A cohort study of employees of a manufacturing plant using trichlorethylene

A prospective study was conducted of 2,646 employees who worked three months or more during the period January, 1957, through July, 1983, in a manufacturing plant that used trichlorethylene as a degreasing agent throughout the study period. Ninety-eight percent of the study cohort were traced; they accounted for 16,388 person-years of employment and 38,052 person-years of follow-up. Mortality experience was found to be generally more favorable than that of the comparable segment of the U.S. population over the same period of time. For the white male cohort there were fewer deaths than expected from heart disease, cancer, and trauma (standard mortality rate for all causes = 0.79, p less than .01). Reports by current and former employees of health problems requiring medical treatment showed that there were only one third as many persons with heart disease or hypertension as were reported in a comparable reference population studied over the past five years.