Pneumoconioses

Definition (ILO):
“Pneumoconiosis is the accumulation of dust in the lungs and the tissue reaction to its presence”
• ‘Pneumoconioses’ is the plural
• Dust within the size range of 0.5 to 3 micron pose maximum risk as these can easily enter the alveoli.
– Particles larger than 3 microns don’t reach the alveoli
– Particles smaller than 0.5 microns are exhaled out
– The dust particles which get deposited in the alveoli, cause inflammation in the lungs that can eventually lead to fibrosis of the lung tissue
• In addition to causing fibrosis, the deposition of dust also leads to:
– Reduced ciliary clearance
– The chemical composition may be cytotoxic
– Some dust may cause more fibrosis than others e.g. silica
– coal appears to be relatively inert and may accumulate in sizable amounts with minimal tissue response
• Mostly the exposure to dust occurs as a result of occupation, hence pneumoconioses are included under occupational diseases
• The specific types of pneumoconioses are named by the substance inhaled (e.g., silicosis, asbestosis, anthracosis)
Factors affecting the development of disease
1. Chemical composition of dust particles
2. Size of dust particles (fineness)
3. Concentration of dust in atmosphere
4. Duration of exposure
5. Individual susceptibility or health status of the person exposed
• Pneumoconiosis usually take years to develop and may progress even after the exposure has discontinued
• There is no cure for pneumoconiosis. Hence prevention is essential
Types of Pneumoconioses
Types of Pneumoconiosis

You are here