[ survey on Pb, Cr, Ni and Cu concentrations in Tehran consumed black tea: a short report]

ABSTRACT

Heavy metal pollution has always been a major type of environmental contamination and a main concern for food health. Tea is the most popular beverage in Iran and the presence of heavy metal in tea has received special attention because of their direct effect on health. The aims of this study were to measure the concentrations of Pb, Cr, Ni and Cu in consumed tea. A cross- sectional study was designed for this research. Eleven type of the most widely consumed brands of dry black tea were purchased from local market in Tehran. Certain volumes of four samples of each brand were collected and digested with Nitric acid and Chloridric acid using wet digestion method. The final solution of digestion was used to determine the level of these metals. Heavy metal contents in each sample were determined by atomic absorption spectrometry. The result showed that the mean concentrations of Pb, Cr, Cu and Ni in tea samples were 6.97 +/- 4.78, 5.75 +/- 1.08, 23.85 +/- 9.68, 2.91 +/- 1.9 [mg/kg], respectively. The maximum concentrations of Pb, Cr, Cu and Ni in tea samples were recorded for Ahmad tea Bag, S hilan, Golaby and dochakoshi, respectively. The results indicated that Pb and Ni concentrations in the black tea were higher than the permissible limit for the human foods, while for the other heavy metals, the amounts were lower than that. Regarding increasing trend of food sources, contamination with heavy metals and also due to their bioaccumulation in human body and the subsequent health risks, it is recommended to control these products