Enhanced esterase activity and azinphosmethyl exposure association in target and non-target organisms

MONTAGNA M; FERRARI A; SOLEÑO J; VENTURINO A; ANGUIANO L

Porto-Portugal

Congreso; 17th Annual Meeting SETAC-Europe; 2007

Society of Environmental Toxicology and Chemistry

ENHANCED ESTERASE ACTIVITY AND AZINPHOSMETHYL EXPOSURE ASSOCIATION IN TARGET AND NON-TARGET ORGANISMS C. Montagna1, A. Ferrari2, L. Soleño3, A. Venturino3,  and L. Anguiano3 1Escuela Superior Salud y Ambiente, 2Facultad de Medicina, 3Facultad de Ingeniería. Neuquén, Argentina, The organophosphate azinphosmethyl (AzMe) is extensively applied in the Alto Valle (Argentinean Patagonia) to control codling moths (Cydia pomonella) from apples. This area is irrigated by fast-flowing channels providing a favourable habitat for many species including black fly (Simulium spp) and amphipods (Hyalella curvispina). Previously, we have observed differences in toxicity to AzMe between insecticide exposed and non-exposed populations. In this study, we individually assayed esterase activities from all populations. The three populations of organisms from pesticide exposed sites showed significantly higher (p<0.001) esterase activities (µmol x min-1 x mg prot-1) than the control ones. Mean enzyme activities were 2.17 ± 1.71 and 0.81 ± 0.35 for Simulium spp; 0.27 ± 0.10 and 0.14 ± 0.07 for H. curvispina and at last, 0.21 ± 0.16 and 0.016 ± 0.011 for C. pomonella. Therefore, we conclude that the differences in toxicity to AzMe between insecticide exposed and non-exposed populations of simuliids, amphipods and codling moths are at least due to enhanced esterase activity.