CONICET | Buscador de Institutos y Recursos Humanos

Introduction The agrochemicals market has been strongly expanded over recent years, with an increase in consumption of pesticides. Chlorpyrifos (CPF) and Cypermethrin (CYP) are widely used insecticides in Argentine for agriculture and domestic purposes. As a result both pesticides have been detected in surface waterbodies in different countries. CPF is an organophosphate pesticide. Its main target is acetylcholinesterase (AchE), an enzyme which hydrolyses acetylcholine in cholinergic synapses at neuromuscular junctions. CYP is a pyrethroid compound, that is extremely toxic to fish and aquatic arthropods1. The aim of the present study was to evaluate the single and joint effect of CPF and CYP in technical and commercial mix in swimming behaviour and AchE activity in order to discern the toxicity of both pesticides either alone or in mixtures. Methodology Adult female fishes (n= 10) were exposed over 96 h to low and high concentrations of pesticides as follow: 0.04 and 0.4 µg/L of CYP; 0.4 and 4 µg/L of CPF; 0.04 µg/L CYP + 0.4 µg/L CPF and 0.4 µg/L CYP + 4 µg/L CPF in a technical mixture; as well as 0.04 µg/L CYP + 0.4 µg/L CPF and 0.4 µg/L CYP + 4 µg/L CPF in a mixture of a commercial product. After 24 h and 96 h of exposure, the animals were carefully removed from the exposure tanks and placed individually in the filming tank, where their behavioral activity was recorded for 10 min. A digital camera was connected to a laptop for recording the videos and the behavioural parameters (as velocity and distance, among others) were afterward analysed using appropriate video-tracking software (ANY-maze, Stoelting CO, USA). After 96 h behaviour record the animals were sacrificed and, brain and muscle taken to measure AchE activity2. Results Our present results show that fish exposed to CYP exhibit increased swimming activity only after 96 h of exposure at the higher concentration tested (0.4 µg/L) when compared to the control group (p