Acute, chronic and neurotoxic effects of dimethoate pesticide on Rhinella arenarum throughout the development

ACQUARONI, MERCEDES; SVARTZ, GABRIELA; PÉREZ COLL, CRISTINA

JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART B - PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES

TAYLOR & FRANCIS INC

Año: 2022 p. 1 - 11

0360-1234

Among the factors implicated in amphibian global decline, agrochemicals have been gaining increasing attention. In order to evaluate the toxicity of a dimethoate-based insecticide on the early development of an autochthonous amphibian, Rhinella arenarum, continuous and 24 h pulse exposure bioassays were carried out. Lethal and sublethal effects, neurotoxicity and the ecological risk were assessed. Results demonstrate that larvae were more sensitive than embryos with 504 h-LC50 of 12.82 and 16.38 mg L-1 respectively. 24 h pulse experiments showed a high toxicity increment at early embryonic stages, while the sensitivity at later stages was high and constant. Dimethoate caused teratogenesis and several sublethal effects as morphological and behavioral alterations but also disruption in the metamorphic process. About neurotoxicity, dimethoate inhibited the activity of butyrylcholinesterase at 0.5 and 1 mg L-1 exposed larvae. The results obtained in this study as the risk assessment revealed that dimethoate represents a hazard on Rhinella arenarum survival and development but also a potential risk for the continuity of the populations of this species in agroecosystems.