Assessment of human exposure to food crops contaminated with lead and cadmium in Owerri, South-eastern Nigeria

作者：Joseph Ikechukwu Nwachukwu, Leon J. Clarke, Elías Symeonakis, Francis Q. Brearley · 发表于：Journal of Trace Elements and Minerals · 年份：2022 · DOI：10.1016/j.jtemin.2022.100037 · 被引用次数：10 · 研究领域：Heavy metals in environment、Heavy Metal Exposure and Toxicity、Heavy Metals in Plants

Food safety and security have remained an emerging global challenge amidst increasing human activities that potentially contaminate the food chain. With the rapid population growth, urbanisation and unrestrained emission of toxic substances, urban-dwelling Nigerians are particularly vulnerable to consuming contaminated food crops. This study presents a framework for critical analysis of human exposure patterns to potentially contaminated food crops using the city of Owerri (Nigeria) as case study. It systematically assessed the metal burden of soil and staple food crops and the potential health risk associated with dietary exposure of humans to contaminated food crops. Samples of soil, cassava (Manihot esculenta) tubers and fluted pumpkin (Telfairia occidentalis) leaves were collected from household gardens and analysed for concentration of selected metals (Al, As, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb and Zn) using ICP-OES. A risk assessment of human exposure to Pb contamination using both the Target Hazard Quotient (THQ) and Hazard Index (HI) was estimated. The majority of metals measured below the respective health-based maximum concentration limits of the Nigerian Department of Petroleum Resources target value, except for Pb in soil, which was above the limit of 85 µg g−1 in 0.9 % of sampled soils. However, Pb measured above the threshold of 0.3 µg g−1 stipulated by the FAO/WHO Codex Alimentarius in 46 % of sampled pumpkin leaves with no correlation established with soil ...