- Exposure (herbicide)
- Cancer (brain) (glioblastoma multiforme)
The issue under appeal was whether the worker's estate had entitlement for the worker's brain cancer. The ARO determined that there was insufficient evidence linking the worker's exposure to herbicides and electromagnetic fields (EMF), from 1960 to 1993.
The appeal was denied.Occupational diseases are adjudicated under the provisions of section 2(1), and section 15, as well as Schedules 3 and 4 of the WSIA. Section 15 provides for certain stipulated presumptions or deemed causation related to specific occupational diseases and specified processes that are set out in Schedules found in the WSIA and Board policy. Brain cancer due to herbicide and pesticide exposure is not listed in the relevant Schedules. Therefore, the worker's claim for entitlement for brain cancer due to exposure over time was subject to the same rules and principles where a worker claims a gradual onset injury (a disablement claim) under the definition of accident found in section 2(1) of the WSIA. The statutory presumption set out in section 13(2) does not apply to an injury by disablement.The issue to be decided therefore was whether the worker's brain cancer arose out of and in the course of his employment. The Panel found, on a balance of probabilities, that the worker's employment did not significantly contribute to his brain cancer. In the Panel's view, the epidemiological evidence did not support a causal relationship between exposure to herbicides/pesticides and electromagnetic fields, and brain cancer. It was noted that brain cancer is rare among cancers, and the causes and risk factors of brain tumours have been difficult to study. It was indicated that the only environmental factor unequivocally associated with an increased risk of brain tumours, including gliomas, is therapeutic x-rays (high doses of ionizing radiation). The worker's representative submitted that the Panel is not bound by strict legal precedent and that it is open to the Panel to adopt a "common sense" approach in deciding entitlement in this case. He submitted that the epidemiology respecting the occupational risk factors in this case is still evolving, with some studies awaiting confirmation of their conclusions which suggest a causal link to brain cancer. He submitted that given the remedial nature of the applicable legislation, and the uncontested evidence that the worker was exposed to hazardous chemicals in the workplace, a "common sense" approach ought to be adopted granting entitlement for the worker's cancer. In Decision No. 914/05, the Panel agreed that decision-makers should not wait for scientific certainty; however, the standards of proof of "the balance of probabilities" and the "benefit of the doubt" continued to apply. In this case, there was no basis upon which to grant the estate entitlement for the worker's cancer. The medical opinions had expressly concluded that the worker's cancer was not likely caused by his occupational exposures.