Heavy Metals Concentrations in Tea and Herbal Tea and Potential Human Health Risk.

Food consumption is an important route for human exposure to pollutants. Tea (Camellia sinensis L.) is a widely-consumed beverage and may accumulate toxic metals. Concentrations of heavy metals plus Al, including total and infusion, were determined in 47 kinds of traditional and herbal tea from different countries to assess their potential health risk. The data showed that herbal tea exhibited significantly higher As (0.26 mg kg^-1), Cd (0.19 mg kg^-1) and Pb (2.4 mg kg^-1) compared to the teas containing Camellia sinesis. Black tea from India had the highest Cr at 31 mg kg^-1 while white tea from China had the lowest Cr at 0.39 mg kg^-1. Arsenic, Cd and Pb did not exceed the WHO limit for medicinal plants except one herbal tea with 1.1 mg kg^-1 As and 26 mg kg^-1 Pb. However, Cr in 47% herbal tea and 73% traditional tea exceeded the WHO Cr limit. Total Al and its infusion was lower in herbal tea (47-1287 mg kg^-1 and 4.5-70 µg L^-1) than traditional tea (1168-2517 mg kg^-1 and 205-751 µg L^-1), with 0.9-12% and 7.9-31% of Al was released into water in infusion. Seven samples from traditional teas had chronic daily intake (CDI) values of Al > 7 mg/d/kg dw, the stipulated permissible limits of Al intake from all sources. Considering the HQ, drinking teas posed no imminent health hazards to both adults and children. However, since we did not consider Al from food and drink sources, health risks from tea consumption cannot be ruled out.