The application of pesticide in agriculture has improved food production, however, the resultant pesticide residues released to the environment are potentially harmful to human health and the ecosystem even at low concentrations. Organophosphorus and Organochlorine multi- pesticide residue analysis were determined in soil and water samples from the vegetable growing floodplains in Minna, North Central, Nigeria, where urban and peri-urban agriculture is practiced with extensive application of pesticides. Pesticide residue analysis was determined using the gas chromatograph with mass spectrometry (GC-MS) detection technique. Organophosphorus pesticide residues detected in soil and water included ethion, diclofenthion, malathion and diazinon whereas the organochlorine pesticide residues detected in soil and water in Minna included endosufan-II, p,p'-DDT, δ-BHC and heptachlor. Ethion and diclofenthion were the most frequently detected organophosphorus pesticide residues in soil and water while heptachlor and p,p'-DDT were the frequently detected organochlorines in the soil and the water samples. All the detected pesticide residues in soil and water had concentrations that exceeded the maximum residue limits (MRLs). The high pesticide levels in soil and water in the floodplains in Minna is of great concern because the soil is used for cereal and vegetable cropping and the water used for domestic purposes. Plant uptake of pesticides poses health risks to domestic livestock that forage on crop stubble and to consumers of food products from these animals. There is therefore a need for regular and stringent monitoring of pesticide residues in soil and water in the floodplains in Minna, North Central, Nigeria and for farmers to adopt good agricultural practice.
Keywords: Floodplain, Pesticide Residues, Organophosphorus, Oganochlorines, GC-MS.