2. Pneumoconiosis
It can be deïŹned as a permanent alteration of lung
structure due to the inhalation of mineral dust and
the tissue reactions of the lung to its presence.
Strictly speaking the term âpneumoconiosis
includes those occupational lung diseases which
are due to exposure to inorganic or mineral dust
that is retained in the lung parenchyma and
incites ïŹbrosis.â
3. Diseases due to
inorganic dust
Coal workerâs
pneumoconiosis
Silicosis
Asbestosis
Siderosis
Berylliosis
Diseases due to organic
dust
Bysinosis
Farmerâs lung
Malt workerâs lung
Mushroom workerâs
lung
Bagassosis
Aetiology
4.
5. 1.
2.
3.
The type of lung disease varies according to the nature of the
inhaled dust. Some dusts are inert and cause no reaction at all
while the others cause immunologic damage and predispose to
tuberculosis or neoplasia.
The tissue response to the inhaled dust may be one of the following
3 types;
Fibrous nodules e.g. in coal workerâs pneumoconiosis and silicosis
Interstitial ïŹbrosis e.g. Asbestosis
Hypersensitivity reaction e.g. Berylliosis.
6. Signs and symptoms
1.
2.
1.
2.
1.
2.
1.
2.
Simple Coal Workerâs Pneumoconiosis
Develops after prolonged exposure (15-20 years) to coal dust
Patients present with cough and dyspnoea.
Progressive Massive Fibrosis
This condition progresses even after the miner leaves the industry.
Clinically presence of cough with blackish expectoration and progressive
breathlessness.
Silicosis-Chronic or Simple Silicosis
Develops after many decades of exposure to relatively low levels of silica.
Upper lobes mostly involved, presence of gradually progressive dyspnoea dry
cough.
Acute Silicosis
Occurs after exposure to very high levels of dust over few months and fatal
within years.
Characterised by pulmonary oedema interstitial inïŹammation and
accumulation of proteinaceous surfactant like ïŹuid within alveoli.
7. 1.
2.
1.
Asbestosis
Moderate to severe exposure for at least 10 years.
Clinically presence of progressive exertion dyspnoea, ïŹnger
clubbing and end inspiratory crepitations over the lung bases
Berylliosis
Presence of cough, progressive breathlessness, night sweats and
anthralgia.