Heavy metal content of black teas consumed in Iran

Abstract

Tea (Camellia sinensis) is the most widely consumed beverage in several parts of the world. Tea consumption is a major component of the traditional Iranian diet; however, limited data are available indicating heavy metals content of this beverage. This study aimed to assess concentrations of heavy metals, including copper, lead, cadmium, chromium and mercury as well as minerals like zinc and iron in black tea samples. Atomic absorption spectrometry was used to determine the elements of interest in 20 brands of black tea that are widely consumed among Iranians. The mean concentrations were 28.8 for Zn, 135.2 for Fe, 15.9 for Cu and 8.2 for Cr (mg kg⁻¹) and 134.5 for Cd, 209.5 for Pb and 40 for Hg (µg kg⁻¹). It is concluded that tea consumption can be a possible source of some heavy metal intake for the Iranian population.

Keywords:

• tea
• heavy metals
• minerals
• contamination

Acknowledgements

The authors thank the Deputy of Researches and Technology of Lorestan University of Medical Sciences for financial support of the project. We also thank Dr. Ahmad Esmaillzade for language review of the manuscript.