Kidney and liver biomarkers in female dry-cleaning workers exposed to perchloroethylene

Blood and urine perchloroethylene and urine trichloroacetic acid, as markers of exposure, and serum AST, ALT, GGT and creatinine, urine total solutes and proteins, angiotensin converting enzyme, N-acetyl-ß-D-glucosaminidase and glutamine synthetase, as markers of effect, were measured in 40 dry-cleaning and 45 ironing-shop female workers. Average perchloroethylene air level in the dry-cleaning shops was 59.7 mg/m3, i.e. three fold lower than the current A.C.G.I.H. TLV-TWA (170 mg/m3). No statistically significant difference in the mean values of any of the effect markers was observed between the two groups, except for AST which was significantly higher in dry-cleaners. In addition, a statistically significant correlation was observed in dry-cleaners between environmental perchloroethylene and total urinary solutes (r=0.308, p<0.05) or urine glutamine synthetase (r=0.469, p<0.01), between glutamine synthetase and blood perchloroethylene in post-shift (r=0.406, p<0.01) or urinary perchloroethylene in post- (r=0.571, p<0.001) or pre-shift (r=0.586, p<0.001), and between urinary perchloroethylene in pre-shift and GGT (r=0.407, p<0.05). Interestingly, some statistically significant correlations between exposure and effect indices were also found in ironing-shop workers alone and in all subjects. Finally, transaminases, GGT and total urinary proteins were influenced by age and alcohol consumption which were significantly higher in dry-cleaners, thus providing an explanation for some of the correlations observed. In conclusion, our results show a dose-related increase of glutamine synthetase activity, a marker of damage of the pars recta of the kidney proximal tubule, in the urine of female subjects exposed to perchloroethylene concentrations in the work environment lower than current A.C.G.I.H. TLV-TWA.