Sources of perfluoroalkyl substances in the Italian drinking and surface waters

A survey of the distribution of perfluorinated carboxylates (from C 4 to C 10 ) and perfluorinated sulphonates (from C 4 to C 8 ) in the main Italian river basins have been carried out. Concentrations of selected PFAS higher than 1 ?g/L were measured in three Italian rivers (Tanaro, Bormida and Brenta rivers). Maximum PFOA concentrations of 1.9 and 6.5 ?g/L were measured respectively in Tanaro and in its tributary Bormida which receives the discharge of a fluoropolymer plant. Brenta river showed the highest measured concentration for PFBS (1.4 ?g/L), together with significant concentrations of PFOA (292 ng/L), PFPeA and PFHxA (both about 200 ng/L). Sources of PFAS in Brenta river are both textile and tannery districts as well as a factory which produces fluorochemical intermediates. Substances which were present in concentrations > 100 ng/L in the other Italian surface waters were PFBA (in Adda and its tributary Serio rivers), PFPeA (in Adda, Arno, Serio rivers), PFHxA (in Adda, and Serio rivers) and PFOS (in Serio river). From these data two further hot spots for shorter chain PFCAs were identifies which were the Arno river, where important textile and tannery districts are present, and Adda river with its tributary Serio. In the latter case it was more difficult to individuate the source of these compounds because the basin is not characterised by specific manufacturing activities. Two other important Italian rivers, Tevere and Adige, were not impacted by PFAS, also downstream to important urban WWTPs. Finally, the concentrations at the basin closure of the river Po, the major Italian river, were 10 times lower (25 ng/L) than those measured in previous campaigns on Po, suggesting a possible decrease in PFOA use. Concentrations of drinking waters in central Italy (from Tevere and Arno river basins) were all under the detection limits, while the detection frequency of PFAS in drinking waters from Northern Italy, the most urbanised and industrialised area of the country, was higher. The highest concentrations were measured for PFOA (up to 1.9 ?g/L) in drinking water produced from groundwater which are impacted by discharges from two big textile and tannery districts to which is added a factory which produces fluorochemical intermediates. High concentrations of PFOS (up to 150 ng/L) were also measured in drinking water produced from groundwater in an area with a diffuse and historical pollution coming from agricultural pressure.