Contamination of cadmium, lead and mercury on Iranian herbal medicines

In spite of the increasing usage of herbal medicine in Iran, considerable research on their contaminations has not been carried out yet. Herbal medicines have been reported to contain many health hazards for herbal therapy patients. For this group, one of the health hazards is contamination to heavy metals such as Cadmium (Cd), Mercury (Hg) and Lead (Pb). Therefore, the aims of this study were the measurements of the level of Cd, Hg and Pb in oral herbal drops available in Iranian market. 10 different herbal products were purchased from market. A certain volume of each samples were digested with nitric acid by wet digestion method, then the final solutions of digestion were used to determine the contamination level of Cd, Hg and Pb. The measurements of Pb, Cd and Hg were performed by spectrometry of flame atomic absorption (AA), graphite furnace atomic absorption (GFAA) and cold vapor atomic absorption, respectively. The lead, cadmium and mercury contents in the investigated samples were found at different levels. Lead and cadmium were present in the majority of samples while mercury was detected on 3 of 10 samples. By a comparison between acceptable global standards and the level of cadmium, lead and mercury on investigated herbal medicines, our results showed that the quantities of these heavy metals were well below acceptable intake recommended by global standards. However, risk assessments needs considerable attention for herbal therapy patients on illness who may be more susceptible to these toxic elements.