MORTALITY STUDY OF EMPLOYEES WITH POTENTIAL EXPOSURE TO EPICHLOROHYDRIN - A 10-YEAR UPDATE

Objectives-A 10 year extension of follow up (up to 1993) of 863 employ ees who had potential exposure to epichlorohydrin at two chemical plan ts between May 1948 and December 1965 was conducted to further evaluat e the previously reported potential association between exposure to ep ichlorohydrin and heart disease.Methods-The mortality observed was com pared with that expected from the death rates from the local male popu lation where these chemical plants are located. Workers were assigned to one of five exposure categories based on their job with the highest level of potential exposure. Vital status was ascertained to the end of 1993. Results-Among diseases of particular interest, there were no excess deaths from disease (standardised mortality (SMR) 63.3), lung c ancer (SMR 63.8), or non-malignant respiratory disease (SMR 37.7) for employees with 20 or more years after first exposure. Based on the lev el of potential exposure to epichlorohydrin, mortality for heart disea se was slightly higher (SMR 75.7, 95% confidence interval (95% CI) 51. 8-106.7) in the moderate to heavy exposure group than in the none to l ight exposure group (SMR 59.5, 95% Cl 37.7-89.3); this difference is w ell within the range of random variation. The SMR for heart disease wa s 90.4 among employees who had both probable exposure to allyl chlorid e and moderate to heavy exposure to epichlorohydrin, although it was 8 8.1 among employees who had moderate to heavy potential exposure to ep ichlorohydrin but no exposure to allyl chloride. Conclusions-This stud y does not support an association between exposure to epichlorohydrin and heart disease or lung cancer. There were no additional deaths from leukaemia in this update; the raised SMR for leukaemia noted in the p revious study has substantially decreased from 500.0 to 161.3 (95% CI 33.2-471.0) and is not significant. The overall mortality and cancer m ortality of employees potentially exposed to epichlorohydrin continued to be lower than that of the local population.