Abstract

OBJECTIVES: A previous study reported a fivefold increase in mortality from pancreatic cancer and a threefold increase in lymphopoietic and haematopoietic cancer among 278 men who were assigned to a now dismantled Union Carbide chlorohydrin unit in the Kanawha Valley of West Virginia. There were also significant trends with duration of employment. The purpose of this study was to determine whether a comparable increased risk in mortality from pancreatic cancer and lymphopoietic and haematopoietic cancer occurred among male employees assigned to the Dow Chemical Company's ethylene and propylene chlorohydrin production processes. METHODS: The cohort consisted of 1361 male employees who worked at the company's Freeport, Texas, Plaquemine, Louisiana or Midland, Michigan plants. Subjects were considered to have had a minimum of 30 days of workplace experience in 1940-92, in the ethylene chlorohydrin and propylene chlorohydrin process areas. These process areas were located within the ethylene oxide and propylene oxide production plants. A total of 300 deaths was observed to 31 December 1992. RESULTS: The standardised mortality ratio (SMR) for all malignant neoplasms was 94 (95% CI 74 to 118). There was one pancreatic cancer death compared with 4.0 expected (SMR 25, 95% CI 1 to 140). There were 10 lymphopoietic and haematopoietic cancer deaths compared with 7.7 expected (SMR 129, 95% CI 62 to 238). Additional analyses, which examined location, production process, duration of employment, and a 25 year induction latency period, were not significant. CONCLUSIONS: The results provide some assurance that the Dow Chemical cohort, to date, has not experienced increased risks of pancreatic cancer and lymphopoietic and haematopoietic cancer as previously reported in a different cohort of chlorohydrin workers. Possible reasons are discussed for the inconsistent findings between the two cohorts.