Analysis of Heavy Metal Content in Vegetables Grown Near Refuse Dumpsites in Warri, Delta State

Urban agriculture practiced near refuse dumpsites raises significant concerns about heavy metal accumulation in food crops, posing risks to consumer health. This study analysed the concentrations of lead, cadmium, chromium, and nickel in three leafy vegetables, namely Amaranthus hybridus, Telfairia occidentalis, and Lactuca sativa, grown on farmlands adjacent to Ekpan and Effurun dumpsites in Warri, Delta State, South South Nigeria. Vegetable and corresponding soil samples were collected from three farmland plots within 50 metres of each dumpsite and from a reference site 2 kilometres away. Samples were digested using nitric-perchloric acid and analysed by atomic absorption spectrophotometry. Results showed that lead and cadmium concentrations in dumpsite-adjacent vegetables significantly exceeded Food and Agriculture Organization and World Health Organization maximum permissible limits. Amaranthus hybridus accumulated the highest levels of all four metals, likely due to its fibrous root structure. Soil analysis confirmed elevated metal concentrations at contaminated sites, with transfer factors indicating active phytoaccumulation. The reference site vegetables showed safe metal levels across all parameters. The findings highlight the public health risks of consuming vegetables from dumpsite-adjacent farms and underscore the need for spatial zoning of urban farming in Delta State. Keywords: heavy metals, vegetables, dumpsites, food safety, Warri.