甘肃陇东地区室内222Rn、220Rn浓度季节变化的调查分析

Investigation and analysis on seasonal variations of indoor 222 Rn and 220 Rn concentrations in Longdong district, Gansu Province

目的研究我国传统住房室内222Rn220Rn随季节变化的规律。方法选择甘肃省陇东地区5种不同类型的传统建筑44间及普通砖瓦房5间。采用LD—P型。222Rn-220Rn分辨累积探测器，按冬、春、夏、秋4个季节对室内。222Rnx220Rn浓度进行测量。结果室内222Rn浓度随季节变化而变化，不同种类房屋变化规律不同。普通砖房、土砖房及箍窑建筑室内222Rn浓度秋冬季高，夏季低，其中，冬季为55．3—90．3Bq／m3，春季为36．4—65．7Bq／m3，夏季为35．6～63．9Bq／m3，秋季为60．7～87．2Bq／m3。明窑、半明半暗窑、地坑窑室内222Rn浓度夏秋季高，冬春季较低，冬季为139～184Bq／m3，春季为135—199Bq／m3，夏季为179—252Bq／m3，秋季为172～242Bq／m3。6类房屋中室内220Rn的季节变化规律较为一致，呈现出冬春季较低，秋季最高的趋势，冬季为43．4～64．3Bq／m3，春季为60．6～537Bq／m3，夏季为77．7～792Bq／m3，秋季为63．2～1077Bq／m3。结论室内222Rn和220Rn浓度随季节变化而变化，不同类型的房屋有着不同的变化规律。

Objective To study the seasonal variation of indoor 222Rn and 220Rn concentrations in Longdong district, Gansu Province. Methods A total of 44 houses from 5 different types of raw soil architectures and 5 ordinary brick houses from a typical area were selected in Longdong district, Gansu Province in China. The LD-P discriminative 222Rn and 220Rn detectors were used to measure the indoor concentrations of 222Rn and 220Rn during four seasons in one year. Results The indoor concentrations of 222Rn showed a significant seasonal variation, which varied with different types of houses. 222Rn concentrations of ordinary brick houses, soil brick houses and the cave dwellings were higher in winter and autumn and lower in summer. The average concentrations of 222Rn were 55.3-90.3 Bq/m3 in winter, 36.4- 65.7 Bq/m3 in spring, 35.6-63.9 Bq/m3 in summer, and 60.7-87.2 Bq/m3 in autumn. For cave dwellings, open-cut cave dwellings and the underground cave dwellings, 222Rn concentrations were higher in summer and autumn, and lower in winter and spring. The average concentrations of 222Rn ranged from 139-184 Bq/m3 in winter, 135-199 Bq/m3 in spring, 179-252 Bq/m3 in summer, 172-242 Bq/m3 in autumn. The seasonal variation of indoor 222Rn was basically consistent in six types of houses, and lower in winter and spring and highest in autumn. The average concentrations of 220Rn ranged from 43.4-64.3 Bq/ m3 in winter, 60. 6-537 Bq/m3 in spring,77.7-792 Bq/m3 in summer,63.2-1077 Bq/m3 in autumn. The indoor concentrations of 222Rn and 220Rn were different among different types of houses, and they were generally higher in type of raw soil architectures than in that of ordinary brick houses. Conclusions 222 Rn concentrations indoors showed a significant seasonal variation and varied with different types of houses.