Assessment of Type and Concentration of Pesticide Residues in Fluted Pumpkin (Telfairia occidentalis) and Green Amaranth (Amaranthus hybridus) Sold in Akure, Ondo State, Nigeria

Abstract

Pesticide residues have been reported in edible agricultural products, posing a huge public health risk. This study investigated the type and concentration of pesticide residues present in common vegetables, Fluted Pumpkin (Telfairia occidentalis) and Green Amaranth (Amaranthus hybridus), sold in four major markets in a capital city, Akure, Ondo State, Southwest Nigeria. Using a series of Gas Chromatography techniques, twenty-three (23) pesticide residues including herbicides, organophosphates, organochlorines and pyrethroids were identified. The mean pesticide residues with the highest concentration (in ppm) in each group include Herbicide: Atrazine (Fluted pumpkin – 0.35, Amaranth – 0.18, Maximum Residue Limit (MRL) – 0.05); Organophosphate: Mevinphos (Fluted Pumpkin – 0.047, Amaranth – 0.043, MRL – 0.01); Organochlorine: Lindane (Fluted Pumpkin – 0.67, Amaranth – not detected (ND), MRL – 0.01) and Aldrin (Fluted Pumpkin – ND, Amaranth – 0.19, MRL – 0.01); Pyrethroid: Permethrin (Fluted Pumpkin – 1.13, Amaranth – 0.23, MRL – 0.05). The frequency of pesticide residues contamination was higher in Fluted Pumpkin (12) than in Green Amaranth (9). The presence of multi-pesticide residues in the vegetables at levels above the WHO MRL and the attendant toxic effect makes pesticide contamination of leafy vegetables a priority public health concern in Akure. This study has brought to the fore the need for more attention to be paid to pesticide contamination of locally-consumed agricultural products against the high incidence of health challenges (such as cancer, birth defect, impaired immune function, and neurobehavioral disorder) linked to pesticide contamination.