| SHANG Bing,CUI Hong-xing,WU Yun-yun.A preliminary investigation of 222Rn and 220Rn levels in non-uranium mines in China[J].Chinese Journal of Radiological Medicine and Protection,2008,28(6):559-565 |
| A preliminary investigation of 222Rn and 220Rn levels in non-uranium mines in China |
| Received:July 31, 2008 |
| DOI： |
| KeyWords:Non-uranium mine Radon Thoron Equilibrium factor Cumulative concentration |
| FundProject:科技部科研院所社会公益研究专项(2005DIB1J087) |
| Author Name | Affiliation | | SHANG Bing | National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, 100088 Beijing, China | | CUI Hong-xing | National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, 100088 Beijing, China | | WU Yun-yun | National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, 100088 Beijing, China | | 张庆召 | National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, 100088 Beijing, China | | 苏旭 | National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, 100088 Beijing, China |
|
| Hits: 2742 |
| Download times: 2065 |
| Abstract:: |
| Objective To measure levels of 222Rn and 220Rn in typical non-uranium mines, China, and to estimate dose from the occupational radon exposure in the miners.Methods Using typical sampling scheme, 44 mines were selected in 12 provinces, which can be classified into 4 categories and 17 types of mines. The radon-thoron discriminative detectors were used to measure 222Rn and 220Rn concentrations in mines.Result The concentration of 222Rn or 220Rn was log-normally distributed. The arithmetic mean (AM) concentration and geometric mean (GM) concentration of 222Rn and 220Rn in 25 metal mines (n=147) were estimated to be (1211±2359) Bq m3 (AM) and (311±5.5) Bq m3 (GM), and (269±700) Bq m3 (AM) and (71±4.4)Bq m3 (GM), respectively. The mean concentrations of 222Rn and 220Rn in 18 non-metal mines (n=118) were (98±207) Bq m3 (AM) and(55±2.5) Bq m3 (GM), and (60±76) Bq m3 (AM) and (38 ± 2.4)Bq m3(GM), respectively. In total, we measured 222Rn concentration in 44 underground mines,6 of them, accounted for 15%, with the mean radon concentration exceeding 1000 Bqm-3 (limit of workplace in China). Approximately 7% of radon concentration in mines measured were higher than 3700Bq m3 (current limit in uranium mine in China), some points even exceeded 10?000 Bq m3. Based on this typical measurements, the equilibrium factor for 222Rn was estimated to be 0.33±0.15 in underground mines and 0.47±0.18 in nearby houses. Equilibrium factor for 220Rn ranged from 0.001 to 0.032. Using the data obtained in this typical survey, the average annual effective dose of underground miners exposed to radon and thoron was estimated to be 8.15 mSv/a.Conclusions High levels of 222Rn exists in metal mines, such as copper, tin, lead and zinc, gold, and aluminum mines among others. More study and administrative measures are needed to address the radiation protection of workers occupationally exposed to high radon in mines. |
| HTML View Full Text View/Add Comment Download reader |
| Close |
|
|
|
