- Cancer (lung)
- Chronic obstructive lung disease
- Evidence (epidemiological)
- Exposure (asbestos)
- Exposure (silica dust)
- Smoking
- Procedure (reconsideration) (Tribunal initiative)
- Reconsideration (consideration of evidence)
The worker was employed for 27 years with a fibreglass manufacturer. He passed away at age 70 in 1992. In Decision No. 80/20, the Tribunal granted entitlement for chronic obstructive pulmonary disease (COPD) but denied entitlement for lung cancer. In January 30, 2024, the Tribunal Chair directed the Tribunal to reconsider Decision No. 80/20 on its own motion, based on significant new evidence.
The Vice-Chair found that the reconsideration threshold was met in this case. There was significant new evidence presented, in the nature of medical literature linking COPD to the development of lung cancer, as well as relevant material that was gathered and applied in Decision No. 2097/12R2, including information regarding the constitution of the plants in the Marsh study. On the merits, the appeal was allowed, in part. In addition to the allowance of COPD and survivors' benefits (as set out in Decision No. 80/20), the worker was granted entitlement for lung cancer, this based on the increased risk identified for COPD. Any health care benefits that may derive from this entitlement were remitted to the WSIB for determination. The worker did not have entitlement for lung cancer as a result of asbestos exposure. In considering the mixed evidence that was approximately equal in nature, the Vice-Chair applied the benefit of the doubt to find that the worker did have COPD. The worker's occupational exposures made a significant contribution to the development of his COPD and entitlement was in order. The OH assessment likely underestimated the duration of the worker's exposure to respirable dust. In applying the relevant calculations, approximately 35% of the worker's loss of lung function would have been attributable to his workplace exposures. Thus, entitlement was in order, even though it did not meet the 40 mg/m3-yr threshold set out in the COPD binder. It was noted that the COPD binder, including the threshold, is a guideline not a "bright line." Further, based on the new evidence, the Vice-Chair found that the worker's compensable COPD significantly contributed to the development of his lung cancer, a contribution that was not rendered insignificant by his smoking history.The OWA submitted the WSIB's current practice of accepting two years of asbestos exposure prior to 1975 should be accepted in this case. The Vice-Chair found that the worker was not an asbestos worker, the occupational hygienist's calculations were broadly correct, and they were not arrived at in a manner unfair to the worker. Lastly, the worker did not meet the threshold criteria as the worker's cumulative exposure of .47 mg/m3-yr was below the lowest end for a likely association. In considering the epidemiological evidence, the Vice-Chair found that the Marsh study, while it has some limitations, established no increased risk of lung cancer for their workers. This was also true of the Boffetta study. The Vice-Chair agreed that the Shannon study was not reliable for the purposes of establishing a general causal connection between fibreglass plant processes and lung cancer.