Correlation Between Industrial Activities and Heavy Metal Levels in Vegetables Grown Near Aba Industrial Zone, Abia State

Urban and peri-urban vegetable cultivation near industrial zones creates potential pathways for heavy metal accumulation in food crops through soil uptake and aerial deposition. This study examines the concentrations of cadmium, lead, zinc, nickel, and copper in three commonly consumed vegetables, specifically Amaranthus hybridus, Telfairia occidentalis, and Solanum macrocarpon, grown near the industrial area of Aba, Abia State, South East Nigeria. Vegetable and corresponding soil samples were collected from five farms within one kilometre of industrial facilities and two control farms located five kilometres away. Samples were digested using a mixture of nitric and perchloric acids and analysed by atomic absorption spectrophotometry. Transfer factors were calculated to assess metal mobility from soil to plant tissue. Results indicate that zinc and copper concentrations in vegetables from industrial-proximate farms were significantly higher than in controls and exceeded the maximum permissible concentrations stipulated by the FAO-WHO Codex Alimentarius in several samples. Lead was detected in all vegetable samples, with Amaranthus hybridus showing the highest bioaccumulation. Transfer factors for cadmium were particularly elevated for leafy vegetables. Daily dietary intake estimates for adults and children consuming these vegetables indicate potential health concerns under regular exposure. The study recommends the relocation of vegetable farms away from industrial areas and the establishment of soil quality standards for urban agriculture. Keywords: heavy metals, vegetables, Aba Industrial Zone, bioaccumulation, food safety