Heavy Metal Contamination in Two Tilapia Species ( Oreochromis macrochir and Coptodon rendalli ) From the Kabompo River, Zambia: A Food Safety and Human Health Risk Assessment

ABSTRACT Aquaculture sustainability is threatened by heavy metal contamination, particularly in regions where rivers are the primary water sources. The present study assessed the concentrations of cadmium (Cd), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) in two key aquaculture species, Oreochromis macrochir and Coptodon rendalli , from the Kabompo River, Zambia. Using atomic absorption spectrophotometry (AAS), Ni (0.003–0.065 mg/kg ww), Zn (0.41–3.90 mg/kg ww), Cu (3.42–6.81 mg/kg ww) and Mn (0.04–0.24 mg/kg ww) were detected in muscle tissue, while Cd, Co and Pb were below detection limits. All detected metal concentrations were within permissible limits set by national and international standards for food safety, indicating a negligible immediate health risk to both fish and human consumers. A two‐way ANOVA showed that concentrations of Cu, Zn and Mn were significantly influenced by both sampling site and fish species ( p < 0.05), whereas Ni varied significantly only by site. The overall order of metal concentration was Cu > Zn > Mn > Ni. Furthermore, key physicochemical water parameters (dissolved oxygen, pH, temperature, conductivity, salinity and total dissolved solids) showed no significant spatial variation and remained within optimal ranges for tilapia aquaculture. This study provides baseline information on heavy metal concentration in edible tissues of Oreochromis macrochir and Coptodon rendalli from the Kabompo River, contributing to food safety assessment and aquaculture management in the region. However, continued monitoring is recommended to safeguard long‐term fishery sustainability and food security.