Kinetics of trichloroethylene in repeated exposure of volunteers

Abstract

Five male volunteers inhaled 70 ppm trichloroethylene (TRI) for 4 h on 5 consecutive days. TRI, trichloroethanol (TCE) and trichloroacetic acid (TCA) were measured, as far as present in exhaled air, blood, and urine. The uptake was 6.6 ± 0.4 mg/kg lean body mass in 4 h. The concentration of TRI in blood and exhaled air at 18 h after the 5th exposure was twice as high as at 18 h after the 1st exposure. The amount of TCE excreted per 24 h reached a level during the last exposure days, a diurnal rythm was evident. TCA in blood and urine increased during exposure days. Total recovery of the amount absorbed of TRI was 78%, 11% as TRI excreted unchanged by the lung, 43% as WE and 24% as TCA excreted in urine. Amounts of WE and TCE+TCA excreted in urine were related to lean body mass. Because of its small interindividual variation TCA in blood seems to be the most promising parameter for biological monitoring in repeated exposure.