A map of European emissions and concentrations of PFOS and PFOA.

A spatially distributed data set of measured concentrations of perfluorooctansulfonate (PFOS) and perfluorooctanoate (PFOA) was used, together with climatological averages of river flow, to estimate their overall aqueous emissions from the European Continent. This estimate relies on the assumption that PFOA/S are conservative chemicals. PFOS correlates rather well with river basin population, and its emissions can be estimated by regression for nonmonitored catchments. As such, regression equations were derived in both linear and log-linear form, the latter explaining a much higher portion of variance. Unlike PFOS, PFOA discharges are strongly influenced by point emissions from industrial facilities; they only correlate with catchment population below a threshold of 0.5 tons per year, and point source industrial emissions cannot be neglected in the estimation of PFOA loads. The lumped loads of PFOA from diffuse and point sources are reasonably described by a single log-linear regression model as a function of population in the catchment, likely owing to the fact that fluoropolymer industries located in highly populated catchments are more frequent as well. Overall, by using the log-linear models derived in this paper, PFOS and PFOA discharges along the whole European river network to coastal areas in Europe have been estimated for the year 2007 to be in the order of 20 and 30 tons per year, respectively.