title: Concentration and risk of pharmaceuticals in freshwater systems are related to the population density and the livestock units in Iberian Rivers.
abstract: Considerable amounts of pharmaceuticals are used in human and veterinary medicine, which are not efficiently removed during wastewater and slurries treatment and subsequently entering continuously into freshwater systems. The intrinsic biological activity of these non-regulated pollutants turns their presence in the aquatic environment into an ecological matter of concern. We present the first quantitative study relating the presence of pharmaceuticals and their predicted ecotoxicological effects with human population and livestock units. Four representative Iberian River basins (Spain) were studied: Llobregat, Ebro, Júcar and Guadalquivir. The levels of pharmaceuticals were determined in surface water and sediment samples collected from 77 locations along their stream networks. Predicted total toxic units to algae, Daphnia and fish were estimated for pharmaceuticals detected in surface waters. The use of chemometrics enabled the study of pharmaceuticals for: their spatial distribution along the rivers in two consecutive years; their potential ecotoxicological risk to aquatic organisms; and the relationships among their occurrence and predicted ecotoxicity with human population and animal farming pressure. The Llobregat and the Ebro River basins were characterized as the most polluted and at highest ecotoxicological risk, followed by Júcar and Guadalquivir. No significant acute risks of pharmaceuticals to aquatic organisms were observed. However potential chronic ecotoxicological effects on algae could be expected at two hot spots of pharmaceuticals pollution identified in the Llobregat and Ebro basins. Analgesics/antiinflammatories, antibiotics and diuretics were the most relevant therapeutic groups across the four river basins. Among them, hydrochlorothiazide and gemfibrozil, as well as azithromycin and ibuprofen were widely spread and concentrated pharmaceuticals in surface waters and sediments, respectively. Regarding their predicted ecotoxicity, sertraline, gemfibrozil and loratidine were identified as the more concerning compounds. Significantly positive relationships were found among levels of pharmaceuticals and toxic units and population density and livestock units in both surface water and sediment matrices.
authors.affiliation: Water and Soil Quality Research Group, IDAEA-CSIC, c/ JordiGirona, 18-26, 08034 Barcelona, Spain.
authors.forename: Victoria
authors.initials: V
authors.lastname: Osorio
authors.affiliation: Laboratory of Stream Ecology, Dept. of Plant Biology and Ecology, University of the Basque Country, UPV/EHU, PO Box 644, 48080 Bilbao, Spain.
authors.forename: Aitor
authors.initials: A
authors.lastname: Larrañaga
authors.affiliation: Water and Soil Quality Research Group, IDAEA-CSIC, c/ JordiGirona, 18-26, 08034 Barcelona, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Aceña
authors.affiliation: Water and Soil Quality Research Group, IDAEA-CSIC, c/ JordiGirona, 18-26, 08034 Barcelona, Spain. Electronic address: spsqam@idaea.csic.es.
authors.forename: Sandra
authors.initials: S
authors.lastname: Pérez
authors.affiliation: Water and Soil Quality Research Group, IDAEA-CSIC, c/ JordiGirona, 18-26, 08034 Barcelona, Spain; Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, Emili Grahit 101, 17003 Girona, Spain.
authors.forename: Damià
authors.initials: D
authors.lastname: Barceló
mesh_terms: D000818:Animals; D004784:Environmental Monitoring; D006801:Humans; D058751:Livestock; D004364:Pharmaceutical Preparations / Q000032:analysis*; D011156:Population Density; D018570:Risk Assessment; D045483:Rivers / Q000737:chemistry; D013030:Spain; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data*
chemical_list: D004364:Pharmaceutical Preparations; D014874:Water Pollutants, Chemical
keywords: Mediterranean rivers; Sediments; Spatial databases; Surface waters; Toxic units