Table 4.
Levels of radon emitted from the faults in the study area in accordance with the Code for Indoor Environmental Pollution Control of Civil Building Engineering in China (GB 50325–2010)27.
| Levels | Radon concentration (kBq m−3) | Radon flux (mBq m−2 s−1) | Locations | Prevention regulations |
|---|---|---|---|---|
| 1 | 0~20 | 0~50 | NCY, DHZK, YJY, YLK, ZZK,YJG, ZJY, NKC, YXZ, BKC, XHZ, DYZ, LTTC, BYC, NYC | No need of pollution prevention and control of radon |
| 2 | 20~30 | 50~100 | CFY, WQX, QBK, HJP, YHM, CJA, HJW, WFS, SJC, SHZ, DTHS | The underlying surface of the structure should be fixed in order to prevent cracking |
| 3 | 30~50 | 100~300 | QXZ, BHC, WZ, BHD, DSG | Underlying surface of the structure should be remedied in order to prevent cracking, and water proof processing |
| 4 | >50 | >300 | DDG, PGZ, WJKC, ZTD, FN | Comprehensive prevention and control of radon pollution |