Inhalation of the airborne short-lived radon progeny is regarded as the most crucial way of internal exposure to the natural radiation dose delivered to the human lung. In this respect, this study aims to determine the unattached and aerosol-attached activities of radon progeny and to estimate some important physical parameters employed to assess the radiological impact of this radiation on humans. For this purpose, radioactive aerosol samples collected on polycarbonate membrane filters to measure total alpha activity by passive alpha dosimetric technique using CR-39 detectors in sixteen different locations including some houses and workplaces in El Jadida city, in Morocco. In addition, the room-specific parameters and aerosol physical processes that affect the unattached and attached activity concentrations were determined. The obtained experimental results by the three-count method and room model parameters were used as input data on a developed PC-based software that we have developed to solve mathematical equations and calculate required physical quantities. Accordingly, the individual activities of radon progeny namely ²¹⁸Po, ²¹⁴Pb, and ²¹⁴Po as well as radon activity concentration were determined. Simultaneously, the unattached and aerosol-attached activity concentrations ($C_j^u$ and $C_j^a$) of radon progeny were calculated based on the room model calculation. Consequently, some radiological quantities used in the calculation of the lung dose were estimated. The results showed that the indoor radon activity concentration in different targeted locations ranges between 38 and 143 Bq. m⁻³ with an average value of 84.8 ± 9.5 Bq. m⁻³. The average obtained values of the equilibrium-equivalent concentration $\left(C_{eq}\right)$, unattached fraction $\left(f_p\right)$, and equilibrium factor ($F)$ at low and good ventilation rates change respectively from (24 Bq. m⁻³, 0.08, and 0.25) to (34 Bq. m⁻³, 0.02, and 0.41). Under normal environmental conditions, the average obtained values of $C_{eq}$, $f_p$, and $F$, in houses and at workplaces were (17 Bq. m⁻³, 0.07, and 0.25) and (32 Bq. m⁻³, 0.04, and 0.35) respectively. Depending on the different aerosol conditions and obtained values of unattached fraction $f_p$, the calculated average values of dose conversion factors (DCFs) were 8.70 mSv.WLM⁻¹ and 11 mSv.WLM⁻¹ in houses and workplaces respectively. These values were in good agreement with the recommended values by ICRP, which are in the order of 9 mSv.WLM⁻¹ and 12 mSv.WLM⁻¹ for houses and workplaces respectively.

吸入空气中的短寿命氡子体被认为是体内暴露于输送到人体肺部的自然辐射剂量的最重要方式。在这方面，本研究旨在确定氡子体的独立和气溶胶附着活动，并估计一些重要的物理参数，用于评估这种辐射对人类的放射学影响。为此，在聚碳酸酯膜过滤器上收集放射性气溶胶样本，通过被动 α 剂量测定技术使用 CR-39 探测器在 16 个不同地点（包括摩洛哥 El Jadida 市的一些房屋和工作场所）测量总 α 活性。此外，还确定了影响独立和附加活动浓度的房间特定参数和气溶胶物理过程。通过三计数法获得的实验结果和房间模型参数被用作我们开发的基于 PC 的软件的输入数据，该软件用于求解数学方程和计算所需的物理量。因此，氡子代的个体活动即测定了²¹⁸ Po、²¹⁴ Pb 和²¹⁴ Po 以及氡活度浓度。同时，独立和气溶胶附着的活动浓度（$C_j^{你}$ 和 $C_j^{\mathrm{一种}}$) 的氡子代是根据房间模型计算得出的。因此，估计了一些用于计算肺剂量的放射学量。结果表明，不同目标位置的室内氡活度浓度在38~143 Bq之间。m ^-3的平均值为 84.8 ± 9.5 Bq。米^-3。平衡当量浓度的平均获得值$\left(C_{\mathrm{电子}q}\right)$, 独立分数 $\left(F_{磷}\right)$, 和平衡因子($F)$在低通风率和良好通风率下，分别从 (24 Bq. m ^-3、0.08 和 0.25) 变为 (34 Bq. m ^-3、0.02 和 0.41)。在正常环境条件下，获得的平均值为$C_{\mathrm{电子}q}$, $F_{磷}$， 和 $F$, 在房屋和工作场所分别为 (17 Bq. m ^-3、0.07 和 0.25) 和 (32 Bq. m ^-3、0.04 和 0.35)。取决于不同的气溶胶条件和未附着分数的获得值$F_{磷}$，计算的剂量转换因子 ( DCF s)平均值分别为 8.70 mSv.WLM ^-1和 11 mSv.WLM ^-1在房屋和工作场所。这些值与 ICRP 的推荐值非常吻合，分别为住宅和工作场所的 9 mSv.WLM ^-1和 12 mSv.WLM ^{-1 的}数量级。