Title: Comparative toxicity of endosulfan and diazinon on the embryo-larval development of the South American toad, Rhinella arenarum

Authors: Carolina Aronzon; Gabriela Svartz; Cristina Pérez Coll

Addresses: Instituto de Investigación e Ingeniería Ambiental (3iA), Universidad Nacional de San Martín, Campus Miguelete, 25 de Mayo y Francia, C.P.: 1650. San Martín, Provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina ' Instituto de Investigación e Ingeniería Ambiental (3iA), Universidad Nacional de San Martín, Campus Miguelete, 25 de Mayo y Francia, C.P.: 1650. San Martín, Provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina ' Instituto de Investigación e Ingeniería Ambiental (3iA), Universidad Nacional de San Martín, Campus Miguelete, 25 de Mayo y Francia, C.P.: 1650. San Martín, Provincia de Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina

Abstract: The toxicities of endosulfan and diazinon were comparatively analysed on the early development of the South American toad, Rhinella arenarum. Pesticides varied greatly in their effects on survival, with concentration-, time- and stage-dependent sensitivity. Endosulfan was 227 times more toxic than diazinon. The larval period was the most sensitive for both pesticides (LC-504 h: 0.01 mg L-1 and 1.92 mg L-1 for endosulfan and diazinon, respectively). Endosulfan toxicity increased 587 and 60 times from acute to chronic exposure in treatments with embryos and larvae, respectively, while diazinon toxicity increased about four and five times, respectively. Both pesticides caused important neurotoxic effects expressed as behavioural disturbances. Risk evaluation assessed by hazard quotient (HQ) was over 1, the level of concern (LOC), for both pesticides at chronic exposure periods and even at acute endosulfan exposure. Results obtained in the present study highlight that these pesticides should be considered potential threats for this species.

Keywords: endosulfan; diazinon; amphibians; embryo-larval toxicity; neurotoxic effects; organochlorine; organophosphate.

DOI: 10.1504/IJENVH.2017.086181

International Journal of Environment and Health, 2017 Vol.8 No.3, pp.225 - 234

Received: 30 Jul 2016
Accepted: 03 Mar 2017

Published online: 29 Aug 2017 *

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