Environmental pollution arising from industrial activities, urbanization, and agricultural practices has become a major concern worldwide because of its potential effects on environmental sustainability and human health. Among the various environmental contaminants, heavy metals are particularly important due to their persistence, toxicity, and ability to accumulate in living organisms. Leafy vegetables form an essential part of the human diet and are widely consumed in Nigeria; however, they can serve as pathways through which contaminants present in the environment enter the food chain. This study investigated the concentration of selected heavy metals in commonly consumed leafy vegetables cultivated around the Otu-Jeremi axis in Delta State, Nigeria. The vegetables examined included bitter leaf (Vernonia amygdalina), fluted pumpkin (Telfairia occidentalis), waterleaf (Talinum triangulare), and scent leaf (Ocimum gratissimum). A control sample was collected from Ugbomro community, located away from major industrial activities. The vegetable samples were air-dried, pulverized, and subjected to microwave-assisted acid digestion prior to analysis using Atomic Absorption Spectrophotometry (AAS). The metals analyzed included iron (Fe), copper (Cu), zinc (Zn), chromium (Cr), cadmium (Cd), and lead (Pb). The results showed that Fe concentrations ranged from 0.115–0.227 mg/kg, Cu from 0.005–0.011 mg/kg, and Zn from 0.034–0.050 mg/kg. Chromium, cadmium, and lead were not detected in any of the analysed samples. Statistical evaluation indicated mean concentrations of Fe (0.153 ± 0.044 mg/kg), Cu (0.0084 ± 0.0023 mg/kg), and Zn (0.0412 ± 0.0073 mg/kg). All detected metals were far below the permissible limits recommended by FAO and WHO for vegetables intended for human consumption. The findings suggest that vegetables cultivated within the Otu-Jeremi axis are presently safe for consumption with respect to heavy metal contamination. Nevertheless, considering the ongoing petroleum exploration and industrial activities within the Niger Delta region, continuous environmental monitoring remains essential to ensure long-term food safety.
