A recent report by the Occupational Cancer Research Centre (OCRC) in Toronto has identified solar radiation, asbestos, diesel-engine exhaust and crystalline silica as the four major causes of work-related cancer in Ontario.
Burden of Occupational Cancer in Ontario, published on Sept. 28, was based on statistics from CAREX Canada, a Burnaby, B.C.-based organization that tracks carcinogens, as well as input from scientific and policy experts, according to an OCRC news release. The study found that about 1,400 Ontario workers are diagnosed with non-melanoma skin cancer from on-the-job sun exposure every year, while asbestos exposure causes nearly 800 occupational cancer cases in the province annually.
“The objective of the study was really to raise awareness about the importance of occupational cancer, the size of the issue, and to promote prevention,” explained OCRC director Dr. Paul A. Demers, one of the report’s three authors. “We were funded for a large project by the Canadian Cancer Society to estimate the number of new cancers that are diagnosed each year that are caused by workplace carcinogens.”
The 60-page report stated that diesel-engine exhaust in workplaces causes an estimated 170 lung-cancer cases and 45 bladder-cancer cases in Ontario each year, while crystalline silica accounts for nearly 200 cases of occupational lung cancer.
“The report actually does identify a number of other carcinogens that cause cancers and other ones where we know there’s exposure and the number of cases may be uncertain,” added Dr. Demers. But sun, asbestos, diesel-engine exhaust and crystalline silica are the four “big hitters.”
About 450,000 Ontarians are exposed to solar radiation on the job, the study revealed, while approximately 301,000 workers in the province are exposed to diesel-engine exhaust and about 142,000 are exposed to crystalline silica. Among the diseases that asbestos exposure causes in Ontario are mesothelioma and lung, laryngeal and ovarian cancer.
The numbers did not surprise Dr. Demers and his colleagues, but he conceded that the statistics on sun exposure might startle people unfamiliar with previous research on it.
“Most people don’t realize how common skin cancer is, and we tend to attribute them in the healthcare community to just recreational sun exposure,” he said. “But in fact, there’s a large segment of the working population that really works outdoors almost all the time and has no choice but to be out there in the sun.
“The only way to protect them is, I think, a programmatic approach,” added Dr. Demers, “which would involve a number of different aspects, and really not the same approach you would necessarily use for recreational sun exposure.”
The report made several general policy recommendations to reduce occupational cancer cases in Ontario, including strengthening occupational exposure limits, establishing exposure registries and surveillance and reducing the use of toxic substances.
“This report does make recommendations that are broad and crosscutting, and sometimes, they’re fairly specific in terms of, for instance, sun exposure and the need to have more sun-protection programs,” said Dr. Demers.
“Here in Ontario, we have a Toxics Reduction Act, where we can proactively try to eliminate carcinogens in the workplace through changes in technology and substitution. So we have tools in place.”
Burden of Occupational Cancer in Ontario is available online at http://www.occupationalcancer.ca/wp-content/uploads/2017/09/Occupational-Risk-Factors-Report_2017.pdf.