Understanding the WSIB's Updated Policy on Gastrointestinal (GI) Cancer-Asbestos Exposure

  • 18 octobre 2024
  • Michael Edmonds, associate counsel to the chair, Workplace Safety and Insurance Appeals Tribunal

The Workplace Safety and Insurance Board (WSIB) has released a preview copy of its updated Gastrointestinal (GI) Cancer-Asbestos Exposure Policy (OPM Document No. 16-02-11). The updated policy takes effect on October 1, 2024 and will apply to all decisions made on or after October 1, 2024.

The policy will also have retroactive application to previously decided decisions in the following circumstances:

  • Initial entitlement was previously denied in the claim,
  • The date of the decision falls on or after April 19, 2021 and before October 1, 2024, and
  • The denial decision was made by either a front-line decision-maker of the WSIB or an Appeals Resolution Officer (ARO), provided a notice of appeal of the final decision has not been filed with the Workplace Safety and Insurance Appeals Tribunal (WSIAT).

Summary Note

The updated policy sets out three criteria for entitlement for GI cancers related to workplace asbestos exposure. The updated policy also provides general pre-1987 asbestos exposure data for a number of occupations. This exposure data may help streamline GI cancer entitlement – particularly for workers who had five or more years of pre-1987 work in one of the listed occupations.

Current Policy

Under the pre-October 2024 policy, claims for entitlement for GI cancers arising from work-related exposure to asbestos are favourably considered if:

  • There is a clear and adequate history of occupational exposure to asbestos dust, and while such occupational exposure cannot be quantitatively described, it should be of a continuous and repetitive nature, and should represent or be a manifestation of the major component of the occupational activity, AND
  • There is a minimum interval of 20 years between the first exposure to asbestos and the diagnosis of gastro-intestinal cancer.

Entitlement

The updated policy sets out three entitlement criteria.

  • First, the worker must have a diagnosis of a GI cancer.
  • Second, the worker must have substantial occupational exposure to asbestos. This requirement replaces the “clear and adequate history of occupational exposure” that must be “continuous and repetitive” and a “major component of the occupational activity.” The updated policy provides a series of tables setting out work activities and job roles with levels of asbestos exposure and duration needed to reach the “substantial occupational exposure to asbestos” requirement. This defined level of “substantial” exposure and the tables should provide a more useful framework to ensure quicker adjudication where a worker clearly falls within the exposure requirements.
  • Third, the latency period for the GI cancer diagnosis must be “biologically plausible” with the date of the worker’s first occupational exposure. This replaces the more rigid minimum interval of 20 years set out in the current policy.

Diagnosis of a GI Cancer

The updated policy states that a diagnosis is required and can come from a qualified regulated health professional based on supporting evidence such as a diagnostic test, or the diagnosis can be shown through a medical certificate of death which identifies GI cancer as a cause or contributing factor in the worker’s death.

Substantial Occupational Exposure to Asbestos

The updated policy notes that substantial exposure combined with a biologically plausible latency period will give rise to work being considered a significant contributing factor “unless it is determined that the worker had such significant non-occupational risk factors that they overwhelmed any occupational exposure to asbestos, rendering it insignificant in the development of their GI cancer.” Of note, the updated policy does not state or provide examples of what types of “risk factors” could render insignificant the workplace exposure where the exposure was substantial and the cancer arose following a biologically plausible latency period.

The updated policy identifies the cumulative measure of 25 fibre/mL-years (number of fibres found in each millimetre of air, in the air which a worker breathes at work and multiplied by the number of years worked at that level) as the threshold for substantial occupational exposure. The policy clarifies that this is the threshold used for asbestos-related lung cancer and is being used for GI cancers as a “reasonable proxy” because a quantitative exposure-response relationship for asbestos and GI cancer has not been established.   

Because specific data around asbestos exposure can be difficult to find, particularly with historical cases, the updated policy contains tables to help streamline adjudication. The tables are based on a review of quantitative exposure data for workers in manufacturing, construction, trades, and other occupations before 1987.

Note: The updated policy tables are only relevant for work prior to 1987. The policy notes that after 1986, legislative changes in Ontario meant the overall asbestos exposures for workers in Ontario significantly declined.

The updated policy also notes that occupations outside those listed in the tables must be assessed based on their individual facts, which may include an occupational hygiene review of the worker’s employment and exposure history. The updated policy also lists several occupations not listed in the tables that may, nonetheless, indicate substantial occupational exposure to asbestos. These include pre-1975 employment in shipyards, pre-1987 dockyard or longshoreman work, and several other occupations.

Biologically Plausible Latency Period

The updated policy points out that latency period may vary depending on several factors including the intensity, duration, and frequency of occupational exposures. The updated policy notes that if the diagnosis of a GI cancer falls within the biologically plausible range from the worker’s asbestos exposure, the worker’s substantial exposure to asbestos will be considered to have significantly contributed to the GI cancer. The policy, however, does not define what a “biologically plausible range” of latency is for specific GI cancers.

Any article or other information or content expressed or made available in this Section is that of the respective author(s) and not of the OBA.