Riverine discharge of perfluorinated carboxylates from the European continent.

The discharge of C6-C9 perfluorinated carboxylates (PFCAs) from major European rivers was studied and employed to assess European emissions of these compounds. Water samples were collected close to the mouths of 14 major rivers including the Rhine, Danube, Elbe, Oder, Seine, Loire, and Po. PFCA concentrations were determined using LC-MS/MS and used together with the mean annual water flow to estimate the riverine discharge of the PFCAs. The highest concentration measured was 200 ng/L for perfluorooctanoate (PFOA) in the Po River. The Po accounted for two-thirds of the total PFOA discharge of all the rivers studied, suggesting a major industrial source of PFOA in the Po watershed. All other nonremote rivers showed PFOA concentrations in the lower ng/L range, which indicates that widely distributed sources are also significant contributors to PFOA emissions in Europe. The total discharge of PFOA from the European rivers was estimated to be 14 tonnes/year, which is in reasonable agreement with reported emissions estimates. However, the total riverine discharge of perfluorohexanoate (PFHxA) of 2.8 tonnes/year estimated in this study was three times greater than the reported global emissions estimate, suggesting that there are significant, as yet unidentified sources of this compound.