Exposure to 226Ra from consumption of vegetables in the high level natural radiation area of Ramsar-Iran

The vegetable-to-soil concentration ratio (CR) for 226Ra and the related effective dose were studied in Talesh Mahalleh, a district of the city of Ramsar in Iran with a high level of natural radiation (HLNR). Maximum and minimum CR were measured in leafy and root vegetables with average values of 1.6 × 10−2 and 4.0 × 10−3, respectively. The mean effective dose resulting from 226Ra due to consumption of edible vegetables by adults in the critical group in this region was estimated to be 72.3 μSv a−1. This value is about 12 times greater than the average of effective dose resulting from this radionuclide due to combined intake of all foods and drinking water in normal background areas.