title: Triclosan persistence through wastewater treatment plants and its potential toxic effects on river biofilms.
abstract: Triclosan is a commonly used bactericide that survives several degradation steps in WWTP (wastewater treatment plants) and potentially reaches fluvial ecosystems. In Mediterranean areas, where water scarcity results in low dilution capacity, the potential environmental risk of triclosan is high. A set of experimental channels was used to examine the short-term effects of triclosan (from 0.05 to 500μgL⁻¹) on biofilm algae and bacteria. Environmentally relevant concentrations of triclosan caused an increase of bacterial mortality with a no effect concentration (NEC) of 0.21μgL⁻¹. Dead bacteria accounted for up to 85% of the total bacterial population at the highest concentration tested. The toxicity of triclosan was higher for bacteria than algae. Photosynthetic efficiency was inhibited with increasing triclosan concentrations (NEC=0.42μgL⁻¹), and non-photochemical quenching mechanisms decreased. Diatom cell viability was also affected with increasing concentrations of triclosan. Algal toxicity may be a result of indirect effects on the biofilm toxicity, but the clear and progressive reduction observed in all the algal-related endpoints suggest the existence of direct effects of the bactericide. The toxicity detected on the co-occurring non-target components of the biofilm community, the capacity of triclosan to survive through WWTP processes and the low dilution capacity that characterizes Mediterranean systems extend the relevance of triclosan toxicity beyond bacteria in aquatic habitats.
authors.affiliation: Catalan Institute for Water Research, University of Girona, Spain. mricart@icra.cat
authors.forename: Marta
authors.initials: M
authors.lastname: Ricart
authors.forename: Helena
authors.initials: H
authors.lastname: Guasch
authors.forename: Mireia
authors.initials: M
authors.lastname: Alberch
authors.forename: Damià
authors.initials: D
authors.lastname: Barceló
authors.forename: Chloé
authors.initials: C
authors.lastname: Bonnineau
authors.forename: Anita
authors.initials: A
authors.lastname: Geiszinger
authors.forename: Marinel la
authors.initials: Ml
authors.lastname: Farré
authors.forename: Josep
authors.initials: J
authors.lastname: Ferrer
authors.forename: Francesco
authors.initials: F
authors.lastname: Ricciardi
authors.forename: Anna M
authors.initials: AM
authors.lastname: Romaní
authors.forename: Soizic
authors.initials: S
authors.lastname: Morin
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Proia
authors.forename: Lluís
authors.initials: L
authors.lastname: Sala
authors.forename: David
authors.initials: D
authors.lastname: Sureda
authors.forename: Sergi
authors.initials: S
authors.lastname: Sabater
mesh_terms: D000891:Anti-Infective Agents, Local / Q000633:toxicity*; D001419:Bacteria / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects*; D017377:Diatoms / Q000187:drug effects; D045483:Rivers / Q000737:chemistry / Q000382:microbiology; D014260:Triclosan / Q000633:toxicity*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000891:Anti-Infective Agents, Local; D014874:Water Pollutants, Chemical; D014260:Triclosan