Acute toxicity of the organophosphorus pesticide diclorvos and the mix with the piretroid deltamethrin in Danio rerio and Hyphessobrycon bifasciatus

Abstract

Pesticides such as Dichlovos (DDVP) and Deltamethrin (DTM) are commonly used in agricultural production. To evaluate the toxicity of commercial formulations of DDVP, mixed or not with DTM, were realized tests for acute toxicity in fish species Danio rerio and Hyphessobrycon bifasciatus. To the mixture, the highest concentrations of pesticides tested that caused no lethality were used. The results showed that on the concentrations used, the pesticide DDVP promotes the "all or nothing effect, i.e., 100% of animals dying or 100% surviving. In the case of the mixture, the results demonstrated the occurrence of 100% lethality at concentrations of pesticides that did not produce lethal effect if administered alone, indicating a synergistic effect of the pesticide mixture. These data suggest that the use of mixtures of these pesticides may represent an important factor. Finally, the toxicity effect showed on the two species was similar, suggesting that Hyphessobrycon bifasciatus fish may be used for environmental assessments in Brazilian conditions.