Asbestos is a group of naturally occurring fibrous minerals that have been used previously or are currently used in industry due to their exceptional qualities such as tensile strength, low thermal conductivity and relative resistance to chemical attack. For these reasons, asbestos is used for insulation in buildings and as an ingredient in a range of products such as roofing shingles, water pipes, fire retardant coatings, as well as grip and brake pads, O-rings and car supports.
The main varieties of asbestos are chrysotile (white asbestos) and crocidolite (blue asbestos). Other varieties are amosite, anthophyllite, tremolite and actinolite.
Why is asbestos a problem?
All types of asbestos are carcinogens to humans. Exposure to asbestos, including chrysotile, causes lung, laryngeal and ovarian cancer, as well as mesothelioma (pleural and peritoneal cancer). Exposure to asbestos also causes other diseases such as asbestosis (pulmonary fibrosis) and pleural plaques, thickening and effusion.
Approximately 125 million people worldwide are currently exposed to asbestos in the workplace. Approximately half of occupational cancer deaths are caused by asbestos. In addition, it is estimated that several thousand annual deaths may be caused by exposure to asbestos in the home.
Simultaneous exposure to tobacco smoke and asbestos fibers has also been shown to significantly increase the risk of lung cancer – and the more a person smokes, the higher the risk.
What materials can replace asbestos?
Many fibrous substitutes for chrysotile asbestos have been assessed by the WHO to pose a relatively low risk to human health, although the carcinogenic hazard of some fibrous substitutes has been found to be high. However, there are numerous non-fibrous materials with low hazards that can substitute for asbestos in a variety of uses, such as as common building materials.
Elimination of asbestos-related diseases is of particular importance for countries still using chrysotile asbestos. Assistance is also being provided in connection with the past use of all varieties of asbestos and its impact on health.
WHO, in cooperation with the International Labour Organization and other intergovernmental organizations and civil society, is working with countries to eliminate asbestos-related diseases along the following strategic lines:
- Recognizing that the most effective way to eliminate asbestos-related diseases is to stop using all types of asbestos;
- providing information on ways of substituting asbestos with safer substances and developing economic and technological mechanisms to incentivize its substitution;
- taking measures to prevent exposure to asbestos in the workplace and during removal; and
- improving early diagnosis, treatment and rehabilitation services for asbestos-related diseases;
- compiling registers of people previously and/or currently exposed to asbestos, and organizing medical surveillance of workers who have been exposed;
- providing information on the hazards associated with asbestos-containing materials and products and raising awareness that asbestos-containing waste should be treated as hazardous waste.