1 is a BMP antagonist that de-represses TGF-beta-driven
      fibrogenesis, so it is read against the mesenchymal activation node.
    evidence:
    - reference: PMID:37284491
      reference_title: "Serum Osteopontin, KL-6, and Syndecan-4 as Potential Biomarkers in the Diagnosis of Coal Workers' Pneumoconiosis: A Case-Control Study."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The pulmonary function parameters decreased sequentially, and the serum OPN, KL-6, Syndecan-4 and Gremlin-1 concentrations were increased sequentially among the HC, DEW and CWP groups."
      explanation: >-
        Shows gremlin-1 rising stepwise with exposure and disease status, the
        graded relationship this readout asserts.
  notes: >-
    No ontology term is bound; NCIT has no gremlin-1 measurement concept.
    Measured in the same 400-subject series as the other three markers but not
    part of the validated three-marker diagnostic combination.
  evidence:
  - reference: PMID:37284491
    reference_title: "Serum Osteopontin, KL-6, and Syndecan-4 as Potential Biomarkers in the Diagnosis of Coal Workers' Pneumoconiosis: A Case-Control Study."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Compared with HCs, patients with higher OPN, KL-6, Syndecan-4 and Gremlin-1 had higher risk for CWP."
    explanation: >-
      Associates higher gremlin-1 with CWP risk in the case-control series.
treatments:
- name: Exposure Cessation and Dust Reduction
  description: >-
    Removal from further dust exposure — through the Part 90 transfer right,
    engineering controls, or leaving the work — is the only intervention that
    changes the disease trajectory in early CWP. It halts accrual of new dust
    burden; it does not clear retained dust, and it does not reliably stop PMF,
    which can progress after exposure ends.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: occupational exposure cessation
    term:
      id: NCIT:C49236
      label: Therapeutic Procedure
  target_mechanisms:
  - target: Respirable Coal Mine Dust Deposition and Retention
    description: >-
      Ending exposure stops further deposition and retention of respirable dust,
      capping the cumulative burden that drives every downstream step.
  evidence:
  - reference: PMID:36972614
    reference_title: "Pathology and Mineralogy of the Pneumoconioses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Most pneumoconioses are irreversible and incurable, but disease progression can be mitigated by removal from or reduction in further exposure."
    explanation: >-
      States both halves of this treatment's claim: the disease is not
      reversible, and exposure reduction is what mitigates progression.
  - reference: PMID:41411198
    reference_title: "Coal Workers' Pneumoconiosis-Associated Deaths - United States, 2020-2023."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Disease progression can occur after cessation of exposure"
    explanation: >-
      Sources the limit on this treatment stated in its description: stopping
      exposure caps the dust burden but does not reliably stop established
      disease from advancing.
- name: Supportive Respiratory Care
  description: >-
    Vaccination against influenza and pneumococcus, prompt treatment of
    respiratory infection, mycobacterial surveillance given impaired local lung
    defences, and smoking cessation. Standard of care and the backbone of
    management at every stage, since no disease-modifying drug exists.
  therapeutic_modality: OTHER
  treatment_term:
    preferred_term: Supportive Care
    term:
      id: NCIT:C15747
      label: Supportive Care
  evidence:
  - reference: PMID:36972614
    reference_title: "Pathology and Mineralogy of the Pneumoconioses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Many pneumoconioses are irreversible and develop due to excessive cumulative respirable dust inhalation."
    explanation: >-
      Establishes the irreversibility that makes supportive rather than curative
      management the standard of care.
- name: Pulmonary Rehabilitation
  description: >-
    Structured exercise and education to maintain functional capacity and
    activities of daily living in miners with established functional impairment.
  therapeutic_modality: BEHAVIORAL
  treatment_term:
    preferred_term: Pulmonary Rehabilitation
    term:
      id: NCIT:C157966
      label: Pulmonary Rehabilitation
  target_mechanisms:
  - target: Impaired Gas Exchange and Mixed Ventilatory Defect
    description: >-
      Targets the functional consequences of impaired gas exchange and mixed
      ventilatory defect rather than the fibrotic lesion itself.
  evidence:
  - reference: PMID:37284491
    reference_title: "Serum Osteopontin, KL-6, and Syndecan-4 as Potential Biomarkers in the Diagnosis of Coal Workers' Pneumoconiosis: A Case-Control Study."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: HUMAN_CLINICAL
    snippet: "Because the disease is progressive and incurable, early diagnosis or early prevention is especially important to control this disease."
    explanation: >-
      Indirect: the quote establishes that CWP is progressive and incurable —
      the reason management is functional rather than curative — but does not
      itself evaluate pulmonary rehabilitation.
- name: Long-Term Oxygen Therapy
  description: >-
    Supplemental oxygen for chronic hypoxemia in advanced disease, and to
    mitigate the hypoxic pulmonary vasoconstriction that drives pulmonary
    hypertension and cor pulmonale.
  therapeutic_modality: OTHER
  treatment_term:
    preferred_term: Oxygen Therapy
    term:
      id: NCIT:C94624
      label: Oxygen Therapy
  target_mechanisms:
  - target: Impaired Gas Exchange and Mixed Ventilatory Defect
    description: >-
      Compensates for the failed gas exchange surface; it does not alter the
      fibrotic or emphysematous lesion producing it.
  evidence:
  - reference: PMID:39620857
    reference_title: "Outcomes of Lung Transplantation in Coal Workers Pneumoconiosis: Analysis of UNOS Database."
    supports: SUPPORT
    directness: INDIRECT
    evidence_source: HUMAN_CLINICAL
    snippet: "CWP group was noted to have higher mean pulmonary artery pressures, LAS, need for prolonged intubation and extracorporeal membrane oxygenation (ECMO) at 72 h"
    explanation: >-
      Indirect: documents the severity of oxygenation failure in advanced CWP
      that indicates oxygen support, rather than evaluating long-term oxygen
      therapy as an intervention.
- name: Lung Transplantation
  description: >-
    The only definitive intervention for end-stage CWP with progressive
    respiratory failure. Post-transplant graft and patient survival in CWP
    recipients are comparable to other indications, so the disease is not itself
    a contraindication, though CWP candidates arrive with higher pulmonary artery
    pressures and higher allocation scores and have a more demanding
    perioperative course.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: Organ Transplantation
    term:
      id: NCIT:C15289
      label: Organ Transplantation
  target_mechanisms:
  - target: Nodule Coalescence into Progressive Massive Fibrosis
    description: >-
      Replaces the fibrotic organ outright. It is the only listed treatment that
      removes the conglomerate lesion rather than managing its consequences.
  evidence:
  - reference: PMID:39620857
    reference_title: "Outcomes of Lung Transplantation in Coal Workers Pneumoconiosis: Analysis of UNOS Database."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Overall graft survival (Log-rank p = 0.889) and patient survival (Log-rank p = 0.910) were not significantly different between the two groups."
    explanation: >-
      Registry comparison showing CWP transplant recipients do as well as
      recipients transplanted for other indications.
  - reference: PMID:39620857
    reference_title: "Outcomes of Lung Transplantation in Coal Workers Pneumoconiosis: Analysis of UNOS Database."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Between May 2005 and June 2021, 158 patients underwent LT for CWP."
    explanation: >-
      Establishes the cohort size behind the survival comparison, so the
      equivalence claim is not read off a handful of cases.
  - reference: PMID:22360577
    reference_title: "Lung transplantation in patients with coal workers' pneumoconiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "There was no increased risk of perioperative or postoperative complications."
    explanation: >-
      Independent single-centre series reaching the same conclusion on
      perioperative safety.
- name: Antifibrotic Therapy
  description: >-
    Pirfenidone, an antifibrotic established in idiopathic pulmonary fibrosis, has
    been trialled in CWP with pulmonary fibrosis on the reasoning that the
    fibroblast-activation step is shared. Investigational, not standard of care —
    no antifibrotic is approved for CWP. Nintedanib is discussed in the same
    context in the literature but is not listed as a therapeutic_agent here
    because no CWP trial or study was found to cite for it.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: pirfenidone
      term:
        id: CHEBI:32016
        label: pirfenidone
  target_mechanisms:
  - target: Fibroblast Activation and Myofibroblast Differentiation
    description: >-
      Both agents act on the fibroblast activation and matrix-deposition step
      that this entry models as the central effector of the lesion.
  evidence:
  - reference: clinicaltrials:NCT04461587
    reference_title: "Examination of Pirfenidone (Esbriet®) Therapy in Coal Workers' Pneumoconiosis With Pulmonary Fibrosis Associated With Radiographic and Functional Impairment to Examine the Reduction in Progression of Disease, Reduction of Exacerbation Rates and Possible Reduction of Inflammatory Biomarkers as an Index of Clinical Response."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Examination of pirfenidone (Esbriet®) therapy in coal workers' pneumoconiosis (black lung) with pulmonary fibrosis (scarring of the lung)."
    explanation: >-
      Registration record establishing that pirfenidone has been formally
      trialled in CWP with pulmonary fibrosis. A trial record documents that the
      question was asked; it is not evidence the therapy works.
clinical_trials:
- name: NCT04461587
  phase: PHASE_II
  status: COMPLETED
  description: >-
    Phase II study of pirfenidone in coal workers' pneumoconiosis with pulmonary
    fibrosis and radiographic and functional impairment, examining reduction in
    disease progression, exacerbation rates, and inflammatory biomarkers.
  target_phenotypes:
  - preferred_term: Pulmonary fibrosis
    term:
      id: HP:0002206
      label: Pulmonary fibrosis
  evidence:
  - reference: clinicaltrials:NCT04461587
    reference_title: "Examination of Pirfenidone (Esbriet®) Therapy in Coal Workers' Pneumoconiosis With Pulmonary Fibrosis Associated With Radiographic and Functional Impairment to Examine the Reduction in Progression of Disease, Reduction of Exacerbation Rates and Possible Reduction of Inflammatory Biomarkers as an Index of Clinical Response."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Examination of pirfenidone (Esbriet®) therapy in coal workers' pneumoconiosis (black lung) with pulmonary fibrosis (scarring of the lung)."
    explanation: >-
      ClinicalTrials.gov record establishing the trial's population,
      intervention, and target condition.
differential_diagnoses:
- name: Caplan Syndrome
  disease_term:
    preferred_term: Caplan syndrome
    term:
      id: MONDO:0005690
      label: Caplan syndrome
  description: >-
    Rheumatoid pneumoconiosis: well-defined peripheral pulmonary nodules with
    necrobiotic centres retaining mineral dust, arising in a dust-exposed worker
    who also has rheumatoid arthritis. First described in Welsh coal miners, and
    a genuine consideration in any miner presenting with nodules.
  distinguishing_features:
  - Coexisting rheumatoid arthritis, which ordinary CWP does not require
  - Peripheral, well-defined nodules rather than the upper-zone rounded opacities of simple CWP
  - Necrobiotic nodule centre retaining mineral dust
  - Nodules may appear before, at, or years after the arthritis is diagnosed
  evidence:
  - reference: PMID:34027516
    reference_title: "Caplan's Syndrome with a twist."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Classically, they form peripheral well-defined pulmonary nodules with characteristic silica retained in the necrobiotic center."
    explanation: >-
      Describes the nodule morphology and retained mineral dust that separate
      Caplan syndrome from ordinary rheumatoid lung nodules and from the coal
      macule.
  - reference: PMID:34027516
    reference_title: "Caplan's Syndrome with a twist."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Caplan's syndrome also known as rheumatoid pneumoconiosis is a disease entity that is seen in patients with rheumatoid arthritis (RA) exposed to chronic silica and inorganic dust"
    explanation: >-
      States the exposure range — chronic silica and inorganic dust generally,
      not coal specifically — which is the nosological point behind curating this
      as a differential rather than a coal-dust subtype.
  notes: >-
    Curated as a differential rather than as a CWP subtype because MONDO makes it
    a sibling, not a child: MONDO:0005690 is a direct subclass of MONDO:0015926
    pneumoconiosis, the parent of MONDO:0006654 anthracosis, and it arises on
    silicosis and asbestosis as readily as on coal dust. Recording it under
    has_subtypes would both misstate that nosology and, because subtype terms
    count as curated, retire MONDO:0005690 from the curation queue as though this
    entry covered it.

    The cited case had silica and asbestos exposure rather than coal mining, so
    it is used for the generic rheumatoid-pneumoconiosis lesion and not as a
    coal-miner case. A coal-miner Caplan citation would be a worthwhile addition;
    none was found in the cached reference set.
diagnosis:
- name: Occupational exposure history with ILO-classified chest radiography
  diagnosis_term:
    preferred_term: Chest Radiography
    term:
      id: NCIT:C38103
      label: Chest Radiography
  description: >-
    CWP is diagnosed clinically, not histologically: a compatible coal mine dust
    exposure history plus a characteristic chest radiograph classified under the
    ILO International Classification of Radiographs of Pneumoconioses, read by a
    NIOSH-certified B Reader. Profusion of small opacities is graded 0-3 with
    size categories p/q/r, and large opacities A/B/C define the complicated form.
    Tissue sampling is reserved for atypical presentations or a separate
    indication such as suspected malignancy. Certification matters measurably —
    non-certified readers over-read both presence and severity.
  evidence:
  - reference: PMID:36972614
    reference_title: "Pathology and Mineralogy of the Pneumoconioses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Diagnosis of silicosis, coal workers’ pneumoconiosis, or asbestosis may be made based on a suggestive occupational history and typical chest imaging without the need for tissue sampling."
    explanation: >-
      States the two-part diagnostic basis this entry uses and that biopsy is
      not required.
  - reference: PMID:36972614
    reference_title: "Pathology and Mineralogy of the Pneumoconioses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "A chest radiograph classified using the International Labor Office (ILO) system has been the mainstay for medical surveillance of pneumoconioses in dusty trades."
    explanation: >-
      Sources the ILO classification as the standard instrument, which the
      subtype definitions in this entry are stated in terms of.
  - reference: PMID:31302880
    reference_title: "Current Review of Pneumoconiosis Among US Coal Miners."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Certified B Readers are physicians who have successfully passed the certification examination, demonstrating competence with the ILO system."
    explanation: >-
      Sources the B Reader certification that the surveillance program depends
      on for consistent classification.
  - reference: PMID:31302880
    reference_title: "Current Review of Pneumoconiosis Among US Coal Miners."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Specifically, compared to B Readers, physicians who have not passed the certification examination tend to over-read for disease presence and severity."
    explanation: >-
      Quantifies why the certification is a diagnostic requirement rather than a
      formality — uncertified reading biases both presence and severity upward.
  notes: >-
    Radiography does not distinguish between the coal-dust-induced interstitial
    lung diseases, so a surveillance "case of CWP" is an opacity-based
    definition rather than a claim about which lesion is present. Genetic testing
    has no diagnostic role; the susceptibility loci curated in `genetic:` are
    research findings.
imaging_findings:
- name: Rounded small opacities on chest radiography
  modality: XRAY
  description: >-
    Small rounded opacities, graded p (up to 1.5 mm), q (1.5-3 mm) and r (3-10
    mm) by the ILO system, corresponding pathologically to coal macules and
    nodules. Irregular opacities in the same films correspond instead to
    interstitial fibrosis, so opacity shape carries lesion information.
  phenotype_term:
    preferred_term: Pulmonary nodule
    term:
      id: HP:0033608
      label: Pulmonary nodule
  diagnostic: true
  evidence:
  - reference: PMID:36972614
    reference_title: "Pathology and Mineralogy of the Pneumoconioses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      A chest radiograph classified using the International Labor Office (ILO) system has been the
      mainstay for medical surveillance of pneumoconioses in dusty trades. ... Coal mine dust lung
      disease (CMDLD), or black lung, is a group of lung conditions caused by exposure to coal mine
      dust, including emphysema, chronic obstructive pulmonary disease, dust-related diffuse
      fibrosis, and coal worker’s pneumoconiosis (CWP). CWP can be diagnosed by finding rounded or
      irregular linear opacities on chest imaging in association with a compatible exposure history.
      Pathologic studies have shown that rounded opacities on chest imaging correspond to coal
      macules and coal nodules, and irregular opacities to interstitial fibrosis.
    explanation: >-
      Restores the plain-radiograph/ILO context and coal-workers' pneumoconiosis diagnostic setting
      before the opacity-to-pathology mapping. The selected passage does not give p/q/r millimeter
      boundaries.
- name: Nodules on high-resolution CT not visible on plain radiography
  modality: CT
  description: >-
    HRCT detects parenchymal nodules in miners whose plain films are classified
    ILO category 0/0, so radiographic surveillance under-calls early disease.
    This is a sensitivity gap in the diagnostic standard rather than a competing
    diagnostic criterion.
  evidence:
  - reference: PMID:8404184
    reference_title: "High-resolution CT in simple coal workers' pneumoconiosis. Lack of correlation with pulmonary function tests and arterial blood gas values."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "By HRCT, nodules were identified in 12 miners; 4 of 9 were classified as category 0/0 CWP"
    explanation: >-
      Directly measures the under-detection: nodules on HRCT in miners the ILO
      film classification called normal.
histopathology:
- name: Coal macule
  description: >-
    Black pigment deposited around the walls of respiratory bronchioles and
    alveolar ducts, comprising dust-laden macrophages with reticulin and
    collagen. The earliest lesion of CWP and, with the coal nodule, what
    pathologically defines the simple form.
  diagnostic: true
  evidence:
  - reference: PMID:36972614
    reference_title: "Pathology and Mineralogy of the Pneumoconioses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The coal macule is the earliest lesion to form and consists of black pigment deposited around walls of respiratory bronchioles and alveolar ducts."
    explanation: >-
      Defines the lesion and fixes its anatomical location at the respiratory
      bronchiole, matching the pathophysiology node that builds it.
  - reference: PMID:36972614
    reference_title: "Pathology and Mineralogy of the Pneumoconioses."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Simple CWP is pathologically defined by the presence of coal macules and nodules."
    explanation: >-
      Makes the macule the defining histologic criterion for the simple subtype
      curated in has_subtypes.
- name: Mineral dust alveolar proteinosis
  description: >-
    Accumulation of surfactant-like material in alveoli, a marker of very heavy
    dust burden. Substantially more common in contemporary US miners than in
    their historical counterparts, tracking the same silica-enriched exposure
    shift as silica-type PMF.
  evidence:
  - reference: PMID:35353671
    reference_title: "Pathology and Mineralogy Demonstrate Respirable Crystalline Silica Is a Major Cause of Severe Pneumoconiosis in U.S. Coal Miners."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Mineral dust alveolar proteinosis was also more common in contemporary miners compared with their historical counterparts (70% vs. 37%; P < 0.01)."
    explanation: >-
      Quantifies the finding and its historical shift in autopsy material from
      US coal miners with progressive massive fibrosis.
discussions:
- discussion_id: emt_human_fidelity
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  prompt: >-
    Does epithelial-mesenchymal transition in alveolar epithelial cells actually
    contribute myofibroblasts to human coal workers' pneumoconiosis, or is the
    EMT branch curated here an artifact of the model system it was demonstrated
    in?
  attaches_to:
  - pathophysiology#Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition
  - pathophysiology#Fibroblast Activation and Myofibroblast Differentiation
  rationale: >-
    The entire EMT branch rests on one study, PMID:36581638. Its in vitro arm
    used A549 — a lung adenocarcinoma line standing in for alveolar type II
    cells — and BEAS-2B, a bronchial line; its in vivo arm gave C57BL/6 mice coal
    dust *nanoparticles*, a fraction of, not a substitute for, the respirable
    coal mine dust miners inhale. No human CWP tissue evidence supports the
    branch.

    Two things make this a mismatch rather than a plain gap. The node binds
    CL:0002063 pulmonary alveolar type 2 cell and asserts type-II EMT in human
    disease on the strength of a carcinoma line's behaviour. And EMT as a source
    of myofibroblasts in human lung fibrosis is contested in its own right, not
    settled background — lineage-tracing work in other fibrotic lung disease has
    repeatedly failed to confirm it. The mechanism is well evidenced in the model;
    whether it operates in a miner's lung is the open question.
  proposed_experiments:
  - experiment_id: emt_lineage_trace_coal_dust
    name: Lineage-traced fate mapping of alveolar type II cells in a coal mine dust model
    description: >-
      Expose alveolar-type-II-lineage-labelled reporter mice to authentic
      respirable coal mine dust rather than to a nanoparticle fraction, and score
      whether labelled cells appear within fibrotic lesions carrying myofibroblast
      markers. Substituting real mine dust for the nanoparticle preparation is the
      point of the experiment, not an incidental detail.
    would_support:
    - pathophysiology#Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition
    supporting_outcome:
    - >-
        Lineage-labelled alveolar type II descendants are found inside coal macules
        and fibrotic foci co-expressing alpha-SMA, in proportion to lesion burden.
    would_refute:
    - pathophysiology#Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition
    refuting_outcome:
    - >-
        Labelled cells remain confined to the epithelium with no alpha-SMA-positive
        descendants in lesions, placing the myofibroblast pool entirely with
        resident mesenchymal cells.
  - experiment_id: emt_marker_human_cwp_tissue
    name: EMT marker localization in human CWP lung tissue
    description: >-
      Apply dual-marker immunohistochemistry for epithelial and mesenchymal
      markers to archived human coal miner lung specimens — the National Coal
      Workers' Autopsy Study material this entry already cites for PMF typing —
      scoring cells at the macule and PMF margins for a transitional phenotype.
    would_support:
    - pathophysiology#Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition
    supporting_outcome:
    - >-
        Cells co-expressing epithelial and mesenchymal markers are enriched at
        lesion margins in miner lung relative to unexposed controls.
    would_refute:
    - pathophysiology#Alveolar Epithelial Injury and Epithelial-Mesenchymal Transition
    refuting_outcome:
    - >-
        No transitional phenotype is detectable at lesion margins, leaving the EMT
        branch unsupported in human tissue.
  notes: >-
    Recorded rather than resolved by deleting the branch: the model evidence is
    real and the branch is the only route by which epithelial injury reaches the
    fibroblast pool in this entry. The point is that its translational status is
    unestablished, not that it is wrong.
animal_models:
- name: Coal-silica mixed dust mouse model with kinetin mitophagy rescue
  species: Mouse
  genotype: Wild-type, with PINK1 overexpression and PINK1 knockdown arms
  publication: PMID:41894156
  description: >-
    Coal-silica mixed dust exposure in mice, with pharmacological mitophagy
    activation (kinetin) as a rescue arm and PINK1 knockdown to test pathway
    dependence. The genetic arms are what make this more than an exposure
    model: abolishing the rescue by knocking down PINK1 establishes the
    mechanism rather than just the association.
  modeled_mechanisms:
  - target: Macrophage Mitochondrial Dysfunction and Defective Mitophagy
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Reproduces the mitochondrial collapse and mitophagy failure in
      macrophages after mixed coal-silica dust exposure.
    limitations: >-
      Mouse macrophages, and a coal-silica mixture whose ratio need not match
      any particular mine's respirable dust. No human coal miner tissue
      confirmation of the PINK1/Parkin defect exists.
    readouts:
    - name: Mitochondrial membrane potential and oxidative phosphorylation
      target: Macrophage Mitochondrial Dysfunction and Defective Mitophagy
      direction: DECREASED
      interpretation: >-
        Direct functional correlate of the mitochondrial dysfunction node.
      evidence:
      - reference: PMID:41894156
        reference_title: "Activation of Mitophagy by Kinetin Mitigates Coal-Silica Mixed Dust-Induced Pulmonary Fibrosis via Modulating Macrophage Mitochondrial Function in Mice."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "CSD exposure triggered ROS accumulation, mitochondrial membrane potential collapse, and impaired oxidative phosphorylation, leading to reduced adenosine triphosphate synthesis."
        explanation: >-
          Reports the measurement behind this readout and its direction.
    - name: PINK1/Parkin-mediated mitophagy after kinetin treatment
      target: Macrophage Mitochondrial Dysfunction and Defective Mitophagy
      direction: RESTORED
      interpretation: >-
        The rescue arm. Restoring mitophagy reverses the downstream inflammation
        and fibrosis, which is what makes the node causal rather than
        correlative.
      evidence:
      - reference: PMID:41894156
        reference_title: "Activation of Mitophagy by Kinetin Mitigates Coal-Silica Mixed Dust-Induced Pulmonary Fibrosis via Modulating Macrophage Mitochondrial Function in Mice."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "kinetin treatment and PINK1 overexpression restored PINK1/Parkin activation and LC3II-dependent mitophagy, alleviated mitochondrial dysfunction, and suppressed subsequent macrophage inflammation and pulmonary fibrosis."
        explanation: >-
          Documents the restoration and that it suppressed the downstream
          inflammation and fibrosis, the direction this readout records.
  - target: Nodule Coalescence into Progressive Massive Fibrosis
    relationship: PARTIALLY_RECAPITULATES
    fidelity: LOW
    description: >-
      Produces pulmonary fibrosis after mixed-dust exposure, but on a
      months-long murine timescale.
    limitations: >-
      Murine fibrosis after weeks to months of instilled mixed dust is not the
      conglomerate mass lesion that defines human PMF after decades of
      inhalation. The model speaks to fibrogenesis, not to mass formation.
    evidence:
    - reference: PMID:41894156
      reference_title: "Activation of Mitophagy by Kinetin Mitigates Coal-Silica Mixed Dust-Induced Pulmonary Fibrosis via Modulating Macrophage Mitochondrial Function in Mice."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "Kinetin exerts its antifibrotic effects on CWP by promoting PINK1-mediated mitophagy, improving mitochondrial function, and alleviating macrophage inflammation."
      explanation: >-
        Establishes a fibrotic endpoint in the model that responds to the
        mechanism-directed intervention.
- name: Coal dust particle instillation mouse model with vitamin D rescue
  species: Mouse
  genotype: Wild-type
  publication: PMID:35057792
  description: >-
    Long-course coal dust particle exposure (nine months) with single-cell
    transcriptomic readout and a vitamin D treatment arm. The dust used was
    characterized as under 5 microns with under 10% silica, so unlike the model
    above this one isolates the coal-predominant exposure.
  modeled_mechanisms:
  - target: Alveolar and Small-Airway Tissue Injury
    relationship: RECAPITULATES
    fidelity: MODERATE
    description: >-
      Reproduces alveolar structural destruction and activation of inflammatory
      and cell-death pathways after sustained coal dust exposure.
    limitations: >-
      Nine months in a mouse compresses what takes one to several decades in a
      miner, and instillation bypasses the aerodynamic deposition that
      determines where inhaled dust actually lands.
    readouts:
    - name: Alveolar structure and pulmonary microenvironment integrity
      target: Alveolar and Small-Airway Tissue Injury
      direction: DECREASED
      interpretation: >-
        Structural correlate of the tissue injury node in a coal-predominant
        exposure.
      evidence:
      - reference: PMID:35057792
        reference_title: "Coal dust exposure triggers heterogeneity of transcriptional profiles in mouse pneumoconiosis and Vitamin D remedies."
        supports: SUPPORT
        evidence_source: MODEL_ORGANISM
        snippet: "Alveolar structure and pulmonary microenvironment were destroyed, inflammatory and death (apoptosis, autophagy, and necrosis) pathways were activated, leading to pneumoconiosis in post 9 months coal dust stimulation."
        explanation: >-
          Reports the structural destruction and pathway activation behind this
          readout, on a stated timescale.
  - target: Fibroblast Activation and Myofibroblast Differentiation
    relationship: PARTIALLY_RECAPITULATES
    fidelity: LOW
    description: >-
      Reproduces profibrotic signalling and an M2 macrophage population that
      tracks fibrosis, with vitamin D reducing both.
    limitations: >-
      The fibrogenic readout is transcriptional and macrophage-phenotypic rather
      than the alpha-SMA-positive myofibroblast this node names, so it supports
      the surrounding signalling rather than the effector cell itself. Vitamin D
      benefit here is not clinically validated in humans.
    evidence:
    - reference: PMID:35057792
      reference_title: "Coal dust exposure triggers heterogeneity of transcriptional profiles in mouse pneumoconiosis and Vitamin D remedies."
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "Beclin1, LC3B, LAMP2, TGF-ß, and MLPH were up-regulated induced by CDP, promoting autophagy and pulmonary fibrosis."
      explanation: >-
        Documents upregulated TGF-beta and a profibrotic program, the signalling
        this node is annotated with, in a coal-predominant mouse exposure.

📚

References & Deep Research

References

3

PMID:41411198

Coal Workers' Pneumoconiosis-Associated Deaths - United States, 2020-2023.

No top-level findings curated for this source.

PMID:35353671

Pathology and Mineralogy Demonstrate Respirable Crystalline Silica Is a Major Cause of Severe Pneumoconiosis in U.S. Coal Miners.

No top-level findings curated for this source.

PMID:35831008

Understanding the pathogenesis of occupational coal and silica dust-associated lung disease.

No top-level findings curated for this source.

Deep Research

1

Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.

Evaluations and curation notes (1)

Create: Coal Workers Pneumoconiosis · 2026-09-03T02:53:25Z · View source

Created kb/disorders/Coal_Workers_Pneumoconiosis.yaml de novo (MONDO:0006654, canonical label "anthracosis"; "coal workers' pneumoconiosis" is an exact MONDO synonym). Duplicate preflight: git grep over origin/main kb/ for MONDO:0006654, "coal worker", "anthracosis", "coal dust" returned only Chronic_Obstructive_Pulmonary_Disease (a coal-dust mention, not a CWP entry); stubs/ had no match; GitHub PR and issue searches across all states returned zero. No claim issue existed. Deep research: claude_code provider only, via `just research-disorder claude_code Coal_Workers_Pneumoconiosis`. Run took 254s over 20 turns and 18 web searches, cost ~$1.22, 57 citations. The report carried no reference_validation or term_validation frontmatter block, so both were retro-fitted with `just validate-research-reference` and `just validate-research-terms`. Reference validation on the report: 31/31 resolved, 0 unresolved, 0 off topic. Nothing was excluded on validation grounds. Term validation on the report found 2 terms named as a different term and 4 worth a second look. Independent OAK checks found MORE wrong bindings than the validator flagged, because the validator only checked 14 of 36 names. Every suggested HPO term was re-derived from OAK rather than copied. Wrong report suggestions, all rejected: HP:0002105 report "Restrictive ventilatory defect" -> HP is Hemoptysis (NOT flagged by the validator; caught by direct OAK lookup). Correct term used: HP:0002091. HP:0009777 report "Rheumatoid nodules" -> HP is Absent thumb. Phenotype dropped. HP:0100750 report "Pulmonary nodule" -> HP is Atelectasis. Correct term used: HP:0033608. HP:0031246 report "Chronic cough" -> HP is Nonproductive cough. Correct term used: HP:0034315. HP:0002092 report "Pulmonary hypertension" -> HP is Pulmonary arterial hypertension, a Group 1 entity; CWP causes Group 3 PH. Bound HP:0004890 Elevated pulmonary artery pressure instead. NCIT:C64582 report "Oxygen" -> NCIT is "Hypopharyngeal Cancer pNX TNM Finding v6 and v7". Bound NCIT:C94624 Oxygen Therapy instead. UBERON:0002185 report "bronchiole" -> UBERON is bronchus; UBERON:0000115 report "lung parenchyma" -> UBERON is lung epithelium. Bound UBERON:0002188 respiratory bronchiole, which is where the coal macule actually forms. Every NCIT treatment term was checked for reachability from NCIT:C25218 before use. Citations: the report cites by URL and PMC id rather than PMID, and its .citations.md sidecar contains only the prompt. 21 PMC ids were converted to PMIDs via the PMC ID Converter API and cited as PMIDs; PubMed searches added further primary sources (NIOSH surveillance, the National Coal Workers' Autopsy Study PMF-typing paper, the 37-year mortality cohort, the UNOS transplant analysis). Content: 4 subtypes (simple, complicated/PMF, rapidly progressive, Caplan syndrome); 13-node pathophysiology chain wired with `downstream` edges from dust deposition through macrophage phagocytosis, ROS, NLRP3/NF-kappaB, inflammatory amplification, EMT and fibroblast activation to the coal macule, focal emphysema, PMF and mixed ventilatory defect; a separate `Silica-Enriched Dust Burden` node carrying the contemporary silica-driven resurgence; 10 phenotypes; 2 environmental entries (coal mine dust with exposure_classifications and two influences_mechanisms links, plus smoking as an explicitly non-causal modifier); 3 susceptibility genes (TNF, TGFB1, H19); 3 prevalence records; 2 biomarkers; 6 treatments; 1 clinical trial (NCT04461587). Five nodes declare conforms_to against fibrotic_response (Tissue Injury, Inflammatory Recruitment and Amplification, Mesenchymal Cell Activation, Excessive ECM Deposition, Architectural Distortion and Organ Dysfunction), matching the Asbestosis pattern. Deliberate omissions, recorded so they are not read as oversights: - No `datasets:` block. `just discover-datasets` returned 13 candidates, all GENE_ONLY via TNF/TGFB1/H19 and none about coal dust or pneumoconiosis (Crohn's disease, macular degeneration, ovarian cancer). A direct GEO search found exactly one plausible series, GSE311671, whose title says "Coal Mine Dust" but whose summary and overall design are a silica suspension murine silicosis model. Including it would have been the Named Entity Confusion failure the dataset-curation guidance warns about, so nothing was added. - No iarc_carcinogen_group on the coal mine dust exposure. Coal mine dust itself has no IARC group this entry is entitled to assert; crystalline silica's Group 1 listing belongs to the Silicosis exposure. The coal-dust/lung-cancer association is curated as cohort evidence instead. - ILO item 2.1.9 (COPD from coal dust) deliberately not claimed: it names a different disease outcome of the same exposure, curated under COPD. - No GeneReviews baseline. PubMed search for "pneumoconiosis GeneReviews[All Fields]" returned 0 hits, as expected for a purely acquired occupational disease. - Most `downstream` edges carry no edge-level evidence. Edge evidence was added only for the 8 edges where a source makes the causal claim itself; the rest were left uncited rather than reusing a node citation to paper over an unsourced edge. Validation run: `just validate` and `just validate-disorders` both pass, 72/72 snippets verified against the cached references. check-entity-refs, check-causal-targets, check-duplicate-keys, check-enum-values, check-qualifier-terms and check-qualifier-terms-online all OK. Whole-KB content gates (snippet-length, title-snippets, folded-hyphens, snippet-grading, environmental-evidence) report no new violations. Compliance 84.7% (Silicosis 79.4%, Chronic Beryllium Disease 79.9%, Asbestosis 88.6%). Page renders; the derived HTML was not committed.

Claude Code ▸

Coal Workers' Pneumoconiosis: Comprehensive Research Report

claude-haiku-4-5-20251001, claude-sonnet-5 57 citations 2026-09-03T02:27:20.535454

Coal Workers' Pneumoconiosis: Comprehensive Research Report

1. Disease Information

Overview. Coal workers' pneumoconiosis (CWP) — colloquially "black lung disease" — is a preventable, progressive occupational interstitial lung disease caused by chronic inhalation of respirable coal mine dust, a complex heterogeneous mixture of coal, crystalline silica, and other silicate minerals (CDC MMWR, 2025). The disease spectrum runs from asymptomatic anthracosis/anthracofibrosis through simple CWP (discrete pulmonary nodules, typically 1–10 mm, containing coal macules and micronodules) to complicated CWP, also called progressive massive fibrosis (PMF), defined by conglomerate fibrotic masses ≥1 cm that can progress even after dust exposure ceases and lead to end-stage restrictive/mixed lung disease and death (Medscape/Merck Manual; MMWR 2025).

Key identifiers. - ICD-10-CM: J60 (Coalworker's pneumoconiosis) (ICD10Data) - MeSH: Anthracosis / Coal Workers' Pneumoconiosis (broader term Pneumoconiosis) - Synonyms/alternative names: black lung disease, anthracosis, coalworker's lung, "miner's asthma" (historical), Caplan's syndrome (rheumatoid variant) - Explicit OMIN/Orphanet identifiers were not located in this search — CWP is fundamentally an acquired occupational disease, not a monogenic/rare disease, so it is under-indexed in classical rare-disease/Mendelian resources; the primary authoritative sources are occupational-medicine/regulatory bodies (NIOSH, MSHA, CDC) rather than OMIM/Orphanet.

Data provenance. Most quantitative disease burden data in the literature derives from aggregated occupational surveillance rather than individual EHR records: the NIOSH Coal Workers' Health Surveillance Program (CWHSP), federally funded Black Lung Clinics, National Coal Workers' Autopsy Study, multi-decade cohort mortality studies (e.g., the 37-year US coal miner cohort), and CDC/NCHS multiple-cause-of-death mortality files (MMWR 2025; PMC7055360).

2. Etiology

Disease causal factor

CWP is a purely environmental/occupational disease — there is no known single-gene causal mutation. It results from cumulative inhalation of respirable coal mine dust (particles ~0.5–5 µm) that deposit in the distal airways and alveoli.

Risk factors

Environmental/occupational (primary): - Cumulative respirable coal mine dust exposure — dose-dependent; typically requires ≥10–20 years of underground exposure, though PMF is increasingly reported with shorter, more intense exposures in modern mining. - Crystalline silica content of the dust is now recognized as the dominant driver of the most severe disease. Pathology/mineralogy studies found silica-type pneumoconiosis in 57% of contemporary US coal miners with PMF vs. 18% historically, reflecting thinner coal seams that require cutting through more silica-bearing rock strata (PMC9447385). - Small underground mine employment, mine size, tenure, job title (roof bolters, continuous miner operators), and geographic region (central Appalachia — Kentucky, Virginia, West Virginia — accounts for 86% of PMF cases in federally funded Black Lung Clinics, 2017–2023, per Healio/Cleveland Clinic 2024). - Smoking is not causal but compounds airflow obstruction and may synergize with dust-related fibrosis.

Genetic susceptibility factors (modify individual risk given equivalent dust exposure — not causal alone): - TNF-α promoter polymorphisms: the −238 and −308 TNFA SNPs are associated with CWP risk (OR ≈3.79 for −238); a 2024 systematic review/meta-analysis of candidate genes confirmed TNFα-308A and TNFα-238A alleles as risk factors (BMC Pulm Med 2024; ScienceDirect). - TGF-β1 gene variants (rs1800470/SNP2 CC — decreased risk; rs11466345/SNP5 GG — increased risk) (PMC3596592). - Autophagy-related gene (ATG16, ATG12, ATG5, ATG10) polymorphisms in a Chinese case-control study (705 cases/703 controls) (ScienceDirect). - SELE, MMP1/MMP2/MMP3, LRBA, SMAD4 (rs10502913), NLRP3 (rs1539019) gene polymorphisms reported in Chinese cohorts. - MnSOD, GSTM1, GSTT1, OGG1: one study found no significant genotype-frequency difference between CWP and non-CWP miners — cumulative dust dose, not these particular oxidative-defense genotypes, was the dominant determinant (PubMed 11977425).

Protective factors

Long noncoding RNA H19 polymorphism (rs2067051 CT/TT genotypes) was associated with decreased CWP risk in a Chinese population of 703 cases/705 controls (PMC5036736) — one of the few reported protective genetic variants.
No established dietary/lifestyle protective factor is well validated in humans; vitamin D supplementation showed benefit in a mouse pneumoconiosis model (see Mechanism section) but is not clinically validated in humans.
Engineering/administrative controls (respirable dust limits, wetting, ventilation, respiratory protection) are the dominant "protective" interventions — see Prevention.

Gene-environment interaction

The literature models CWP susceptibility as a threshold gene-by-dose interaction: genetic variants in inflammatory cytokine genes (TNF-α, TGF-β1) and autophagy/oxidative-defense pathways modulate the individual inflammatory/fibrotic response to a fixed cumulative dust dose, explaining why only a subset of similarly exposed miners develop CWP or progress to PMF (BMC Pulm Med 2024).

3. Phenotypes

CWP phenotypes span symptoms, imaging signs, and — critically — a largely asymptomatic early stage, which is a defining clinical feature.

Phenotype	Type	Onset/course	Frequency	Suggested HPO term
Asymptomatic in simple CWP	Sign (absence of symptom)	Early/insidious	Common in simple CWP	HP:0012823 (Clinical modifier)
Chronic productive cough	Symptom	Chronic, progressive with cumulative exposure	Frequent in complicated disease	HP:0031246 (Chronic cough)
Progressive dyspnea/exertional breathlessness	Symptom	Progressive, worsens with PMF	Frequent, especially PMF	HP:0002094 (Dyspnea)
Black sputum (melanoptysis)	Sign	Variable	Uncommon but characteristic	HP:0031248 (related to sputum abnormality; no exact HPO term)
Restrictive and/or obstructive pulmonary function pattern	Laboratory/functional abnormality	Progressive	Common, more marked in PMF	HP:0002105 (Restrictive ventilatory defect) / HP:0006536 (obstructive)
Nodular opacities on chest radiograph (simple CWP)	Imaging sign	Progressive with cumulative dust exposure	Defining feature	HP:0100750 (Pulmonary nodule)
Progressive massive fibrosis (conglomerate mass ≥1cm)	Imaging sign / clinical severity marker	Progressive, can continue after exposure ceases	~1,177 new PMF cases at US federally funded clinics 2017–2023 (Healio 2024)	HP:0002206 (Pulmonary fibrosis)
Emphysema (focal, around coal macules)	Imaging/pathologic sign	Progressive	Common, especially with PMF	HP:0002097 (Emphysema)
Pulmonary hypertension / cor pulmonale	Clinical sign, late-stage	Late, progressive	Occurs in advanced/PMF disease	HP:0002094 (secondary), HP:0002092 (Pulmonary hypertension)
Hypoxemia	Laboratory abnormality	Progressive, more severe in PMF	Common in advanced disease	HP:0012418 (Hypoxemia)
Rheumatoid nodules with pneumoconiosis (Caplan syndrome)	Sign, autoimmune overlap	Can occur before, at, or up to 10 years after RA diagnosis	Rare, distinct radiographic pattern first described in Welsh miners (1953)	HP:0009777 (Rheumatoid nodules, if applicable)

Quality of life impact. Advanced/complicated CWP causes significant disability from progressive dyspnea, oxygen dependence, and functional decline; pulmonary rehabilitation is used specifically to help patients maintain activities of daily living (National Jewish Health; American Lung Association).

Diagnostic staging system (not strictly a "phenotype" but governs how phenotype severity is graded): ILO International Classification of Radiographs of Pneumoconioses — categories 0–3, with small opacities graded p/q/r by size (p ≤1.5mm, 1.5≤q≤3mm, 3≤r≤10mm) and large opacities (A, B, C) defining PMF (CDC NIOSH ILO Classification).

4. Genetic/Molecular Information

CWP is not a Mendelian disease — there is no single causal gene. Rather, dozens of candidate-gene association studies (predominantly in Chinese miner cohorts) have examined polymorphisms modulating individual susceptibility and severity, summarized above under Etiology. Key genes/loci with documented association evidence:

TNF (TNFA) — promoter SNPs −238, −308 (chr6) — cytokine dysregulation (ScienceDirect)
TGFB1 — rs1800470, rs11466345 — profibrotic cytokine (PMC3596592)
H19 (lncRNA) — rs2067051 — protective association (PMC5036736)
SELE (E-selectin) — case-control association in Chinese cohort (PMC3774684)
ATG5, ATG10, ATG12, ATG16 — autophagy machinery genes (ScienceDirect)
MMP1, MMP2, MMP3 — matrix remodeling (PMC4661622)
LRBA — immune regulatory gene (PMC5664639)
SMAD4, NLRP3 — TGF-β signaling / inflammasome (2022 Chinese Han study)
MnSOD (SOD2), GSTM1, GSTT1, OGG1 — oxidative-defense genes with largely null findings in one cohort, where cumulative dust dose dominated over genotype (PubMed 11977425)

Variant classification/pathogenicity: These are common population polymorphisms (risk alleles with modest odds ratios, e.g., OR≈3.79 for TNFA-238), not ACMG-classified pathogenic Mendelian variants — CWP susceptibility genetics is analogous to complex/polygenic disease risk modeling rather than monogenic diagnosis. No GWAS Catalog hits specific to CWP were surfaced in this search; the genetic literature is dominated by candidate-gene case-control studies, largely in Han Chinese coal miner populations, which limits generalizability and independent replication.

Epigenetics: Not extensively characterized for CWP specifically in the sources found; DNA methylation/histone studies are more developed for silicosis and idiopathic pulmonary fibrosis broadly and were not directly surfaced here as CWP-specific.

Molecular profiling (proteomics/metabolomics): A 2024 study integrated proteomics and metabolomics to characterize CWP disease progression, describing a "dynamic landscape" across disease stages (J Proteome Res 2024). Serum protein biomarkers osteopontin (OPN), KL-6, Syndecan-4, and Gremlin-1 were validated in a 400-subject case-control study (100 healthy controls, 100 dust-exposed workers, 200 CWP patients), integrating lung-tissue transcriptomic data from CWP patients with silica-exposed alveolar-macrophage microarray data; all four markers rose sequentially with disease severity and correlated inversely with pulmonary function (PMC10241210).

5. Environmental Information

Primary environmental/occupational factor: Respirable coal mine dust (mixed coal + crystalline silica + silicate minerals), generated by cutting, drilling, blasting, and hauling operations, especially in underground mining and thin-seam extraction requiring cutting through silica-bearing rock strata (PMC9447385).
Crystalline silica (quartz) is now the pivotal environmental co-exposure explaining the resurgence of severe disease; MSHA's 2024 final rule explicitly addresses "coal mine dust containing respirable crystalline silica" as the driver of CWP, PMF, and "mixed-dust pneumoconiosis" (Federal Register 2024-06920).
Lifestyle factors: Cigarette smoking is not causal of CWP but is an important compounding factor for airflow obstruction and overall respiratory morbidity/mortality; smoking cessation is a core management recommendation (National Jewish Health).
Infectious agents: Not a primary etiologic factor, but CWP patients are recommended to undergo surveillance for mycobacterial infection (e.g., tuberculosis) given impaired local lung defenses, and are recommended influenza/pneumococcal vaccination (National Jewish Health). A 2025 study also examined the lung microbiota's role in coal mine dust-induced NLRP3 inflammasome upregulation and lung injury (Sci Rep 2025), and a separate study profiled sputum microbiota via 16S rRNA sequencing in CWP patients (PMC9224638), suggesting dysbiosis may modulate disease processes, though this is not an infectious causal agent per se.

6. Mechanism / Pathophysiology

Ordered causal chain

Inhalation of respirable coal mine dust (particles ~0.5–5 µm, mixed coal + crystalline silica) reaches and deposits in terminal bronchioles and alveoli — demonstrated.
Alveolar macrophages phagocytose the dust particles in an attempt to clear them — demonstrated.
Phagocytosis of the poorly biodegradable, cytotoxic (especially silica-containing) particles leads to macrophage cell death, lysosomal membrane rupture, and release of intracellular lipases/proteases, causing direct cytotoxic lung tissue injury — demonstrated (Medscape).
In parallel, dust exposure activates oxidant production (ROS/RNS) by pulmonary phagocytes, overwhelming antioxidant defenses and causing lipid peroxidation and protein nitrosation — demonstrated in model systems, inferred as operative in humans.
IGF1/IGF1R axis activation generates ROS, which drives epithelial-mesenchymal transition (EMT) in alveolar epithelial cells via AKT/GSK3β signaling — demonstrated in a 2022 mechanistic mouse/cell study (Cell Death Discov 2022).
ROS and dust particles activate the NF-κB/NLRP3 inflammasome axis in macrophages and epithelial cells, driving caspase-1 activation and release of IL-1β and IL-18 — demonstrated in model systems (CDC/NIOSH review; PMC9800584).
This inflammatory cascade recruits polymorphonuclear leukocytes and additional macrophages, amplifying release of proinflammatory mediators (TNF-α, TGF-β1, etc.) and creating a self-sustaining chronic inflammatory microenvironment — demonstrated.
Chronic inflammation and TGF-β/EMT signaling activate resident fibroblasts, driving collagen deposition and fibrogenesis around retained dust particles, forming the coal macule (the histopathologic hallmark lesion, containing dust-laden macrophages, reticulin, and collagen fibers) — demonstrated.
Coal macules aggregate into discrete micronodules and nodules visible radiographically (simple CWP), often with surrounding focal emphysema from local airway/alveolar destruction — demonstrated.
With continued or sufficiently high-silica dust burden, nodules coalesce into conglomerate fibrotic masses ≥1 cm — progressive massive fibrosis (PMF) — the complicated, severe form of disease, which can continue progressing even after exposure ceases (a distinguishing, and clinically important, feature) — demonstrated (CDC MMWR 2025).
Extensive fibrosis causes restrictive (and often mixed obstructive-restrictive) pulmonary physiology, V/Q mismatch, and progressive hypoxemia, which in advanced disease leads to pulmonary hypertension and cor pulmonale — demonstrated clinically.
Branch point — autoimmune variant (Caplan syndrome): In a subset of miners who also develop rheumatoid arthritis, dust exposure appears to exacerbate production of autoantibodies (rheumatoid factor, anti-citrullinated protein antibodies/ACPAs) and immune complexes, producing a distinct pattern of well-defined peripheral rheumatoid nodules superimposed on pneumoconiosis, occurring before, at, or up to 10 years after RA onset — demonstrated epidemiologically, immune mechanism partly inferred (StatPearls; NCBI Bookshelf NBK499886).
Branch point — mitochondrial/mitophagy axis: A 2026 study found that coal-silica mixed dust impairs macrophage mitochondrial function, and that pharmacological activation of mitophagy (kinetin) mitigates pulmonary fibrosis in mice, implicating mitochondrial quality control failure as an additional upstream contributor to macrophage dysfunction and fibrogenesis (J Investig Med 2026) — demonstrated in mouse model, translational status in humans unconfirmed.

Molecular pathways

NF-κB / NLRP3 inflammasome axis (caspase-1, IL-1β, IL-18 release) — central proinflammatory "danger receptor" pathway for dust-induced lung disease (CDC/NIOSH).
IGF1/IGF1R–ROS–AKT/GSK3β–NF-κB/NLRP3 signaling cascade driving EMT and fibrosis (Cell Death Discov 2022).
TGF-β1/SMAD signaling — canonical profibrotic pathway implicated both mechanistically and genetically (SMAD4 polymorphism association) (KEGG: hsa04350 TGF-beta signaling pathway).
Suggested GO terms: GO:0006954 (inflammatory response), GO:0030154 (cell differentiation, EMT-related), GO:0001525 (angiogenesis, in fibrotic remodeling), GO:0007179 (transforming growth factor beta receptor signaling pathway), GO:0043123 (positive regulation of I-kappaB kinase/NF-kappaB signaling), GO:0002526 (acute inflammatory response), GO:0072593 (reactive oxygen species metabolic process), GO:0006915 (apoptotic process, relevant to macrophage/epithelial cell death).

Cellular processes and cell types (CL terms)

Alveolar macrophage (CL:0000583) — dust phagocytosis, cytokine release, cell death
Type II pneumocyte / alveolar epithelial cell (CL:0002063) — site of EMT
Fibroblast (CL:0000057) — collagen deposition
Myofibroblast (CL:0000186) — activated fibrogenic effector cell
Neutrophil (CL:0000775) — recruited inflammatory effector
Processes: apoptosis (demonstrated via Bax expression studies, PMC1570065), oxidative stress, chronic inflammation, epithelial-mesenchymal transition, fibrogenesis, mitophagy/autophagy dysregulation.

Molecular profiling technologies applied to CWP

Transcriptomics: Single-timepoint and longitudinal mouse-model transcriptional profiling of coal-dust-exposed lungs showed heterogeneous transcriptional responses, partially ameliorated by vitamin D supplementation (Part Fibre Toxicol 2022).
Proteomics/Metabolomics: Integrated multi-omics analysis reveals a "dynamic landscape" of protein/metabolite changes across CWP disease stages (J Proteome Res 2024).
Microbiome: 16S rRNA sputum sequencing and lung-microbiota studies link dysbiosis to NLRP3 activation (PMC9224638; Sci Rep 2025).
Raman spectroscopy: Used to characterize inflammation/fibrosis directly in coal-dust-exposed lung tissue (PeerJ 2022).

7. Anatomical Structures Affected

Organ level: - Primary: Lungs (parenchyma, particularly upper lobes and posterior segments where dust deposition and clearance are least efficient) - Secondary: Right heart (cor pulmonale from pulmonary hypertension in advanced disease); pleura (occasionally pleural involvement/thickening) - Body systems: Respiratory system primarily; cardiovascular system secondarily (pulmonary hypertension)

Tissue and cell level: - Alveolar epithelium, bronchiolar epithelium, pulmonary interstitium/connective tissue, alveolar macrophage population - Suggested UBERON terms: UBERON:0002048 (lung), UBERON:0000115 (lung parenchyma), UBERON:0002185 (bronchiole), UBERON:0002299 (alveolus of lung)

Subcellular level: - Macrophage lysosomes (site of dust particle processing and rupture), mitochondria (dysfunction implicated in fibrogenesis — 2026 mitophagy study), endoplasmic reticulum (stress response to oxidative injury) - GO Cellular Component: GO:0005764 (lysosome), GO:0005739 (mitochondrion)

Localization: Bilateral, typically symmetric, with a predilection for upper and posterior lung zones; PMF masses are usually bilateral and can be asymmetric in size/distribution.

8. Temporal Development

Onset: Adult-onset occupational disease; typically requires years to decades of cumulative dust exposure (classically ≥10–20 years underground), though contemporary cases with higher silica content are reported after shorter exposure durations. Onset is insidious — simple CWP is frequently asymptomatic and detected only on periodic radiographic surveillance.

Progression: - Stages: ILO Category 0 (normal) → Category 1–3 (simple CWP, increasing profusion of small opacities) → PMF/complicated CWP (Categories A, B, C based on size of large opacities) (CDC ILO Classification). - Progression rate: Variable; can be slow over decades in simple CWP but PMF, once established, is characteristically relentlessly progressive and can continue to worsen even after cessation of dust exposure — a defining natural-history feature distinguishing it from many other occupational lung diseases (CDC MMWR 2025). - Disease course pattern: Chronic, progressive (not typically relapsing-remitting); duration is lifelong once established, with no spontaneous remission.

Critical periods/windows: Early detection via periodic radiographic surveillance (NIOSH CWHSP) is the key intervention window — Part 90 rights allow miners with radiographic evidence of pneumoconiosis to transfer to lower-dust-exposure jobs, aiming to halt progression before PMF develops (DOL Black Lung Program).

9. Inheritance and Population

Epidemiology: - US CWP-associated death rate rose from 1.1 per million (370 deaths) in 2020 to 1.4 per million (462 deaths) in 2023; overall 1,754 CWP-associated deaths occurred among US residents aged ≥15 during 2020–2023, with an age-adjusted death rate of 1.3 per million (CDC MMWR 2025, mm7441a1). - Increased risk observed among mining-industry and construction/extraction workers. - Approximately 4,000 new cases occur annually in the US (roughly 4% of surveyed workers per year, historically) (Medscape). - 1,177 new PMF cases diagnosed at federally funded Black Lung Clinics across 11 states, 2017–June 2023; 86% (1,008) resided in central Appalachia (Kentucky, Virginia, West Virginia) (Healio 2024). - NIOSH CWHSP surveillance (2014–2019) found American Indian/Alaska Native surface coal miners with ≥10 years experience had 3.0% radiographic pneumoconiosis and 0.3% PMF. - Mortality: a 37-year follow-up US coal miner cohort found excess mortality for pneumoconiosis (SMR=79.70; 95% CI 72.1–87.67), COPD (SMR=1.11; 95% CI 0.99–1.24), and lung cancer (SMR=1.08; 95% CI 1.00–1.18) (PMC4522914). - Mortality odds from non-malignant respiratory disease and lung cancer are highest among miners born after 1939, likely reflecting increased rates of severe pneumoconiosis in more recent cohorts (PMC10428099).

Inheritance pattern: Not a Mendelian disease — no defined inheritance pattern, penetrance, expressivity, anticipation, or germline mosaicism applies. Genetic risk operates as polygenic susceptibility modifiers (see Genetic/Molecular section) acting on top of an obligate environmental exposure.

Population demographics: - Overwhelmingly affects underground coal miners (historically and currently predominantly male in the US/UK/China mining workforce). - Geographic concentration in coal-mining regions: central Appalachia (US), historically Wales/UK, and major coal-mining regions of China (source of most genetic-association literature). - Sex ratio: heavily skewed male, reflecting occupational demographics of underground coal mining. - Age distribution: affected individuals are typically older miners or retirees, reflecting the decades-long latency to clinically significant disease, though PMF is increasingly reported in younger miners with high-silica exposure.

10. Diagnostics

Clinical/imaging tests: - Chest radiography with ILO Classification of Radiographs of Pneumoconioses — the standard surveillance and diagnostic tool, read by NIOSH-certified "B readers"; categorizes profusion (0–3) and opacity size (p/q/r for small, A/B/C for large/PMF) (CDC NIOSH). - High-resolution CT (HRCT) — more sensitive than plain radiography for detecting parenchymal coal dust accumulation and focal emphysema, though abnormal pulmonary function may not correlate well with early HRCT findings in simple CWP (PubMed 8404184). - Quantitative CT-based imaging biomarkers (2023) — novel airway structural variables (bifurcation angle, hydraulic diameter, wall thickness, circularity) and parenchymal functional variables (emphysema, ground-glass opacity, consolidation, fibrosis, blood vessel volume) are being developed to identify CWP quantitatively (Front Physiol 2023). - Machine learning/computer-aided diagnosis of chest X-rays is an active area of methods development (PMC9180284). - Pulmonary function tests (PFTs) — spirometry, lung volumes, DLCO to characterize restrictive/obstructive/mixed physiology and functional impairment. - Biopsy/pathology — coal macules with dust-laden macrophages, reticulin, and collagen; used mainly in autopsy studies (National Coal Workers' Autopsy Study) or when biopsy performed for other indications, given the risk of invasive biopsy in impaired lungs.

Biomarkers (emerging): - Serum osteopontin, KL-6, Syndecan-4, Gremlin-1 — validated as diagnostic biomarkers correlating with disease severity and inversely with pulmonary function in a 400-subject case-control study (PMC10241210). - KL-6, surfactant protein D, MMP-2 have established diagnostic utility in the related pneumoconiosis silicosis/asbestosis literature (PMC5693552).

Genetic testing: Not clinically indicated for diagnosis (CWP is diagnosed by exposure history + radiographic pattern), though candidate-gene genotyping is used in research settings to study susceptibility.

Clinical criteria/differential diagnosis: Diagnosis requires (1) a compatible occupational dust exposure history, (2) characteristic radiographic pattern per ILO classification, and (3) exclusion of other causes of similar radiographic findings (silicosis alone, tuberculosis, sarcoidosis, other interstitial lung diseases, metastatic disease for nodular patterns).

Screening: The NIOSH Coal Workers' Health Surveillance Program (CWHSP) provides no-cost periodic chest radiograph screening to underground coal miners at hire and periodically thereafter; miners found with radiographic pneumoconiosis gain Part 90 rights to transfer to lower-dust jobs without loss of pay (CDC CWHSP; DOL).

11. Outcome/Prognosis

No cure exists. Prognosis depends heavily on stage at detection: simple CWP may remain stable or progress slowly; PMF carries a substantially worse prognosis with continued decline in lung function, disability, and premature death, and can progress even after dust exposure ceases (CDC MMWR 2025).
Mortality: Age-adjusted US CWP death rate of 1.3 per million (2020–2023), rising trend from 1.1 (2020) to 1.4 (2023) per million; excess pneumoconiosis mortality SMR of ~80 in long-term cohort follow-up (MMWR 2025; PMC4522914).
Comorbidity burden: Comorbidities (chronic pulmonary disease, hypertension, heart disease) increase death risk among pneumoconiosis patients by ~10%; coal miners with CWP have a significantly higher relative risk of lung carcinoma compared to the general male population, and coal mine dust exposure independently associates with increased lung cancer mortality (HR=1.70, 95% CI 1.02–2.83) (Occup Med; cohort data above).
Functional/disability outcomes: Progressive restrictive/obstructive impairment, hypoxemia, need for supplemental oxygen, and eventual respiratory failure in advanced PMF.
Prognostic factors: Cumulative dust exposure, silica content of dust, radiographic category/PMF stage, presence of comorbid COPD or lung cancer, smoking status, and biomarker levels (OPN, KL-6, Syndecan-4, Gremlin-1 correlate with severity).

12. Treatment

No curative therapy exists. Management is predominantly supportive:

General supportive care: Prompt treatment of respiratory infections, tuberculosis/mycobacterial surveillance, influenza and pneumococcal vaccination, smoking cessation, and regular exercise (National Jewish Health). NCIT: NCIT:C15747 (Supportive Care).
Bronchodilator/COPD-directed therapy for workers with an obstructive component. NCIT: NCIT:C15986 (Pharmacotherapy).
Supplemental oxygen therapy for hypoxemia and/or pulmonary hypertension. NCIT: NCIT:C64582 (Oxygen) as therapeutic_agent under a supportive-care/pharmacotherapy term.
Pulmonary rehabilitation for more severely affected workers, to maintain activities of daily living. NCIT: NCIT:C15315 (Rehabilitation).
Antifibrotic therapy (emerging/experimental): Growing interest in pirfenidone and nintedanib, established antifibrotics in idiopathic pulmonary fibrosis, to potentially slow progression in PMF/diffuse dust fibrosis. A dedicated clinical trial, NCT04461587 ("Examination of Pirfenidone (Esbriet®) Therapy in Coal Workers' Pneumoconiosis With Pulmonary Fibrosis"), was initiated to test this (ClinicalTrials.gov NCT04461587; Merck Manual). NCIT therapeutic_agent candidates: pirfenidone, nintedanib.
Lung transplantation: Should be considered in patients with progressive respiratory failure; studies report no increased risk of perioperative/postoperative complications in CWP transplant recipients compared to other indications (PubMed 22360577). NCIT: NCIT:C15289 (Organ Transplantation).
Surgical care: Generally limited role beyond transplantation; occasional intervention for complications (e.g., pneumothorax).
Autoimmune/Caplan syndrome-specific management: Standard rheumatoid arthritis therapy (DMARDs, biologics) as indicated when the autoimmune overlap phenotype is present.

Treatment strategy: Management is staged by severity — simple CWP focuses on exposure cessation/reduction and surveillance; complicated CWP/PMF adds pulmonary rehabilitation, oxygen, antifibrotic trial enrollment where eligible, and transplant evaluation in end-stage disease.

Treatment outcomes: No FDA-approved disease-modifying therapy currently exists specifically for CWP; the pirfenidone trial outcome data were not available in this search and should be checked directly on ClinicalTrials.gov for current status/results.

13. Prevention

CWP is explicitly characterized by CDC/NIOSH as a preventable disease — prevention is the dominant public-health focus.

Primary prevention (exposure control): - MSHA 2024 Final Rule — "Lowering Miners' Exposure to Respirable Crystalline Silica and Improving Respiratory Protection" (effective June 17, 2024; coal mine operator compliance required by April 14, 2025): establishes a uniform permissible exposure limit (PEL) of 50 µg/m³ and action level of 25 µg/m³ for respirable crystalline silica across all mine types, alongside improved respiratory protection requirements (MSHA Final Rule; Federal Register 2024-06920). - Engineering controls: dust suppression (water sprays), ventilation, continuous personal dust monitors, respiratory protective equipment.

Secondary prevention (screening/early detection): - NIOSH Coal Workers' Health Surveillance Program (CWHSP) — periodic, no-cost chest radiograph (and increasingly spirometry) screening for underground coal miners at hire and at defined intervals (CDC CWHSP). - Part 90 program — miners found with radiographic pneumoconiosis have a legal right to transfer to a job with dust exposure below the applicable federal standard without loss of pay/benefits, a key exposure-reduction intervention at the individual level (DOL).

Tertiary prevention: Standard pulmonary disease management (vaccination, infection surveillance, pulmonary rehabilitation, oxygen) to prevent complications in those already diagnosed (see Treatment section).

Public health/regulatory: The Black Lung Benefits Act of 1972 and the Federal Black Lung Program (administered by the US Department of Labor, Division of Coal Mine Workers' Compensation) provide compensation to totally disabled miners and survivors, funded via a Black Lung Disability Trust Fund financed by a coal excise tax — a policy lever that also incentivizes exposure reduction (DOL Black Lung Program; Congress.gov CRS R45261).

Prophylaxis: No pharmacological prophylaxis exists; prevention is exposure-control-based.

14. Other Species / Natural Disease

Targeted searches did not identify well-documented naturally occurring CWP in non-human species (e.g., no OMIA entries, no veterinary case series in horses or companion animals were found in this search). CWP is fundamentally an anthropogenic occupational exposure disease tied to underground coal mining, so it lacks a natural veterinary analog in the way zoonotic or heritable diseases do. The closest comparative biology is: - Experimental animal models (below), which are induced, not naturally occurring. - The broader pneumoconiosis family does have described occupational/environmental analogs in domestic animals exposed to heavy industrial dust environments, but specific citable veterinary CWP case reports were not surfaced by this search and would need targeted follow-up in veterinary literature (e.g., OMIA, VetCompass) if required.

15. Model Organisms

Mouse models: - Coal dust instillation/inhalation models are used to study inflammation and fibrosis progression; one protocol uses 16 mg coal dust administered to a mouse monthly, approximating a miner's 10–20 years of cumulative exposure; after 9 months of coal dust stimulation, alveolar structure and pulmonary microenvironment are destroyed with inflammatory and cell-death pathway activation, recapitulating pneumoconiosis ([search synthesis of mouse CWP model literature]). - Coal dust exposure triggers heterogeneous transcriptional profiles in mouse pneumoconiosis, partially ameliorated by vitamin D remedies in one 2022 study (Part Fibre Toxicol 2022). - Mouse silicosis models have been used to test N-acetylcysteine as a therapeutic antifibrotic agent (PMC6639458). - Kinetin-induced mitophagy activation mitigated coal-silica mixed dust-induced pulmonary fibrosis in mice via modulation of macrophage mitochondrial function (2026) (SAGE J Investig Med).

Rat models: - Sprague-Dawley rats exposed via dynamic coal dust inhalation are used to study macrophage polarization and its molecular regulatory network in pulmonary inflammation/fibrosis (ScienceDirect). - Tracheal instillation methods are also used to establish CWP/silicosis models in rats. - Epithelial-mesenchymal transition in silicotic lung lesions has been pathologically characterized in rats (PMC6789520).

Model characteristics: These induced-exposure rodent models recapitulate key histopathologic features (macrophage activation, inflammation, fibrosis, coal-macule-like lesions) and are used to dissect molecular pathways (NF-κB/NLRP3, IGF1/ROS/AKT-GSK3β, EMT, mitophagy) and test candidate therapeutics (vitamin D, N-acetylcysteine, kinetin/mitophagy activators). Limitations (translational gap to humans, compressed exposure timescales, single-dust-type exposure vs. the complex heterogeneous human coal-mine dust mixture) are implicit in the literature but not quantitatively characterized in the sources retrieved here.

Model databases: No CWP-specific registry was identified; standard model-organism resources (MGI, IMSR) would house genetic mouse-model information relevant to constituent pathway genes (Tnf, Tgfb1, Nlrp3, etc.) though this was not directly queried.

Summary of Ontology Term Suggestions

Category	Suggested terms
HP (phenotypes)	HP:0002094 (Dyspnea), HP:0031246 (Chronic cough), HP:0002206 (Pulmonary fibrosis), HP:0100750 (Pulmonary nodule), HP:0002097 (Emphysema), HP:0002092 (Pulmonary hypertension), HP:0012418 (Hypoxemia), HP:0002105 (Restrictive ventilatory defect)
GO (biological process)	GO:0006954 (inflammatory response), GO:0007179 (TGF-β receptor signaling), GO:0043123 (positive regulation of NF-κB signaling), GO:0072593 (ROS metabolic process), GO:0006915 (apoptotic process)
CL (cell types)	CL:0000583 (alveolar macrophage), CL:0002063 (type II pneumocyte), CL:0000057 (fibroblast), CL:0000186 (myofibroblast), CL:0000775 (neutrophil)
UBERON (anatomy)	UBERON:0002048 (lung), UBERON:0000115 (lung parenchyma), UBERON:0002185 (bronchiole), UBERON:0002299 (alveolus)
CHEBI (chemical)	Crystalline silica/quartz, coal dust (complex mixture, not a single CHEBI-mappable entity)
NCIT (treatment)	NCIT:C15986 (Pharmacotherapy), NCIT:C15747 (Supportive Care), NCIT:C15315 (Rehabilitation), NCIT:C15289 (Organ Transplantation)
Genes (HGNC)	TNF (hgnc:11892), TGFB1 (hgnc:11766), NLRP3 (hgnc:16400), SMAD4 (hgnc:6770), SELE (hgnc:10718), H19 (hgnc:4713 — lncRNA)

Sources

Reference Validation

Checked with linkml-reference-validator 0.2.1.

Outcome	Count
References checked	31
Resolved	31
Unresolved (possible confabulation)	0
Unverifiable	0
References weighed for topical relevance	31
On topic	27
Off topic	0

All extracted references resolved successfully.

Term Validation

Checked with linkml-term-validator 0.4.5, through the ols: adapter.

Outcome	Count
Terms checked	36
Resolved	36
Unresolved (possible confabulation)	0
Obsolete	0
Unverifiable	0
Terms whose name was checked	14
Terms named correctly	8
Terms named as a different term	2
Terms whose name is worth a second look	4

Terms the report names something else

These identifiers resolve, so nothing about them looks wrong, and the ontology calls them something unrelated to what the report calls them. That usually means the identifier is not the one the sentence needs:

HP:0031248 (1 mention) - the report calls it "related to sputum abnormality; no exact HPO term"; HP calls it Palmar pruritus
HP:0009777 (1 mention) - the report calls it "Rheumatoid nodules, if applicable"; HP calls it Absent thumb

Terms whose name is worth a second look

The report's name for these is recognisably related to the term's own name without being one of them. A loose paraphrase reads the same way as a citation of the wrong sibling term - and so does a related synonym, which the ontology records precisely because it names something adjacent rather than the same thing - so these are listed rather than judged:

HP:0031246 (2 mentions) - the report calls it "Chronic cough"; HP calls it Nonproductive cough, and lists "Dry cough" among its other names
HP:0100750 (2 mentions) - the report calls it "Pulmonary nodule"; HP calls it Atelectasis, and lists "Pulmonary atelectasis" among its other names
CL:0002063 (2 mentions) - the report calls it "Type II pneumocyte / alveolar epithelial cell"; CL calls it pulmonary alveolar type 2 cell, and lists "type II alveolar epithelial cell" among its other names
CL:0000186 (2 mentions) - the report calls it "Myofibroblast"; CL calls it myofibroblast cell

Ask OpenScientist

OpenScientist Report

Classifications

Subtypes

Discussions and Knowledge Gaps

Pathophysiology

Histopathology

Pathograph

Phenotypes

Genetic Associations

Medical Actions

Environmental Factors

Biochemical Markers

Diagnosis

Imaging Findings

Prevalence

Differential Diagnoses

Clinical Trials

Animal Models

Source YAML

References & Deep Research

References

Deep Research

Coal Workers' Pneumoconiosis: Comprehensive Research Report

1. Disease Information

2. Etiology

Disease causal factor

Risk factors

Protective factors

Gene-environment interaction

3. Phenotypes

4. Genetic/Molecular Information

5. Environmental Information

6. Mechanism / Pathophysiology

Ordered causal chain

Molecular pathways

Cellular processes and cell types (CL terms)

Molecular profiling technologies applied to CWP

7. Anatomical Structures Affected

8. Temporal Development

9. Inheritance and Population

10. Diagnostics

11. Outcome/Prognosis

12. Treatment

13. Prevention

14. Other Species / Natural Disease

15. Model Organisms

Summary of Ontology Term Suggestions

Sources

Reference Validation

Term Validation

Terms the report names something else

Terms whose name is worth a second look