Environmental and occupational cancers
- Cancer is a leading cause of death worldwide, with 12.7 million new cases and 7.6 million deaths in 2008.
- Globally, 19% of all cancers are attributable to the environment, including work setting resulting in 1.3 million deaths each year.
- WHO has classified 107 agents, mixtures, and exposure situations as carcinogenic to humans.
- External environmental causes of cancer are factors in the environment that increase risk of cancer such as air pollution, UV radiation and indoor radon.
- Every tenth lung cancer death is closely related to risks in the workplace.
- Lung cancer, mesothelioma, and bladder cancer are among the most common types of occupational cancers.
What are occupational and environmental causes of cancer?
Cancer is a leading cause of death worldwide, with 12.7 millions new cases and 7.6 million deaths in 2008. Currently, 63% of all cancers deaths are reported from low- and middle-income countries and this figure is predicted to increase. Globally, 19% of all cancers are attributable to the environment, including work setting, resulting in 1.3 million deaths each year.
WHO's International Agency for Research on Cancer (IARC) has classified 107 agents, mixtures, and exposure situations as carcinogenic to humans. These include all forms of asbestos and a number of agents found in the environment such as benzene, arsenic in water, cadmium, ethylene oxide, benzo[a]pyrene, silica, ionizing radiation including radon, ultraviolet radiation including tanning devices, aluminium and coke production, iron and steel founding, or the rubber manufacturing industry.
Most of the exposure risks for occupational cancer are preventable. About 125 million people in the world are exposed to asbestos at the workplace. According to WHO estimates, more than 107 000 people die each year from asbestos-related lung cancer, mesothelioma and asbestosis resulting from occupational exposures. One in three deaths from occupational cancer is caused by asbestos.
External environmental causes of cancer are factors in the environment such as pollutants that increase risk for cancer. For example, indoor radon exposure was estimated to cause between 3-14 % of all lung cancers in 2004, the second most important cause of lung cancer in many countries.
Air pollution caused 165 000 lung cancer deaths globally in 2004 of which:
- 108 000 were caused by outdoor air pollution
- 36 000 were due to solid fuels used for cooking and heating
- 21 000 were due to second-hand smoke.
UV radiation was estimated to cause 60 000 deaths in 2002 of which:
- 48 000 were melanomas
- 12 000 were basal and squamous skin carcinomas.
In 2005, a resolution on cancer prevention and control by the World Health Assembly urged countries to develop programmes aimed at reducing cancer incidence and mortality. This resolution calls on all Member States to develop national cancer programmes, which include increased prevention measures, early detection and screening, as well as improved treatment and palliative care.
The resolution advocates for special attention to cancers preventable by avoiding exposure to chemicals and tobacco smoke at the workplace and in the environment, certain infectious agents and ionizing and ultraviolet radiation. It recommends including preventable tumours (such as those of lung, colon, rectum, skin and liver): to avoid and reduce exposure to risk factors (such as tobacco use, unhealthy diets, harmful use of alcohol, sedentariness, excess exposure to sunlight, communicable agents, and occupational exposures), in national cancer control programmes.
WHO developed a number of tools for prevention of cancer arising from environmental exposures, including:
- WHO Framework Convention on Tobacco Control;
- policy on elimination of asbestos-related diseases;
- guidelines for air quality and drinking water quality;
- policy options for prevention and mitigation of radon;
- practical advice and information on health effects of UV exposure;
- safety standards for chemicals and food, including cancer-causing contaminants like dioxins and aflatoxins;
- the International Programme on Chemical Safety, including Ten chemicals of major public health concern;
- WHO's global plan of action on workers' health.
Furthermore, WHO developed a guide to effective programmes on cancer prevention (Cancer control: knowledge into action - prevention) which deals with all risk factors, including environmental and occupational risks and radiation. The module aims to assist national managers of cancer control to develop effective plans for cancer prevention according to the realities in their countries. It provides directions on how to assess the magnitude of the problem, and devise core, recommended and extended sets of preventive actions, and how to monitor the effects of cancer prevention programmes.