Chlorinated solvents in drinking water in Lombardy: the need for and consequences of a change in Italian regulations

The current Italian regulations on water intended for human use is derived from the 80/778 EEC Directive. For chlorinated solvents (parameter no. 32), the maximum allowed concentration (MAC) is 30 μg l -1 , which corresponds to the sum of the contaminants, but no limits have been established for any single compound. Chronic and acute toxicity greatly differs for chlorinated solvents (e.g. 1,2-dichloroethane vs perchloroethylene), and considering only the sum of individual concentrations results in an unsatisfactory evaluation of the potability of water. Individuals could be exposed to concentrations of single components exceeding the MAC established by the World Health Organization (WHO) or the current revision of the EEC Directive, under examination by the European Union (EU) Council. A close examination of the results of an analysis performed on more than 700 samples over seven years from wells in the Province of Varese highlights this issue and stresses the need for a rapid change of the Italian regulations. It is therefore desirable to take into account the toxicological potency of each individual compound rather than simply relying upon the sum of the concentrations of the contaminants.