Neves L J P F, Barbosa S M, Pereira A J S C
IMAR, Department of Earth Sciences, University of Coimbra, 2 Coimbra, Portugal.
J Environ Radioact. 2009 Oct;100(10):896-904. doi: 10.1016/j.jenvrad.2009.06.017. Epub 2009 Jul 26.
Indoor radon activities were measured during a period of 6 months, as well as several physical environmental variables (temperature, pressure, humidity and rainfall). The location was a small room at an administrative building of the University of Coimbra, usually undisturbed by human activities and situated over bedrock of low-uranium Triassic red sandstones. A low average activity of radon was observed (36 Bq m(-3)), however showing a very well marked daily periodicity (10+/-5 Bq m(-3)), with maximum values occurring more frequently between 9 and 10 a.m. Daily variations are shown to have no relation with earth tides, and their amplitudes exhibit a significant correlation with outdoor temperature; no dependence on barometric pressure was found. Rainfall disturbs the observed daily radon cycles through a strong reduction of their amplitude, but has no effect on the long-term variability of the gas concentration.
在6个月的时间里对室内氡活度以及几个物理环境变量（温度、压力、湿度和降雨量）进行了测量。测量地点是科英布拉大学行政楼的一个小房间，该房间通常不受人类活动干扰，位于低铀三叠纪红砂岩基岩之上。观察到氡的平均活度较低（36 Bq m(-3)），不过显示出非常明显的每日周期性（10±5 Bq m(-3)），最大值更频繁地出现在上午9点到10点之间。结果表明，每日变化与地球潮汐无关，其幅度与室外温度呈现显著相关性；未发现与气压有依赖性关系。降雨通过大幅降低其幅度干扰了观察到的每日氡循环，但对气体浓度的长期变异性没有影响。
