Effects of pesticides recidues on Tilapia zillii, sediment and surface water of Erinle Dam and River Osun in Osun State

Abstract

This study investigates the effects of selected pesticides on the health of aquatic ecosystems and humans in Erinle Dam and River Osun,  Osun State, Nigeria. Focusing on Tilapia zillii, a commonly consumed fish in the region, the research assesses the potential health risks  posed by pesticides found in the water, sediments, and fish tissues. Samples were collected following APHA guidelines and tested for  pesticides like DDT, Heptachlor, Dieldrin, Aldrin, and Chlorpyrifos. The findings revealed high levels of DDT and Chlorpyrifos in both the  water and fish, with Erinle Dam showing higher concentrations than River Osun. Specifically, DDT levels in River Osun's water averaged 199.08mg/kg, while Erinle Dam had 271.58mg/kg. Dieldrin and Chlorpyrifos also showed high concentrations, with Heptachlor and Aldrin  absent in the water samples from both sites. Fish tissue analysis indicated higher pesticide levels in specimens from Erinle Dam  compared to River Osun. DDT and Chlorpyrifos concentrations were notably high, while Dieldrin, Aldrin, and Heptachlor were present in  lower amounts. Similarly, sediment analysis showed Erinle Dam with higher pesticide concentrations, particularly for DDT, Dieldrin, and  Chlorpyrifos, while Heptachlor and Aldrin were absent.Overall, the study highlights significant pesticide contamination in Erinle Dam and  River Osun, posing health risks to local fish consumers and indicating a need for stringent pesticide regulation and monitoring in the  region.