Background: 226 Ra and 228 Ra contents in foodstuffs of Ramsar which is a coastal city in the northern part of Iran were determined by gamma spectrometry. Measurement results together with food consumption rates were used to estimate annual effective dose from 226 Ra and 228 Ra, due to consumption of food stuffs by inhabitants of Ramsar city.
Materials and Methods: A total of 33 samples from 11 different foodstuffs including root vegetables (beetroot), leafy vegetables (lettuce, parsley and spinach) and tea, meat, chicken, pea, broad bean, rice, and cheese were purchased from markets of Ramsar city and were analyzed for their 226 Ra and 228Ra concentration. 1-8 kg of fresh weight sample was placed in Marinnelli beaker and sealed. The measurement of natural radioactivity levels as performed by gamma-spectrometry system, using a high purity germanium (HPGe) detector with 40% relative efficiency.
Results: The highest concentrations of 226Ra and 228 Ra were determined in tea samples with 1570 and 1140 mBq/kg , respectively , and the lowest concentration of 226Ra was in pea, cheese, chicken, broad bean, and beetroot.
Conclusion: The maximum estimated annual effective dose from 226 Ra and 228 Ra due to consumption of foodstuffs were determined to be 19.22 and 0.71 mSv from rice and meat samples respectively, where as, the minimum estimated annual effective dose for 226Ra was 0.017, 0.018 and 0.019 mSv from beetroot, cheese and pea samples respectively.