Assessment of cellular dose and damage induced by radon and its progeny using the BEAS-2B cell mesh model

The decay of radon and its progeny mainly produces alpha particles and beta particles. Due to their short range and high linear energy transfer (LET) of alpha particles, it is necessary to evaluate the dose deposition at the cellular and subcellular levels so as to better assess their health effects on the human body. Given that the lung is the primary target organ for radon exposure, we utilized human bronchial epithelial cells (BEAS-2B cells) to construct a realistic mesh model. Using Monte Carlo simulation software PHITS, we computed cellular S-values under conditions of radon and progeny irradiation, the deposited does inside cells of nuclide that distribute outside cells has been calculated. These calculations were contrasted with results obtained from traditional geometric models and MIRDcell calculations. To quantify the damage effects caused by radon and its progeny, this study used MCDS to calculate the DNA damage, for various nuclides, Rn-222 produces the highest number of double-strand breaks (DSBs) up to 21.8 Gy-1cell-1, while Tl-210 produces the least DSBs with 8.32 Gy-1cell-1. Additionally, other damage metrics such as single-strand breaks (SSBs), "OTHER", and "ALL CLUSTERS" were quantified. This research, based on the BEAS-2B cell model, offers more precise information on cellular doses and damage effects of radon and its progeny. It holds significant implications for the future development of radiation protection strategies and applications in radon therapy.