Health surveillance of workers exposed to tetrachloroethylene in dry-cleaning shops.

Behavioral, renal, hepatic and pulmonary tests were applied to 22 subjects exposed to tetrachloroethylene in 6 dry-cleaning shops. The results were compared with those obtained in 33 subjects non-occupationally exposed to organic solvents. The intensity of exposure was monitored by personal environmental monitoring and by urine analysis for trichloroacetic acid and expired air and venous blood analysis for tetrachloroethylene. The time-weighted average exposure to tetrachloroethylene amounted to 21 ppm (range 9 to 38 ppm). The correlation between the concentration of tetrachloroethylene in ambient air sampled with the charcoal tube method and with a passive dosimeter indicates that the latter can correctly estimate the time-weighted average exposure to the solvent. In view of the long biological half-life of tetrachloroethylene, the internal dose may be better estimated by measuring its concentration in blood 16 h after the end of exposure (i.e. before resuming work the next morning). The present study suggests that if the blood concentration of tetrachloroethylene does not exceed 1 mg/l, 16 h after the end of exposure, the time-weighted average exposure is likely to have been below 50 ppm. Exposure to such level for 6 years on the average does not seem to exert any adverse effect on the central nervous system, the liver and the kidney.