Environmental pollution

Environmental pollution of air, water and soil with carcinogenic chemicals accounts for 1–4% of all cancers (IARC/WHO, 2003). Exposure to carcinogenic chemicals in the environment can occur through drinking water or pollution of indoor and ambient air. In Bangladesh, 5–10% of all cancer deaths in an arsenic-contaminated region were attributable to arsenic exposure (Smith, Lingas & Rahman, 2000). Exposure to carcinogens also occurs via the contamination of food by chemicals, such as afl atoxins or dioxins. Indoor air pollution from coal fires doubles the risk of lung cancer, particularly among non-smoking women (Smith, Mehta & Feuz, 2004). Worldwide, indoor air pollution from domestic coal fires is responsible for approximately 1.5% of all lung cancer deaths. Coal use in households is particularly widespread in Asia.

World Health Organization website, November 2012

In Canada, environmental pollution is not responsible for as significant a proportion of cancer cases as it is worldwide. However, certain populations may be at an increased risk of developing cancer due to environmental factors. For example, farmers are often exposed to pesticides through work and thus have a higher risk than the average person of getting Hodgkin lymphoma, non-Hodgkin lymphoma, leukemia, multiple myeloma, soft tissue sarcoma and cancers of the prostate and brain1. There is also strong evidence that air pollution can cause lung cancer2 and those living in large cities and highly industrial cities are at higher risk.

1. Canadian Cancer Society (2015) Pesticides. Retrieved from http://www.cancer.ca/en/prevention-and-screening/be-aware/harmful-substances-and-environmental-risks/pesticides/?region=on in August 2015.

2. Arden Pope III, C., Burnett, R.T., Thun, M.J., Calle, E.E., Krewski, D., Ito, K., and Thurston, G.D. (2002) Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. The Journal of the American Medical Association 287: 1132-1141.