Workplace exposures account for a significant number of cancers in Ontario: Report

Solar radiation, asbestos among top cancer-causing exposures

Workplace exposures account for a significant number of cancers in Ontario: Report

Thousands of Ontario workers are exposed to cancer-causing hazards in the workplace, with solar ultraviolet radiation, asbestos, diesel engine exhaust and silica contributing to the majority of occupational cancers, according to a new report. 

The report, Burden of Occupational Cancer in Ontario: Major Workplace Carcinogens and Prevention of Exposure, profiles 11 priority carcinogens that are well-established causes of cancer and the most common known or suspected carcinogens found in Ontario workplaces. 

“Occupational exposures are associated with a substantial and often overlooked burden of cancer in Ontario. These cancers are almost entirely preventable,” said Paul Demers, director of the Occupational Cancer Research Centre, which co-presented the report with Cancer Care Ontario. “The findings in this report will inform evidence-based actions to enhance prevention efforts, particularly in the industries where workers are regularly exposed to carcinogens.”

According to the report, the best opportunity to decrease the burden of occupational cancer is to prevent and control exposure to four key carcinogens: solar ultraviolet radiation, asbestos, diesel engine exhaust and silica.

•Solar ultraviolet radiation: Nearly half a million workers (450,000) are exposed to solar radiation each year, primarily in the construction and agricultural industries, which causes an estimated 1,400 non-melanoma skin cancer cases annually.

•Asbestos: Fewer than 55,000 workers are exposed to asbestos (the commercial term for six different types of related mineral fibres), but it is the cause of approximately 630 lung cancers, 140 mesotheliomas, 15 laryngeal cancers and less than five ovarian cancers annually in Ontario. Most occupational exposure occurs in construction, primarily due to the maintenance, renovation and modification of existing public, residential and commercial buildings.

•Diesel engine exhaust exposure: Exposure to diesel engine exhaust affects about 301,000 workers and accounts for an estimated 170 lung and 45 bladder cancer cases each year. The burden is highest in the mining industry as well as transportation and warehousing.

•Silica: Around 142,000 Ontario workers are exposed to fine crystalline silica dusts, primarily in the construction, manufacturing and mining industries, which causes almost 200 lung cancer cases each year.

The report proposes four overarching policy recommendations to help reduce the burden of occupational cancers, including strengthening occupational exposure limits so they are up to date, rigorous and based on evidence of health effects. It also recommends reducing or eliminating the use of toxic substances in the workplace and creating registries of worker exposure to occupational carcinogens for tracking and monitoring purposes. Lastly, the groups behind the report want to see construction workers and employers included in the Designated Substances Regulation.

“The best way to prevent occupational cancer is through system-level actions that are based on strong evidence,” said Alice Peter, director of population health and prevention at Cancer Care Ontario. “The policy recommendations in this report have been developed with several sectors in mind, and it is our hope that this information will be a call to action for governments, employers and other health and safety organizations to drive change and help prevent future occupational cancers among Ontario workers.”