Elemental composition and health risk assessment of heavy metals in medicinal plant Origanum elongatum from Northern Morocco

Abstract

This study evaluates the elemental composition of Origanum elongatum leaves and the potential health risks associated with their consumption. This endemic Moroccan medicinal plant is widely recognized for its therapeutic benefits. Leaf samples were collected from three locations in the Senhaja Srair region (northern Morocco), and thirty-two elements were quantified using k₀-Instrumental Neutron Activation Analysis (k₀-INAA) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). High levels of essential macroelements were found, including potassium (22,953 ± 608 mg·kg⁻¹), calcium (14,539 ± 612 mg·kg⁻¹), magnesium, phosphorus, and chloride. Trace amounts of rare earth elements and toxic metals were also detected, such as cadmium (0.041 ± 0.002 mg·kg⁻¹) and lead (1.005 ± 0.02 mg·kg⁻¹). Health risk assessment was conducted by calculating Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), and Hazard Index (HI). Iron, manganese, zinc, and copper showed the highest EDI values. All THQ values and the total HI were below 1, indicating minimal non-carcinogenic risk. Overall, O. elongatum appears to be a rich source of essential minerals with low levels of toxic elements, supporting its safe use in traditional and functional food applications. • Elemental Variability : The study analyzed the elemental composition of Origanum elongatum from three sites in northern Morocco. • Advanced Analysis Techniques : Instrumental Neutron Activation Analysis (INAA) and Inductively Coupled Plasma–Mass Spectrometry (ICP-MS) identified 32 elements. • Major Elements : High concentrations of Mg, K, Ca, Cl, and Na were detected, while toxic and rare earth elements were in trace amounts. • Health Risk Assessment : Estimated Daily Intake (EDI) was highest for Fe, followed by Mn, Zn, Cu, V, Cr, Pb, Co, Sb, As, and Cd. • Safety Evaluation : The Target Hazard Quotient (THQ) and Hazard Index (HI) were below 1, indicating minimal health risks. • Conclusion : Consumption of Origanum elongatum leaves from northern Morocco poses no significant heavy metal exposure risk.