Heavy metal content in tea soils and their distribution in different parts of tea plants, Camellia sinensis (L). O. Kuntze.

Soils contaminated with heavy metals may pose a threat to environment and human health if metals enter the food chain over and above threshold levels. In general, there is a lack of information on the presence of heavy metals in tea [Camellia sinensis (L). O. Kuntze] plants and the soils in which they are grown. Therefore, an attempt was made to establish a database on the important heavy metals: cadmium (Cd), chromium (Cr), nickel (Ni), and lead (Pb). For an initial survey on heavy metals, soil samples were collected randomly from tea-growing areas of Tamil Nadu, Kerala, and Karnataka, India. Parallel studies were conducted in the greenhouse on uptake of Pb, Cd, and Ni from soils supplemented with these metals at different concentrations. Finally, metal distribution in the tea plants under field conditions was also documented to assess the accumulation potential and critical limit of uptake by plants.