Radiation Physics Laboratory, COMSATS Institute of Information Technology, Chak Shahzad, Park Road, Islamabad, Pakistan.
Environ Monit Assess. 2012 Aug;184(8):4623-34. doi: 10.1007/s10661-011-2290-5. Epub 2011 Sep 3.
Studies on naturally occurring radioactive material (NORM) in the limestone from the Margalla Hills have been carried out by measuring gamma activity and to access its radiological implications if any. For data acquisition, a High-Purity Germanium detector was employed. The activity concentrations of (226)Ra, (232)Th, and (40)K were found to be 14.32 ± 0.24, 2.05 ± 0.04, and 13.80 ± 0.20 Bq kg(-1), respectively. These values are relatively lower as compared to that in the limestone of other countries and much lower than the values reported for the natural building stones. The average specific activities due to (226)Ra were found to be higher when compared with (40)K and (232)Th. Indices of radium equivalent activity (Ra(eq)), internal hazard (H(in)), indoor absorbed gamma dose rate (D(R,)), and corresponding annual effective dose (E(eff)) were also determined for the limestone-made rooms. All of these indices were found to be in the lower ranges. The Margalla Hills limestone does not pose any excessive radiological health hazard as a building material and in industrial uses for a common man.
对玛格拉山石灰石中天然放射性物质（NORM）的研究已经通过测量伽马活性来进行，并评估其可能存在的放射性影响。为了进行数据采集，使用了高纯锗探测器。研究发现，（226）Ra、（232）Th 和（40）K 的活度浓度分别为 14.32 ± 0.24、2.05 ± 0.04 和 13.80 ± 0.20 Bq kg(-1)。这些值与其他国家的石灰石相比相对较低，比天然建筑石材报告的值低得多。与（40）K 和（232）Th 相比，（226）Ra 的平均比活度较高。还确定了由（226）Ra 引起的镭当量活度（Ra(eq)）、内部危害（H(in)）、室内吸收伽马剂量率（D(R,)）和相应的年有效剂量（E(eff)）等指数。所有这些指数都处于较低范围。玛格拉山石灰石作为建筑材料和工业用途，不会对普通民众的放射性健康造成任何过度危害。
