Bioaccumulation of Heavy Metals and Health Risk Assessment in Taro (Colocasia Esculenta) Grown with Mine-Affected Irrigation Water in the Atiwa East Municipality, Ghana

In tropical countries such as Ghana, small-scale mining poses serious threats to the environment and human health, while also affecting essential crops like taro (Colocasia esculenta) and endangering the livelihoods of smallholder farmers. The study analyzed heavy metal concentrations (As, Cd, Cu, Cr, Pb, Hg) in soils and taro tubers from an irrigated agricultural area, collecting 75 samples from three points at distances of 10 m, 20 m, and 40 m from the water source. Heavy metal levels were analyzed via ICP-OES, assessing health risks for adults and children from taro intake. The results showed that As, Cd, Cu, Cr, Pb, Hg concentrations in soil ranged from 0.0001 to 0.99 mg/kg, 0.001–0.092 mg/kg, 20.44–28.28 mg/kg, 0.5991–2.281 mg/kg, 0.041–0.112 mg/kg, and 0.001– 0.010 mg/kg, respectively. Heavy metal concentrations in soil were mostly within limits, with isolated arsenic exceedances at S1 and S2. Mean heavy metal concentrations in taro tubers (As, Cd, Cu, Cr, Pb, Hg) across Sites T1, T2, and T4 ranged from 0.0010 to 4.2090 mg/kg and were generally below the limits set by WHO/FAO. Site-specific exceedances of Cd and As indicate localized contamination risks at T1, S1, and S2. Bioaccumulation factor values indicated moderate bioaccumulation for chromium (0.64 – 0.97) and moderate accumulation for cadmium (0.40 – 0.45) and mercury (0.23 – 0.37). Health risk assessment revealed potential concerns at T2 and T4, where Cr and Cd exceeded safe thresholds (HQ > 1). Risks were lower for adults, but children showed higher dietary intake of Cd and Pb, indicating greater vulnerability. Arsenic risk from taro consumption is within acceptable limits, posing no significant lifetime cancer risk for adults and children. This study asserts that regular monitoring of irrigation water and agricultural products is crucial for reducing health risks associated with heavy metals.