Thousands of new cancer cases in Ontario each year due to environmental exposures

News Release

8 Aug 2016

Between 3,540 and 6,510 new cancer cases in Ontario each year result from environmental factors, says a new report from Cancer Care Ontario and Public Health Ontario (PHO).

The report, Environmental Burden of Cancer in Ontario, estimates how many new cancer cases occur each year in the province as a result of exposure to cancer-causing agents, or carcinogens, that exist in our environment. The estimated burden of cancer from environmental carcinogens is significant, particularly when compared to other known cancer risk factors. The report found that environmental carcinogens represent roughly twice the cancer burden from drinking alcohol and about one-half the cancer burden from smoking.

“This report focuses on cancer-causing agents that Ontarians are exposed to every day simply by breathing, eating, drinking and being in the sun,” says Dr. Ray Copes, chief of environmental and occupational health, PHO. “Interestingly, three main carcinogens stand out as being particularly important – ultraviolet (UV) radiation from the sun, radon gas, and fine particle (PM2.5) air pollution.”

The report ranks 23 environmental carcinogens according to the estimated annual number of new cancer cases in Ontario that each carcinogen would be associated with at current exposure levels.  Key findings include:

  • 2,090 to 2,990 new cancer cases from UV radiation in sunlight;
  • 1,080 to 1,550  new cancer cases from radon;
  • 290 to 900 new cancer cases from fine particles in outdoor air pollution.

“Understanding the factors that affect our cancer risk is an important step on the path to a healthier future. By focusing prevention efforts on the carcinogens associated with the highest number of new cancer cases, we can significantly reduce the environmental cancer burden in Ontario,” says Alice Peter, director, population health & prevention, Cancer Care Ontario. “With this report, we can effect change through awareness of these environmental carcinogens; this will require the coordinated efforts and expertise from all levels of government, scientists, industry experts, non-governmental organizations and Ontarians.”

Environmental Burden of Cancer in Ontario is the fifth report in Cancer Care Ontario’s Cancer Risk Factors in Ontario series, and the first produced jointly by Cancer Care Ontario and PHO in the series.


About Cancer Care Ontario:
Cancer Care Ontario plays an important role in equipping health professionals, organizations and policy-makers with the most up-to-date cancer knowledge and tools to prevent cancer and deliver high quality patient care. 

It does this by collecting and analyzing data about cancer services and combining it with evidence and research that is shared with the healthcare community in the form of guidelines and standards. It also monitors and measures the performance of the cancer system, and oversees a funding and governance model that ties funding to performance, making healthcare providers more accountable and ensuring value for investments in the system.

Cancer Care Ontario actively engages people with cancer and their families in the design, delivery and evaluation of Ontario’s cancer system, and works to improve the performance of Ontario’s cancer system by driving quality, accountability, innovation and value.

About Public Health Ontario:
Public Health Ontario is a Crown corporation dedicated to protecting and promoting the health of all Ontarians and reducing inequities in health. Public Health Ontario links public health practitioners, front-line health workers and researchers to the best scientific intelligence and knowledge from around the world. For the latest PHO news, follow us on Twitter: @publichealthON.

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Updated 8 Aug 2016