Assessment of Organochlorine Pesticide Residue Levels in Fruits and Vegetables Sold in Federal Capital Territory (FCT), Nigeria

Abstract

The study evaluated the organochlorine pesticide residue levels in fruits and vegetables sold in Federal Capital Territory, Abuja. Six samples were bought from eleven major markets across the six Area Councils of FCT, Abuja. The samples were mixed to form composite groups of the fruits and vegetables, and prepared using QuEChERS method. It was analysed using Agilent 7890 Gas Chromatography equipped with a micro-cell Electron Capture Detector (μECD). The analysis revealed that the hazard index (HI) for all the fruits and vegetables studied were well below the levels of adverse health effect for chronic exposure except for Onion in children which was 1.2287. The HI for the various fruits and vegetables in children were higher than those for the adult. For example, the HI for Tomato, Green Amaranth Leaves and Pepper all in children were 0.4485, 0.4411 and 0.3981 respectively while the HI for Tomato, Green Amaranth Leaves and Pepper all in adult were 0.1121, 0.1103 and 0.0995 respectively. The calculated cancer risk associated with the consumption of these fruits and vegetable showed values well below the upper bound of 1.0x10-6 except for Aldrin, Dieldrin, Heptachlor, Heptachlor Epoxide. a-BHC, b-BHC, and d-BHC especially in children. From the hazard index and cancer risk analysis, Aldrin and Dieldrin have been implicated as the pesticides of concern since they were present in reasonable concentrations for almost all the samples and age groups studied. The highest potential of cancer risk was found in Onions for children. Also, the total cancer risk implicated Onions (with a value of 1.2x10-4 for adult and 4.7x10-4 for children) and Pepper (with a value of 5.5x10-5 for adult and 2.2x10-4 for children) as the most contaminated foodstuffs with pesticide residues in the studied area. The order of the total cancer risk from the study was Onions > Pepper > Tomato > Green Amaranth Leaves > Fluted Pumpkin Leaves > Okra for both adult and children. In conclusion it was observed that pesticide residues of Endrin, o,p'-DDE and Heptachlor in Onions, Green Amaranth Leaves and Pepper were above the Codex maximum residue level (MRL). Endrin in Onions had 858.0%, o, p'-DDE in Onions had 276.0%, o, p'-DDE in Green Amaranth Leaves had 100.8%, Heptachlor in Pepper had 168.4% and Heptachlor in Onions had 119.2%. Also, the hazard index of chronic exposure and cancer risk of children for Onions requires urgent attention as their values were well above the acceptable limit. Therefore, periodic monitoring of pesticides residues in these fruits and vegetables cannot be over emphasized, but will go a long way to prevent, control and reduce environmental pollution and health risks. Also, taking precautionary measures like proper cooking before consumption of these foodstuffs is advised.