Journal of Hazardous Materials 263P (2013) 256–265 Contents lists available at ScienceDirect Journal of Hazardous Materials j o ur nal homep age: www.elsevier.com/locate/jhazmat Is Atyaephyra desmarestii a useful candidate for lethal and sub-lethal toxicity tests on pharmaceutical compounds? Elena Nieto ∗ , Julián Blasco, Enrique González-Ortegón, Pilar Drake, Miriam Hampel Instituto de Ciencias Marinas de Andalucía (ICMAN-CSIC), Campus Universitario Rio San Pedro, 11510 Puerto Real, Spain h i g h l i g h t s • The toxicity of three pharmaceutical compounds has been assessed. • Diclofenac is the most toxic com- pound followed by Ibuprofen and Carbamazepine. • Mixture toxicity models Concen- tration Addition and Independent Action were applied. • Ingestion and respiration rates and osmoregulatory capacity were evalu- ated. g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 20 May 2013 Received in revised form 13 August 2013 Accepted 14 August 2013 Available online 29 August 2013 Keywords: Atyaephyra desmarestii Pharmaceuticals Mixture toxicity Risk assessment Sublethal responses a b s t r a c t Single and mixture toxicity tests on three pharmaceutical compounds, Diclofenac (DF), Ibuprofen (IB) and Carbamazepine (CBZ), were carried out with the freshwater shrimp Atyaephyra desmarestii. Lethal and sublethal responses were analyzed for single compounds. Lethal concentrations (LC 50 ) obtained for each individual compound, after 96 h of exposure, were 6.3 mg L -1 for DF, 13.3 mg L -1 for IB and 94.3 mg L -1 for CBZ. The selected sublethal endpoints of food ingestion, osmoregulatory capacity and respiration rates were not affected by the exposures to environmentally-relevant concentrations. Based on mortality data obtained, the predictive no effect concentration (PNEC) was calculated for each of the compounds, and compared with predicted environmental concentrations (PEC) reported in surface waters. The environmental risk of each compound was estimated as the ratio between PEC/PNEC, and indicated that IB could represent a medium risk in freshwater environments. Additionally, binary and ternary mixture toxicity assays of the selected compounds were carried out. The data obtained was applied to two predictive toxicity models: Concentration Addition (CA) and Independent Action (IA). Finally, risk assessment was estimated using risk quotients (RQ) for the compound mixtures based on EC 50 and LC 50 values. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Pharmaceuticals are emerging contaminants whose presence in the environment is causing concern. After consumption, non- metabolized traces are eliminated from the human body and collected in sewage treatment plants (STPs) or discharged directly into rivers and coastal waters. However, most STPs are not ∗ Corresponding author. Present address: Instituto de Ciencias Marinas de Andalucía (ICMAN), Spain. Tel.: +34 956832612x283; fax: +34 956834701. E-mail address: elena.nieto@icman.csic.es (E. Nieto). equipped for the adequate treatment of pharmaceuticals, and this contributes to their release into aquatic ecosystems. Although new treatment systems are being investigated, most of them are still in the experimental phase [1,2]. Many studies have been carried out on the quantification of levels of pharmaceuticals in river basins [3–5]. Generally, concen- trations are low and in the range of g L -1 or ng L -1 [3,6–8]. Their detection has triggered an increase in the studies on the effects of various pharmaceuticals in non-target organisms [9–11]. Some are considered to be included in the priority list of the Water Frame- work Directive (WFD) of the European Union [12] through the Directive on Environmental Quality Standards (EQSD) [13]. In 2012, 0304-3894/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jhazmat.2013.08.035