Deriving environmental quality standards for perfluorooctanoic acid (PFOA) and related short chain perfluorinated alkyl acids

The evidence that in Northern Italy significant sources of perfluoroalkylacids (PFAA)are present induced the Italian government to establish a Working Group on Environmental Quality Standard (EQS) for PFAA in order to include some of them in the list of national specific pollutants (Ministerial Decree 260/2010) for surface water monitoring and classification in the context of the Water Framework Directive (2000/60/EC) The substances have been chosen by considering the statistical distribution of concentrations and frequency of detection in the Italian surface and ground waters. The substances in the list included perfluorooctanoic acid (PFOA) and related short chain (number of carbon < 7) perfluorocarboxylic acids such as perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA) and perfluorohexanoic acid (PFHxA). Perfluorobutanesulphonic acid (PFBS), which is a common substitute of perfluorooctanesulphonic acid (PFOS), has been included too. For each of these substances a dossier has been prepared which collects available data on regulation, physico-chemical properties, emission and sources, occurrence, acute and chronic toxicity on aquatic species and mammals, including humans. Quality standards (QS) have been derived for the different protection objectives (pelagic and benthic communities, predators by secondary poisoning, human health via consumption of fishery products and water) according to the protocol recommended by the Technical Guidance Document on deriving EQS (CIS-WFD Guidance n. 27). The most protective QS has been chosen as the national EQS. For all compounds it is not possible to derive a QS for sediments because in some cases compounds do not accumulate in sediment and in other cases data on toxicity on benthic community are lacking. For PFBA, PFPeA, PFHxA and PFBS it is not possible also to back-calculate a QS for water from QS for biota because they have low bioaccumulation properties or data on bioconcentration factors (BCF) are lacking. For these compounds limits derived for the protection of human health by drinking water consumption are adopted as EQS. In the case of PFOA it is possible to derive a QS for biota both for the protection of predators and human via fish consumption and backcalculate QS for water. The calculation resulted in a QS for secondary poisoning of 0.1 ?g L-1 which has been proposed as EQS for PFOA in internal surface waters. SETAC