在本文中,对天然放射性水平的评估,氡呼气,金属污染,和Stilo的花岗闪长岩岩石样品的矿物学,在卡拉布里亚地区,意大利南部是一个案例研究。该岩石被用作研究区域的建筑材料。226Ra的比活性,通过高纯度锗(HPGe)γ射线光谱法评估了232Th和40K天然放射性同位素。然后,几个指标,如吸收γ剂量率(D),年有效剂量当量(AEDE),活性浓度指数(ACI)和α指数(Iα),被量化以确定与被分析岩石的辐射暴露相关的任何潜在的辐射健康风险。此外,进行了E-PERM驻极体离子室和电感耦合等离子体质谱(ICP-MS)测量,以适当地量化氡析出率和任何可能的金属污染,分别。特别是,为了进一步解决金属污染因素,计算了地球积累指数(Igeo),以适当解决源自检测到的金属的生态系统的毒性水平。最后,为了成功地辨别这种天然存在的放射性核素的来源,采用X射线衍射(XRD)和µ-拉曼光谱的组合方法来鉴定表征所研究花岗闪长岩的主要含放射性同位素矿物。在此案例研究中获得的结果可以作为进一步调查用作建筑材料的天然石材中放射性和化学污染背景水平的基础。
In this paper, an assessment of the natural radioactivity level, radon exhalation, metal contamination, and mineralogy of a granodiorite rock sample from Stilo, in the Calabria region, Southern Italy is presented as a case study. This rock was employed as a building material in the area under study. The specific activity of 226Ra, 232Th and 40K natural radioisotopes was assessed through high-purity germanium (HPGe) gamma-ray spectrometry. Then, several indices such as the absorbed gamma dose rate (D), the annual effective dose equivalent (AEDE), the activity concentration index (ACI) and the alpha index (Iα), were quantified to determine any potential radiological health risk related to radiation exposure from the analyzed rock. Furthermore, E-PERM electret ion chambers and inductively coupled plasma mass spectrometry (ICP-MS) measurements were carried out to properly quantify the radon exhalation rate and any possible metal
pollution, respectively. In particular, to further address metal
pollution factors, the geo-accumulation index (Igeo) was calculated to properly address the toxicity levels of the ecosystem originating from the detected metals. Finally, with the aim of successfully discriminating the provenance of such naturally occurring radionuclides, a combined approach involving X-ray diffraction (XRD) and µ-Raman spectroscopy was employed for the identification of the main radioisotope-bearing minerals characterizing the investigated granodiorite. The results achieved in this case study can be taken as the basis for further inquiries into background levels of radioactivity and chemical contamination in natural stone employed as building materials.