ABSTRACT
The application of a mixture of pesticides to the agricultural field may adversely affect the health of non-target organisms besides the target ones. In the present study, the antagonistic effect of triazophos and deltamethrin (DM) in combination compared with individuals has been observed on earthworm, Eudrilus eugeniae. The LC50 value for formula grade pesticides viz. triazophos, DM and their combination was found as 76, 31 and 66 ng/cm2, respectively. To study the effect of sub-lethal dose (5% and 10% of LC50) of these pesticides on earthworm, E. eugeniae was exposed for 48 h by the paper contact toxicity method. Significant perturbations in oxidative stress parameters such as nonenzymatic (MDA, GSH) and enzymatic (SOD, CAT, GST, LDH, ACP, ALP, ALT and AST) were observed in tissue-specific (pre-clitellar, clitellar and post-clitellar) and dose-dependent manner. Histopathological studies of post-clitellar region of the body of earthworm showed severe damage in the exposed groups compared with control. The findings further indicate that the toxicity of pesticides was more pronounced in an individual than in the co-exposed group. Therefore, the changes speculate the potential health risk to these organisms on exposure at higher concentrations of the pesticides accumulated in soil.
Acknowledgements
The authors express their gratitude to the Head of the Department of Zoology for providing Central Instrumental facility developed with financial assistance from DST-FIST and UGC-SAP Phase I & II, New Delhi, India, for carrying out this work. Financial assistance to the authors (SS and RKT) from UGC is gratefully acknowledged.
Disclosure statement
No potential conflict of interest was reported by the authors.
Notes on contributors
Ms Shikha Singh is a PhD scholar doing research which mainly focuses on biochemical and molecular aspects of toxicological impact of pesticides on fish and earthworm.
Mr Rishikesh K. Tiwari is a PhD scholar doing research which mainly focuses on biochemical and molecular aspects of toxicological impact of pesticides on fish and earthworm.
Dr Ravi S. Pandey is Professor and chairman of Zoology at University of Allahabad (India). He has more than 35 years of teaching and 40 years of research experience. He has published a good number of research papers in the journals of national and international repute (peer-reviewed journals). His present research field is mainly focused on biochemical and molecular studies on impact of environmental toxicants on fish and earthworm.