Radionuclides and heavy metals concentrations in Turkish market tea

Abstract

Tea is one of the most popular beverages in the world. The Eastern Black Sea Region of Turkey is one of the main tea producers in Turkey and the fifth in the world. Thus, the chemical components in tea have received great interest because they are related to health. Since this region was contaminated by the Chernobyl accident in 1986, a comprehensive study was planned and carried out to determine the radioactivity level in the tea growing region. The activity concentrations of Th-232, U-238, Cs-137 were measured in 29 black tea and one green tea samples from local Turkish markets using gamma spectrometry with an HpGe detector. The average activity concentration of Th-232, Ra-226, K-40 and Cs-137 were found 3.2 +/- 0.6 Bq/kg, 6.4 +/- 0.7 Bq/kg, 445.6 +/- 17.8 Bq/kg and 42.0 +/- 1.4 Bq/kg in tea samples, respectively. In addition, the concentration of five heavy metals including Fe, Mn, Zn, Cu and Pb were determined by inductively coupled plasma spectroscopy (ICP/OES) on tea samples. Among the investigated metals, Mn was the highest levels. The levels of manganese were in the range of 1850.75-292.65 mu g/g (mean: 1286.35 +/- 0.58 mu g/g). Levels of Pb in the tea samples analyzed were below the detection limits. The concentrations of all elements for daily intake are below safety levels for human consumptions. (C) 2011 Elsevier Ltd. All rights reserved.