Flurochloridone-based herbicides induced genotoxicity effects on Rhinella arenarum tadpoles (Anura: Bufonidae)

Acute toxicity and genotoxicity of the flurochloridone (FLC)-containing commercial formulation herbicides Twin Pack Gold(®) (25 percent a.i.) and Rainbow(®) (25 percent a.i.) were evaluated on Rhinella arenarum (Anura: Bufonidae) tadpoles exposed under laboratory conditions. Lethal effect was evaluated as end point for lethality, whereas frequency of micronuclei (MN) and single cell gel electrophoresis (SCGE) were employed as end points for genotoxicity. Lethality studies revealed equivalent LC-5096 h values of 2.96 and 2.85 mg/L for Twin Pack Gold(®) and Rainbow(®), respectively. Twin Pack Gold(®) did not induce DNA damage at the chromosomal level, whereas Rainbow(®) increased the frequency of MN only when the lowest concentration (0.71 mg/L) was used. However, all concentrations of Twin Pack Gold(®) and Rainbow(®) increased the frequencies of primary DNA lesions estimated by alkaline SCGE. This study represents the first evidence of the acute toxic and genotoxic effects exerted by two FLC-based commercial formulations, Twin Pack Gold(®) and Rainbow(®), on tadpoles of an amphibian species native to Argentina under laboratory conditions. Finally, our findings highlight the importance of minimizing the impacts on nontarget living species exposed to agrochemicals.

Comet assay; Commercial formulations; Micronuclei; Rainbow(®); Twin Pack Gold(®).