Hewamanna R, Sumithrarachchi C S, Mahawatte P, Nanayakkara H L, Ratnayake H C
Radioisotope Centre, University of Colombo, Sri Lanka.
Appl Radiat Isot. 2001 Feb;54(2):365-9. doi: 10.1016/s0969-8043(00)00107-x.
The specific radioactivity concentrations of 226Ra, 232Th and 40K have been determined by gamma ray spectrometry with an HPGe detector in clay brick samples from kiln sites located in 17 towns. The average values of the measured activities are 35, 72, and 585 Bq kg(-1), respectively, for the above radionuclides. The average estimated radium equivalent concentration is 183 Bq kg(-1) and is comparable with reported values for many countries in the world. This value and the value obtained from the criteria formula suggest that the use of local clay bricks do not pose a radiological hazard. The calculated average absorbed dose rate in air within buildings was found to be 102 nGy h(-1) while the population weighted indoor annual effective dose was 0.20 mSv.
使用高纯锗探测器通过伽马射线能谱法测定了来自17个城镇窑址的粘土砖样品中226镭、232钍和40钾的比放射性浓度。上述放射性核素的测量活度平均值分别为35、72和585贝可勒尔每千克。平均估算镭当量浓度为183贝可勒尔每千克，与世界上许多国家报告的值相当。该值以及从标准公式获得的值表明，使用当地粘土砖不会造成辐射危害。建筑物内空气中计算出的平均吸收剂量率为102纳戈瑞每小时，而人口加权室内年有效剂量为0.20毫希沃特。
