Metal Concentration in Commonly Used Medicinal Herbs and Infusion by Lebanese Population: Health Impact

The levels of K, Ca, Fe, Zn, Cu, Mn, Pb, As, Cd, Cr, and Pb in commonly used medicinal herbs and their infusions by Lebanese were analyzed by EDXRF and ASS techniques, respectively. The order of metal contents in the herbs was found to be: K (6990-19850 ug/g) > Ca(1630-14450 ug/g) > Fe(80-3650 ug/g) > Mn (28-458 ug/g) > Zn (23-108 ug/g) > Cu (5-71 ug/g) > Cr (3.1-55 ug/g) Pb> (1.1-10.3 ug/g) > As (nd-10.8 ug/g) > Cd (nd-1.7 ug/g). The mean levels of toxic metals in herbs Pb, As and Cd were below WHO permissible levels. Cluster analysis indicated metals are most probably in plants due to wastes disposal and irrigation with contaminated wastes and/or from atmospheric waste particulates. The levels of Mn, Cr, Pb and As in herbal infusions were found to be higher in soaked than boiled preparations and correlated with Fe, while Zn and Cu levels were higher in boiled infusions. The highest weekly intake from herbal infusions of toxic metals Cr (492.8 ug), As (77.0 ug), Pb (291.2 ug) and Cd (19.0 ug) were below the recommended permissible tolerable weekly intake respectively 1260 ug, 900 ug, 1500 ug, and 150 ug. Therefore, the consumption of these traditional medicinal herbs does not pose any health risk provided full compliance with recommended daily doses.