Occupational cancer: experience in Ontario

Area of Science:

• Occupational Health
• Epidemiology
• Toxicology

Background:

• The Workmen's Compensation Board of Ontario (WCB) manages worker compensation claims.
• Identifying occupational cancer is crucial for worker protection and compensation.
• Previous data on the prevalence of occupationally induced cancers is limited.

Purpose of the Study:

• To review the WCB of Ontario's experience in identifying occupationally related cancers.
• To determine the proportion of cancer cases attributable to occupational hazards.
• To analyze the types of cancers and associated carcinogens or industries.

Main Methods:

• Review of WCB case files and compensation claims.
• Analysis of cancer diagnoses and their correlation with occupational exposures.
• Comparison of occupationally caused cancer deaths with total cancer mortality in Ontario (1971-1975).

Main Results:

• Worker compensation claims are approved based on medical evidence linking cancer to occupational risk factors.
• Approximately 50% of identified occupational cancer cases were associated with specific, often temporary, industrial operations.
• Occupationally induced cancer deaths represented less than 1% of total cancer deaths in Ontario between 1971 and 1975.

Conclusions:

• The WCB has a system for identifying occupational cancer, though underidentification may occur.
• Specific industrial activities, even those of short duration, can be significant sources of occupational carcinogens.
• While occupational cancer is a serious concern, it constitutes a small fraction of overall cancer burden in the studied population.