What is asbestos?
Asbestos is a group of naturally occurring fibrous minerals with current or historical commercial usefulness due to their extraordinary tensile strength, poor heat conduction, and relative resistance to chemical attack. For these reasons, asbestos is used for insulation in buildings and as an ingredient in a number of products, such as roofing shingles, water supply lines, and fire blankets, as well as clutches and brake linings, gaskets, and pads for automobiles.
The main forms of asbestos are chrysotile (white asbestos) and crocidolite (blue asbestos). Other forms include amosite, anthophylite, tremolite and actinolite.
Why is asbestos a problem?
All forms of asbestos are carcinogenic to humans. Exposure to asbestos, including chrysotile, causes cancer of the lung, larynx, and ovaries, and also mesothelioma (a cancer of the pleural and peritoneal linings). Asbestos exposure is also responsible for other diseases such as asbestosis (fibrosis of the lungs), and plaques, thickening and effusion in the pleura.
Currently, about 125 million people in the world are exposed to asbestos at the workplace. Approximately half of the deaths from occupational cancer are estimated to be caused by asbestos. In addition, it is estimated that several thousand deaths annually can be attributed to exposure to asbestos in the home.
It has also been shown that co-exposure to tobacco smoke and asbestos fibres substantially increases the risk for lung cancer – and the heavier the smoking, the greater the risk.
What about asbestos substitute materials?
Many fibre substitutes for chrysotile asbestos assessed by WHO pose a relatively low hazard to human health, though, the carcinogenic hazard of some fibre substitutes was found to be high. However, there are many non-fibre low hazard materials that can substitute for chrysotile asbestos in various uses, such as conventional building materials.
The World Health Assembly resolution 58.22 on cancer prevention urges Member States to pay special attention to cancers for which avoidable exposure is a factor, including exposure to chemicals at the workplace and in the environment.
With resolution 60.26, the World Health Assembly requested WHO to carry out a global campaign for the elimination of asbestos-related diseases "…bearing in mind a differentiated approach to regulating its various forms - in line with the relevant international legal instruments and the latest evidence for effective interventions…". Cost-effective interventions for prevention of occupational lung diseases from exposure to asbestos are among the policy options for implementing the "Global Action Plan for the Prevention and Control of Noncommunicable Diseases" (2013-2020), as endorsed by the Sixty-sixth World Health Assembly in resolution WHA66.10 in 2013.
Eliminating asbestos-related diseases is particularly targeted at countries still using chrysotile asbestos, in addition to assistance in relation to exposures arising from historical use of all forms of asbestos.
WHO, in collaboration with the International Labour Organization and other intergovernmental organizations and civil society, works with countries towards elimination of asbestos-related diseases by:
- recognizing that the most efficient way to eliminate asbestos-related diseases is to stop the use of all types of asbestos;
- providing information about solutions for replacing asbestos with safer substitutes and developing economic and technological mechanisms to stimulate its replacement;
- taking measures to prevent exposure to asbestos in place and during asbestos removal (abatement);
- improving early diagnosis, treatment, and rehabilitation services for asbestos-related diseases;
- establishing registries of people with past and/or current exposures to asbestos and organizing medical surveillance of exposed workers; and
- providing information on the hazards associated with asbestos-containing materials and products, and by raising awareness that waste containing asbestos should be treated as hazardous waste.