Comparative toxicity of two glyphosate-based formulations to Eisenia andrei under laboratory conditions

Journal or Publishing Institution: Chemosphere

Study: http://www.sciencedirect.com/science/article/pii/S0045653512015378

Author(s): Piola, L., Fuchs, J., Oneto, M.L., Basack, S., Kesten, E. and Casabé, N.

Article Type: Peer Reviewed Study

Record ID: 1898

Abstract: Glyphosate-based products are the leading post-emergent agricultural herbicides in the world, particularly in association with glyphosate tolerant crops. However, studies on the effects of glyphosate-based formulations on terrestrial receptors are scarce. This study was conducted to evaluate the comparative toxicity of two glyphosate-based products: Roundup FG (monoammonium salt, 72% acid equivalent, glyphosate-A) and Mon 8750 (monoammonium salt, 85.4% acid equivalent, glyphosate-B), towards the earthworm Eisenia andrei. Median lethal concentration (LC₅₀) showed that glyphosate-A was 4.5-fold more toxic than glyphosate-B. Sublethal concentrations caused a concentration-dependent weight loss, consistent with the reported effect of glyphosate as uncoupler of oxidative phosphorylation. Glyphosate-A showed deleterious effects on DNA and lysosomal damage at concentrations close to the applied environmental concentrations (14.4 μg ae cm⁻²). With glyphosate-B toxic effects were observed at higher doses, close to its LC₅₀, suggesting that the higher toxicity of formulate A could be attributed to the effects of some of the so-called “inert ingredients”, either due to a direct intrinsic toxicity, or to an enhancement in the bioavailability and/or bioaccumulation of the active ingredient. Our results highlight the importance of ecotoxicological assessment not only of the active ingredients, but also of the different formulations usually employed in agricultural practices.

Keywords: Glyphosate Formulations, Eisenia Andrei, Sublethal Biomarkers, Neutral Red Retention Time, Comet Assay; Animals, Glycine, Herbicides, Laboratories, Lethal Dose 50, Ogliochaeta, Risk Assessment, Soil Pollutants; Toxicity; DNA, DNA Damage, Active Ingredients, Bioaccumulation, Bioavailability, Crops, Earthworms, Glyphosate, Insert Ingredients, Lethal Concentration 50, Oxidative Phosphorylation, Weight Loss

Citation: Piola, L., Fuchs, J., Oneto, M.L., Basack, S., Kesten, E. and Casabé, N., 2013. Comparative toxicity of two glyphosate-based formulations to Eisenia andrei under laboratory conditions. Chemosphere, 91(4), pp.545-551.