Occupational Lung Diseases

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Article Last Updated:26/03/2026

Exposure-Associated Overview Table

Exposure	Disease	Disease pattern
Asbestos (shipbuilding, insulation work)	Pleural plques	Benign condition
	Asbestosis	Restrictive lung disease
	Mesothelioma	Malignancy
Coal dust (coal mining)	Coal worker’s pneumoconiosis	Restrictive lung disease
Silica dust (mining, sandblasting)	Silicosis	Restrictive lung disease
Isocyanates (spray painting)	Occupational asthma	Obstructive lung disease
Bird droppings (bird handlers, pigeon breeders)	Bird fancier’s / pigeon lung (hypersensitivity pneumonitis)	Restrictive lung disease
Mouldy hay (farmers)	Farmer’s lung (hypersensitivity pneumonitis)	Restrictive lung disease

Pneumoconoises

Pneumoconioses are occupational lung diseases caused by inhalation of inorganic dust, leading to chronic lung inflammation and pulmonary fibrosis.

The top 3 most common pneumoconioses are silicosis > asbestosis (see separate section below) > coal worker’s pneumoconiosis

Feature	Coal Worker’s Pneumoconiosis	Silicosis
Exposure	Coal mine dust	Crystalline silica
Common Occupations	Coal miners (esp. underground ones) Mining machine operators	Mining (gold, hard rock) Tunnelling, quarrying Construction Stone fabrication
Key clinical features	Clinical features are largely shared: Asymptomatic in early stages Cough (dry / productive) Progressive dyspnoea Notably, silicosis has an acute form (rapid onset of weeks to 5 years) + constitutional symptoms + respiratory failure
Complications	Shared complications: Progressive massive fibrosis (upper lobes) COPD (independent of smoking) Respiratory failure Silicosis has a stronger association with TB and autoimmune disease
Lung function tests	Restrictive pattern (FEV₁/FVC >0.7) ↓ DLCO
Imaging findings	Initial: chest X-ray, preferred: HRCT Imaging findings: Upper lung zone small nodules Progressive massive fibrosis Eggshell calcifications of hilar lymph nodes Rationale: Coal dust often contains silica, so many miners develop mixed-dust pneumoconiosis with overlapping imaging features. Eggshell calcification is classically associated with silicosis but is not specific. Therefore, differentiation is primarily based on occupational exposure history rather than imaging.
Management	No curative treatment Remove exposure Supporitve care (e.g. bronchodilators for airflow obstruction, smoking cessation, vaccination) Compensation for affected workers Consider lung transplantation if eligible

Asbestos-Related Lung Disease

There are 3 main manifestations of asbestos-related lung disease

Benign Pleural Disease

There are several entities of benign pleural disease:

Condition	Key feature
Pleural plaques – most common	Asymptomatic (often incidental diagnosis on imaging) Chest X-ray / CT shows bilateral calcified plaques (posterolateral chest wall and diaphragm mainly) No treatment is required Provide reassurance Pleural plaques are NOT pre-malignant
Diffuse pleural thickening	May cause dyspnoea due to restrictive impairment Chest X-ray / CT shows continuous pleural thickening, often involving costophrenic angles Supportive management
Benign asbestos pleural effusion	The earliest manifestation of asbestos exposure Often mild symptoms (e.g. dyspnoea, chest discomfort) Diagnosis: exudative pleural effusion (often haemorrhagic) Usually self-limiting +/- effusion drainage if symptomatic

Condition

Key feature

Pleural plaques – most common

Asymptomatic (often incidental diagnosis on imaging)
Chest X-ray / CT shows bilateral calcified plaques (posterolateral chest wall and diaphragm mainly)
No treatment is required
- Provide reassurance
- Pleural plaques are NOT pre-malignant

Diffuse pleural thickening

May cause dyspnoea due to restrictive impairment
Chest X-ray / CT shows continuous pleural thickening, often involving costophrenic angles
Supportive management

Benign asbestos pleural effusion

The earliest manifestation of asbestos exposure

Often mild symptoms (e.g. dyspnoea, chest discomfort)
Diagnosis: exudative pleural effusion (often haemorrhagic)
Usually self-limiting +/- effusion drainage if symptomatic

Asbestosis (Parenchymal Fibrosis)

Definition	Progressive interstitial pulmonary fibrosis caused by asbestos fibre deposition in lung parenchyma
Onset	Typically >20 years after exposure Dose-dependent
Clinical features	Progressive dyspnoea Dry cough Bi-basal late fine inspiratory crackles
Diagnosis	Lung function tests: Restrictive pattern (FEV₁/FVC >0.7) Reduced DLCO Imaging (initial: chest X-ray, preferred: HRCT): Lower lobe predominant ground-glass opacities Reticular opacities Honeycombing
Management	Supportive management (no curative treatment) Eliminate ongoing asbestos exposure Smoking cessation Vaccinations (influenza and pneumococcal) Supplemental oxygen if necessary Symptom management

Asbestos-Related Malignancies

Key principles:

Asbestos exposure causes more lung cancer (bronchial carcinoma) than mesothelioma (2x risk)
If someone has mesothelioma, it is almost always caused by asbestos
Unlike lung cancer, mesothelioma is NOT related to smoking

For more information on lung cancer, see the Lung Cancer article.

Mesothelioma:

Definition	Aggressive cancer arising from the mesothelial cells of the lung pleura
Onset	Latency period of 20-50 years
Clinical features	Patients typically present late due to asymptomatic early development Key symptoms: Dyspnoea (from pleural effusion) Chest wall pain (from direct invasion into chest wall / mediastinum) Constitutional symptoms (weight loss, fatigue, night sweats) – usually a late feature Key signs: Pleural effusion features (e.g. stone dull percussion, reduced breath sounds) Fixed hemithorax (lack of chest expansion due to extensive tumour) Late signs of local invasion (e.g. SVC obstruction, Horner’s syndrome, spinal cord compression, pericardial involvement)
Investigation and diagnosis	Imaging: (screening: chest X-ray, most sensitive: contrast CT) Unilateral pleural effusion Pleural-based masses Signs of local tumour growth (e.g. reduced lung field size, mediastinal shift) Pleural fluid analysis (if there is effusion): Indicated in patients with pleural effusion Typical findings: bloody exudate, malignant mesothelial cells Definitive: thoracoscopic biopsy Mesothelioma cells Psmmoma bodies
Management	Mesothelioma is typically advanced at diagnosis, treatment is often palliative 1st line is typically systemic therapy Immunotherapy is typically 1st line (nivolumab + ipilimumab) Chemotherapy Surgery is only considered in early-stage disease + good performance status

Occupational Asthma

Key triggers:

Isocyanates (e.g. from spray painting)
Flour dust

Suspect occupational asthma in:

Adult-onset asthma
Poorly controlled established asthma
Reappearance of childhood asthma

Screen occupational asthma with the following questions:

Are symptoms the same / better / worse on days away from work
Are symptoms the same / better / worse on time away from work, longer than usual breaks, at weekends, or between shifts

If occupational asthma is suspected:

Refer to occupational asthma specialist for serial PEF
- Typical finding is PEF is lower during work periods, but improves when away from work (e.g. evenings, weekends, holidays)
Most important: identification and complete avoidance of the causative exposure

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