en Radiation Biology Radiation Biology تحقيق بديع Original Research <b> Background:</b> Tea is one of the most popular beverages all over the world which is prepared from the leaves of a shrub camellia sinensis. Eastern Black Sea Region of Turkey which account for around 100% of all tea production in Turkey was among the areas contaminated by Chernobyl accident. <b>Materials and Methods: </b>A comprehensive study was planned and carried out to determine the level of gross α and β radioactivity and annual effective dose equivalent in different Turkish market tea using LSC. <b>Results: </b>The average measurements for digestion and infusion are 5.0 mBql^-1 and 1.8 mBql^-1 for gross α, 80.7 mBql^-1 and 9.0 mBql^-1 for gross β in tea samples. Contributions of the infusion tea samples to total annual effective dose equivalent from ²³⁸U, ²³⁴U, ²³⁰Th, ²²⁶Ra, ²¹⁰Po, ²³²Th, ²³⁸Th, ²¹⁰Pb and ²²⁸Ra are 0.103, 0.112, 0.480, 0.640, 2.742, 0.525, 0.164, 7.740 and 7.740 μSvy^-1 for adults. <b>Conclusion:</b> The obtained results showed that natural activity concentrations of α- and β-emitting radionuclides and annual effective dose equivalent in tea samples did not exceed WHO recommended levels.<b> Iran. J. Radiat. Res., 2012 10(2): 67‐72 </b> Gross α, gross β, activity, tea, effective dose equivalent 67 72 http://ijrr.com/browse.php?a_code=A-10-1-423&slc_lang=en&sid=1 F.K. Görür filizkorkmaz@yahoo.com 790031947532846002889 790031947532846002889 Yes R. Keser 790031947532846002890 790031947532846002890 No N. Akçay 790031947532846002891 790031947532846002891 No N. As 790031947532846002892 790031947532846002892 No S. Dizman 790031947532846002893 790031947532846002893 No