Revisiting the influence of the equilibrium factor and the contribution of Rn, Tn and their progeny in dose assessment

IF 2.9 4区环境科学与生态学 Q3 ENVIRONMENTAL SCIENCES

Air Quality Atmosphere and Health Pub Date : 2025-02-08 DOI:10.1007/s11869-025-01708-5

Gondji Dieu Souffit , Koyang François, Oumar Bobbo Modibo, Eka Djatnika Nugraha, Ndjana Nkoulou II Joseph Emmanuel, Jalaluddin Shah, Rosaline Mishra, Chutima Kranrod, Yasutaka Omori, Masahiro Hosoda, Balvinder K Sapra, Saïdou, Shinji Tokonami

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Abstract

This study is a comparative analysis of the methodology for estimating the total effective inhalation dose of radon (Rn), thoron (Tn) and their decay products. In particular, it considers the influence of the equilibrium factor and the contribution of Rn, Tn and their decay products in dose estimation. Radon and thoron concentrations and their progeny were measured using two types of passive integrated discriminative radon-thoron detectors commercially known as RADUET and DRPS/DTPS. The concentration of Rn ranged from 33 to 75 Bq m⁻³, with a mean value of 49 Bq m⁻³. The concentration of Tn ranged from 11 to 742 Bq m⁻³, with a mean value of 203 Bq m⁻³. It was determined that 93% of dwellings exhibited EERC values below the global mean of 15 Bq m⁻³, with the EETC mean value being 22 times greater than the global average value of 0.5 Bq m⁻³. The research provides substantial contributions for the implementation of the national radon plan in Cameroon. The equilibrium factor for radon (F_Rn) was found to be 60% higher than the UNSCEAR average value of 0.4. The study underscores the limitation in the application of the UNSCEAR equilibrium factor in assessment of total effective inhalation dose, as it could potentially lead to an underestimation of the risk of public exposure to thoron and radon in many regions worldwide. The annual effective inhalation dose was estimated directly, with radon, thoron, EERC, and EETC contributing to the total effective inhalation dose at 2% (0.04 mSv), 5% (0.11 mSv), 38% (0.93 mSv), and 55% (1.34 mSv), respectively. These results highlight the importance of direct measurements of the progeny concentrations either for radon and thoron for accurately estimation of the effective inhalation dose.

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重新探讨平衡因子对剂量评估的影响及Rn、Tn及其子代的贡献

本研究对氡（Rn）、钍（Tn）及其衰变产物的总有效吸入剂量估算方法进行了比较分析。特别考虑了平衡因子的影响以及Rn、Tn及其衰变产物对剂量估计的贡献。RADUET和DRPS/DTPS两种无源综合判别氡-钍探测器测量了氡和钍的浓度及其子代。Rn的浓度范围为33 ~ 75 Bq m−3，平均值为49 Bq m−3。Tn浓度范围为11 ~ 742 Bq m−3，平均值为203 Bq m−3。结果表明，93%的住宅的EERC值低于全球平均值15 Bq m−3，EETC平均值是全球平均值0.5 Bq m−3的22倍。这项研究为喀麦隆国家氡计划的实施作出了重大贡献。氡的平衡因子（FRn）比UNSCEAR的平均值0.4高60%。这项研究强调了科委会平衡因子在评估总有效吸入剂量方面的局限性，因为它可能导致低估全世界许多地区公众接触钍和氡的风险。直接估算年有效吸入剂量，氡、钍、EERC和EETC对总有效吸入剂量的贡献分别为2% （0.04 mSv）、5% （0.11 mSv）、38% （0.93 mSv）和55% （1.34 mSv）。这些结果强调了直接测量氡和钍的子代浓度对于准确估计有效吸入剂量的重要性。

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来源期刊

Air Quality Atmosphere and Health ENVIRONMENTAL SCIENCES-

CiteScore

8.80

自引率

2.00%

发文量

146

审稿时长

>12 weeks

期刊介绍： Air Quality, Atmosphere, and Health is a multidisciplinary journal which, by its very name, illustrates the broad range of work it publishes and which focuses on atmospheric consequences of human activities and their implications for human and ecological health. It offers research papers, critical literature reviews and commentaries, as well as special issues devoted to topical subjects or themes. International in scope, the journal presents papers that inform and stimulate a global readership, as the topic addressed are global in their import. Consequently, we do not encourage submission of papers involving local data that relate to local problems. Unless they demonstrate wide applicability, these are better submitted to national or regional journals. Air Quality, Atmosphere & Health addresses such topics as acid precipitation; airborne particulate matter; air quality monitoring and management; exposure assessment; risk assessment; indoor air quality; atmospheric chemistry; atmospheric modeling and prediction; air pollution climatology; climate change and air quality; air pollution measurement; atmospheric impact assessment; forest-fire emissions; atmospheric science; greenhouse gases; health and ecological effects; clean air technology; regional and global change and satellite measurements. This journal benefits a diverse audience of researchers, public health officials and policy makers addressing problems that call for solutions based in evidence from atmospheric and exposure assessment scientists, epidemiologists, and risk assessors. Publication in the journal affords the opportunity to reach beyond defined disciplinary niches to this broader readership.