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Harmful substances and environmental risks

Many Canadians are worried about harmful environmental substances and cancer. We share your concerns, and we believe that you shouldn’t be exposed to substances that cause cancer at work, at home or in your environment. But we need a lot more research to help us understand how toxic or environmental substances may be linked to cancer. Until we have clear answers on this complex topic, we will do our best to keep you informed about the substances that are being studied.

  • Our perspective

    We believe substances that cause cancer should be replaced with safer alternatives. If it isn’t possible to get rid of the cancer-causing substance or find a safer option, then exposure to it should be reduced as much as possible.

  • Level of risk

    Certain environmental contaminants might play a role in the development of some cancers, but current scientific evidence has not confirmed or ruled them out as possible risk factors. Scientists continue to study and debate the role of environmental contaminants in the development of cancer.

    There is currently a lot of debate about how many cancers are related to exposure to environmental contaminants. While the exact percentage of cancers associated with this type of exposure is not known, research suggests that people who are continually exposed to cancer-causing substances in the environment generally have a higher risk of developing certain cancers.

    Most of the environmental contaminants known to cause cancer in humans were identified through studies that looked at groups of people who shared occupational exposure to carcinogens. These people had a greater exposure to these potential cancer-causing substances than in people the community or at home.

  • Exposure

    Sometimes people can’t avoid being exposed to environmental contaminants or they may not know they are being exposed to them. People are exposed to different environmental contaminants for varying lengths of time and at different levels. This makes it hard to figure out how much exposure a person has had to any one substance or chemical. Also, exposure to a combination of environmental contaminants may increase a person’s risk more than each substance or chemical alone.

  • How we form our policies and recommendations

    We constantly monitor new research and scientific evidence so we can tell you more about how to prevent cancer. We take into account the positions of internationally renowned bodies such as the World Health Organization’s International Agency for Research on Cancer, and the National Toxicology Program and Environmental Protection Agency in the United States. Scientific evidence constantly changes – and when it does, we update our information on

    The following pages provide more information about our methodology when evaluating current research and making recommendations to help you protect yourself from cancer risk.

  • Reducing your risk

    Both individual action (taking steps to reduce your exposure) and public policies can help prevent or reduce exposure to cancer-causing substances in the environment. Whenever possible, exposure to cancer-causing substances should be identified and stopped by using safer alternatives. When it is not possible to stop exposure completely, exposure should be reduced to the lowest possible levels.

    Some general actions you can take to reduce or prevent exposure to cancer-causing substances in the environment include:

    • Avoid cancer-causing substances.
    • Eliminate or limit exposure to potentially harmful and cancer-causing substances by using non-toxic materials (for example, non-toxic glue and paint) whenever possible.
    • Follow safety instructions at home and at work when using, storing and disposing of harmful materials or chemicals. Read and carefully follow the manufacturers’ directions for safely using and storing hazardous chemicals. Health Canada and Environment Canada often have guidelines for handling harmful substances.
  • Suggested links for more information
    General information about the environment

    Environment Canada
    This federal government resource provides information about pollution, weather, climate change, and federal activities that protect the environment. The site is a source of information about the National Pollutant Release Registry.

    Environmental Protection Agency (EPA) (US)
    The EPA is responsible in the United States for protecting human health and the environment. Its website provides information about pesticides, clean air, clean water, environmental contaminants and many other environmental issues.

    California Environmental Protection Agency (US)
    Like the federal EPA, the California EPA is responsible for protecting human health and the environment. As a result of Proposition 65 in that state, they produce a regularly updated list of chemicals that are known to cause cancer.

    National Institute of Environmental Health Sciences (NIEHS) (US)
    The NIEHS is focused on how the environment influences human disease. Their section on cancer contains an index of research examining various environmental factors that may be linked to cancer.

    World Health Organization – Public Health and Environment
    This section of the WHO website contains information about the potentially harmful effects of chemicals, radiation, air pollution, occupational health and climate change.

    General information about cancer

    Public Health Agency of Canada – Cancer
    This site provides information about different types of cancer and about the Canadian government’s action plan to fight cancer through prevention, research, screening and other methods.

    Centers for Disease Control and Prevention (CDC) – Cancer Prevention and Control (US)
    The CDC is responsible for protecting human health and safety. The cancer section of their website contains information about research, statistics, prevention, survivorship and more.

    International Agency for Research on Cancer (IARC)
    IARC is part of the World Health Organization. Its objective is to promote international collaboration in cancer research. Their website provides access to a number of useful (but technical) resources including the IARC Monographs on the Evaluation of Carcinogenic Risks to Humans.

    Occupational health, safety and exposure

    Canadian Centre for Occupational Health and Safety
    This website provides information about occupational health and safety, including chemical profiles of over 1,200 substances and chemical hazard information for over 200,000 chemicals.

    Health Canada – Healthy Environments and Consumer Safety
    This website provides information about environmental contaminants, workplace safety, product safety and substance abuse.

    CAREX Canada
    This website provides general information about a large number of known or potentially cancer-causing substances. In addition, it provides estimates regarding how many Canadians are exposed to each substance in the workplace and in general.

    National Institute for Occupational Health and Safety (NIOSH) – Occupational cancer (US)
    NIOSH is focused on preventing work-related disease and injury. The cancer section of their website contains information about cancer clusters, carcinogenic agents found in the workplace, surveillance and health and safety standards in the US.

    Information about toxic chemicals

    Health Canada – Environmental Contaminants
    This website provides information about the environmental impact of toxic substances, including lists of toxic substances and information about human biomonitoring studies being conducted in Canada.

    Government of Canada – Chemical Substances
    This website provides information about the federal government’s actions around chemical management and current chemical-related issues that affect Canadians.

    National Library of Medicine ToxTown (US)
    This website provides information about exposure to toxic chemicals at home, at work, at school, and in the community in everyday life. (Note that not all the substances are available in Canada.)



Sophie Lebel My family is proud of the work I’m doing that is making a positive change in people’s lives.

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Taking action against all cancers

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