Coal worker’s Pneumoconiosis Dr. Gopalrao Jogdand, M.D. Ph.D. Professor & Head, Department of Community Medicine
A chronic inflammatory disease of the lungs caused by inhalation of coal dust. This disease is also called as black lung.
First documented in Scottish coal miners in 1836.
Following world war I condition was detected in coal miners of South Wales.
In 1942 committee on industrial pulmonary diseases of the medical research council introduced the term coal workers pneumoconiosis.
Prevalence & Risks
Prevalence (1917-1920): 22/1000 miners.
Current Prevalence: Less than 8/1000 Miners.
Risk: 24 years exposure vs 36 years
Low dust 5% 10%
High dust 15% 40%
What causes CWP
The disease is caused by inhalation of the coal dust.
Inhalation of the respirable dust causes CWP.
Respirable dust:. coal dust particles of the size 0.5 to 3 microns.
Clinical signs & symptoms
First stage is called as simple pneumoconiosis which is characterized by chronic cough, fever, expectoration and dysponea on exertion, this is associated with little ventilatory impairment. This stage will develop after 10-12 years of exposure.
Second stage is called progressive massive fibrosis. It is irreversible and continues even after cessation of the exposure, prognosis is not good.
simple pneumoconiosis: Hard grey/black nodules found in the upper lobes and perihilar region.
Progressive Massive fibrosis: Large firm masses, shrunken upper lobes, emphysematous lower lobes and sub pleural blebs.
Central zone: hyaline connective tissue in concentric layers, acellular, capillaries not present.
Middle zone: cellular connective tissue found.
Peripheral zone: halo of macrophages projecting in lung parenchyma, high coal content.
History of exposure.
Lung function Test: varies from normal to obstructive or restrictive or combination of both.
Dysponea on exertion.
X-ray chest: small nodules, 1-10 mm in upper lung zones, ground glass appearance of the lung.
Radiograph of CWP
Pulmonary function tests
Used to test the ability of the lungs to take in air (inspiration). Often used in conjunction of the X ray chest.
Forced vital capacity (FVC) and FEV1 (forced expiratory volume in one second) are used to diagnose lung disease