摘要
天然放射性气溶胶粒径分布的变化会引起氡及其子体所致肺剂量的较大涨落。由于我国对其报道甚少，在肺剂量估算中均引用ＵＮＳＣＥＡＲ的推荐值。为验证这种引用的合理性和建立气溶胶粒径分布的测量方法，开展本项研究。方法采用金属丝网筛（１６５目）扩散法测量天然空气经不同数目网筛扩散前后的放射性浓度比（衰减比）来绘制衰减曲线，然后用池边模式计算出粒径分布曲线。衰减比、粒径分布的计算和曲线的绘制均采用计算机。结果室内外天然放射性气溶胶粒径呈几何正态分布，分布的峰值的平均值分别为（０．２０±０．０９）μｍ和（０．２７±０．１１）μｍ。粒径分布和氡浓度、气压、气温、湿度等未发现相关关系。结论本研究结果与ＵＮＳＣＥＡＲ报告书（１９８８）的推荐值相比，室内值相同，室外值略高，与Ｊａｃｏｂｉ的研究相近。由此可得出结论，福州地区引用ＵＮＳＣＥＡＲ报告书的推荐值来估算氡及其子体所致肺剂量是合适的。此结论能否推广到其他地区，还需作进一步的研究。
Objectives The variation of the size distribution of radioactive aerosols may cause a large fluctuation of lung dose caused by radon and its daughters.Since the information on the size distribution of radioactive aerosols in China is scanty,authors usually quote the recommended data by UNSCEAR(1988) to estimate the lung dose.In order to check whether the quoted data are reasonable and establish the method of measuring the size distribution of the aerosols,we carried out this study.Methods The penetration curve can be bloffed by measuring the atomospheric radioactiveity ratio for the different diffusion using the wire screen (165 meshes) type diffusion battery.The size distribution of atomospheric radioactive aerosols was calculated by ikebe anatical method. Results The size distribution for outdoors and indoors showed a geometric normal distribution. The arithmetic mean peak diameter for indoor and outdoor size distribution were (0.20±0.09) μm and (0.27±0.11) μm,respectivery.The correlation between the size distribution and the concentrations of radon and meteological factors was not significant.Conclusion The measured result for indoors is the same as the recommended data by UNSCEAR(1988),while the result for outdoors is slightey higher than the recommended data,but it is similiar to that reported by Jacobi. It is basically feasible for Fujian Province to estimate lung dose using the recommented data by UNSCEAR(1988). Futher studies are needed to extend this conclution nationwide.
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
1997年第2期94-97,共4页
Chinese Journal of Radiological Medicine and Protection
基金
福建省医药卫生科研基金
