Workers’ compensation provides benefits for workers who suffer not only work-related injuries but also illnesses. Some illnesses are designated as “occupational diseases” by the workers’ comp laws and automatically covered. But other types of illnesses are only considered an “occupational disease” when they arise out of and in the course of the worker’s employment. Here are two cases in which workers’ comp boards had to answer this question: Was the worker’s illness an occupational disease under the workers’ comp law?
BRLH = Occupational Disease
A worker began working in a pulp mill in 1991. He did maintenance and clean-up work, including draining lines, unplugging drains, unloading chemicals and blowing away woodchips and sawdust with an air hose. While working throughout various parts of the mill, he was exposed to numerous chemicals. The worker developed benign reactive lymphoid hyperplasia (BRLH), the non-cancerous enlargement of lymph tissues. He filed for workers’ comp benefits but the workers’ comp board denied his claim. So the worker appealed.
The BC Workers’ Compensation Appeals Tribunal ruled that the worker’s BRLH was an occupational disease.
The Tribunal noted that two specialists in occupational medicine had concluded that the worker’s employment likely exposed him to wood dust, chlorine, chlorine dioxide, hydrogen sulphide, methyl mercaptan and lime dust, which are known to irritate the skin and respiratory tract. The specialists also tied the worker’s development of BRLH to his exposure to chlorine dioxide, chlorine gas and wood dust at work. And there was no evidence to suggest another cause for the worker’s condition. Thus, the Tribunal concluded that the worker’s occupational exposure to these substances, at a minimum, was a “likely material cause of the worker’s BRLH.” As a result, the worker’s illness was an occupational disease covered by workers’ comp.
WCAT-2009-01388,  CanLII 36878 (BC W.C.A.T.), May 22, 2009
Small Fiber Polyneuropathy ≠ Occupational Disease
While employed as a mechanic for 30 years, a worker dealt with chemicals and organic solvents marked with danger symbols. He often cut his hands while working and then had to immerse his hands in degreasing solvents. The worker developed “small fiber polyneuropathy,” which affects nerve fibres near the skin’s surface that carry sensation. He filed a worker’s comp claim, which was denied. So he appealed.
The Alberta Workers’ Compensation Appeals Commission ruled that the worker’s small fiber polyneuropathy wasn’t an occupational disease.
The worker’s family physician believed that there was a connection between the worker’s illness and his exposure at work to organic solvents. However, the Commission noted that neither the occupational medicine consultant nor the neurologist who was treating the worker reported a relationship between his occupational exposure and illness. In addition, although there were studies indicating that exposure to organic solvents can lead to peripheral neuropathy, they referred to neuropathy mainly to the large fibres—not to the small fibres. Based on the weight of the evidence, particularly the medical evidence, the Commission concluded that the worker hadn’t shown, on a balance of probabilities, that his general work duties caused or contributed to his small fiber polyneuropathy. As a result, the worker’s illness wasn’t an occupational disease covered by workers’ comp.
Decision No. 2009-721,  CanLII 57364 (AB W.C.A.C.), Aug. 5, 2009