深圳新建住宅室内氡水平及分布特征

Levels and distribution of indoor radon concentrations in Shenzhen, China

目的 初步调查深圳市新建住宅室内氡水平及分布特征。方法 选择深圳市低层、多层、中高层和高层结构住宅108户，采用固体径迹法累积测量室内氡浓度。结果 深圳市居室内氡浓度算数均值为64 Bq/m^3，几何均值为58 Bq/m^3，范围15-155 Bq/m^3；宝安区室内氡浓度均值最低，为50 Bq/m^3，坪山新区室内氡浓度均值最高，为87 Bq/m^3。深圳室内氡浓度 〉 100 Bq/m^3的测量点有12个，占总数的11.1%。Shapiro-Wilk检验表明，深圳室内氡浓度频数分布呈对数正态分布（P 〉 0.05）。建筑年代为1990—2015年的房屋，室内氡浓度随建筑年代呈降低趋势。除10层及以上，室内氡浓度随楼层的升高呈降低趋势。结论 本次调查比以往调查深圳市室内氡浓度相比升高了35%。建议继续加强完善建材放射性标准，加强高层住宅的自然通风，降低室内氡的辐射危害。

Objective To investigate the levels and distribution of radon in dwellings in Shenzhen cities of China. Methods A total of 108 low-, multi-, middle- and high-rise buildings were selected. Indoor radon concentrations were measured by using solid track detector. Results The arithmetic mean of indoor radon concentrations in Shenzhen was 64 Bq/m^3, and geometric mean was 58 Bq/m^3, in range of 15 to 155 Bq/m^3. The average indoor radon concentration in Bao＇an district was 50 Bq/m^3 with the lowest value, and that in Pingshan new district was 87 Bq/m^3 with the highest value. There were 12 measuring points where indoor radon concentrations were higher than 100 Bq/m^3 in Shenzhen, accounting for 11.1% of the total number. Shapiro-Wilk test showed that the frequency distribution of indoor radon concentration in Shenzhen follows lognormal distribution （P 〉 0.05）. The indoor radon concentrations showed a downward trend from 1990 to 2015. The indoor radon concentration decreases with the elevated floors except 10th and above floors. Conclusions The indoor radon concentrations in Shenzhen increased by 35%, compared to the previous investigations. It is recommended that efforts continue to improve radioactive materials standards about building material and to enhance the natural ventilation in high-rise buildings in order to lower the radiation hazards from radon.