Omori Yasutaka, Sorimachi Atsuyuki, Gun-Aajav Manlaijav, Enkhgerel Nyamdavaa, Oyunbolor Galnemekh, Palam Enkhtuya, Yamada Chieri
Department of Radiation Physics and Chemistry, Fukushima Medical University, 1 Hikarigaoka, Fukushima, Japan.
The Executive Office of the Nuclear Energy Commission, Uildverchid Street 2, Khan Uul District, Ulaanbaatar, Mongolia.
Radiat Prot Dosimetry. 2019 Jul 1;184(1):127-134. doi: 10.1093/rpd/ncy173.
The present study aimed at examining changes of gamma radiation level associated with road construction in Mongolia. A car-borne survey of gamma dose rate was made for a paved, ~450-km long part of the Asian Highway 3 between Ulaanbaatar and Sainshand. The gamma dose rates ranged from 48 to 173 nGy/h. Elevation of the gamma dose rates was observed only on a 86-km long segment of the survey route which was newly constructed from 2011 to 2013. The gamma dose rates over the newer paved segment were twice as high as those over the bare dirt surface alongside it. Outdoor measurements of gamma-ray pulse height distributions also indicated an abundance of natural radionuclides, especially 232Th-series elements in road materials. These findings suggest that the gamma dose rates were elevated by introduction of road materials containing large amounts of natural radionuclides.
本研究旨在调查蒙古国道路建设相关的伽马辐射水平变化。对乌兰巴托和赛音山达之间亚洲公路3号线一段约450公里长的铺砌路段进行了车载伽马剂量率测量。伽马剂量率范围为48至173纳戈瑞/小时。仅在2011年至2013年新建的86公里长的调查路线段上观察到伽马剂量率升高。新建铺砌路段的伽马剂量率是其旁边裸露土路表面剂量率的两倍。伽马射线脉冲高度分布的户外测量也表明道路材料中存在大量天然放射性核素，尤其是钍-232系列元素。这些发现表明，含有大量天然放射性核素的道路材料的引入导致了伽马剂量率升高。
