Mortality patterns among cleaning workers.

Death records maintained from 1971 through 1980 by the All-Japan Laundry and Dry-cleaning Association (AJLDA) as part of a death benefits program were utilized in a proportional mortality study. 1,711 death certificates were classified according to the B List or the Eighth Revision of the ICD. Data on smoking and drinking habits and history of exposure were obtained by questionnaire from the families of AJLDA members who died from 1979 through 1981. Expected deaths were calculated for five-year age groups by applying the proportional mortality of Japanese males and females for 1975 or 1980 to the total number of deaths among cleaning workers. Expected deaths over a broader age range were calculated by summation. The statistical significance of the difference between observed and expected deaths was determined by a Mantel-Haenzel one degree of freedom summary chi square. The most significant finding was an excess of deaths from "other forms of heart disease" and "other diseases of the liver" among dry cleaning workers, regardless of personal habits, with a history of exposure to organic solvents.