title: Triclosan--the forgotten priority substance?
abstract: BACKGROUND
  Triclosan (TCS) is a multi-purpose biocide. Its wide use in personal care products (PCPs) fosters its dispersal in the aquatic environment. Despite enhanced awareness of both scientists and the public in the last decade with regard to fate and effects, TCS received little attention regarding its prioritisation as a candidate river basin-specific pollutant or even priority substance, due to scarce monitoring data.
  
  
  METHODS
  Applying a new prioritisation methodology, the potential risk of TCS was assessed based on a refined hazard assessment and occurrences at 802 monitoring sites in the Elbe River basin.
  
  
  RESULTS
  The suggested acute-based predicted no-effect concentration (PNEC) of 4.7 ng/l for the standard test species Selenastrum capricornutum was in good agreement with effect concentrations in algal communities and was exceeded in the Elbe River basin at 75% of the sites (limit of quantification of 5 ng/l). The 95th percentile of the maximum environmental concentrations at each site exceeded the PNEC by a factor of 12, indicating potential hazards for algal communities. Among 500 potential river basin-specific pollutants which were recently prioritised, triclosan ranks on position 6 of the most problematic substances, based on the Elbe River data alone.
  
  
  CONCLUSIONS
  Considering the worldwide application of PCPs containing triclosan, we expect that the TCS problem is not restricted to the Elbe River basin, even if monitoring data from other river basins are scarce. Thus, we suggest to include TCS into routine monitoring programmes and to consider it as an important candidate for prioritisation at the European scale.
authors.affiliation: Department of Effect-Directed Analysis, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany. peter.vonderohe@ufz.de
authors.forename: Peter Carsten
authors.initials: PC
authors.lastname: von der Ohe
authors.forename: Mechthild
authors.initials: M
authors.lastname: Schmitt-Jansen
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Slobodnik
authors.forename: Werner
authors.initials: W
authors.lastname: Brack
mesh_terms: D000460:Chlorophyta / Q000187:drug effects* / Q000254:growth & development; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring; D018570:Risk Assessment; D045483:Rivers / Q000737:chemistry; D014260:Triclosan / Q000032:analysis* / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D014260:Triclosan