Biological monitoring of exposure to perchloroethylene in dry cleaning workers.

Background: Perchloroethylene (PCE) is the most widely used solvent in dry cleaning. Objectives: The aim was to evaluate PCE pollution and to identify the most reliable biological indicators for the assessment of workers’ exposure. Methods: The study was performed in 40 dry cleaning shops covering a total of 71 subjects. Environmental monitoring was carried out with personal diffusive samplers (Radiello) for the entire work shift; biological monitoring was performed by measuring PCE in urine and blood and trichloroacetic acid (TCA) in urine on Thursday evening at end-of-shift and on Friday morning pre-shift. Results: The mean concentration of PCE in air was 52.32 mg/m3, about 30% of the TLV-TWA and the mean value of the PCE in pre-shift blood samples was 0.304 mg/l, slightly more than 50% of the BEI. In dry cleaning shops employing less than 3 persons PCE in air exceeded the TLV-TWA in 7.8% of cases; the size of the shops was inversely related to pollution. Statistically significant correlations were found between PCE exposure and PCE in blood end-of-shift (r=0.67) and pre-shift (r=0.70), and PCE in urine end-of-shift (r=0.68); no correlation was found between exposure and PCE in urine pre-shift and urinary TCA. Conclusions: Dry cleaning shops still register conditions of exposure and pollution by PCE, although to a lesser extent than in the past. The most reliable indicators for biological monitoring are PCE in end-of shift urine and PCE in blood both at end-of-shift and pre-shift at the end of the workweek.