Yamazawa H, Yamada S, Xu Y, Hirao S, Moriizumi J
Department of Energy Engineering and Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
Department of Energy Engineering and Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
Radiat Prot Dosimetry. 2015 Nov;167(1-3):171-5. doi: 10.1093/rpd/ncv238. Epub 2015 May 1.
An experimental method for quantitatively evaluating the elemental processes governing the indoor behaviour of naturally occurring radioactive aerosols was proposed. This method utilises transient response of aerosol concentrations to an artificial change in aerosol removal rate by turning on and off an air purifier. It was shown that the indoor-outdoor exchange rate and the indoor deposition rate could be estimated by a continuous measurement of outdoor and indoor aerosol number concentration measurements and by the method proposed in this study. Although the scatter of the estimated parameters is relatively large, both the methods gave consistent results. It was also found that the size distribution of radioactive aerosol particles and hence activity median aerodynamic diameter remained not largely affected by the operation of the air purifier, implying the predominance of the exchange and deposition processes over other processes causing change in the size distribution such as the size growth by coagulation and the size dependence of deposition.
提出了一种定量评估控制天然放射性气溶胶室内行为的基本过程的实验方法。该方法利用通过打开和关闭空气净化器使气溶胶去除率发生人为变化时气溶胶浓度的瞬态响应。结果表明，通过连续测量室外和气溶胶室内数量浓度以及本研究提出的方法，可以估算室内外交换率和室内沉积率。尽管估计参数的离散度相对较大，但两种方法给出了一致的结果。还发现放射性气溶胶颗粒的尺寸分布以及因此的活度中值空气动力学直径在很大程度上不受空气净化器运行的影响，这意味着交换和沉积过程比其他导致尺寸分布变化的过程（如通过凝聚的尺寸增长和沉积的尺寸依赖性）占主导地位。
