Abstract: Purpose: To evaluate the cytogenetic effects of trichloroethylene(TCE) on the workers, and to determine the dose-response and time-response correlations among the exposure level and duration. Methods:TCE concentration in the work place and TCA in urine of the workers exposed to TCE were determined using gas chromatography and pyridine spectrophotometry, respectively. Conventional micronucleus(MN), cytokinesis-block micronucleus(CB-MN), sister-chromatid exchanges(SCE), and single cell gel electrophoresis (SCGE) from 141 workers exposed to TCE and 39 controls were carried out to determine chromosomal and DNA damage. Results: In the TCE-exposed group(the average concentration of TCE in work place was 90.4 mg / m 3, the average level of urine TCA of the workers exposed to TCE was 61.79 mg / L), the frequencies of MN, CB-MN, SCE and the percentage of lymphocytes with comet-like tail in peripheral blood lymphocytes(PBLs) were 1.66 ‰, 2.73 ‰, 4.33 and 7.48 ％, respectively, and were higher than those in the control groups(1.13 ‰, 1.66 ‰, 2.95 and 3.74 ％, respectively, P<0.05 or P<0.01). Except for SCE, there were positive correlations between the percentage of MN，CB-MN, the percentage of lymphocytes with comet-like tail in PBLs and the exposing time(r=0.222, 0.246, 0.320; P<0.05 or P<0.01). The positive correlations were also evidant between the percentage of MN，CB-MN, SCE and the percentage of lymphocytes with comet-like tail in PBLs and the the average level of urine TCA of the workers exposed to TCE (r=0.294, 0.260, 0.229, 0.268; P<0.05 or P<0.01). Conclusions: TCE is genotoxic, and long term exposure to the high dose of TCE may induce chromosome breakage and DAN damage.

Key words: Trichloroethylene, Genotoxic damage, Lymphocyte