Lung cancer mortality of workers employed in chromate pigment factories. A multicentric European epidemiological study.

This study was designed in an attempt to quantify the mortality from cancer and other diseases among workers of European factories producing chromate pigments. The prevailing mixed exposures to zinc as well as lead chromate pigment--although the latter was produced predominantly over the whole period of time made it impossible to distinguish those persons exposed to lead chromate pigment. This report deals with cancer of the respiratory tract and lung cancer in particular. The total workforce of each factory included in the study was followed up, more successfully when they were employed before 1960 than after that time owing to the rising number of foreign nationals. Observed deaths from five factories were compared with expected deaths calculated on the basis of mortality figures for the region in which a given factory was located. Further analysis concerned data of relevant cohorts, which comprised only persons observed for a minimum of 10 years (i.e., exposure beginning before 1965), certainty of complete records for the entire staff to assure a complete cohort instead of prevailing healthy survivors, and exclusion of all foreign nationals. As a result, the overall mortality did not deviate from the expected rates. Lung-cancer rates were always in excess of expected numbers, although only in one cohort to a statistically significant extent. The pattern of duration of exposure indicates that the lung-cancer risk does not show a clear dose-response effect with time of employment. Due to the mixed nature of exposure, conclusions must be limited with the effect that the results obtained are consistent with the hypothesis that working in a chrome-processing plant environment is associated with an increased incidence of lung cancer and with a higher probability of dying from lung cancer compared with the general population.