Measurements of Natural Radioactivity and Radiological Hazards Assessment in Some Commercial Ceramic Tiles used in Ethiopia.

Ceramic tile is a widely used decorative building material. The natural radionuclideconcentration ( 226 Ra, 232 Th, and 40 K) of ceramic wall and floor tiles typically used in Ethiopia was determined using an HPG detector. The study's goals are to determine the activity concentration of ceramic tiles as well as evaluate their health-related effects. The average activity concentrations of 226 Ra, 232 Th, and 40 K were 68.06 ± 2.07 Bq kg -1 , 131.19 ± 3.82 Bq kg -1 , and 802.04 ± 23.41 Bq kg -1 , respectively, which was found to be greater than the global mean. The calculated average value of Raeq was < 370 Bq kg -1 , which is the limiting dose recommended for bulk medium. In addition, the related radiological hazard metrics, such as absorbed dose, annual effective dose equivalent, excess lifetime cancer risk (ELCR), internal (H in ) and external (H ex ) hazard indexes, gamma index (I γ ), and alpha index (I α ), were determined. The findings were contrasted with regional, global,and national legal frameworks as well as other similar studies' findings. According to the results, using the examined ceramic tiles in buildings does not significantly increase radiation exposure.瓷砖是一类应用广泛的装饰性建筑材料。本研究采用高纯锗（High Purity Germanium, HPG）探测器，对埃塞俄比亚市场常用陶瓷墙砖与地砖中的天然放射性核素（²²⁶Ra、²³²Th及⁴⁰K）活度浓度进行了测定。本研究的目标为明确瓷砖的放射性活度浓度，并评估其相关健康危害。研究测得²²⁶Ra、²³²Th与⁴⁰K的平均活度浓度分别为68.06±2.07 Bq·kg⁻¹、131.19±3.82 Bq·kg⁻¹与802.04±23.41 Bq·kg⁻¹，上述数值均高于全球平均水平。计算得到的镭等效活度（Raeq）平均值小于370 Bq·kg⁻¹，符合散装介质推荐的剂量限值。此外，本研究还测定了相关辐射危害参数，包括吸收剂量、年有效剂量当量、终身超额癌症风险（ELCR）、内（H_in）与外（H_ex）辐射危害指数、γ辐射指数（I_γ）及α辐射指数（I_α）。将本次研究结果与区域、全球及国家层面的相关法规框架，以及其他同类研究的结论进行了对比分析。结果表明，在建筑中使用本次检测的陶瓷瓷砖不会显著增加辐射暴露水平。