Analysis of radioactive nuclides in soil around Xi'an

The radioactive nuclides in soil samples collected from the wasteland and the cultivated land in 24 communes around Xi'an City were analyzed by means of Ge(Li) gamma ray spectrometry. The distributions of the radioactive nuclides in various regions and at various depth of soil layer have been investigated. The mean levels of the radioactive nuclides in the soil from these 24 communes are: 238U 1.13 +- 0.17, 226Ra 1.00 +- 0.08, 232Th 1.46 +- 0.08, 40K 18.5 +- 0.6, and 137Cs (depth 10 cm) 0.15 +- 0.06 pCi/g for the wasteland (depth of 20 cm was divided into four layers); 238U 1.16 +- 0.35, 226Ra 0.98 +- 0.09, 232Th 1.45 +- 0.08, 40K 18.6 +- 0.9 and 137Cs 0.15 +- 0.05 pCi/g for the cultivated land (10 cm deep, only one layer). The gross α and radioactivities in the soil samples of the 24 communes were also measured and were found to be averaged 21 +- 10 and 30.0 +- 2.9 pCi/g for the wasteland, and 19 +- 12 and 28.6 +- 3.4 pCi/g for the cultivated land, respectively