The concentration and health risk of potentially toxic elements in black and green tea—both bagged and loose-leaf

Abstract

The concentration of potentially toxic elements (PTEs), including lead (Pb), cadmium (Cd), arsenic (As), zinc (Zn), and copper (Cu), among 160 samples of black and green tea—both bagged and loose-leaf—in Iran was determined using a graphite furnace atomic absorption spectrophotometer (GF-AAS). Besides, the transfer rate of PTEs from made tea into tea infusion was investigated, and the related health risk for consumers was assessed. According to the results, the content of the PTEs is dependent on the type of tea (black or green), the place of cultivation (Iran or India), and the supplied form (both bagged and loose-leaf). The concentration of Pb, Cd, and As in green tea was significantly lower than black tea (P-value < 0.05). On the other hand, the contents of Zn and Cu in green tea were higher than the corresponding values for black tea. The mean concentration of Pb, As, and Zn in bagged tea samples was significantly higher than those of loose-leaf tea, while the Cd and As levels in Iranian tea samples were significantly lower than the Indian samples. Generally speaking, the mean concentration of Pb, Cd, As, Zn, and Cu were 0.59 ± 0.12, 0.12 ± 0.06, 0.16 ± 0.12, 14.23 ± 4.90, and 11.10 ± 2.49 mg kg?1, respectively. The mean transfer rates of Pb, Cd, As, Zn, and Cu were 7.78, 6.29, 9.27, 12.91, and 13.08%, respectively. The estimated daily intake (EDI) and noncarcinogenic quotient (target hazard quotient [THQ]) due to the ingestion of PTEs besides the carcinogenic risk of As and Cd were considered as acceptable.