Evaluation of 226Ra activity concentration in market consuming food staples of Ramsar, Iran

Introduction: Among High Level Natural Radiation Areas (HLNRAs) all over the world, the northern coastal city of Ramsar has been considered enormously important. People living in this area have been exposed by several sources, one of which could be foodstuff. However, many studies have been carried out to measure the environmental radioactivity in Ramsar, but no survey has been undertaken to measure concentrations in theall stapled consumed foods yet. This study was dedicated to determine 226Ra activity concentration in the daily diets of Ramsar residents as a probable exposure. Materials and Methods: About 70 different market samples were collected during the four seasons based on the daily consumption patterns of residents which have the highest consumption and their availability in the seasons. In these samples, after washing and drying and pretreatment, the radionuclide was determined by a-spectrometry. Results: The mean radioactivity concentration of 226Ra ranged between 7 ± 1 mBq Kg−1 wet weight in meat, and 318 ± 118 mBq Kg−1 for tea dry leaves. The 226Ra activity concentrations in collected samples varied from below the minimum detectable activity up to 530 ± 30 mBq Kg−1. The 226Ra activity concentrations compared with the reference values of UNSCEAR appear to be higher in milk, chicken and eggs and less in grain products, vegetables, fruits and fish products. These results indicate that no significant 226Ra contamination is present in market foodstuffs and provide reference values for the foodstuffs in Ramsar. Conclusion: The results show that the existence of 226 Ra in a variety of amounts, depending on the location of the food cultivation, proving the fact that residents could be exposed daily by food consumption, which include foodstuff from local and markets. Of the total daily dietary 226 Ra exposure from market consuming foodstuffs for adults in Ramsar, the largest percentage was from wheat. The residents consuming wheat and manufacturing wheat products such as bread, pasta, porridge, crackers, biscuits, pancakes, pies, pastries, cakes, cookies, muffins, rolls, doughnuts, breakfast cereals and so on may receive an elevated dose in the diet. In conclusion, with regards to presence of ²²⁶Ra in foodstuffs it is necessary to monitor regularly the activity of ²²⁶Ra in foodstuffs including market and local foods.