The occurrence of eight organic UV filters (UV-Fs) was assessed in fish from four Iberian river basins. This group of compounds is extensively used in cosmetic products and other industrial goods to avoid the damaging effects of UV radiation, and has been found to be ubiquitous contaminants in the aquatic ecosystem. In particular, fish are considered by the scientific community to be the most feasible organism for contamination monitoring in aquatic ecosystems. Despite that, studies on the bioaccumulation of UV-F are scarce. In this study fish samples from four Iberian river basins under high anthropogenic pressure were analysed by liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Benzophenone-3 (BP3), ethylhexyl methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4MBC) and octocrylene (OC) were the predominant pollutants in the fish samples, with concentrations in the range of ng/g. dry. weight (d.w.). The results indicated that most polluted area corresponded to Guadalquivir River basin, where maximum concentrations were found for EHMC (241.7. ng/g. d.w.). Sediments from this river basin were also analysed. Lower values were observed in relation to fish for OC and EHMC, ranging from below the limits of detection to 23. ng/g. d.w. Accumulation levels of UV-F in the fish were used to calculate biota-sediment accumulation factors (BSAFs). These values were always below 1, in the range of 0.04-0.3, indicating that the target UV-Fs are excreted by fish only to some extent. The fact that the highest concentrations were determined in predators suggests that biomagnification of UV-F may take place along the freshwater food web

This work was funded by the Spanish Ministry of Economy and Competitiveness, through the project SCARCE (Consolider Ingenio 2010 CSD2009-00065). This study has also been financially supported by the EU through the FP7 project GLOBAQUA (Grant agreement No 603629), and by the Generalitat de Catalunya (Consolidated ResearchGroups “2014 SGR 418—Water and Soil Quality Unit” and 2014 SGR 291—ICRA)