Mortality among employees of an ontario factory that manufactured construction materials using chrysotile asbestos and coal tar pitch

This paper describes mortality in a cohort of 324 men exposed to chrysotile asbestos and coal tar pitch used in the manufacture of electrical conduit pipe from a mixture of newsprint, bentonite, and asbestos. One death in a factory worker was attributed to pleural mesothelioma, and long-term employees experienced an increased risk of lung cancer (Standardized Mortality Ratio (SMR) 221; six deaths) and non-malignant respiratory disease (SMR 215; four deaths). In a case-control analysis, men whose jobs involved adding asbestos to the mix of raw materials were found to have a risk of lung cancer sevenfold higher (lower 95% confidence limit: 2.3) than men who had never worked at this job. Exposure to coal tar pitch is presumed to be responsible for the death of one worker from squamous cell carcinoma of the scrotum.