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| Distribution Characteristics of Rn-222 and Rn-220 Concentrations in Air in High Background Radiation Area of Yangjiang, China |
| YUAN Yongling1, H. Morishima2, SHEN Hong1, et al |
| Labor Hygiene Institute of Hunan province, Changsha 410007, China |
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Abstract Objective This paper reports on distribution characteristics of Rn-222 and Rn-220 concentrations in air in investigated areas Methods A pair of passive integrating cup monitors method is used for the measurement of Rn-222 and Rn-220 concentration in air in the High Background Radiation Area (HBRA) and the neighboring Control Area (CA), for one year.Results The concentrations in indoor air of Rn-222 and Rn-220 in the HBRA were still higher significantly than that in outdoor air, while the concentrations in CA were similar between the indoor air and outdoor air.The concentrations in indoor and outdoor air of Rn-222 and Rn-220 from different seasons are no distinct which showed that it is little higher in autumn and winter.it is clear that there are some relationships among concentrations in indoor air of Rn-222 and Rn-220, and external radiation level of households, construction materials in HBRA, while CA did not discover this relationship.The measured data indicate that the distance from wall or height above the ground does not much influence the concentration of Rn-222 in the room.However, they, prominently influence the concentration of Rn-220.The average concentration of Rn-220 measured at 5-10cm from wall was 12.9 times higher than that at 80-100cm;and the average concentration of Rn-220 measured at 5-10cm above the ground was 6.21 times higher than that at 80-100cm above the ground.Conclusion The average indoor concentration of Rn-222 in the HBRA was little higher than the populationweighted average of indoors Rn-222 concentration.The ratio of indoor concentration of Rn-222 between HBRA and CA are 2.6:1.0.The indoor concentration of Rn-220 in HBRA is significantly higher comparing to CA (7.18 times) and the population-weighted average (29.7 times), respectively.The distribution in indoor concentration of Rn-220 in HBRA is very heterogeneous.We noted that Rn-220 and its decay products are very important component of effective dose for the inhabitants living in the HBRA.
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Received: 23 October 2000
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| [1] |
LI Xiaoliang, ZHAO Xipeng, ZHAO Yuqian, ZHU Weiguo, HUANG Zhibiao, CHEN Chisong, LEI Shujie, SUN Quanfu. A survey of terrestrial γ radiation level in high background radiation area of Yangjiang, Guangdong[J]. , 2018, 27(5): 427-429. |
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