Highlights of Noteworthy Decisions

Decision 12 20
J. Smith
  • Leukemia (chronic lymphocytic)

The worker was employed between 1940 and 1980 in various departments with the accident employer, a manufacturer primarily of nuclear reactors fuel bundles, large hydro generators and electric motors.

In this appeal the worker's estate was seeking entitlement for chronic lymphocytic leukemia (CLL) resulting from occupational exposures.
The Vice-Chair based on evidence found that the worker's exposure to ionizing radiation was rare and at low levels and to trichloroethylene (TCE) was rare and at low to moderate levels. With regard to benzene exposure, the Vice-Chair accepted that the worker had rare exposure, that being 25% or less of the worker's usual job shifts when using petroleum solvents to clean metal parts.
In determining the causal link between these exposures and CLL, the Vice-Chair noted the International Agency for Research on Cancer (IARC) Monographs, updated in 2012 which commented that several cohort studies in the petroleum industry showed mixed results in respect of benzene exposure and CLL, with some non-significantly increased risks reported and other studies showing no association.
On the basis of the evidence as a whole, and particularly noting Board's ODPRB Memorandum, the opinion of the Board Medical Consultant and the IARC Monograph, the Vice-Chair found that it had not been established that benzene was a significant contributing factor in the development of CLL. Further, the evidence did not establish a causal connection between TCE or ionizing radiation at the low to modest exposure levels evident in this case and CLL.
The worker's estate submitted that the Board's policy regarding firefighter exposures presumed that the exposures contribute to the onset of AML, ALL and CLL. The estate therefore argued that, as was the case in Decision No. 2238/14, the worker should be given the same presumption and should not be discriminated against simply because he was not employed as a firefighter. The Vice-Chair found however that this case was distinguishable as in that case the worker developed CLL at a relatively young age, did not smoke, worked in the painting industry not electrical manufacturing, was found to be predisposed to cancer and thus the thin skull principle applied. Also in that case a medical assessor had provided an opinion that the Panel accepted in granting entitlement.
The worker's appeal was denied.