INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Toxic effects of a carbamate insecticide on a non-target freshwater gastropod: active ingredient versus commercial formulation
Autor/es:
YUSSEPPONE M. S.; KRISTOFF G.; COSSI P.F:; RÍOS DE MOLINA M.C.; HERBERT THOMSETT L.; PÉREZ A.F.
Lugar:
Roma
Reunión:
Congreso; Congreso SETAC Europe 28th Anual Meeting; 2018
Institución organizadora:
SETAC Europe
Resumen:
Carbamate insecticides are commonly used in agriculture for crop protection exerting their toxicity through the inhibition of the enzyme acetylcholinesterase. In Argentina, the maximum concentration of carbaryl (CAR) detected in surface and subsurface drainages was 45.7 µg L-1. In this study, we evaluated the subchronic toxicity of environmental concentrations of the active compound and a commercial formulation of CAR on biochemical and reproductive parameters in Biomphalaria straminea, a freshwater gastropod native to Argentina.Five treatments were included in this study: dechlorinated tap water, acetone in dechlorinated tap water (solvent control), CAR active compound (dissolved in acetone) in dechlorinated tap water at 12.68 and 126.8 μg L-1, and the equivalent to 126.8 μg L-1 CAR of a formulation (dissolved in dechlorinated tap water) with 85% of the active compound. The concentrations used were chosen so as to have the same molarity as azinphos-methyl, an insecticide previously used in our laboratory.In a first bioassay, eight glass vessels per treatment were used with six snails each. After 14 days of exposure, homogenates were made with the organisms? soft tissues (pool of 5 snails per vessel). In the supernatant fraction, the following parameters were measured: cholinesterases (ChEs), carboxylesterases (CEs) with two substrates, glutathione S-transferase (GST), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT). In a second bioassay, ten containers per treatment were used with a single recently-laid egg mass each. The time and success of hatching were registered and, after one month, the survival of the offspring was evaluated. In both bioassays, CAR solutions were renewed every 48 h based on previous stability studies.The active compound caused an increase in the activity of SOD with both CAR concentrations (28 and 83%, respectively, compared to the solvent control). The formulation, besides increasing SOD activity (72%), augmented GSH levels by 23% and inhibited CAT activity by 47% (compared to the water control). Regarding the reproductive endpoints analyzed, no toxic effects were found neither with the active compound nor the formulation. Our findings show that a subchronic exposure of B. straminea to CAR, active compound or formulation, does not affect the primary target, ChEs. However, other toxicity pathways, in which antioxidant enzymes are involved, seem to be affected by this insecticide, mainly by the commercial formulation.