首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到3条相似文献,搜索用时 0 毫秒
1.
Sand samples were collected from Adasiah (near Amman), Jerash and Ghor As-Safi (near Karak). 226Ra, 232Th and 40K activities, present in these samples, were measured using a gamma ray spectroscopy technique. The average values of the radium equivalent activities were calculated and were found to be 41.06 Bq kg−1, 54.7 Bq kg−1 and 85.53 Bq kg−1 in samples collected from Adasiah, Jerash and Ghor As-Safi, respectively. These values are within the limit (i.e. less than 370 Bq kg−1) recommended for the safe use of construction materials for dwellingsby OECD.  相似文献   

2.
This study was aimed at providing the baseline data of terrestrial gamma dose rates and natural radioactivity to assess the corresponding health risk in the ambient environment of the Pahang State. Terrestrial gamma radiation (TGR) from 640 locations was measured with the mean value found to be 176?±?5 nGy h?1. Ninety-eight soil samples were analysed using a high-purity germanium detector (HPGe), and the mean concentrations of the radionuclides 226Ra, 232Th and 40K are 110?±?3, 151?±?5 and 542?±?51 Bq kg?1, respectively.226Ra and 232Th concentrations were found to be three times the world average, while that of 40K is quite higher than the world average value. The acid-intrusive geological formation has the highest mean concentrations for 226Ra (215?±?6 Bq kg?1), 232Th (384?±?12 Bq kg?1) and 40K (1564?±?153 Bq kg?1). The radium equivalent activities (Req) and the external hazard index (Hex) for the various soil types were also calculated. Some of the soil types were found to have values exceeding the internationally recommended levels of 370 Bq kg?1 and the unity value, respectively.  相似文献   

3.
Radionuclides are released together with fly ash from the coal-fired power plant and thus add to the natural radiation. Fifty soil samples were collected around the Baoji coal-fired power plant from 25 locations and the natural radionuclide concentrations were determined by a gamma ray spectrometric system. The results show that the activity concentrations in soil samples range from 12.54 to 40.18 Bq kg?1, 38.02 to 72.55 Bq kg?1 and 498.02 to 1126.98 Bq kg?1 for 226Ra, 232Th and 40K with the mean values of 27.35, 52.66 and 764.72 Bq kg?1, respectively. In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity (Raeq), the absorbed dose rate (D) and the annual effective dose rate have been calculated and compared with the internationally approved values. The radium equivalent activity in all the soil samples is lower than the safe limit set in the Organization for Economic Cooperation and Development report (370 Bq kg?1). The average value of the calculated dose rates is higher than the global average value 55 nGy h?1, and the calculated annual effective dose rate is significantly lower than the average annual external effective dose rate (460 μSv y?1) of the normal background radiation.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号