Impact of commercial formulations of herbicides alone and in mixtures on the antioxidant system and body condition parameters in tadpoles of Rhinella icterica (Spix 1824)

Pesticide usage has increased over the last decades, leading to concerns regarding its effects on non-target or-ganisms, especially amphibians. Tadpoles of Rhinella icterica were collected in a pesticide-free place, acclimated in the laboratory (21 days) and exposed (7 days) to three herbicides (20 mu g/L atrazine (A); 250 mu g/L glyphosate (G); 20 mu g/L quinclorac (Q)) and their mixtures. Only 2% mortality was observed over the 28 days of the study. Despite this, significant variations were observed for markers of oxidative balance and body condition when comparing all experimental groups. K and Kn factor showed the lowest values in the group A+G+Q, as well as the activity levels of GST and SOD. In contrast to this, the CAT activity was higher in the same group (A+G+Q). The mixture of the three herbicides proved to be more harmful, which points to the need for more restrictive laws for the use of mixed herbicides.

Automated summary

Pesticide usage has raised concerns about its impact on non-target organisms, particularly amphibians. In this study, tadpoles of Rhinella icterica were collected from a pesticide-free site and exposed to three herbicides and their mixtures. Although the mortality rate was low, significant variations in oxidative balance and body condition were observed among the experimental groups. The mixture of the herbicides was found to be more harmful, highlighting the need for stricter regulations on the use of mixed herbicides.