Neotropical bioindicators of ecotoxicity and environmental risk of drugs with aquaculture interest

Abstract

The aims of this research were to evaluate the acute toxicity (LC/EC50) and the environmental risk of toltrazuril (TOL) and florfenicol (FFC) for plant Lemna minor, snail Pomacea canaliculata, fish Piaractus mesopotamicus and Hyphessobrycon eques and the microcrustacean Daphnia magna. The organisms were acclimated in bioassay room with controlled temperature according to the standard to each one. They were exposed at nominal concentrations in static system. For environmental risk (RQ), it was used the estimated environmental concentration (EEC) that is the dosage indicate to treatment and the lethal or effective concentration (LC/CE50) from each drug in acute exposure. FFC showed LC50;7d of 97.03 mg L^-1 for L. minor; >100.0 mg L^-1 for P. mesopotamicus and H. eques and EC50;48h > 100.0 mg L^-1 for P. canaliculata and D. magna, and it was classified low risk (RQ = 0.01) for all bioindicators. TOL showed LC50;7d >100.0 mg L^-1 for L. minor, 3.72 mg L^-1 for P. mesopotamicus; 6.22 mg L^-1 for H. eques and CE50;48h of 7.59 mg L^-1 for P. canaliculata, and 18.57 mg L^-1 for D. magna, and it was classified low risk (RQ = 0.01) for L. minor and high risk for P. mesopotamicus (RQ = 2.68), H. eques (RQ = 6.22), P. canaliculata (RQ = 1.31) and D. magna (RQ = 0.53). Lemna minor was the bioindicator indicating of FFC toxicity and H. eques, bioindicator of the TOL. FFC is safety in aquaculture, however, the use of TOL needs cautions to treat the wastewater before discard on the environment.