Investigation of environmental natural penetrating radiation in Shanxi Province

The methods and results of the investigation on natural penetrating radiation level in Shanxi Province are presented. 262 25 x 25 km-netted measuring points were set unformly up all over the province, with 255 densely measuring points of different types added. The results showed that: (1) The point-weighted, area-weighted and population-weighted average value of natural γ radiation dose rate over field was 5.39, 5.41 and 5.43 x 10-8 Gy·h-1, respectively; (2) The point-weighted average value of natural γ radiation dose rate over road was 4.84 x 10-8 Gy·h-1; (3) The point-weighted and population-weighted average value of natural γ radiation dose rate inside buildings was 8.09 and 8.24 x 10-8 Gy·h-1; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray was 3.46 and 3.36 x 10-8 Gy·h-1, and outside buildings was 3.85 and 3.73 x 10-8 Gy·h-1, respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings was 11.55 and 11.60 x 10-8 Gy·h-1 and outside buildidngs was 8.97 and 8.42 x 10-8 Gy·h-1, respectively; (6) The annual effective dose equivalent from natural γ radiation, cosmic ray and natural penetrating radiation was 0.46, 0.30 and 0.76 mSv, respectively, and correspondingly, the annual collective effective dose equivalent was 1.2, 0.77 and 2.0 x 104 man·Sv, respectively