© 2015 Asociacion de Quimicos del Instituto Quimico de Sarria. All rights reserved. The neonicotinoid pesticide imidacloprid is among the top sold agrochemicals worldwide. Due to its widespread use in mixtures with different solvents and co-adjuvants, studying the environmental impact of its derived commercial formulations has become mandatory. In this study we used laboratory ecotoxicological tests to quantify the impact of the imidacloprid-containing formulation Confidor® 20SL on the terrestrial and aquatic compartments. Lethal and sublethal effects of recommended application doses of the product were assessed on standard terrestrial invertebrates Eisenia fetida and Folsomia Candida whereas the toxicity of leachates from contaminated soils was evaluated in the aquatic model organisms Oaphnia magna and Raphidocelis subcapitata. The exposure to environmentally relevant concentrations of imidacloprid caused no mortality to earthworms (LC50 of 4.23 mg imidacloprid kg'1 dry soil) but altered their behavior and reproduction patterns (EC50 values for avoidance and reproduction tests of 0.43 and i .40 mg imidacloprid kg-1 dry soil, respectively). Effects on collembolans F. Candida were negligible. Imidacloprid presented moderate teachability, with recovery rates that ranged from 25.4 to 50.4% of the amount present in soils and concentrations in water extracts from 13.05 to 71.8 μg L-1. Standard aquatic ecotoxicity tests were not able detect chronic or acute toxicity in standard test organisms. Nonetheless, concentrations of the insecticide in water extracts were high enough to pose a lethal threat to several other non-standard aquatic organisms.
|Publication status||Published - 1 Jan 2015|