Comparative Assessment of Pesticide Residues in Beans (Vigna unguiculata) Sold by Itinerant Street Vendors and Market Traders in Benin City, Nigeria

Abstract

Pesticides are chemical substances used to control or eliminate pests. They are commonly used by farmers and it plays an important role in food supply globally. However, excessive and unregulated usage of pesticides can result to environmental degradation due to the accumulation of these pesticide residues in the environment as well as the cultivated crops. There are social media reports that shows evidences of post-harvest application of pesticides by itinerant street vendors. This study seeks to compare the levels of contamination of these pesticide residues in bean (Vigna unguiculata) samples obtained from itinerant street vendors and market traders in Benin City. Samples were obtained from itinerant street vendors (as sample A) and market traders (as sample B) across the four (04) local government areas in Benin City, Nigeria. Ethyl acetate and sodium sulphate were used to extract the samples and thereafter, the concentration of pesticide residues was determined using Gas Chromatography coupled with Mass Spectrophotometer (GC-MS). Results obtained shows that the concentration of pesticide residues in sample A ranged from 0.008 – 0.710 mg/kg, and 0.032 – 1.360 mg/kg in
sample B. Bean from sample A contains the highest number of pesticide residues compared to sample B. Dichlorvos (sniper) was only detected in sample A (0.090 mg/kg). Although, the concentration of dichlorvos detected was below the maximum residue limit set by WHO/FAO, stringent measures need to be taken to avoid health risk that may result from bioaccumulation of this pesticide residues. Public awareness campaign on the dangers of post-harvest application of pesticides is highly recommended to safeguard food security and consumers’ health.