Human environmental exposure to trichloro- and tetrachloroethylene from water and air in Milan, Italy

Annual consumption of trichloro- (TRI) and tetrachloroethylene (PER) in the Milan city area is estimated to be between 1,500 and 2,000 tons. Improper use and disposal of TRI and PER for many years have led to a serious pollution of groundwater, which is used untreated by 1,750,000 inhabitants through the municipal aqueduct. Two separate sub-areas of the city were considered, namely zone A (TRI and PER concentrations: 80 and 20 μg/L, respectively) and zone B (12 and 4 μg/L). Trento, a 70,000 inhabitants town of northern Italy, supplied with drinking water not contaminated with TRI and PER, was chosen as a control (zone C). Atmospheric levels of TRI and PER were also measured: TRI concentrations were similar in zones A and B (7.6 and 7.1 mg/m3), but higher levels of PER were found in zone A (14.8 vs 9.5 μg/m3), where many dry-cleaning laundries are located. In human subjects from the three zones, the total exposure to TRI and PER was biologically evaluated by measuring the plasmatic level of their metabolite trichloroacetic acid (TCA). Median plasmatic TCA levels were 38.2 μg/L in zone A, 19.0 in zone B and only 7.5 in the control zone. The observed differences were highly significant, and unrelated to sex, age, body weight, residence, and the amount of water consumption.