title: The influence of salinity on the toxicity of selected sulfonamides and trimethoprim towards the green algae Chlorella vulgaris.
abstract: This paper presents the investigation of the influence of salinity variations on the toxicity of sulfapyridine, sulfamethoxazole, sulfadimethoxine and trimethoprim towards the green algae Chlorella vulgaris after exposure times of 48 and 72 h. In freshwater the EC50 values ranged from 0.98 to 123.22 mg L(-1) depending on the compound. The obtained results revealed that sulfamethoxazole and sulfapyridine were the most toxic, while trimethoprim was the least toxic pharmaceutical to the selected organism. Deviations between the nominal and real test concentrations were determined via instrumental analysis to support the interpretation of ecotoxicological data. The toxicity effects were also tested in saline water (3, 6 and 9 PSU). The tendency that the toxicity of selected pharmaceuticals decreases with increasing salinity was observed. Higher salinity implies an elevated concentration of inorganic monovalent cations that are capable of binding with countercharges available on algal surfaces (hydroxyl functional groups). Hence it can reduce the permeability of pharmaceuticals through the algal cell walls, which could be the probable reason for the observed effect. Moreover, for the classification of the mode of toxic action, the toxic ratio concept was applied, which indicated that the effects of the investigated drugs towards algae are caused by the specific mode of toxic action.
authors.affiliation: Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Borecka
authors.affiliation: Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland. Electronic address: a.bialk-bielinska@ug.edu.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Białk-Bielińska
authors.affiliation: Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Łukasz P
authors.initials: ŁP
authors.lastname: Haliński
authors.affiliation: Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55, 81-712 Sopot, Poland.
authors.forename: Ksenia
authors.initials: K
authors.lastname: Pazdro
authors.affiliation: Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Stepnowski
authors.affiliation: Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland; Center for Environmental Research and Sustainable Technology, University of Bremen, LeobenerStraße, D-28359 Bremen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Stolte
mesh_terms: D048408:Chlorella vulgaris / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D012098:Reproduction / Q000187:drug effects; D054712:Salinity; D013449:Sulfonamides / Q000633:toxicity*; D014295:Trimethoprim / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D013449:Sulfonamides; D014874:Water Pollutants, Chemical; D014295:Trimethoprim
keywords: Chlorella vulgaris; Ecotoxicity; Pharmaceuticals; Salinity