Current level and distribution of environmental radiation in Beijing

The environmental radiation level in Beijing was reported. The monitoring sits were set up by net grid method. In Beijing the grid point-weighted average values for γ radiation dose and cosmic ray outdoors radiation dose are 56.2 and 32.3 nGy/h, respectively. The area-weighted average values of U-238. Th-232, Ra-226, K-40 and Cs-137 in soil are 19.4, 34.1, 21.4. 662 and 8.3 Bq/kg, respectively. The concentration range of U, Th and Ra-226, K-40 in various waters are 0.12-8.94, 0.02-0.66 μg/L and 6.0-98.1, 19.2-643 mBq/L, respectively. The geographical distribution of the environmental radiation levels is higher in the west-north mountain area and lower in the east-south plain of Beijing