Exposure and Risk of Toxic Elements through Medicinal Hydrophytes

Aquatic medicinal plants are widely consumed in Ghana, yet their safety is threatened by contamination from polluted water bodies. This study examined concentrations of arsenic, cadmium, lead, copper, and zinc in twelve hydrophyte species from rivers in Mampong Municipality and assessed associated health risks. Samples were digested using nitric acid and analyzed by atomic absorption spectrometry (AAS). Method validation yielded recovery rates between 90-110% and detection limits of 0.001-0.01 mg/kg, confirming high analytical accuracy and precision. Mean concentrations showed substantial accumulation, especially in roots and leaves, with As, Cd, and Pb often exceeding WHO limits. Statistical analysis revealed significant species- and part-level variation only for Cu and Zn, whereas As, Cd, and Pb accumulated uniformly across taxa and tissues. Exposure assessment demonstrated that estimated daily intakes (EDIs) of As, Cd, and Pb from several species exceeded recommended thresholds. Hazard quotients (HQ) and hazard indices (HI) were frequently above the safety limit of 1.0, indicating potential non-carcinogenic risks, with children consistently more vulnerable than adults. Carcinogenic risk (CR) values for As were above the acceptable range (10⁻⁶-10⁻⁴), identifying arsenic as the primary driver of long-term health risks. Leaves posed the greatest concern due to their widespread medicinal use, followed by roots. These findings suggest that habitual consumption of contaminated hydrophytes may present significant health risks. Strengthened monitoring, regulation, and public education are essential to protect consumers.