摘要：In this research, by using solid radio alpha detector (RAD7) the amount of radon and thoron isotopes at a depth of 80 cm of soil has been measured in fifteen regions in south of Ardabil. By using Arc GIS software, fitting shows an radon 222 vessels in north of Lake Shourabil with the maximum measured 81600±1800 Bq m-3. The minimum amount of Radon, 12700±430 Bq m-3 was measured and also the average measured amount of radon, thoron and gamma dose level have been respectively 35993 Bq m-3, 1343 Bq m-3 and 0.15 μ Sv h-1 for all the 15 places in the studied area. Besides, the correlation between radon 222 isotopes and gamma dose level was calculated as 0.63 which can demonstrate existence of uranium 238 in the soil of the area. Since Radon 222 is obtained from decay of uranium 238, it indicates the possible presence of traces of radon 222 lode of uranium 238 in the studied area
