Workers Health & Safety Centre

Supreme Court ruling may set new standard of evidence for occ disease claims

Supreme Court ruling may set new standard of evidence for occ disease claims
The Supreme Court of Canada has ruled in favour of three British Columbia medical workers seeking compensation benefits for breast cancer they believe resulted from work.
Katrina Hammer, Patricia Schmidt and Anne MacFarlane were initially denied compensation by the Workers’ Compensation Board of British Columbia (WCB of BC) after being diagnosed with the disease between 2002 and 2005. This decision was based on expert reports that did not find, on a scientific basis, a causative link between their work and the development of breast cancer.
The three women were among seven workers at a single hospital medical laboratory diagnosed with breast cancer.
According to Tonie Beharrell, lead counsel for Hammer and MacFarlane, an investigation of the lab failed to uncover a specific cause, but the cluster of cancers was roughly eight times the expected rate and workers were known to have worked with carcinogens. 
“The report didn’t say there was no workplace causation, it just said that they couldn’t determine a cause to a scientific certainty,” explained Beharrell.
The three women appealed to the British Columbia (BC) Workers’ Compensation Appeals Tribunal (WCAT). The majority of members of the Tribunal acknowledged the need for “positive evidence linking the disease to employment” but cited an earlier decision that offered the “ability to draw a common sense inference of causation in the absence of scientific proof of causation.” They sided with the applicants finding the workers’ breast cancers were occupational diseases and granted entitlement to compensation.
The BC Courts then struck down the WCAT decision citing the expert reports lacking scientific certainty of a causative link first considered by the WCB of BC. They found the Tribunal decision “patently unreasonable”.
Still seeking justice, the women sought to have the case heard by the Supreme Court of Canada. Some 15 years after their initial compensation application, the Supreme Court ruled 6-1 in favour of the women.
Justice Russell Brown of the Supreme Court, writing for the majority, said the Tribunal's finding was not patently unreasonable. "While the record on which that decision was based did not include confirmatory expert evidence, the Tribunal nonetheless relied upon other evidence which, viewed reasonably, was capable of supporting its finding of a causal link between the workers’ breast cancers and workplace conditions." In particular, he cited the evidence of past carcinogenic exposure and the “significant cluster” of breast cancer cases among the laboratory workers. This comprised positive evidence supporting a conclusion that it was as likely as not that the workers’ breast cancers were caused by workplace exposure.
Justice Brown explained the law sets a lower burden of proof in such cases and must favour the women.
Many believe this ruling may establish a new bar for the standard of evidence required to establish causation in occupational diseases cases.
“Hopefully workers who have been hesitant to argue causation will be encouraged to pursue their claims, knowing that they don’t actually need a medical opinion that says ‘your work caused your cancer,'” Beharrell said. “They can rely on a range of evidence to make those claims.”
Want to read the Supreme Court decision?
For our part, the Workers Health & Safety Centre assists workplace parties through training programs, including a new Globally Harmonized WHMIS training, and information services aimed at raising awareness about hazardous exposures and how to prevent them, including those which can contribute to work-related cancer.

To learn more:
Call:   1-888-869-7950 and ask to speak with a training services representative