Gammarus fossarum as a sensitive tool to reveal residual toxicity of treated wastewater effluents.
Wastewater treatment plants (WWTPs) are one of the main sources of freshwater pollution eventually resulting in adverse effects in aquatic organisms. Treated effluents can contain many micropollutants at concentrations often below the limit of chemical quantification. On a regulatory basis, WWTP effluents have to be non-toxic to the aquatic environment, wherefore not only chemical abatement but also ecotoxicological evaluation through relevant bioassays is required. Standardized bioassays currently used are often not sensitive enough to reveal a residual toxicity in treated effluents. Therefore, attention must be paid to the development of better-adapted approaches implementing more sensitive organisms and relevant endpoints. In this study, the toxicity of two differently treated effluents (activated sludge treated effluents with and without ozonation) towards the ecologically relevant species Gammarus fossarum was evaluated. Organism fitness traits such as reproduction and sperm DNA integrity were followed in exposed organisms. In complement, enzymatic biomarkers were measured indicating the presence of neurotoxic compounds (acetylcholinesterase activity), the presence of pathogens likely to increase the toxic effects of chemical compounds (phenol-oxidase activity), and the presence of toxic compounds inducing detoxification mechanisms (glutathione-S-transferase activity). Enzymatic activities were not modified, but significant sub-lethal effects were observed in exposed organisms. In both effluents, females showed a retarded molt cycle, a reduced fecundity and fertility, and >90% of developed embryos exhibited developmental malformations. In addition, a slight but significant genotoxic effect was measured in gammarid sperm. In a whole, no difference in toxicity was found between both effluents. Coupling reproduction impairment and genotoxicity assessment in Gammarus fossarum seems to be a valuable and sensitive tool to reveal residual toxicity in effluents containing a mixture of micropollutants at very low concentrations. Finally, a direct relationship between the observed toxic responses and the quantified micropollutant concentrations could not be evidenced.
ENTPE, INRA, CNRS UMR 5023 LEHNA, rue Maurice Audin, 69518 Vaulx-en-Velin Cedex, France.
Adriana
A
Wigh
Irstea - Groupement de Lyon, Unité de recherche Milieux Aquatiques, Ecologie et Pollutions (MAEP), 5 rue de la Doua, 69626 Villeurbanne Cedex, France.
Olivier
O
Geffard
Irstea - Groupement de Lyon, Unité de recherche Milieux Aquatiques, Ecologie et Pollutions (MAEP), 5 rue de la Doua, 69626 Villeurbanne Cedex, France.
Khedidja
K
Abbaci
Irstea - Groupement de Lyon, Unité de recherche Milieux Aquatiques, Ecologie et Pollutions (MAEP), 5 rue de la Doua, 69626 Villeurbanne Cedex, France.
Adeline
A
Francois
Irstea - Groupement de Lyon, Unité de recherche Milieux Aquatiques, Ecologie et Pollutions (MAEP), 5 rue de la Doua, 69626 Villeurbanne Cedex, France.
Patrice
P
Noury
Université de Lyon, Institut des Sciences Analytiques, UMR5280 CNRS, Université Lyon 1, ENS-Lyon, 5 rue de la Doua, 69100 Villeurbanne, France.
Alexandre
A
Bergé
Université de Lyon, Institut des Sciences Analytiques, UMR5280 CNRS, Université Lyon 1, ENS-Lyon, 5 rue de la Doua, 69100 Villeurbanne, France.
Emmanuelle
E
Vulliet
SUEZ International - Treatment Infrastructure, Wastewater Technical Division, Degrémont, 183 avenue du 18 juin 1940, 92508 Rueil-Malmaison, France.
Bruno
B
Domenjoud
SUEZ International - Treatment Infrastructure, Wastewater Technical Division, Degrémont, 183 avenue du 18 juin 1940, 92508 Rueil-Malmaison, France.
Adriana
A
Gonzalez-Ospina
ENTPE, INRA, CNRS UMR 5023 LEHNA, rue Maurice Audin, 69518 Vaulx-en-Velin Cedex, France.
Sylvie
S
Bony
ENTPE, INRA, CNRS UMR 5023 LEHNA, rue Maurice Audin, 69518 Vaulx-en-Velin Cedex, France. Electronic address: alain.devaux@entpe.fr.
Alain
A
Devaux
D033304:Amphipoda; D000818:Animals; D054750:Ecotoxicology; D005260:Female; D008297:Male; D012722:Sewage; D018675:Toxicity Tests; D014865:Waste Disposal, Fluid; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D012722:Sewage; D062065:Wastewater; D014874:Water Pollutants, Chemical
Genotoxicity; Micropollutant; Ozonation; Reprotoxicity