An Epidemiological Study of Exposure to Coal Tar Pitch Volatiles Among Coke Oven Workers

Abstract

Recent studies of mortality among coke plant workers indicate that there is an excess of respiratory cancer among men employed at the coke ovens and that the mortality is related to work areas and length of exposure to coal tar effluents, the body of information presented in this paper is directed to categorization of coke oven jobs into different work areas in terms of exposure to coal tar pitch volatiles developing an index of cumulative exposure to investigate the dose-response relationship between exposure and mortality. The exposure data have been taken from a study conducted by the Pennsylvania Department of Health, State Division of Occupational Health, and mortality data are based on a long-term study of steelworkers, conducted by the Department of Biostatistics, University of Pittsburgh. A summary index calculated for each worker combining the level of exposure and length of time exposed indicates that, as expected, both these factors are related to the development of cancer, particularly cancers of the respiratory system. Conclusions of note are: Measured levels of coal tar pitch volatiles are 2-3 times higher for men who work at the top of coke ovens as compared to men employed at the side of the ovens. Even though the specific carcinogenic element or elements in the coke oven environment are not known at the present time, in-. creasing levels of exposure to coal tar pitch volatiles are related to art increased risk of dying from malignant neoplasms. Further coal tar pitch volatile measurements need to be made and analyses designed which will specify the dose-response relationship more precisely. This will provide information necessary to evaluate the recommended Threshold Limit Value.