过滤室内空气对降低居民室内氡照射的效果研究

目的 研究空气净化器过滤室内空气对室内氡子体行为的影响，探讨该方法对降低居民室内氡照射的效果。方法 构建理论模型计算室内空气过滤前后室内氡子体的浓度，基于结合态和未结合态氡子体的剂量转换系数，评估过滤室内空气对居民氡照射剂量的降低效果，并在密闭房间内进行部分实验验证。结果 室内空气的过滤速率越大，氡子体的去除效率越明显。在一个气溶胶初始浓度为10 000 cm^-3的密闭室内，当过滤速率>10 h^-1时，氡子体总浓度可下降90%以上。但不同过滤速率下，未结合态氡子体浓度均有所增高。室内氡子体浓度变化和居民氡照射剂量下降与净化器的过滤速率密切相关，过滤速率越大，降低剂量的效果越快越好。当过滤速率>5 h^-1时，净化器可降低居民内照射剂量70%以上。结论 空气净化器过滤室内空气虽然会导致未结合态氡子体浓度上升，但仍能有效地降低氡子体所致居民的暴露剂量。

The study on effects of indoor air filtration on radon exposure to residents

Objective To evaluate the influence of indoor air filtration by air purifier on the behavior of indoor radon progeny and estimate its effects on indoor radon exposure to residents. MethodsThe concentrations of indoor radon progeny with and without the air filtration were calculated by the theoretical model developed in this study. Based on the dose conversion factors of attached and unattached radon progeny, the mitigation effects of indoor radon exposure due to the air filtration were estimated. Verification experiments were conducted in an airtight room. Results With the air filtration rate increased, the removal efficiency of indoor radon progeny would appear more obvious. For an airtight room with its initial aerosol concentration of 10 000 cm^-3, the concentration of total radon progeny would decrease by more than 90% when the air filtration rate exceeded 10 h^-1. But the concentrations of indoor unattached radon progeny would increase by using the air purifier in different extents. The variations of radon progeny concentrations and the decrease of internal doses were closely related to the filtration rate of air purifier. With the air filtration rates increased, the mitigation effects would be better and faster. The internal dose would reduce by more than 70% when the filtration rate exceeded 5 h^-1. ConclusionsAlthough the indoor concentration of unattached radon progeny will increase by using the air purifier, it is still effective in reducing the exposure dose to residents due to the inhalation of radon progeny.