Bioaccumulation and distribution behavior of endosulfan on a cichlid fish: Differences between exposure to the active ingredient and a commercial formulation.

DA CUÑA, RODRIGO HERNÁN; LO NOSTRO, FABIANA LAURA; SHIMABUKURO, V; ONDARZA, P; MIGLIORANZA, KARINA S.B.

ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY

SETAC PRESS

Lugar: Pensacola; Año: 2020 vol. 39 p. 604 - 611

0730-7268

Persistent organic pollutants reach aquatic ecosystems during application and can bioconcentrate/biomagnificate due to their lipophilic nature. Toxicological studies focus almost exclusively on the active ingredients (AIs) of pesticides, instead of commercial formulations (CFs), whose toxicity can differ due to non-specified ingredients. The intensive use of endosulfan (ES) as a wide range insecticide over the last few decades make it one of the most frequently detected contaminants in the aquatic environment, even after it has been restricted worldwide. The aim of this study was to evaluate the bioaccumulation and organ distribution of waterborne ES in the freshwater fish Cichlasoma dimerus, comparing between the AI and a CF. Males were exposed to 0.7 μg.L-1 ES for two weeks. ES was quantified (GC-ECD) in liver, testes, gills, brain and muscle. Results suggest rapid metabolization of ES isomers to ES sulfate (ES-S) in tissues. Isomers levels were highest in gills, indicative of recent uptake. ES-S levels were highest in liver and testes for the AI, and testes and brain for the CF. For the AI, ES-S levels showed a positive correlation with organ-lipid %. No correlation was evident for CF indicating that the presence of adyuvants alters ES distribution, as gills and liver showed a higher uptake and mobilization of β-ES. These differences in organ distribution may alter tissue-specific toxicity,therefore additives cannot be considered inactive even if non-toxic.