Cadmium and Lead Content in Several Brands of Black Tea (Camellia sinensis) in Iran

Tea is one of the most popular beverages in the world and contains several important essential micro nutrients, that are beneficial to human health. The contamination of tea leaves by heavy metals may pose serious problems to human health, because they are not biodegradable and remain in the environment and might enter the food chain. In this study, the concentration of heavy metals; Cd and Pb was measured by atomic absorption spectrometry (GFAAS) according to AOAC method of analysis. Ten samples of black tea cultivated in Iran were compared with 10 samples of imported black tea in 2011. The results of analysis showed that the mean level of Pb was 497.5 ± 175 ppb for Iranian and 293.3 ± 269.5 ppb for imported black tea. However, the value for Cd was 45 ±17ppb for Iranian and 9.14 ±7 ppb for imported black tea. The average contents of detectable heavy metals were significantly (P<0.05) higher in Iranian black tea. Cadmium and Lead concentrations in the sampled brands of black tea were lower in comparison with their upper limits (0.2 and 2 ppm for Cd and Pb, respectively), therefore, it might be concluded that there are not any health problems concerned with tea consumption, for these two elements