Ecotoxicological assessment of pesticide residues in Thryonomys Swinderianus (grasscutters) in Nigeria

The increase in the usage of pesticides and the persistence of their residues in the environment present significant risks to both wildlife and public health. This study investigated the presence, distribution and potential toxicological implications of pesticide residues in Thryonomys swinderianus (grascutter) harvested from three ecological zones of Nigeria. Tissue samples (liver, kidney and flesh) were analyzed for nineteen pesticide residues; including fifteen organochlorines, two pyrethroids (α- and β-cypermethrin) and one each from the triazine (atrazine) and organophosphate (glyphosate) classes. Results revealed widespread contamination, particularly in the liver and kidney, with several residues such as heptachlor, DDT and its metabolites (p,p’-DDT, p,p’-DDE, o,p’-DDE), aldrin, dieldrin and endosulfan exceeding or approaching international Maximum Residue Limits (MRLs). Organochlorine pesticides were the most dominant, with regional variations in concentration levels reflecting differences in pesticide application practices and environmental dynamics. Flesh samples contained the lowest residue levels, though detectable traces of persistent compounds like DDT and its metabolites were present. Atrazine and glyphosate were largely undetected. The findings underscore the persistence use of banned and restricted pesticides in the Nigerian environment and highlight the potential public health risks associated with the consumption of contaminated bushmeat.