Environmental Lung Diseases (Pneumoconiosis)

• Invironmental lung diseases are certain pulmo­nary diseases for which environmental exposure or occupational conditions are responsible.
• asbestos lung, asbestos lung cancer, asbestos lung disease, asbestos lung mesothelioma,
• Mineral dust may give rise to restrictive lung diseases. There may be bronchial asthma called occupational asthma in which there is obstructive lung disease which is reversible.
• Diagnostic procedures for pneumoconiosis are – chest x-ray, CT scan, MRI, heavy metal concentration in urine, bacteriology, fungal studies, serology, lung biopsy asbestos lung disease, asbestos lung mesothelioma,asbestos lung, asbestos lung cancer,

Environmental Lung Diseases (Pneumoconiosis)

ASBESTOSIS

• asbestos lung cancer, asbestos lung disease, asbestos lung mesothelioma,
• Asbestosis occurs in workers involved in building, boiler maker, ‘pipes, insulation materials, painters, electricians, fiber glass.
• Asbestos includes  Silicates, chrysolite and other or­ganic materials involved in mining, milling and quarry work.
• There is pulmonary fibrosis, cancers of respiratory tract, pleura, peritoneum.
• There is typically diffuse interstitial fibrosis and pul­monary fibrosis.
• There is reduction in diffusion capacity. There is thick­ening and calcification of parietal pleura especially at the bases. There may be pleural effusion.
• X-ray shows irregular or linear opacities in lower lung fields. HRCT (High resolution computerized tomogra­phy) shows distinct changes.
• Smoking and asbestosis increases incidence of lung cancer many times.
• Lung cancers in asbestosis are – Squamous cell car­cinoma, adenocarcinoma, mesotheliomas, asbestos lung mesothelioma,  asbestos lung cancer, asbestos lung disease, asbestos lung mesothelioma,

Treatment

• is to avoid exposure and give symptom­atic management.

SILICOSIS

• Free silica or crystalline quartz exposure is common in mining, stone cutting, glass and ceme.nt manufac­turing.
• There is fibrosis, PMF (progressive massive fibrosis), silico tuberculosis.
• There are small rounded opacities in upper lobes, hi­lar adenopathy, calcification of hilar nodes (egg-shell pattern).
• There is progressive nodular fibrosis.
• There is restrictive as well as obstructive lung dis­ease.
• It leads to ventilatory failure.
• Silico-tuberculosis is the term used for patients of silicosis with M. tuberculosis and atypical mycobac­terial infections.
• X-ray, CT are diagnostic.

BERYLLIOSIS

• There is acute pneumonitis and chronic granuloma­tous disease. It is due to exposure to beryllium in workers involved in manufacture of alloys, ceramics, hi-tech electronics.
• There is restrictiv Lung disease as in Sarcoidosis.

COAL WORKERS PNEUMOCONIOSIS Environmental Lung Diseases (Pneumoconiosis)

COAL WORKERS PNEUMOCONIOSIS

• There is fibrosis, and small, round, regular opacities ~ the lung and nodular fibrosi~.
• Calcification is not seen.
• It is found in coal workers in coal mining with expo­sure to coal dust.
• It is a mild disease.
• Chest x-ray shows nodules from 1 cm to entire lobe. Caplan’s syndrome includes pneumoconiosis of coal workers, rheumatoid arthritis and PMF (progressive massive fibrosis). This syndrome is due to immuno­pathologic causes.

COTTON DUST DISEASE (BYSSINOSIS)

• Byssinosis is a disease in persons exposed to cotton, flax, or hemp, especially those involved with blowing and straightening the fibers.
• There is tightness in the chest especially on Mondays that is first work day of the week, decrease in FEV₁, obstructive lung disease and bronchospasm.
• Chest x-ray may show round, irregular, small or big opacities which may obscure (hide) lung markings.

Treatment

• is avoiding exposure, and antihistamines. The disease is severe in cigarette-smokers.

OTHER OCCUPATIONAL DUSTS DISEASE

• Many inorganic and organic dusts can cause environ­mental lung diseases.
• Examples of Inorganic dusts – Antimony, arsenic, cadmium, cement, chromium, mica, iron, graphite.
• Examples of Organic dusts – Cotton, grains, hay.

CHEMICAL AGENTS TOXIC TO THE lUNG

• Acid fumes (sulphuric and nitric acid), ammonia, cya­nides, formaldehyde, ozone, sulphur dioxide, phos­gene.