The chances of developing asbestos-related disease depend on:
- the type and size of the fibre,
- the number of fibres inhaled,
- the length of time of exposure,
- other individual factors such as being a smoker.
Exposure to varying amounts of asbestos is almost universal and fibres may be present in the lungs without causing any disease or loss of function.
The majority of post mortem examinations on people who have died from non asbestos-related diseases have found asbestos fibres in the lungs. This indicates that the chance of developing an asbestos-related condition is strongly linked to the amount, or dose, of fibres inhaled.
Fibres may react with the “skin”, or pleura, of the lung causing a lesion which could be described as a scar which may or may not affect the functioning of the lung. Over time the lesion may become calcified. The pleura may also react to the fibre and become thicker over time which may lead to a reduction in lung function. With exposure to high concentration of fibres over an extended period of time, lung cancer may also develop.
The effects of asbestos exposure on health may not become apparent until 15 to 30 years after the exposure.