²²⁶Ra concentration in the teeth of habitants of areas with high level of natural radioactivity in Ramsar

The level of natural radiation in some regions of Ramsar, a northern coastal city of Iran, is known to be among the highest levels of natural radiation in the world. ²²⁶Ra existing in high concentrations in the soil of this region is washed by underground water and transferred to the surface. In this way, ²²⁶Ra enters the food chain of residents and substitutes within the hard body tissues of humans. ²²⁶Ra is one of the so-called bone seekers as its metabolic processes in the human body are similar to calcium and remains in hard tissues of body because of its long half-life, and being an α emitter causes dangerous effects on human health. The purpose of this study is to determine the concentration of ²²⁶Ra in the teeth of residents of these high-level natural radiation areas, compared with a control group. Thirteen teeth in five groups were studied as the case group and thirteen teeth in five corresponding control groups were inspected. The mean values of the activity of ²²⁶Ra in the case group and in the control group were 0.32 and 0.18 mBq g^-1, respectively.