Diurnal variations of indoor short-lived radon daughters with positive 218Po and 214Pb clusters and their impact on atmospheric air ions

IF 8.2 1区环境科学与生态学 Q1 ENVIRONMENTAL SCIENCES

Science of the Total Environment Pub Date : 2025-05-17 DOI:10.1016/j.scitotenv.2025.179666

Maged Ahmed Saleh Abdo , Fatima Ezzahra Arhouni , Saad Ouakkas , Aziz Boukhair , Hamid Nebdi , Mohammed Fahad

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Abstract

Airborne radon progenies (²¹⁸Po, ²¹⁴Pb and ²¹⁴Po) are classified as radioactive aerosols and pose a significant public health risk when inhaled indoors. They are the largest source of natural radiation exposure and play a key role in environmental ionization, affecting aerosol size distribution. Thus, accurate measurements of these contaminants are crucial for understanding and controlling airborne radioactivity, providing basic parameters for assessing atmospheric air pollution levels. Therefore, continuous indoor measurements were conducted at 2-h intervals across various seasons during 2023 and 2024 in El Jadida, Morocco, considering meteorological parameters. The measurement method involves sampling the aerosol-attached radon progeny on filters, followed by α-counting using nuclear track detectors (CR-39) based on a three-count approach. Additionally, we have developed PC-based software that utilizes experimental measurements as input data to solve differential equations and calculate all necessary physical quantities. The ²²²Rn, ²¹⁸Po, ²¹⁴Pb and ²¹⁴Po annual average concentrations were 80.2 ± 6.6, 44.0 ± 3.6, 34.5 ± 2.8, and 24.3 ± 2.0 Bq/m³, respectively, with ²¹⁸Po and ²¹⁴Pb unattached activity of 11.2 and 0.6 Bq/m³. These concentrations exhibited significant diurnal variations of 3–4 times with maxima in the early morning and minima in the afternoon, while they changed seasonally by 30–50 % with peaks occurring in the colder months. Diurnal variations in radon-linked ionization rates and corresponding air ion concentrations are subject to changes in these radionuclides levels, with annual averages of 27.9 ion-pairs cm⁻³ s⁻¹ and 2113 ions/cm³ respectively. Results indicated that, under normal home conditions, about 52 % of ²¹⁸Po and 49 % of ²¹⁴Pb clusters are positively charged.

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218Po和214Pb阳性簇室内短寿命氡子体的日变化及其对大气离子的影响

空气传播的氡子体（218Po、214Pb和214Po）被归类为放射性气溶胶，在室内吸入会对公众健康造成重大危害。它们是天然辐射暴露的最大来源，在环境电离中起关键作用，影响气溶胶的大小分布。因此，对这些污染物的精确测量对于理解和控制空气放射性至关重要，为评估大气污染水平提供了基本参数。因此，考虑到气象参数，在2023年和2024年，在摩洛哥El Jadida的不同季节，每隔2 h进行连续室内测量。测量方法包括在过滤器上采样气溶胶附着的氡子代，然后使用核径迹探测器（CR-39）基于三计数法进行α计数。此外，我们还开发了基于pc的软件，利用实验测量作为输入数据来解决微分方程并计算所有必要的物理量。222Rn、218Po、214Pb和214Po的年平均浓度分别为80.2±6.6、44.0±3.6、34.5±2.8和24.3±2.0 Bq/m3, 218Po和214Pb的无附着活性分别为11.2和0.6 Bq/m3。这些浓度表现出3 ~ 4倍的显著日变化，清晨最大，下午最小，而季节变化为30 ~ 50%，峰值出现在较冷月份。氡连接电离率和相应的空气离子浓度的日变化取决于这些放射性核素水平的变化，年平均值分别为27.9离子对cm - 3 s - 1和2113离子/cm3。结果表明，在正常的家庭条件下，约52%的218Po簇和49%的214Pb簇带正电。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Science of the Total Environment 环境科学-环境科学

CiteScore

17.60

自引率

10.20%

发文量

8726

审稿时长

2.4 months

期刊介绍： The Science of the Total Environment is an international journal dedicated to scientific research on the environment and its interaction with humanity. It covers a wide range of disciplines and seeks to publish innovative, hypothesis-driven, and impactful research that explores the entire environment, including the atmosphere, lithosphere, hydrosphere, biosphere, and anthroposphere. The journal's updated Aims & Scope emphasizes the importance of interdisciplinary environmental research with broad impact. Priority is given to studies that advance fundamental understanding and explore the interconnectedness of multiple environmental spheres. Field studies are preferred, while laboratory experiments must demonstrate significant methodological advancements or mechanistic insights with direct relevance to the environment.