Prevalence of Organophosphorous Pesticide Residues in Pumpkin, Spinach and Sorrel Leaves Grown in Akwanga, Nasarawa State, Nigeria

Abstract

Three green leafy vegetable samples of pumpkin leaves, spinach leaves, and sorrel leaves were collected from three different locations in a farm in Akwanga and were tested for the presence of organophosphorus (OP) compounds. The concentrations of all the pesticide residues in the vegetable samples were determined using gas chromatography with mass spectrometry (GC-MS). The organophosphorus pesticides detected include carbaryl (0.052 mg/kg) in pumpkin, this is below European maximum residues limit (EU MRL) of 0.1 mg/kg, Dimethoate was found in pumpkin (0.165 mg/kg), spinach (0.103 mg/kg) and sorrel (0.250 mg/kg) all above the EU MRL of 0.05 mg/kg. Dichlofenthion was detected in pumpkin (0.308 mg/kg), pirimiphos methyl was detected in pumpkin and spinach (0.428 mg/kg and 0.149 mg/kg respectively), all these were below the EU MRL of 0.5 mg/kg. Chlorpyrifos was found in spinach (0.230 mg/kg) and sorrel (0.192 mg/kg) only spinach was above the EU MRL of 0.2 mg/kg. The pesticide residue Bromophosethyl was detected in all vegetables, pumpkin leaves (0.501 mg/kg), sorrel (1.571 mg/kg) and spinach (7.981 mg/kg) all above the EU MRL of 0.5 mg/kg. The remaining pesticides detected were all below their EU MRL value; these are Ethion found in spinach (0.167 mg/kg), Methyl Parathion in spinach (0.103 mg/kg) and sorrel (0.335 mg/kg). The levels of some of the organophosphorus pesticide residues found in vegetables were above the maximum residue limits (MRLs) set by the European Union. This calls for laws to regulate the use and circulation of such chemicals. Based on the observation made in these studies, it is proposed that more extensive monitoring investigation covering all vegetables part in Akwanga Nasarawa state be carried out to find the exact position of pesticide residues.