Vol. 31, Issue 3, 306-311, March 2003

Identification of Trichloroethylene and Its Metabolites in Human Seminal Fluid of Workers Exposed to Trichloroethylene

Poh-Gek Forkert, Lawrence Lash, Robert Tardif, Nongnuj Tanphaichitr, Catherine Vandevoort, and Madeleine Moussa

Department of Anatomy and Cell Biology, Queen's University, Kingston, Ontario, Canada (P.G.F.); Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan (L.L.); Department of Environmental and Occupational Health, University of Montreal, Montreal, Quebec, Canada (R.T.); Hormones/Growth/Development Research Group, Ottawa Health Research Institute, Ottawa, Ontario, Canada (N.T.); California National Primate Research Center, University of California, Davis, California (C.V.); and Department of Pathology, London Health Sciences Centre, London, Ontario, Canada (M.M.)

We have investigated the potential of the male reproductive tract to accumulate trichloroethylene (TCE) and its metabolites, including chloral, trichloroethanol (TCOH), trichloroacetic acid (TCA), and dichloroacetic acid (DCA). Human seminal fluid and urine samples from eight mechanics diagnosed with clinical infertility and exposed to TCE occupationally were analyzed. In in vivo experimental studies, TCE and its metabolites were determined in epididymis and testis of mice exposed to TCE (1000 ppm) by inhalation for 1 to 4 weeks. In other studies, incubations of monkey epididymal microsomes were performed in the presence of TCE and NADPH. Our results showed that seminal fluid from all eight subjects contained TCE, chloral, and TCOH. DCA was present in samples from two subjects, and only one contained TCA. TCA and/or TCOH were also identified in urine samples from only two subjects. TCE, chloral, and TCOH were detected in murine epididymis after inhalation exposure with TCE for 1 to 4 weeks. Levels of TCE and chloral were similar throughout the entire exposure period. TCOH levels were similar at 1 and 2 weeks but increased significantly after 4 weeks of TCE exposure. Chloral was identified in microsomal incubations with TCE in monkey epididymis. CYP2E1, a P450 that metabolizes TCE, was localized in human and monkey epididymal epithelium and testicular Leydig cells. These results indicated that TCE is metabolized in the reproductive tract of the mouse and monkey. Furthermore, TCE and its metabolites accumulated in seminal fluid, and suggested associations between production of TCE metabolites, reproductive toxicity, and impaired fertility.