ASBESTOS-ASSOCIATED CANCERS IN THE ONTARIO REFINERY AND PETROCHEMICALSECTOR

Asbestos has been widely used in the refinery and petrochemical sector . Mesothelioma has occurred among maintenance employees, and it was hy pothesized that mesothelioma is a marker for exposures which might inc rease lung cancer risk. A death certificate-based case-control study o f mesothelioma and lung cancer from 1980 to 1992 was conducted in an O ntario county with a substantial presence of these industries. Each of the 17 men who died of mesothelioma and 424 with lung cancer were mat ched with controls who died of other causes. The Job and Industry fiel ds on the death certificates were abstracted. Employment as a maintena nce worker in the refined and petrochemical sector was associated with an increased risk of mesothelioma (odds ratio: 24.5; 90% confidence i nterval 3.1-102). The risk of lung cancer among petrochemical workers, in comparison with ail other workers in the county, was 0.88. In an i nternal comparison of maintenance employees with other blue-collar wor kers in the refinery and petrochemical sector, the odds ratio for lung cancer was 1.73 (90% confidence interval 0.83-3.6). This finding is c onsistent with no difference in risk between maintenance and other emp loyees, but it is also compatible with study power being too low to ac hieve statistical significance. The hypothesis of increased lung cance r risk could be examined more fully with nested case-control studies i n existing cohorts. Meanwhile, it would be prudent to reinforce adhere nce to asbestos control measures in the refinery and petrochemical sec tor. (C) 1996 Wiley-Liss, Inc.