Health risk assessment of organochlorine pesticides in soil and water samples from food waste dumpsites

Abstract

Risk assessment of organochlorine pesticides (OCPs) in soil, leachate, sediment and borehole water samples from two major food wastes dumpsites in lagos and Ogun State, South-west Nigeria was evaluated in this study. Quantification was done using a gas chromatography-mass spectrometry and risk assessment was expressed for non-carcinogenic and carcinogenic risk. Out of the 15 OCPs investigated, 13 OCPs were detected in borehole water and leachate while 14 OCPs were detected in soil and sediment samples. The concentration of OCPs in the samples ranged between 0.196 mg/L (Leachate) and 0.821 mg/kg (Soil). The ƩOCPs in all the samples (mg/kg) are; ≤0.303±0.037, ≤0.387±0.054, ≤0.821±0.095, ≤0.703±0.090 respectively. OCPs with higher concentrations includes; δ-HCH, Endosulfan, Beta lindane, Gama lindane while Endrin was below the detection limit of the instrument. The HQ for non-carcinogenic risk via oral ingestion for all samples is <1 whereas, HQ through dermal contact is >1. Though non-carcinogenic risk of OCPs in the two sites are within the negligible risk level, the carcinogenic risk of all the evaluated OCPs are higher and of concern. Urgent measures should be put in place by policy makers in drastically reducing and regulating the use of OCPs in agricultural soils, homes and ensure treatment of not only municipal and industrial waste but also, agricultural waste before they are discarded on dumpsites. • Agricultural food waste are usually categorized as non-toxic waste and discarded on dumpsites • Organochlorine pesticides (OCPs) were detected in soil and water samples around food waste dumpsites • Higher concentrations of carcinogenic OCPs were found in all the samples from the dumpsites. • The carcinogenic risk of all the evaluated OCPs is higher and of concern. • Urgent measures should be put in place to reduce and regulate the use and disposal of OCPs in agricultural soils and homes.