Frequently Asked Questions

What is CAREX Canada?
CAREX Canada is a multi-institution team of researchers and specialists that combines academic expertise and government resources to generate an evidence-based carcinogen surveillance program for Canada. The purpose of CAREX Canada is to estimate the number of Canadians exposed to substances associated with cancer in workplace and community environments. CAREX stands for CARcinogen EXposure.
What is carcinogen surveillance?
Carcinogen surveillance is defined as the ongoing collection of information about exposure to known or suspected cancer-causing agents in a certain group of people. The information collected may include where exposure occurs in a population, how exposure occurs (for example, indoor air at home or at work, drinking water, or food and beverages), and whether it affects people of a certain sex or living in certain geographical areas.
Why do we need a national carcinogen surveillance program?
According to the Canadian Cancer Statistics 2017, approximately 45% of Canadian women and 49% of men will develop cancer during their lifetimes. Approximately one in four Canadians is expected to die of cancer, making it the leading cause of death in Canada.

The World Health Organization estimates that up to 19% of all cancers result from workplace or environmental exposures and account for 1.3 million deaths annually around the world. The National Collaborating Centre for Environmental Health reports that preliminary estimates suggest that annual health care costs in Canada associated with occupational and environmental cancers range between $3.6 to 9.1 billion (Boyd et al. Environmental Research, Volume 106, Issue 2, February 2008, Pages 240–249).

One way to prevent cancers associated with occupational or environmental exposures – and to minimize their societal and economic costs – is to reduce or eliminate exposures. CAREX Canada identifies which carcinogens occur in Canada, where exposures are occurring, who is exposed, what are the routes of exposure, and where possible, how much people are exposed to. This information helps to target and prioritize different exposure scenarios for exposure reduction.

Have other countries taken this approach?
Yes. CAREX Canada builds on a model established by the Finnish Institute of Occupational Health that was created for the European Union’s “Europe Against Cancer” program. The European CAREX project developed estimates of the burden of occupational cancer in Europe by country, carcinogen, and industry.
What is the history of CAREX?
Prior to the late 1990s, Canada had no centralized repository of data on carcinogens. It was unknown what carcinogens people were exposed to, how many people were exposed and where exposures were occurring. In response to this gap and with funding from WorkSafeBC, a group of researchers at the University of British Columbia piloted a project in 2003 that adapted the original Finnish model to generate estimates of carcinogen exposure in BC workplaces.

The Canadian Strategy for Cancer Control recognized the need to identify which carcinogens exist in the Canadian environment, as well as who is exposed to them, and recommended the surveillance of population exposures to occupational and environmental carcinogens. This recommendation led to the formation of CAREX Canada, a national carcinogen surveillance program funded by the Canadian Partnership Against Cancer (CPAC) in 2007. CAREX Canada has been hosted at Simon Fraser University since 2013.

How does CAREX Canada support cancer prevention in Canada?
Setting policies and priorities for occupational and environmental carcinogens in Canada is often limited by the lack of exposure data and poor characterization of the health risks arising from these exposures. CAREX Canada addresses this gap by generating high quality estimates of the number of Canadians exposed to substances associated with cancer in workplace and community environments. This makes it easier to identify and target high priority exposure scenarios for exposure reduction.
How does CAREX carry out its work?

CAREX Canada is a multidisciplinary team of researchers based at the Faculty of Health Sciences at Simon Fraser University, working in collaboration with researchers at the School of Population and Public Health, University of British Columbia, Department of Health Sciences at Carleton University, and the Occupational Cancer Research Centre, based at Cancer Care Ontario. The team has expertise in epidemiology, occupational hygiene, toxicology, risk assessment, geographic information systems, data visualization, and knowledge translation and exchange. To carry out its work, CAREX Canada has forged a number of strategic connections and relationships with knowledge users. These include longstanding working groups with organizations such as WorkSafeBC and the Canadian Environmental Law Association (CELA), where we collaborate to mobilize and expand CAREX research and expertise over a multi-year timeframe. These relationships and others are highlighted in our annual reports from 2012-17. CAREX Canada actively seeks guidance from experts. A national advisory group provided input to the research project as a whole. This group represented academic institutions and research agencies; public health, health promotion and cancer agencies; occupational health and safety agencies; labour organizations; and industry. Other advisory groups were formed as needed to address specific components of the program. A Knowledge Translation Advisory Committee supports CAREX Canada’s efforts to ensure the relevance and uptake of this national carcinogen surveillance program. The team is currently developing a new advisory committee to support the development of pesticide exposure estimates in workplace and community environments.

How does CAREX Canada classify carcinogens?
CAREX Canada classifies carcinogens based on evaluations made by the International Agency for Research on Cancer (IARC). Group 1 agents are evaluated by IARC as “carcinogenic to humans” based on “sufficient evidence of carcinogenicity in humans.” Carcinogens such as asbestos, benzene, diesel engine exhaust, and wood dust are Group 1 agents. Group 2A includes agents that are “probably carcinogenic to humans” based on “limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals.” Exposures such as shift-work and creosotes are Group 2A agents. Group 2B agents are “possibly carcinogenic to humans” for which there is “limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals.” A wide variety of exposures fall in this category, including toluene diisocyanates, metallic lead, phthalates, and several pesticides.
How did CAREX Canada prioritize which carcinogens to focus on?

Carcinogens were first broadly categorized according to their potential for exposure in the workplace or in the environment. If exposures were unlikely to occur in Canada, they were excluded from further consideration. For the remaining substances selected for critical review, the following key information was collected: characteristics and overall toxicity, potential exposure circumstances, and evidence for exposure in Canada. In the occupational context, “potential exposure circumstances” refers to workplace settings or activities in which workers may be exposed; while in the environmental context, it refers to contact with carcinogens via the air, water, soil, dusts, food, and consumer products. Tables summarizing key information for each substance were then generated.

Each substance was considered according to three criteria: carcinogenicity and other toxic properties, the prevalence of exposure in Canada, and the feasibility of assessing exposure. On the basis of these three criteria, substances were then placed into one of four groups: immediate high priority; possible high priority; moderate priority – further substantial investigation warranted; or low priority – no evidence of use in Canada.

CAREX Canada has produced two documents, one for environmental and one for occupational carcinogens, that summarize the prioritization methods and results in detail. These priorities were revisited in 2015 and a publication summarizing the results is currently under peer review.

What kind of estimates has CAREX Canada developed?

CAREX Canada has produced both occupational and environmental exposure estimates. The occupational exposure estimates calculate the numbers of workers exposed to 45 specific carcinogens by industry, occupation, province, and sex. Where data are available, levels of exposure expected in Canadian workplaces have also been estimated. The environmental exposure estimates provide detailed information on the importance of five exposure pathways (outdoor air, indoor air, indoor dust, drinking water, and food and beverages) to 38 known or suspected carcinogens in Canadian community settings. For outdoor air, detailed models have been developed that allow provincial mapping.

Why are these exposure estimates important?
These estimates are important for developing prevention strategies for cancer and other exposure-related diseases, for targeting high-risk groups, for determining the occupational and environmental burden of cancer in Canada, and for creating new epidemiological studies that further our understanding of occupational and environmental cancers.
In addition to the estimates, what other resources and tools has CAREX Canada created?

CAREX Canada has created carcinogen profiles, the Canadian Workplace Exposure Database (CWED), and eWORK. The carcinogen profiles are technical summaries that offer a concise and convenient integration of the Canadian context for 77 agents classified by the International Agency for Research on Cancer (IARC) as known or suspected human carcinogens. They summarize: general information about each agent, cancer and non-cancer health effects, relevant Canadian regulatory exposure/permissible levels, and occupational and environmental routes and scenarios of exposure. The Canadian Workplace Exposure Database (CWED) is a national occupational exposure database created with data collected from seven provincial and federal regulatory agencies. eWORK is a set of tools developed by our occupational exposures team that allow users to explore the CAREX occupational exposure estimates in a variety of ways, such as by occupation, industry, province, or sex. Two versions of eWORK are available: eWORK Excel and eWORK Online. eWORK Excel is a Microsoft Excel-based tool capable of handling complex filters and queries. It is available by request. eWORK Online is for users who prefer quick, accessible, yet high quality statistics on occupational exposures to various carcinogens. This tool is available via the tools tab on our website.

How is CAREX Canada funded?
CAREX Canada is primarily funded by the Canadian Partnership Against Cancer (CPAC), an independent organization funded by Health Canada to accelerate action on cancer control. CAREX Canada also pursues academic grants in collaboration with other partners to extend the work made possible by CPAC.

Subscribe to our newsletters

The CAREX Canada team offers two regular newsletters: the biannual e-Bulletin summarizing information on upcoming webinars, new publications, and updates to estimates and tools; and the monthly Carcinogens in the News, a digest of media articles, government reports, and academic literature related to the carcinogens we’ve classified as important for surveillance in Canada. Sign up for one or both of these newsletters below.

CAREX Canada

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