Mixture toxicity of pharmaceuticals present in wastewater to aquatic organisms

Abstract

ABSTRACT The aim of this study is the assessment of the impact of mixture of three pharmaceutical substances (ciprofloxacin, 17α-ethinylestradiol and 5-fluorouracil) on aquatic animals, cyanobacteria and plants. Based on previous work and literature data, three concentrations of each substance were used to prepare mixtures: predicted or measured environmental concentrations (PEC/MEC), predicted no effect concentrations (PNEC), concentrations that induced a response of 10% in bioindicators (EC 10 ). Immobilization tests with crustaceans (Daphnia magna and Artemia salina), growth tests with cyanobacteria (Cyanosarcina sp.), algae (Desmodesmus quadricauda, Raphidocelis subcapitata) and plants (Lemna minor), enzymatic test Fluotox and reproduction test with D. magna were performed. The results of this work confirm the importance of low concentration mixture exposure. Effect in PEC/MEC concentrations of the mixture of tested compounds was equal 15% in R. subcapitata growth test. As expected, effects obtained for mixtures of pharmaceuticals in their EC 10 concentrations were frequently higher than 10%. The obtained results were compared with the concept of independent action, which either underestimated or overestimated the effects in concentrations used. The results obtained in this study suggest that the exposure to tested mixtures of pharmaceuticals even in low concentrations of components, that individually cause no harm to organisms, may trigger adverse effects in aquatic environment.