Impact of Trichloroethylene Exposure on Micronucleus Frequency as a Result of Industrial Exposure

Abstract

Trichloroethylene (TCE) is one of the important volatile organic compounds that have been used in industry throughout the world. It is a well-known rodent carcinogen and potent mutagen in humans. Workers occupationally exposed to TCE at variable concentrations are at risk of chromosomal damage. Micronucleus formation in human lymphocytes is widely used as a biomarker for monitoring genetic instability in humans. The purpose of this study was to assess the related risk via the micronucleus frequency through trichloroethylene (TCE) exposure in 64 occupationally exposed workers and 63 normal healthy individuals. The micronucleus frequency was counted in the smear of peripheral blood lymphocytes using the cytokinesis-block micronucleus (CBMN) test. Urinary trichloroacetic acid (TCA), a biological marker of TCE exposure, was subjected to gas chromatography-electron capture detection (GC-ECD) using the modified headspace technique. The effect of donor gender, age, alcohol consumption, smoking and duration of exposure on the micronucleus frequency was studied. Occupational exposure to TCE resulted in significantly increased levels of TCA in urine. The mean urinary TCA concentration of exposed workers was 16.10 ± 3.57 mg.L-1 compared to the control value of 6.21 ± 4.87 mg.L-1. The micronucleus frequency was significantly higher (P < 0.01) in TCE exposed workers (5.53 ± 0.71 per 1,000 cells) than those of controls (3.65 ± 0.34 per 1,000 cells). There was no correlation between the micronucleus frequency and gender, smoking or alcohol consumption in both exposed workers and controls. However, significant correlations were observed between micronucleus induction and the urinary TCA concentration, the duration of exposure and the age of workers. These results indicated that increased micronucleus frequency is associated with occupational trichloroethylene exposure.