Levels and trends of perfluoroalkyl acids (PFAAs) in water (2013–2020) and fish from selected riverine basins in Spain

The aim of the present study was to assess presence perfluoroalkyl acids (PFAAs), namely perfluoroalkane sulfonates and carboxylic acids, in Spanish river basins order to: identify potential spatiotemporal variations; evaluate effectiveness measures implemented for reduction/elimination these pollutants; verify fulfillment Environmental Quality Standards (EQSs) European Union. PFOS PFOA were determined 116 water samples from four sites Duero basin, largest Iberian Peninsula, collected seasonally 2013 2020. In addition, 30 fish sample composites banks Duero, Tagus, Ebro, Eastern Cantabrian Catalonian analyzed 15 PFAAs. Median concentrations 0.72 0.42 ng/L, ranging values below limit quantification (LOQ) 81 22 respectively. During studied period, 51% above EQS 0.65 ng/L PFOS. case fish, range <LOQ-59 with 33% 9.1 ng/g wet weight. Moreover, Tagus showed median EQS. Particularly, around highly populated areas such as Madrid Barcelona greatest PFAA concentrations. Overall, increased significantly population density suggesting urban their main source. Although our results suggested decreasing tendencies water, significant trends only could be confirmed at two sampling sites.