[Exposure of Danish workers to trichloroethylene during the period 1947-1987]

Trichloroethylene, an organic solvent from the group of chlorinated hydrocarbons, has been employed throughout the greater part of this century particularly for degreasing of metals, dry cleaning and as a content in glue and lacquer. Biological monitoring of workers exposed to trichloroethylene as current health supervision has been employed in Danish factories since 1947 as the metabolite trichloroacetic acid in the urine provides an indication of the degree of exposure during the preceding week. In the present investigation, a review was undertaken of all measurements of trichloroacetic acid notified to the Danish Labour Inspection Service during the period 1947-1987 in order to obtain an impression of the historical development in the level of exposure. A total of 2,272 biological measurements distributed among 330 factories, reveal exposure of about the same level from the middle of the fifties to the middle of the seventies but with a distinct fall during the period, as the average value during the first five-year period was 82 mg/l as compared with 18 mg/l at the end of this 40-years period. These data are supplemented by case-histories from the earliest part of the period described by doctors from the Danish Labour Inspection Service.