摘要
目的 观察阳江天然高本底辐射地区空气中氡、的分布特征。方法 采用α径迹蚀刻法 ,用Rn -Tn杯监测器对阳江天然高本底辐射地区 (HBRA)和相邻的正常本底对照地区 (CA)进行了为期一年多的空气中累积氡、浓度的定点测量。结果 HBRA室内空气中氡、浓度明显高于室外 ,CA则无明显差别。调查地区室内外空气中氡、浓度随季节变化不是很明显 ,秋冬季比春夏季稍高。HBRA室内空气中氡、浓度与地表γ外照射辐射水平和建筑材料类型存在着一定关系 ,CA无明显变化规律。HBRA室内空气中氡浓度变化不是很大 ,而室内空气中浓度变化起伏很大 ,在离地面 1 2m高处 ,距墙 5～ 10cm处的平均浓度是距墙 80～ 10 0cm处的 12 9倍 ;在距墙 1 2m ,离地面 5～ 10cm处的平均浓度为距地面 80～ 10 0cm处的 6 2 1倍。结论 HBRA室内空气中氡浓度略高于世界按人口加权平均值 ,是CA的 2 6 3倍 ;但浓度分别是世界均值和CA的 2 9 7和 7 18倍 ,它在室内空气中的浓度变化很大 。
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
出处
《中国辐射卫生》
2001年第1期5-7,共3页
Chinese Journal of Radiological Health
关键词
高本底地区
Rn-Tn杯监测器
氡
气浓度
分布特征
High background radiation area
Rn-Tn cup monitor
Concentrations of Rn-222 and Rn-220
Distribution characteristics.
