A connection between contact with asbestos and cancer was established in the 1960s. The two types of cancer associated with asbestos exposure are lung cancer and mesothelioma (a type of cancer affecting the outer lining of the lung or pleura).
There are three types of asbestos: blue, brown and white. Of these, blue asbestos is the most dangerous, probably because when its fibres are inhaled they stay in the lung for a very long time whereas white asbestos fibres are broken down by the tissues and removed quite quickly.
Imports to the UK of blue and brown asbestos were banned in 1985 but they are still found in older buildings as insulation materials or components of ceiling tiles and fire doors. White asbestos is still used as asbestos cement in a number of items in the building trade.
Asbestos containing materials only become dangerous when they are damaged and release fine asbestos dust, which can then be inhaled. However, even slight exposure can lead to cancer formation so there does not need to have been heavy or prolonged contact for there to be a cancer risk. Occupations where people might come into contact with asbestos dust include demolition workers, insulation workers, builders, roofers, carpenters and electricians. Family members of these workers also have a potential risk of exposure to asbestos fibres, as the fibres can be carried on clothes.
The use of asbestos in building and engineering peaked around about 1970. Because the gap between contact with asbestos and development of cancer can be anywhere from 10 to 60 years this means that the number of cases diagnosed is still rising in men born between 1945 and 1950 and is likely to continue to increase for the next 20 years.
About one in four people who worked with asbestos before 1970 are likely to develop lung cancer (this compares with a risk of about 1 in 20 for the general population). About 1 in 10 people exposed to asbestos will develop the cancer mesothelioma (mesothelioma is an uncommon tumour but it is thought that 9 out of 10 cases are due to asbestos). Smoking increases the risk of lung cancer development after asbestos exposure but has no effect on the risk of developing a mesothelioma.
If someone who develops lung cancer or a mesothelioma can show a link between their tumour and asbestos exposure then the government does offer a compensation scheme for them.