This study was designed to establish the relationship between airborne trichloroethylene concentrations and total trichloro-compounds and trichloroacetic acid in urine samples of the trichloroethylene exposed workers, to examine if the biological screening value for trichioroacetic acid in urine set by the Ministry of Labor is appropriate, and to suggest a suitable biological screening value for total trichloro-compounds in urine. Seventy male workers from the cleaning, the packing, and the inspection areas were selected as the study group and eighty male office workers were chosen as the control group.
The results were as follows:
1. The mean values of total trichloro-compounds and trichloroacetic acid in the exposed group (48.1±1.5 ㎎/ℓ, 19.7±1.9 ㎎/ℓ) were significantly higher than those in the control group(4.3±1.5㎎/ℓ, 1.8±1.2 ㎎/ℓ).
2. The airborne tichloroethyiene concentrations were significantly related with the concentrations of total trichloro-compounds in urine(r=0.8212) and the concentrations of triehloroacetic acid in urine(r=0.7216).
3. The average trichloroethylene concentrations in the manual cleaning plants and that in the automatic cleaning plants were 40.1 ppm and 7.7 ppm, respectively. The difference between two groups was statistically significant.
4. The geometric mean of 49.6 ppm trichloroethylene concentration was resulted in the 185.4 ㎎/ℓ total trichloro-compounds in urine, and the 50 ppm trichloroethylene concentration was expected to produce 170.4±28.5㎎/ℓ total trichloro-compounds in urine.
5. With the geometric mean of 49.6 ppm trichloroethylene concentration, the corresponding geometric mean concentration of trichloroacetic acid in urine was 74.7 ㎎/ℓ.
In conclusion, the level of personal exposure to trichloroethylene concentration was significantly correlated with the concentrations of total trichioro-compounds and trichloroacetic acid in urine. Current biological screening value of 75 ㎎/ℓ for trichloroacetic acid in urine set by the Ministry of Labor was thought to be appropriate, and a biological screening value for total trichloro-compounds in urine should be set in the range of 170.4±28.5 ㎎/ℓ as a reference value for trichoroethylene exposure.
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