Employees engaged in the tanning and finishing of leather are potentially exposed to numerous carcinogens. A previous mortality study among 9,352 workers from two chrome tanneries has been updated with the addition of 11 years of vital status and work history follow-up and 1,153 new deaths. Ninety-two different causes of death were analyzed using a modified life-table approach. Death rates from both the United States and the states in which the tanneries were located were used as the comparison populations in calculating cause-specific standardized mortality ratios (SMRs). The mortality risks from all causes and from all cancers were lower than the expected for the combined cohort. Analyzing the two tanneries separately, no a priori cause of death (i.e., cancer of the lung, pancreas, bladder, kidney, testes, nasal cavity, lymphoma, or soft-tissue sarcoma) was shown to be significantly elevated. An exception was lung cancer at one tannery when state death rates were used (SMR = 130, P < 0.01). Analyzing by duration of employment, no significant trend in any cause of death at either tannery was revealed. Some studies have shown elevated risks for various site-specific causes of cancer; however, sites in excess are not consistent between studies. The differences may have been due to distinct processes used by the tanneries resulting in varying levels, as well as different types, of exposures.
Frank B. Stern, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226