Characteristic of thoron (220Rn) in environment

Masahiro Hosoda; Hiromi Kudo; Kazuki Iwaoka; Ryohei Yamada; Takahito Suzuki; Yuki Tamakuma; Shinji Tokonami

doi:10.1016/j.apradiso.2016.11.014

Characteristic of thoron (²²⁰Rn) in environment

Appl Radiat Isot. 2017 Feb:120:7-10. doi: 10.1016/j.apradiso.2016.11.014. Epub 2016 Nov 22.

Authors

Masahiro Hosoda¹, Hiromi Kudo¹, Kazuki Iwaoka², Ryohei Yamada¹, Takahito Suzuki¹, Yuki Tamakuma¹, Shinji Tokonami³

Affiliations

¹ Hirosaki University Graduate School of Health Science, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
² Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
³ Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan. Electronic address: tokonami@hirosaki-u.ac.jp.

PMID: 27894046
DOI: 10.1016/j.apradiso.2016.11.014

Abstract

This paper describes importance of ²²⁰Rn (hereafter thoron) progeny measurement for the dose estimation. Although the spatial distribution of thoron activity concentration strongly depends on the distance from wall surface as an indoor thoron source), a homogeneous distribution was expected to be observed for ²¹²Pb activity concentration which was one of thoron progeny. Furthermore, the mean equilibrium factor for thoron obtained by the recent measurements in several countries widely ranged from 0.008 to 0.07. Therefore the bronchial dose evaluated using the equilibrium factor and activity concentration of thoron instead of thoron progeny activity concentration may have a large uncertainty. Thus, the thoron progeny measurement should be investigated at each measurement point for the dose estimation for thoron.

Keywords: Dose estimation; Equilibrium factor; Passive-type radon-thoron discrimination monitor; Spatial distribution; Thoron.

Publication types

Review