Coal worker’s Coal worker’s PneumoconiosisPneumoconiosisDr. Gopalrao Jogdand, M.D. Ph.D.Dr. Gopalrao Jogdand, M.D. Ph.D.

Professor & Head,Professor & Head,

Department of Community MedicineDepartment of Community Medicine

DefinitionDefinition

A chronic inflammatory disease of the A chronic inflammatory disease of the lungs caused by inhalation of coal dust. lungs caused by inhalation of coal dust. This disease is also called as black lung.This disease is also called as black lung.

Historical BackgroundHistorical Background

First documented in Scottish coal miners First documented in Scottish coal miners in 1836.in 1836.

Following world war I condition was Following world war I condition was detected in coal miners of South Wales.detected in coal miners of South Wales.

In 1942 committee on industrial In 1942 committee on industrial pulmonary diseases of the medical pulmonary diseases of the medical research council introduced the term coal research council introduced the term coal workers pneumoconiosis.workers pneumoconiosis.

Prevalence & RisksPrevalence & Risks

Prevalence (1917-1920): 22/1000 Prevalence (1917-1920): 22/1000 miners.miners.

Current Prevalence: Less than 8/1000 Current Prevalence: Less than 8/1000 Miners.Miners.

Risk: 24 years exposure vs 36 yearsRisk: 24 years exposure vs 36 years Low dust 5% 10%Low dust 5% 10% High dust 15% 40%High dust 15% 40%

What causes CWPWhat causes CWP

The disease is caused by inhalation of The disease is caused by inhalation of the coal dust.the coal dust.

Inhalation of the respirable dust causes Inhalation of the respirable dust causes CWP.CWP.

Respirable dust:. coal dust particles of Respirable dust:. coal dust particles of the size 0.5 to 3 microns.the size 0.5 to 3 microns.

Clinical signs & Clinical signs & symptomssymptoms

First stage is called as simple pneumoconiosis First stage is called as simple pneumoconiosis which is characterized by chronic cough, fever, which is characterized by chronic cough, fever, expectoration and dysponea on exertion, this is expectoration and dysponea on exertion, this is associated with little ventilatory impairment. This associated with little ventilatory impairment. This stage will develop after 10-12 years of exposure.stage will develop after 10-12 years of exposure.

Second stage is called progressive massive Second stage is called progressive massive fibrosis. It is irreversible and continues even after fibrosis. It is irreversible and continues even after cessation of the exposure, prognosis is not cessation of the exposure, prognosis is not good. good.

Pathological ChangesPathological Changes

Macroscopic appearanceMacroscopic appearance simple pneumoconiosis: Hard grey/black simple pneumoconiosis: Hard grey/black

nodules found in the upper lobes and perihilar nodules found in the upper lobes and perihilar region. region.

Progressive Massive fibrosis: Large firm Progressive Massive fibrosis: Large firm masses, shrunken upper lobes, masses, shrunken upper lobes, emphysematous lower lobes and sub pleural emphysematous lower lobes and sub pleural blebs.blebs.

Continued….Continued….

Microscopic appearance:Microscopic appearance: Central zone: hyaline connective tissue in Central zone: hyaline connective tissue in

concentric layers, acellular, capillaries not concentric layers, acellular, capillaries not present.present.

Middle zone: cellular connective tissue found.Middle zone: cellular connective tissue found. Peripheral zone: halo of macrophages Peripheral zone: halo of macrophages

projecting in lung parenchyma, high coal projecting in lung parenchyma, high coal content.content.

DiagnosisDiagnosis

History of exposure.History of exposure. Lung function Test: varies from normal to Lung function Test: varies from normal to

obstructive or restrictive or combination of obstructive or restrictive or combination of both.both.

Diffusion decreased.Diffusion decreased. Dysponea on exertion.Dysponea on exertion. X-ray chest: small nodules, 1-10 mm in upper X-ray chest: small nodules, 1-10 mm in upper

lung zones, ground glass appearance of the lung zones, ground glass appearance of the lung.lung.

Radiograph of CWPRadiograph of CWP

Pulmonary function testsPulmonary function tests

Used to test the ability of the lungs to Used to test the ability of the lungs to take in air (inspiration). Often used in take in air (inspiration). Often used in conjunction of the X ray chest.conjunction of the X ray chest.

Forced vital capacity (FVC) and FEV1 Forced vital capacity (FVC) and FEV1 (forced expiratory volume in one second) (forced expiratory volume in one second) are used to diagnose lung diseaseare used to diagnose lung disease

ComplicationsComplications

Respiratory: Pneumothorax, chronic Respiratory: Pneumothorax, chronic obstructive pulmonary disease, cor obstructive pulmonary disease, cor pulmonale.pulmonale.

Infectious diseases: Tuberculosis.Infectious diseases: Tuberculosis. Vascular diseases. Vascular diseases.

TreatmentTreatment

Terminate exposure to prevent PMF.Terminate exposure to prevent PMF. Corticosteroids, pulmonary lavage, lung Corticosteroids, pulmonary lavage, lung

transplant.transplant. Treat complications: Pneumothorax, Treat complications: Pneumothorax,

COPD, cor pulmonale, T.B., vascular COPD, cor pulmonale, T.B., vascular diseases.diseases.

Prevention and controlPrevention and control

Preplacement and periodic medical Preplacement and periodic medical examination of workers.examination of workers.

Use of protective equipments by the Use of protective equipments by the workers.workers.

Use of dust suppression measures.Use of dust suppression measures. Gravimetric dust sampling in dusty areas.Gravimetric dust sampling in dusty areas. Exhaust ventilation.Exhaust ventilation.