Systematic literature review of uses and levels of occupational exposure to tetrachloroethylene.

Tetrachloroethylene has been one of the most widely used chlorinated solvents in the United States. This review provides a basis for tetrachloroethylene exposure assessment in population-based case-control studies. We performed literature searches in MEDLINE, TOXLINE, NIOSHTIC, and the NIOSH Health Hazard Evaluation databases using relevant search terms. We calculated weighted arithmetic means from the measurement data and compiled these into three summary tables by type of operation: (1) dry cleaning, (2) degreasing, and (3) other operations. We identified 258 relevant documents, of which 179 (69%) contained useful descriptive information. Within the dry cleaning industry, the overall arithmetic mean (AM) for personal tetrachloroethylene exposures was 59 ppm (range: 0-4636, n = 1395). Machine operators who transferred wet garments to a dryer had the highest levels (AM = 150 ppm [range: 0-1000, n = 441]) of the jobs in this industry. The AM for personal measurements associated with degreasing was 95 ppm (range: 0-1800, n = 206). In addition, we identified several other sources of substantial tetrachloroethylene exposure, including cleaning mining equipment, testing coal, cleaning animal coats in taxidermy, and cleaning and duplicating film. Exposure assessment in population-based, case-control studies is a complex process requiring substantial resources. Researchers conducting these types of studies will be able to use results of the measurements to quantify tetrachloroethylene exposure levels for various jobs.