Determination of natural and artificial radioactivity levels in tea samples in Rize province and districts 30 years after Chernobyl

In this study, tea samples were collected from 11 districts and 32 stations in Rize province in order to determine the levels of natural and artificial radioactivity in tea samples in Rize province and districts 30 years after Chernobyl, and average 238U, 232Th, 137Cs and 40K activities in stations were collected by using HPGe detector system, respectively 4.60 Bq. / kg, 4.93 Bq / kg, 11.98 Bq / kg and 372.25 Bq / kg, average 238U, 232Th, 137Cs and 40K activities in tea samples for the districts were found 4.19 Bq / kg, 4.14 Bq / kg, 10.50 Bq / kg, and respectively. Annual effective dose equivalents for 238U, 232Th, 137Cs and 40K radionuclides in tea samples were found in the range of 3,434 µSv / year to 19.060 µSv / year, and in the range of 10.867 µSv / year to 14.488 µSv / year for districts.