The Supreme Court of Canada ruled this month that breast cancer can be considered work-related under the country’s workers’ compensation law. The 7-1 ruling supported the case of three women who were employed as lab technicians at a hospital in British Columbia. Over a 20 year period, exposures in their work environment included solvents known to be carcinogenic and emissions from incinerated medical waste. Four other workers in the hospital lab also develop breast cancer.

The women filed claims for workers’ compensation arguing that their exposure to carcinogens on-the-job was a factor in causing their aggressive breast cancer. The province’s workers’ comp agency disagreed. It demanded scientific certainty that the exposure(s) led to the disease. The case moved up the judicial ladder ultimately to Canada’s highest court.

The court’s opinion, issued on June 24, notes:

 “Workers covered by workers’ compensation do not need to establish causation on a balance of probabilities, as would be required in a civil court. The workplace need only be of causative significance or more than a trivial or insignificant aspect in the development of the a worker’s illness.”

A (unnamed) reporter with The Canada Press writes:

“[The Supreme Court’s] reasoning looks back to the foundation of the workers’ compensation system, which was set up as a ‘historic compromise’ that sees workers giving up the right to sue their employers over workplace injuries in exchange for no-fault compensation.  …If the evidence is evenly weighed but not conclusive, the issue is supposed to be resolved in favour of the workers.”

In 2013, the Interagency Breast Cancer and Environmental Research Coordinating Committee (IBCERCC) issued a report urging greater spending by government agencies and researchers on cancer prevention. The IBCERCC, housed at the NIH, called for more attention and resources directed at the environmental factors that cause breast cancer. Their message:

“identifying and mitigating the environmental causes of breast cancer is the key to reducing the number of new cases.”

Canadian researchers, including several at the University of Windsor, have been investigating the relationship between breast cancer and endocrine-disrupting chemicals, such as those in plastics. Jim Brophy and Margaret Keith were lead authors on a case-control study of 2,100 women in Windsor and Essex, Ontario. Women who had been employed in manufacturing of plastic automobile parts had more than a two-and-one-half times excess risk of developing breast cancer.

The American Public Health Association (APHA) adopted a policy statement in 2014 on the relationship between breast cancer and occupation. Among its recommendations, APHA calls on:

• The U.S. Surgeon General to declare that there is an association between known classes of chemicals and breast cancer, and that women working with these chemicals are particularly at risk; and
• HHS, National Cancer Institute, NIH, and other relevant federal agencies to alter the balance of breast cancer research funds to focus more on the etiologic and mechanistic pathways of suspect chemicals and breast cancer.

Congratulations to Kristina Hammer, Patricia Schmidt and Anne MacFarlane who were the claimants in the workers’ comp case. They’d filed their cases with the British Columbia’s workers’ comp tribunal in 2010 and 2011.