Levels and health risk assessment of As and Zn in Shirazi thyme, sweet violet, pennyroyal and jujube marketed in Hamedan City

The use of medicinal herbs plays a vital role in improving the health of human society. Since the plants are the most important transmission route of heavy metals into human food chain and biological cycles, this study was conducted to assess the health risk of concentration of As and Zn in Shirazi thyme, sweet viola, pennyroyal and jujube marketed in Hamedan City during 2015. After preparation of 3 samples of each medicinal plant, the samples were digested in acid according to the standard methods. The concentration of each element in the samples was determined using atomic absorption spectroscopy (AAS) in 3 replicates. Statistical analyses were performed using SPSS statistical package. The results showed that the maximum mean concentrations of As and Zn were 0.035±0.026 and 1880±520 µg/kg related to thyme and viola, respectively. The results of health index for all samples were found lower than one. Moreover, the mean concentration of As and Zn in all samples were lower than WHO permissible limits. Although controlled consumption of medicinal plants has not adverse effect on the consumers’ health, concerning to the bioaccumulation of heavy metals in the long-term, regular periodic monitoring of chemical pollutants content especially heavy metals in medicinal plants are recommended for food safety.