Prediction and Health Risk Assessment of Copper, Lead, Cadmium, Chromium, and Nickel in Tieguanyin Tea: A Case Study from Fujian, China

Heavy metal is widespread in food and the environment due to multiple origins, raising concerns over their persistent potential health risks. Contamination of multiple heavy metals in tea leaves is frequently reported. However, the dietary exposure risk that heavy metals in Tieguanyin tea (a famous type of oolong tea,) pose to different subpopulations has not been explored. In this study, contaminations of five heavy metals (Cu, Pb, Cr, Cd, and Ni) of concern in Tieguanyin tea were monitored, then the related health risk was assessed for six different subpopulations based on tea brewing experiments and a previous consumption survey. Results show that the mean levels found were as follows: 8.18 mg/kg (Cu), 0.84 mg/kg (Pb), 0.51 mg/kg (Cr), 0.04 mg/kg (Cd), and 1.90 mg/kg (Ni), respectively, and their transfer rates during tea brewing varied within 10.2-70.4%. All estimated daily intakes of individual targeted elements via Tieguanying tea consumption were far below their corresponding tolerable limits. The adjusted hazard index value ranged from 1.1 x 10(-2) to 1.7 x 10(-2), indicating that exposure to these five elements via drinking Tieguanyin tea would not pose significant non-cancer risks for six subpopulations under the current consumption habit. In addition, the carcinogenic risks associated with heavy metals (Pb, Cd, and Cr) were acceptable because no total cancer risk values exceeded the 10(-4) threshold. However, in order to improve consumer protection, we still suggest that considerable attention should be paid to Pb, Ni, and Cd because of their high concentration in infusion, high extraction rate, and major carcinogenic risk contribution, respectively.