Monitoring and health risk assessment of organochlorine pesticide residue in some leafy and fruiting vegetables from Lagos State, Southwestern Nigeria

Henrietta I. Kelle1*, Emeka C. Ogoko1, Oluade O. Abiola2, Daniel Achem2, Ifeoma P. Udeozo3
1Department of Chemistry, Faculty of Sciences, National Open University of Nigeria, Jabi, Abuja, Nigeria
2Department of Chemistry, Faculty of Science, University of Lagos, Akoka, Lagos State, Nigeria.
3Department of Industrial Chemistry, Faculty of Natural and Applied Sciences, Enugu State University of Technology, Enugu State, Nigeria.

This study investigated the health risk of pesticide residue in some leafy and fruiting vegetables namely fluted pumpkin (f. Telfairia occidentalis), green amaranth (Amaranthus viridis) and scotch bonnet (capsicum chinense) which are commonly eaten in Nigeria. Pesticide can impart harmful effect on health, it can be a source of exposure to health issues to Nigerians. Fluted pumpkin, green amaranth and scotch bonnet were purchased from the major wholesale market in Lagos state, Nigeria through which food stuffs are distributed in Lagos to retailers. Pesticide residues including alpha lindane, delta lindane, heptachlor, heptachlor epoxide, aldrin, trans– chlordane, p,p’- DDE, dieldrin, endrin, endrin ketone, endosulfan, endosulfan sulfate, endosulfan ether and methoxychlor were extracted from each sample using dichloromethane, and anhydrous sodium sulphate and sodium chloride to enhance liquid-liquid partitioning. Solid phase extraction using agilent cartridges was used to clean-up the extracts. The extracts were analysed for pesticide residues using gas chromatography coupled to mass spectrometer (GC-MS). From the results of the study, most of the pesticide residues were below detectable limit. Endosulfan ether was the only pesticide detected in all the vegetables from all the sources of the vegetables. The mean concentration (mg/kg) of the pesticide residues ranged from 0.0003-4.06 mg/kg. The mean
concentration of some of the pesticide residues in the leafy and fruiting vegetables were either above, within and below the maximum residue limit mg/kg (MRL) recommended by FAO/WHO. The estimated daily intake (EDI) mg/kg bw/day of the pesticide residues ranged from 4.25 x 10−7 to 5.76 x 10−3 mg/kg bw/day. The EDI of all the pesticide residues in the samples are below the acceptable daily intake (ADI) mg/kg bw/day of the pesticide residues as recommended by FAO/WHO, except the EDI of heptachlor in all the samples which are above the recommended ADI. The hazard quotient and hazard index of the pesticide residues in the vegetables ranged from 8.50 x 10−7 – 2.50 for hazard quotient and 0.07 – 3.2 for hazard index. Incremental lifetime cancer risk (ILCR) values for carcinogenic pesticide residues in the vegetables ranged from 1.3 x 10−5 – 2.1 x 10−3. Few of the vegetables had ILCR values for the carcinogenic pesticide residues above acceptable values recommended for ILCR. Consumption of the vegetables with high EDI, HQ, HI and ILCR values may pose health issues to consumers. There is need for continuous monitoring of pesticide residues in food samples in Nigeria.

Fluted pumpkin, green amaranth, hazard index, incremental lifetime cancer risk, pesticide residue

Kelle et al. JKCS 15-1 (2022), 3-13
Supporting Information Kelle et al., JKCS 15-1 (2022), 3-13