Annual effective dose measurement from consumption of Dimeh Springs in the highest altitude region of Iran
Two of the main sources of public exposure from natural radioactivity are radium and radon, and their short-lived decay products. The aim of this study is to determine the concentration of these radionuclides in the mineral water resources of one of the highest-altitude regions (Zagros Mountains) in Chaharmahal and Bakhtiari Province, in the south-west of Iran, namely Dimeh Springs. Eighty drinking springwater samples were taken from Dimeh Springs (ten samples for each spring) to determine the radium-226 and radon-222 concentrations using the emanation method and a liquid scintillation counting method, respectively. The results showed that the effective dose from the consumption of drinking water of Dimeh Springs (6.4 µSv y−1) is not comparable with the other annual effective doses, such as inhalation of radon and its products in cosmic and terrestrial rays. Also, the annual effective dose measured here is much less than the worldwide mean value of 0.45 mSv (UNSCEAR, 2000), and is below the proposed limits in other countries. Hence, this source may be regarded as safe drinking water in the region.
Keywords: radium, radon, natural radioactivity, Dimeh Springs, Chaharmahal and Bakhtiari, Iran, radionuclides, mineral water, spring water, low radiation, drinking water, water quality