Abstract
Organochlorine pesticides (OCPs) concentration was evaluated in floodplain soils from the lower sections of River Niger in order to explore their distribution patterns with respect to soil depth, sources, ecosystem and human health risks. The soils at three depths from thirteen (13) locations along the floodplain were collected, Soxhlet extracted with dichloromethane (DCM)/n-hexane and analyzed for OCPs by using gas chromatography-mass spectrometry (GC-MS). The Σ20 OCP concentrations in the soils from 0–15, 15–30 and 30–45 cm depths varied from 5.0–592, 7.1–281 and 8.12–507 ng g− 1 for respectively. On average, the Σ20 OCP concentrations decreased with depth. Chlordane was the predominant OCP in the soil profiles. The results of risk assessment suggested that concentrations of OCP in the soil profiles can pose risks to the ecosystem and farmers in the floodplain. The source apportionment showed predominance of historical sources over recent usage of OCPs in the floodplain soils.