Estimation of human health risk associated with the consumption of pesticide-contaminated vegetables from Kumasi, Ghana

Abstract

Analysis of pesticides consisting of 12 organophosphates (OPs), 10 organochlorines (OCs), and 6 pyrethroids in vegetables from Kumasi was conducted. Vegetable samples comprising 20 each of eggplants, okra, and tomatoes were analyzed. The method involves solvent extraction of pesticide residues followed by cleanup using silica gel. Residue analysis was carried out using a GC equipped with pulsed flame photometric detector for OP residues and electron capture detector for OC and pyrethroid residues. The results revealed that methamidophos exceeded the maximum residue limits (MRLs) in all vegetable commodities. Levels of malathion and dimethoate also exceeded the MRLs in eggplant and tomato samples. Endrin, α-endosulfan, γhexachlorocyclohexane (HCH), γ-chlordane, and heptachlor exceeded their MRLs in okra samples whereas methoxychlor, allethrin, and deltamethrin exceeded in eggplant samples. Health risk estimation revealed that dimethoate in tomato and endrin, heptachlor, γ-HCH, and γ-chlordane in okra could not pose potential toxicity to the consumer. The combined risk index showed no health risk to consumers due to intake of pyrethroid OC and OP residue on these vegetables. The overall risk index for combined pesticides due to consumption of all the vegetables was higher than 1, which signifies potential health risk to consumers. OPs were the major risk contributor for both eggplant and tomatoes which accounted for 87.78 and 95.84 %, respectively, of the combined risk of pesticides in the vegetables. However, OC with 97.94 % of the combined risk index was the major risk contributor for the okra. The carcinogenic risk of the OCs in okra was of no concern since their carcinogenic rates were below the acceptable risk level.