Health Risk Assessment of Toxic Trace Elements in Medicinal Herbs from Algeria

Herbal medicines are widely consumed, yet they may contain toxic trace elements (TEs). We quantified lead (Pb), cadmium (Cd), chromium (Cr), nickel (Ni), and mercury (Hg) in 25 medicinal plant species marketed in northeastern Algeria and assessed risks against international standards. Two hundred samples were purchased in Algiers, Constantine, Sétif, Tizi Ouzou, and Blida. ICP-MS determined TE concentrations using standard digestion with QA/QC. Recovery rates exceeded 80% for all elements, ensuring the reliability of the analytical method. Exceedances were frequent, especially for Pb and Cd. Ginger and peppermint had the highest Pb (37.2 and 35.7 μg·g⁻¹). Fennel, licorice, and clove showed Cd > 2.5 μg·g⁻¹. Hg was elevated in senna and peppermint; coriander and ginger had the highest Cr; Ni contamination was widespread. Health-risk assessment indicated peppermint and ginger exceeded the hazard index (HI > 1), with Pb and Ni as major contributors. Carcinogenic risks for Cd, Cr, and Ni fell within 10⁻⁶-10⁻⁴, though cumulative exposure remains concerning. Findings support stricter oversight, monitoring, and consumer education.