Assessment of Soil-To-Cassava Transfer of Trace Metals and Associated Dietary Health Risks from Cassava (Manihot Esculenta) Consumption in Delta, Nigeria

Abstract

Trace metal contamination of agricultural soils poses a significant challenge to food safety, sustainable agriculture, and public health, directly impacting the achievement of the United Nations Sustainable Development Goals (SDGs), particularly SDG 2 (Zero Hunger) and SDG 3 (Good Health and Well-being). This study investigated the concentrations, soil-to-crop transfer behavior, and associated health risks of copper (Cu), zinc (Zn), manganese (Mn), and lead (Pb) in agricultural soils and cassava (Manihot esculenta) cultivated across eighteen locations in Delta Central, Nigeria. Soil and cassava samples were analyzed using atomic absorption spectrometry (AAS). Mean concentrations of Cu, Zn, Mn, and Pb in soils were 0.054, 0.525, 0.720, and 2.763 mg/kg, respectively, while corresponding concentrations in cassava were 0.140, 0.370, 0.170, and 1.724 mg/kg. Metal abundance followed the order Pb > Mn > Zn > Cu in soils and Pb > Zn > Mn > Cu in cassava. Soil-to-crop transfer factors indicated relatively higher uptake efficiency for Cu and ZN compared with Mn and Pb. Although measured concentrations were below international permissible limits, Pb levels were consistently elevated in both soils and cassava, resulting in higher exposure indices. The findings highlight the potential for chronic dietary exposure to Pb and underscore the need for continuous monitoring and improved soil management practices to safeguard food safety in the region.