Surveillance of occupational cancer risks through linkage of WSIB claims to the Ontario cancer registry


The goal of this project was to develop a new way to monitor and measure workplace risk factors for cancer, by linking occupation and industry data to the Ontario Cancer registry via records of WSIB claims.

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There are approximately 60 well-established workplace carcinogens. However, there are many more industrial chemicals and other agents that are suspected to cause cancer, and still more that have never been studied. Currently, Canada lacks any rapid means to assess whether there is an increased risk associated with an exposure or what the risk of cancer is among people with the same job or working in the same industry. The major challenge is that, although Canada collects very good information on every new cancer that is diagnosed, there is no way to identify where these patients worked. Having a way to link occupation and industry data to Cancer Registry data would allow researchers to identify jobs or substances that carry an increased risk of cancer.


When workers make claims to the Workplace Safety and Insurance Board (WSIB) for time lost, their claims contain information on their occupations and industries. These claims can be linked to records of cancer diagnoses held by Cancer Care Ontario to compare risks of cancer for different occupations and industries. The initial pilot project successfully adapted methods developed by researchers in Alberta and British Columbia for use in Ontario by linking a 20% sample of WSIB claims with Ontario Cancer Registry records.


The initial pilot study is now complete. The linkage was successful, and associations between occupational groups and cancers consistent with established risk factors were observed, including elevated risks of lung cancer in mining workers, mesothelioma in construction workers, and breast cancer among teachers. This indicates the feasibility of using the full linkage to provide a surveillance platform to explore occupational cancer risks. This could enable rapid assessment of the risk associated with various jobs, and highlight industries that require interventions to reduce exposure to workplace carcinogens.

Related work

Building on the success of this pilot study, the linkage was expanded to create the Occupational Disease Surveillance System (ODSS). As of 2022, the ODSS follows 2.4 million workers and includes tumour registry data, hospital records, ambulatory care records, and physician billing records. It monitors risk of cancers, respiratory diseases (e.g., COVID-19, asthma, silicosis) and other health conditions (e.g., heart attacks, opioid-related harms).

For more information visit the project page or our Occupational Disease Surveillance Program website.


The initial pilot study was funded by a grant from the Ontario WSIB Research Advisory Council.

Research Team
Anne Harris
Ryerson University
Paul Demers
Mieke Koehoorn
University of British Columbia
Christopher McLeod
University of British Columbia
Jill MacLeod
Anna Koné
Cancer Care Ontario
Maisah Syed
OCRC and University of Toronto