A pilot study for dose evaluation in high-level natural radiation areas of Yangjiang, China

Abstract

A pilot study to measure ambient gamma dose rate and radon and thoron progeny concentrations was made for eight dwellings selected in Yangjiang, China. Indoor and outdoor ambient gamma dose rates were 110-370 and 100-220 nGy h -1 , respectively. Doses received from indoor terrestrial radiation were estimated to be 0.6-1.8 mSv year -1 . Radon, thoron and thoron progeny concentrations were 19-98, 18-1120 and 0.4-10.3 Bq m -3 , respectively. This pilot study showed that the position of passive-type monitors to be placed and the deployment period should be carefully determined for estimating reliable annual average concentrations.

Radiation dose due to radon and thoron progeny inhalation in high-level natural radiation areas of Kerala, India

“…According to the UNSCEAR report [2], the dose of thoron is often negligible, but it is not so in certain circumstances. In Yangjiang (China), which is an HBRA due to deposition of thorium-bearing monazite sand, a non-negligible contribution of thoron to the dose was reported in some studies [24,35,36]. Similarly, the presence of thorium-bearing monazite sand contributes a large part in elevating the inhalation dose to thoron in the present study area.…”

Indoor exposure levels of radon in dwellings, schools, and offices in China from 2000 to 2020: A systematic review

“…A, Dwellings, (B) School buildings, (C) Office buildings. Sample detail are shown as the table in supplement document [55‐167]…”

Long-term measurements of residential radon, thoron, and thoron progeny concentrations around the Chhatrapur placer deposit, a high background radiation area in Odisha, India

“…The measurements were made by using a CsI(Tl) scintillation survey meter (PDR-101, Hitachi Aloka Medical Ltd., Japan). In order to evaluate air-kerma rate, a conversion factor (0.753 Gy Sv À1 ) was applied to measured values (e.g., Omori et al, 2015).…”