Frequently Asked Questions
What is CAREX Canada?
What is carcinogen surveillance?
Why do we need a national carcinogen surveillance program?
Have other countries taken this approach?
What is the history of CAREX?
How does CAREX Canada support cancer prevention in Canada?
How does CAREX carry out its work?
How does CAREX Canada classify carcinogens?
How did CAREX Canada prioritize which carcinogens to focus on?
What kind of estimates has CAREX Canada calculated?
Why are these exposure estimates important?
In addition to the estimates, what other resources and tools has CAREX Canada created?
How is CAREX Canada funded?
CAREX Canada is a multi-institution team of researchers 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 the workplace and community environments. CAREX is an acronym for CARcinogen EXposure.
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.
According to the Canadian Cancer Statistics 2013, approximately 41% of Canadian women and 46% of men will develop cancer during their lifetimes. Approximately one in four Canadians is expected to die of cancer.
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.
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.
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.
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 the workplace and community environments. This makes it easier to identify and target high priority exposure scenarios for exposure reduction.
CAREX Canada is led by a multidisciplinary team of researchers based at the Faculty of Health Sciences at Simon Fraser University, the School of Population and Public Health at the University of British Columbia, and the Geography Department at the University of Victoria. The team has expertise in epidemiology, occupational hygiene, risk assessment, environmental quality, geographic information systems, and knowledge translation and exchange.
To carry out its work, CAREX Canada has forged a number of strategic stakeholder connections and relationships. For example, CAREX Canada works closely with provincial and territorial governments to improve the application and use of historical workplace exposure records.
CAREX Canada actively seeks guidance from experts. A national advisory group provided input to the 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. An advisory group for Knowledge Translation currently meets on a bi-annual basis. The input from these experts is central to the success of CAREX Canada’s efforts to ensure the relevance and uptake of this national carcinogen surveillance program.
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 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.” Carcinogens/exposures such as shiftwork, creosotes and diesel engine exhaust are Group 2A agents. Group 2B agents are “possibly carcinogenic humans” for which there is “limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals.” Some pesticides used in Canada, such as chlorothalonil and mecoprop (MCPP), fall into this category.
Carcinogens were first broadly categorized according to their potential for human exposure in the workplace or in the environment. If exposures were considered as unlikely to occur in Canada, substances were excluded from further consideration. The remaining substances were selected for critical review. For these substances, 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 humans may be exposed; while in the environmental context, it refers to human 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 in light of 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 both occupational and environmental exposure estimates.
The occupational exposure estimates calculate the numbers of workers exposed to 44 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 the 33 most common known or suspected carcinogens in Canadian community settings. For outdoor air, detailed models have been developed that allow provincial mapping.
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 epidemiologic studies that further our understanding of occupational and environmental cancers.
The carcinogen profiles are technical summaries that offer a concise and convenient integration of the Canadian context for 72 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; environmental releases quantifies; 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.
eRISK is a Microsoft Access tool, available by request, that allows users to explore the data used to produce the environmental estimates and to see how the risk indicators for their own local data might differ from the national levels.
The Emissions Mapping Project (EMP) provides a wide range of files that can be easily downloaded and displayed with Google Earth. It allows users to see how watersheds, provinces, health regions, eco-zones, and major cities rank according to total toxicity of emissions to air, to see how different sources contribute to the total emissions, and to see information on sources and levels of known and suspected carcinogens in outdoor environments.
eWORK Excel is a Microsoft Excel-based tool that makes it easy for interested users to explore the CAREX occupational exposure estimates and results in a variety of ways, such as by occupation, industry, province, and sex.
eWORK Online is an online tool based on Tableau Software. The tool allows users to select specific CAREX agent, occupation, industry, and exposure level of interest, and displays CAREX occupational estimates in various user-friendly visualizations.
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.