Lethal and sublethal effects of carbamazepine, sildenafil, clarithromycin and the binary mixtures on freshwater fish

ELORRIAGA, Y.; RONCO A.E.; CARRIQUIRIBORDE, P.

Buenos Aires

Congreso; Society of Environmental Toxicology and Chemistry, Latin-American XI Biennial Meeting; 2015

Society of Environmental Toxicology and Chemistry, Latin-American

The occurrence of pharmaceuticals has been identify in wastewater effluents and surface waters and concern has risen of the potential adverse effects on the aquatic ecosystems. Toxicity of these compounds on Neotropical species is almost unknown and extrapolation with Holarctic species is usually used for risk assessment. In addition, these compounds typically occur in complex mixtures and the evaluation of potential interactions is necessary. In the present study lethal and sublethal effects of single and binary mixtures of three frequently observed pharmaceuticals in wastewaters and surface waters of Argentina were assessed using freshwater fish. Lethal effects of single and binary mixtures were assessed by means of standardized acute toxicity test using the autochthonous fish species, pejerrey (Odontesthes bonariensis). Sublethal effects of single and binary mixtures were assessed using a selected suit of biomarkers on juveniles of common carp (Cyprinus carpio) exposed to 0.42 and 42 µM of each pharmaceutical and the binary mixture during 96h. Acute lethal toxicity test indicate moderate to slight toxicity induced by the tested pharmaceuticals (96h-LC50 (mg/L): 6.4, 16.2, >solubility, for sildenafil, carbamazepine and clarithromycin, respectively) and agonistic interaction for the binary mixtures. A clear response was not observed for any of the selected biomarkers selected at the hepatic biotransformation (EROD, BROD) or antioxidant (CAT) enzymes, or oxidative stress (TBARs). Alteration of brain AchE was neither observed by carbamazepine, single or in mixtures. In summary, the studied pharmaceuticals or their mixtures seems not to induce generalized acute toxic effects on the studied fish. Longer-term exposures and more specific responses should be assessed to reach a more general conclusion about potential risk of these pharmaceuticals.