ABSTRACT

About 87% of the total dose received by the general public is due to naturally existing radioactive nuclides. Long-term exposure to the relatively long half-life radioactive elements (including Uranium, Thorium, and Potassium) and their decay products pose severe health threats to the population including lung cancer. The related available data has been collected from numerous studies conducted in China over the last two decades. Several studies have been conducted to determine the radioactive content of primordial Uranium-238, Thorium-232, Radium-226, Potassium-40, and anthropogenic Cesium-137 radionuclides in building materials, soil samples from cultivated lands, fertilizers used for reformation of soil, ash (fly, bottom) from coal fired power plant, water for irrigation and dietary items by means of High Purity Germanium HPGe or Sodium Iodide NaI (Tl) detectors. The radium equivalent activity $(R{a}_{eq})$of all the studied materials was found to be less than 370 Bq/kg except in soil from Baoji coal fired power plant (CFPP), building materials from Weinan, Xing, Fly ash from Xiangyang and coal-bearing strata from East china. The glazed tiles from Guandong, Xhaanxi, Shandong, and Zhejiang with $R{a}_{eq}$> 370 Bq/kg, Gamma Index $(I_{\gamma })$ > 6, corresponding to a γ- dose rate higher than the permissible limit of 1 mSv/yr. The volume of the gathered data is vast and scattered, and it is required to compile all data regarding the natural as well as man-made radioactivity in China. The main goal of this paper is to establish a nationwide baseline data on natural radioactivity levels by reviewing and compiling the outcomes of the conducted studies within the entire country.