- Fibrosis (pulmonary)
The issue to be decided in this appeal was whether the worker should have entitlement for interstitial lung disease (idiopathic pulmonary fibrosis - "IPF") claimed to be related to past exposures at work. The Tribunal had obtained a report from an independent health professional (assessor) pursuant to section 134 of the WSIA.The estate's appeal was denied. There was no dispute that the proper diagnosis of the worker's lung condition was IPF. In the Panel's view, there was insufficient evidence to conclude that workplace exposures made a significant contribution to the development of the worker's IPF. This determination took into account that the worker had entitlement to other work-related cancers. While the Board determined that there was sufficient evidence that the worker's workplace exposures were related to his lung and bladder cancers, that determination could not be used as a proxy for concluding that workplace exposures also played a role in the development of the worker's IPF. Workplace exposures contributing to the development of one disease does not necessarily mean that they contributed to another disease. In the Panel's view, each claimed occupational disease has its own pathogenesis and needs to be assessed in terms of specific workplace exposures and other factors that may have led to the development of that disease. There was also limited evidence to support that asbestos and silica played any identifiable role in the development of the worker's IPF. It was noted that exposure to asbestos and silica have "reasonably well-recognized clinical, radiographic, and pathologic patterns, of which none are present here". There was also no record of repeated exposure to the compounds of neurotoxic medications and hard metal dust (tungsten carbide and cobalt). In addition, the worker's non-occupational factors, including the worker's minimal smoking history and his GERD, were not considered significant in this case. It was noted that the term "idiopathic" in the IPF acronym means an unknown cause or origin. Although there was a possibility of a relationship between the worker's occupation and his IPF, this did not meet the requisite evidentiary standard for entitlement to be granted. Similarly, the Panel found that the evidence for and against the worker's claim was not approximately equal in weight, and, as such, he was not entitled to the statutory benefit of the doubt.