Joint Acute Toxicity of Esfenvalerate and Diazinon to Larval Fathead Minnows (Pimephales Promelas)

Abstract

California (USA) agriculture employs pyrethroid and organophosphate insecticides to control insects in orchards and other crops. Diazinon and esfenvalerate were selected for this study because of their application overlaps. Toxicological and biochemical responses of larval fathead minnows (Pimephales promelas) exposed singly and in combinations to esfenvalerate and diazinon were determined. Exposures were 96-h static renewal tests that used standard U.S. Environmental Protection Agency acute toxicity test methods. After pesticide exposures, larvae were evaluated for carboxylesterase and acetylcholinesterase activity, and histopathological effects. Carboxylesterase activity was examined because of its potential influence on the toxicity of both organophosphates and pyrethroids. In vivo studies demonstrated that diazinon significantly inhibited carboxylesterase activity at nominal water concentrations as low as 50 microg/L. However, esfenvalerate did not affect carboxylesterase activity at any concentration tested. Liver glycogen depletion was the only histopathological effect observed; this effect was demonstrated with the individual pesticides and pesticide combinations (i.e., mixtures). The combinations of diazinon and esfenvalerate causing acute toxicity to fathead minnow larvae appeared to be greater than additive (i.e., synergistic) in all three tests.

Cholinesterase and glutathione‐S‐transferase activities in freshwater invertebrates as biomarkers to assess pesticide contamination

“…Piperonil butoxide inhibits monooxygenases and subsequently slows pyrethroid metabolism and detoxification [103]. Although the process of PBO interaction with pyrethroids is well established, limited research has been done on freshwater invertebrates.…”

Repeated and multiple stress (exposure to pesticides) on aquatic organisms

“…The European food Safety Authority reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors. Denton et al (2003) Supporting publications 2012:EN-347 122…”

Proposta conceitual de estudo para a integração e gerenciamento do uso de marcadores bioquímicos de contaminação ambiental

“…A toxicidade das misturas de agrotóxicos ou outros compostos nem sempre é resultante da soma das atividades tóxicas dos compostos (JIN-CLARK et al, 2002;DENTON et al, 2003). Assim, os agrotóxicos podem ter ação conjunta capaz de provocar efeitos tóxicos maiores ou menores nos organismos do que seria esperado a partir do conhecimento sobre os compostos isolados.…”

“…Também as inibições das atividades da acetilcolinesterase e delta-ami nolevulinode-hidratase vêm sendo investigadas em peixes e outros organismos (JIN-CLARK et al, 2002;DENTON et al, 2003). A seleção do indicador biológico deverá também considerar diversas questões como a existência de regulamentações, a escala de paisagem, os produtos recomendados e os utilizados (doses, método e frequência de aplicação).…”