Lively R S, Krafthefer B C
Minnesota Geological Survey, St. Paul 55112.
Health Phys. 1995 Apr;68(4):590-4. doi: 10.1097/00004032-199504000-00019.
222Rn concentrations and meteorological parameters were measured at 4-h intervals over a 2-y period in Mystery Cave, southeastern Minnesota. Continuous radon monitors and meteorological sensors connected to data loggers were installed at several locations along commercial tour routes. 222Rn concentrations ranged as high as 25 kBq m-3 in summer and 20 kBq m-3 in winter. Average winter concentrations were lower than summer by at least a factor of two. Seasonal radon variations were correlative with outside air temperatures. During the winter, radon concentrations were observed to fluctuate periodically by factors of 20 or more in under 24 h. Both the long- and short-term variations are correlative with temperature-induced mixing of cave air with surface air.
在明尼苏达州东南部的神秘洞穴中，对222Rn浓度和气象参数进行了为期两年的测量，测量间隔为4小时。沿着商业游览路线的几个位置安装了与数据记录器相连的连续氡监测器和气象传感器。夏季222Rn浓度高达25 kBq m-3，冬季为20 kBq m-3。冬季平均浓度比夏季至少低一半。季节性氡变化与外界气温相关。在冬季，观察到氡浓度在24小时内周期性波动20倍或更多。长期和短期变化均与温度引起的洞穴空气与地表空气的混合有关。
