Direct measurement of indoor thoron and radon progeny and estimation of inhalation dose in three cities in Gabon: Comparison of the use of thoron typical and measured equilibrium factor values

被引：0

作者：

Mouandza, Sylvere Yannick Loemba ^{[1
,5
]}

Saidou ^{[7
]}

Ndong, W. ^{[1
]}

Kranrod, Chutima ^{[6
]}

Hosoda, Masahiro ^{[6
]}

Meye, P. Ondo ^{[3
,4
]}

Djeune, R. Bipolo ^{[1
]}

Mombo, E. -D. Durastanti-Rabenga ^{[1
]}

Andeme-Abondhoume, H. M. -J. ^{[1
]}

Ndjembidouma, B. C. Mabika ^{[4
,8
]}

Ekogo, T. B. ^{[1
,2
]}

Ben-Bolie, G. H. ^{[4
]}

Tokonami, Shinji ^{[6
]}

机构：

[1] Univ Sci & Tech Masuku, Fac Sci, Dept Phys, Lab Radioanal LARA, BP 943, Franceville, Gabon

[2] Univ Internatl Libreville, Nkok, Gabon

[3] Minist Energie & Ressources Hydraul, Direct Gen Radioprotect & Surete Nucl, Libreville, Gabon

[4] Univ Yaounde I, Fac Sci, Dept Phys, Lab Atom Mol & Nucl Phys, Soa, Cameroon

[5] Univ Strasbourg, IPHC UMR7178, Inst Pluridisciplinaire Hubert Curien, F-67037 Strasbourg, France

[6] Hirosaki Univ, Inst Radiat Emergency Med, Hirosaki, Japan

[7] Inst Geol & Min Res, Nucl Technol Sect, POB 4110, Yaounde, Cameroon

[8] Akanda Canc Inst, Dept Med Phys & Radiotherapy, Libreville, Gabon

来源：

JOURNAL OF ENVIRONMENTAL RADIOACTIVITY | 2024年 / 280卷

基金：

日本学术振兴会;

关键词：

Thoron; Radon; EETC; EERC; Equilibrium factor; Effective inhalation dose; Gabon;

D O I：

10.1016/j.jenvrad.2024.107557

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

This study focuses on public exposure to natural radioactivity caused by the inhalation of radon and thoron progeny in homes in Franceville, Moanda and Mounana in Gabon. The equilibrium factor (F-Tn) between thoron and its progeny was determined experimentally for a proper estimate of the effective dose. In order to assess internal exposure due to radon and thoron progeny, 150 passive radon-thoron discriminative detectors (RADUET) and thoron progeny monitors were deployed for about 3 months in the above-mentioned towns. The results of the measurements obtained showed that the average concentrations of thoron progeny (EETC) were 1.54 +/- 0.08 Bq m(-3), 3.05 +/- 0.09 Bq m(-3) and 1.84 +/- 0.11 Bq m(-3) in Franceville, Moanda and Mounana, respectively. The ranges of the measured thoron equilibrium factors were 0.004-0.710, 0.005-0.750, and 0.006-0.794 in Franceville, Moanda and Mounana, respectively. The arithmetic and geometric mean values were, respectively, 0.183 and 0.117 in Franceville, 0.184 and 0.122 in Moanda, and 0.221 and 0.140 in Mounana. The experimentally determined equilibrium factor (F-Tnexp) allowed us to compare the value of the experimentally determined effective dose with the theoretically determined one calculated using the equilibrium factor proposed by United Nation Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2000 report. F-Tnexp values were around 6-11 times greater than the UNSCEAR typical value. The ranges, arithmetic and geometric mean EERC values determined were 30.40-55.60 Bq m(-3), 24.00 +/- 0.90 Bq m(-3) and 41.68 (1.00) in Franceville, 36.40-62.50 Bq m(-3), 45.30 +/- 0.70 Bq m(-3) and 44.72 (1.00) in Moanda, and 35.00-90.00 Bq m(-3), 50.00 +/- 2.00 Bq m(-3) and 48.50 (1.00) in Mounana. The mean values of the annual effective inhalation dose due to thoron progeny determined using F-Tnexp were 0.32 mSv (compared to 0.049 mSv), 0.63 mSv (compared to 0.103 mSv), and 0.39 mSv (compared to 0.055 mSv) in Franceville, Moanda and Mounana, respectively. The main conclusion of this study is that indirect estimations of thoron progeny concentrations considerably underestimate the estimation of the annual effective inhalation dose.

引用

页数：6