Radionuclide concentration in tea, cabbage, orange, kiwi and soil and lifetime cancer risk due to gamma radioactivity in Rize, Turkey

Abstract

BACKGROUND: In this study, the activity concentrations of 232Th, 238U, 40K and 137Cs were measured in tea, cabbage, orange, kiwi and soil samples collected from different stations using gamma spectrometry with a high-purity germanium detector. RESULTS: The average activity concentrations of 232Th, 238U, 40K and 137Cs were found to be 8.2 ± 1.8, 17.3 ± 3.3, 465.8 ± 11.8 and 20.9 ± 3.8 Bq kg-1 in food samples, and 72.4 ± 9.8, 51.1 ± 8.3, 229.3 ± 14.7 and 312.9 ± 11.5 Bq kg-1 in farm soils, respectively. The internal effective dose to individuals and excess lifetime cancer risk from the consumption of the food type radioactivity ranged between 11.7 and 53.6 ?Sv y-1 and between 0.05 × 10-3 and 0.24 × 10-3, respectively. The annual external gamma effective dose and excess lifetime cancer risk in the farms due to soil radioactivity ranged between 94.1 and 139.8 ?Sv y-1 and between 0.43 × 10-3 and 0.64 × 10-3, respectively. The mean transfer factors of 232Th, 238U, 40K and 137Cs, from the soil to vegetables and fruit were 0.57, 0.32, 2.12 and 0.04, respectively. CONCLUSION: Annual effective gamma doses were found to be higher than the world's average in soil samples. The excess lifetime cancer risks were only found higher than the world's average in soil samples. © 2011 Society of Chemical Industry.