Impact of the glyphosate-based commercial herbicide, its components and its metabolite AMPA on non-target aquatic organisms.

Glyphosate (GLY) is the active ingredient of several herbicide formulations widely used to control weeds in agricultural and non-agricultural areas. Due to the intensive use of GLY-based herbicides and their direct application on soils, some of their components, including the active ingredient, may reach the aquatic environment through direct run-off and leaching. The present study assessed the acute toxicity and genotoxicity of the GLY-based formulation Atanor 48 (ATN) and its major constituents GLY, surfactant polyethoxylated tallow amine (POEA), as well as the main metabolite of GLY aminomethylphosphonic acid (AMPA) on non-target aquatic organisms. The toxic effects of these chemicals were evaluated in the fish embryo acute toxicity test with zebrafish (Danio rerio), while genotoxic effects were investigated in the comet assays with cells from zebrafish larvae and rainbow trout gonad-2 (RTG-2). GLY and AMPA caused no acute toxic effect, while ATN and POEA induced significant lethal effects in zebrafish (LC50-96 h 76.50 mg/L and 5.49 mg/L, respectively). All compounds were genotoxic in comet experiments with zebrafish larvae (LOEC 1.7 mg/L for GLY, ATN, AMPA and 0.4 mg/L for POEA). Unlike in vivo, only POEA induced DNA damage in RTG-2 cells (LOEC 1.6 mg/L), suggesting that it is a direct acting genotoxic agent. In summary, these data indicate that the lethal effects on zebrafish early-life stages can be ranked in the following order from most to least toxic: surfactant POEA > formulation ATN > active ingredient GLY ≈ metabolite AMPA. Genotoxic effects were observed in both RTG-2 cells (only POEA) and zebrafish (all test compounds) with the lowest tested concentrations. Therefore, it is important to evaluate different toxicological endpoints as well as use different non-target organisms to predict the hazards of GLY-based formulations and their components and breakdown product to aquatic biota.

de Brito Rodrigues L ，Gonçalves Costa G ，Lundgren Thá E ，da Silva LR ，de Oliveira R ，Morais Leme D ，Cestari MM ，Koppe Grisolia C ，Campos Valadares M ，de Oliveira GAR ... -  《-》

Safety evaluation and risk assessment of the herbicide Roundup and its active ingredient, glyphosate, for humans.

Williams GM ，Kroes R ，Munro IC 《REGULATORY TOXICOLOGY AND PHARMACOLOGY》

A glyphosate-based herbicide induces sub-lethal effects in early life stages and liver cell line of rainbow trout, Oncorhynchus mykiss.

Most pesticides used in agriculture end up in the aquatic environment through runoff and leaching of treated crops. One of the most commonly used herbicides is glyphosate. This compound or its metabolites are frequently detected in surface water in Europe. In the present study, in vivo and in vitro studies were carried out using the early life stages of rainbow trout (Oncorhynchus mykiss) and the cell line RTL-W1 (a liver cell line from rainbow trout) to characterize the toxic effects of glyphosate at environmentally-realistic concentrations. Both studies were performed using the commercial formulation Roundup® GT Max, and technical-grade glyphosate for the in vitro study. Eyed-stage embryos were exposed for 3 weeks to sub-lethal concentrations (0.1 and 1 mg/L) of glyphosate using Roundup. Numerous toxicity endpoints were recorded such as survival, hatching success, larval biometry, developmental abnormalities, swimming activity, genotoxicity (formamidopyrimidine DNA-glycosylase Fpg-modified comet assay), lipid peroxidation (TBARS), protein carbonyls and target gene transcription. Concentrations neither affected embryonic or larval survival nor increased developmental abnormalities. However, a significant decrease was observed in the head size of larvae exposed to 1 mg/L of glyphosate. In addition, a significant increase in mobility was observed for larvae exposed to glyphosate at 0.1 mg/L. TBARS levels were significantly decreased on larvae exposed to 1 mg/L (a.i.), and cat and cox1 genes were differently transcribed from controls. DNA damage was detected by the Fpg-modified comet assay in RTL-W1 cell line exposed to the technical-grade glyphosate and Roundup formulation. The results suggest that chronic exposure to glyphosate, at environmental concentrations, could represent a potential risk for early life stages of fish.

Weeks Santos S ，Gonzalez P ，Cormier B ，Mazzella N ，Bonnaud B ，Morin S ，Clérandeau C ，Morin B ，Cachot J ... -  《-》

Evaluation of the genotoxic, mutagenic, and histopathological hepatic effects of polyoxyethylene amine (POEA) and glyphosate on Dendropsophus minutus tadpoles.

Herbicides improve the productivity of a monoculture by eliminating weeds, although they may also be toxic and have negative effects on non-target organisms, such as amphibians. The present study evaluated the genotoxic, mutagenic, and histopathological hepatic responses of Dendropsophus minutus tadpoles to acute exposure (96 h) to the herbicide glyphosate (GLY, 65, 130, 260 and 520 μg/L) and the surfactant polyoxyethylene amine (POEA, 1.25, 2.5, 5 and 10 μg/L). On average, 174 % more genomic damage was observed in the tadpoles exposed to all concentrations of POEA in comparison with the control, while up to seven times more micronuclei were recorded, on average, at a concentration of 5 μg/L of POEA. All the individuals exposed to 10 μg/L of POEA died. The tadpoles exposed to GLY presented 165 % more DNA damage than the control, on average, at the highest concentrations (260 and 520 μg/L), and up to six times more micronuclei at 520 μg/L. The Erythrocyte Nuclear Abnormality test (ENA) detected a relatively high frequency of cells with lobed nuclei in the tadpoles expose to POEA at 5 μg/L and binucleated cells in those exposed to GLY at 520 μg/L. The hepatic histopathological observations revealed several types of lesions in the tadpoles exposed to both GLY and POEA. Overall, then, the results of the study indicate that both GLY and POEA have potential genotoxic, mutagenic, and hepatotoxic effects in D. minutus tadpoles. We emphasize the need for further studies to monitor the amphibian populations, such as those of D. minutus, which breed in aquatic environments associated with agricultural areas. The release of pollutants into natural habitats may have significant long-term impacts on the survival of anuran tadpoles.

Lopes A ，Benvindo-Souza M ，Carvalho WF ，Nunes HF ，de Lima PN ，Costa MS ，Benetti EJ ，Guerra V ，Saboia-Morais SMT ，Santos CE ，Simões K ，Bastos RP ，de Melo E Silva D ... -  《-》

In vivo estrogenicity of glyphosate, its formulations, and AMPA on transgenic zebrafish (Danio rerio) embryos.

Tóth G ，Háhn J ，Szabó G ，Bakos K ，Volner C ，Liang X ，Göbölös B ，Bock I ，Szoboszlay S ，Urbányi B ，Kriszt B ，Kaszab E ，Szabó I ，Csenki Z ... -  《-》