Heavy Metal Concentration in Black Tea in Iran

Background & Aims of the Study: Tea is one of the most important beverages that consumes in several parts of the world including Iran. Tea plant can be contaminated during manufacturing processes and growth period by pollutants such as heavy metals. In this study, the concentration of some heavy metals in different brands of both Iranian and imported black tea to Iran was investigated to survey the human exposure to such pollutants. Materials & Methods: The study was carried out on different brands of black tea that most widely consume in Iran. The samples were collected from available supermarkets in Tehran city and concentrations of Mn, Cd and Cu were determined in black tea, using ICP-OES. Finally obtained results, by one way ANOVA analysis, compared to maximum contaminant concentration which is determined by WHO. Results: Results showed that concentrations of measured heavy metals in sampled black tea were different according to the brand of tea. The mean of Mn, Cu and Cd elements in all tea samples were 664.78, 26.15 and 0.194 µg/g, respectively. Generally, Cu content in studied samples was not significantly above WHO but Cd content, in some cases, was significantly higher than WHO. The guideline value is not given by WHO for Mn content of tea. Conclusions: According to the obtained results, Cd content is exceeding than WHO standards, therefore, control of Cd, as a toxic element that can accumulate in living systems, is necessary.