[Mortality among the dye industry workers. II. An analysis of malignant neoplasm mortality]

A mortality study was carried out among workers employed in a plant producing different kinds of dyes, including benzidine. The cohort comprised 8,523 males and 2,006 females whose vital status was recorded between Jan 1, 1945 and Dec. 31, 1991. They had worked in this plant for, at least, 3 months between Jan. 1, 1945 and Dec 31, 1974. The cohort was divided into 4 subcohorts: I. those exposed only to benzidine: II. those exposed to benzidine and other occupational hazards; III. those involved directly in the dye production but not exposed to benzidine, and IV. those not involved directly in the dye production-mainly administrative staff. Death risk was estimated on the basis of standardized mortality ratio (SMR) determined by means of the person-years method. The general population of Poland was taken as a reference group. The observed number of deaths in the cohort and each subcohort was compared with expected deaths. The comparison was based on national rates by adjustment for age, gender and calendar time. Significant excessive mortality due to cancer of urinary bladder was observed in the male subcohort I (SMR = 14.69), II (SMR = 16.34) and III (SMR = 3.17); due to malignant neoplasm of pancreas in the male subcohort II (SMR = 3.26); due to malignant neoplasm of testis in the male subcohort III (SMR = 3.17); due to malignant neoplasm of pancreas in the male subcohort II (SMR = 3.26); due to malignant neoplasm of testis in the male subcohort III (SMR = 3.23). Significant excessive mortality due to malignant neoplasm of liver and intrahepatic bile ducts was found in the female subcohort IV (SMR = = 2.36).