Regional and sector-specific patterns of occupational and environmental exposures (TRA)


This was a pilot project whose goal was to assess the feasibility of creating regional occupational and environmental health profiles for Ontario. Specifically, work force data from the 2006 Canadian Census and carcinogen emissions and use data from environmental programs were analyzed both by industry sector and geographically. The major industries of employment were identified for each health region as well as the top carcinogens reportedly used and released. Additionally, using these data, maps were developed to highlight variations in the use and release of industrial carcinogens among regions in Ontario.

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In 2017, Cancer Care Ontario launched a new online mapping tool, Ontario Cancer Profiles, where cancer statistics such as incidence and mortality rates for 26 cancer sites as well as select cancer risk factors (i.e. smoking, obesity rates etc.) and social determinants of health are reported geographically by Local Health Integration Network (LHIN). Yet, a gap currently exists in our understanding of region-specific environmental and occupational cancer risk factors from industrial exposures.

Fortunately, data from environmental reporting programs such as Canada’s National Pollutant Release Inventory (NPRI) and Ontario’s Toxics Reduction Act (TRA) can provide an indication of how many carcinogens are used and released by industrial facilities in each region and supplement a tool like CCO’s Cancer Profiles. This project served as a feasibility study to examine whether data on occupational and environmental risk factors from the NPRI and TRA could be leveraged to create a compatible data tool based on the existing CCO Cancer Profiles tool that would fill the knowledge gaps identified.


In this feasibility study, data on Ontario’s workforce from the 2006 Census, data on the use of industrial carcinogens from Ontario’s TRA program and data on the release of industrial carcinogens from Canada’s NPRI program were linked. The data were analysed geographically to create occupational and environmental health profiles for Ontario by health region to present each region’s major industries of employment and the top carcinogens used and released by industrial facilities. We analysed the data at the LHIN-level and Public Health Unit (PHU)-level.


The results from this study helped to identify which sectors employed the largest number of workers by LHIN and which carcinogens were used and released in these regions. For example, the transportation equipment manufacturing sector employed large proportions of the working populations in Erie St. Clair, North Simcoe Muskoka, South West and Waterloo Wellington regions. Nickel, a carcinogen commonly used in transportation equipment manufacturing and other manufacturing sectors, was the most commonly used carcinogen in the province and appeared among the top three carcinogens used by industrial facilities in the majority of LHINs analysed.

The study findings indicate that leveraging interactive geographic data tools to display environmental and occupational health data can help highlight particular regions in Ontario where populations may face greater risks of developing cancer arising from exposures to carcinogens at work or in the environment.

Progress (updated June, 2018)

This feasibility study is complete. The OCRC continues to explore the potential applications of environmental and occupational cancer risk profiles for CCO’s Cancer Profiles tool.


This study was funded by a research grant from Cancer Care Ontario.

Research Team
Cathy Slavik
OCRC, McMaster University
Sheila Kalenge
Paul A Demers
OCRC, University of Toronto