title: Pharmaceuticals on a sewage impacted section of a Mediterranean River (Llobregat River, NE Spain) and their relationship with hydrological conditions.
abstract: BACKGROUND
  Mediterranean rivers are characterized by a high flow variability, which is strongly influenced by the seasonal rainfall. When water scarcity periods occur, water flow, and dilution capacity of the river is reduced, increasing the potential environmental risk of pollutants. On the other hand, floods contribute to remobilization of pollutants from sediments. Contamination levels in Mediterranean rivers are frequently higher than in other European river basins, including pollution by pharmaceutical residues. Little attention has been paid to the transport behavior of emerging contaminants in surface waters once they are discharged from WWTP into a river. In this context, this work aimed to relate presence and fate of emerging contaminants with hydrological conditions of a typical Mediterranean River (Llobregat, NE Spain).
  
  
  METHODS
  River fresh water samples were collected twice a week over a period of 5 weeks at three sampling points. Sixty-six pharmaceutical compounds belonging to different therapeutical classes were analyzed by LC-MS/MS.
  
  
  CONCLUSIONS
  Positive and negative correlations between the concentrations of the target analytes and hydrological variables like river flow and dissolved organic matter were observed pointing out the relevance of different hydrological phenomena like dilution effects or sediment re-suspension. Sensitivity calculations showed that the majority of compounds were sensitive to flow variations.
authors.affiliation: Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, Barcelona 08034, Spain.
authors.forename: Victoria
authors.initials: V
authors.lastname: Osorio
authors.forename: Sandra
authors.initials: S
authors.lastname: Pérez
authors.forename: Antoni
authors.initials: A
authors.lastname: Ginebreda
authors.forename: Damià
authors.initials: D
authors.lastname: Barceló
mesh_terms: D002853:Chromatography, Liquid; D004784:Environmental Monitoring; D009930:Organic Chemicals / Q000032:analysis; D004364:Pharmaceutical Preparations / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry; D013030:Spain; D053719:Tandem Mass Spectrometry; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D009930:Organic Chemicals; D004364:Pharmaceutical Preparations; D012722:Sewage; D014874:Water Pollutants, Chemical