Passive-Type Radon Monitor Constructed Using a Small Container for Personal Dosimetry.

Yuki Tamakuma,Chutima Kranrod,Thamaborn Ploykrathok,Ryoju Negami,Takahito Suzuki,Kazuki Iwaoka,Yuki Watanabe,Shinji Tokonami,Eka Djatnika Nugraha,Mirosław Janik,Masahiro Hosoda

doi:10.3390/ijerph17165660

Abstract

The International Commission on Radiological Protection (ICRP) recently recommended a new dose conversion factor for radon based on the latest epidemiological studies and dosimetric model. It is important to evaluate an inhalation dose from radon and its progeny. In the present study, a passive radon personal monitor was designed using a small container for storing contact lenses and its performance was evaluated. The conversion factor for radon (222Rn), the effect of thoron (220Rn) concentration and the air exchange rate were evaluated using the calibration chamber at Hirosaki University. The minimum and maximum detectable radon concentrations were calculated. The conversion factor was evaluated as 2.0 ± 0.3 tracks cm−2 per kBq h m−3; statistical analyses of results showed no significant effect from thoron concentration. The minimum and maximum detectable radon concentrations were 92 Bq m−3 and 231 kBq m−3 for a measurement period of three months, respectively. The air exchange rate was estimated to be 0.26 ± 0.16 h−1, whose effect on the measured time-integrated radon concentration was small. These results indicate that the monitor could be used as a wearable monitor for radon measurements, especially in places where radon concentrations may be relatively high, such as mines and caves.

Highlights

Radon is one of the naturally occurring radionuclides, which is well known as the second leading risk factor for lung cancer after tobacco smoking [1]
The conversion factor (CF) shown in previous papers might have been evaluated using a different type of solid-state nuclear track detector (SSNTD) that has a lower sensitivity than the CR-39 used in the present study
We found a reasonably good agreement between the ratios regardless of the simplified model, indicating that the sensitivity was lower compared with the previous monitor, and the difference in the CFs between the present monitor and RADUET was attributed to the shape of the monitor

Summary

Introduction

Radon is one of the naturally occurring radionuclides, which is well known as the second leading risk factor for lung cancer after tobacco smoking [1]. Public Health 2020, 17, 5660; doi:10.3390/ijerph17165660 www.mdpi.com/journal/ijerph

Methods

Discussion

Conclusion