■尽管许多国家/地区都可以获得有关室外伽马辐射的数据,它们通常是在不受干扰的环境中而不是在大多数人口居住的城市地区进行测量而获得的。只有一次大规模的全国性调查,在城市地区进行现场测量,已在全球范围内确定,可能是由于高成本(例如,人员和仪器)以及选择测量点的困难。
■在整个意大利领土上开展了户外伽马辐射测量运动。所有测量点都是在一家意大利电信公司的基础设施中选择的,作为城市地区人口户外暴露于伽马辐射的所有可能情况的代表。十次重复的便携式伽马(X)探测器进行了所有测量。
■已经进行了大约4,000次测量。它们分布在2,901个意大利城市,占意大利人口的75%。γ环境剂量当量率(ADER)的全国人口加权平均值为117nSvh-1,对于21个地区和107个省,其范围为62至208nSvh-1和40至227nSvh-1,分别。市一级的平均变异性,变异系数(CV)为21%,从3%到84%不等。通过补充测量评估了土地覆盖率和距建筑物的距离对室外伽马辐射水平的影响,导致差异从-40%到50%和50%,分别。
■在意大利进行了具有代表性的户外伽马剂量率测量活动,只有在城市地区,评估户外伽马辐射对人群的暴露影响。这是全球城市地区最大的全国性运动,总共进行了3,876次现场测量。土地覆盖率和与周围建筑物的距离被认为强烈影响室外伽马辐射水平,导致小区域内的高变异性。与一家在人口稠密的国家领土上拥有设施网络的公司的合作使这项调查变得可行且负担得起。其他国家可能会采用这种方法在城市环境中进行国家调查。
UNASSIGNED: Although data on outdoor gamma radiation are available for many countries, they have generally been obtained with measurements performed in undisturbed environments instead of in urban areas where most of the population lives. Only one large national survey, with on-site measurements in urban areas, has been identified worldwide, probably due to high costs (e.g., personnel and instrumentation) and difficulties in selecting measuring points.
UNASSIGNED: A campaign of outdoor gamma radiation measurements has been carried out in the entire Italian territory. All measurement points were selected at the infrastructures of an Italian telecommunications company as representatives of all the possible situations of outdoor exposure to gamma radiation for population in urban areas. Ten replicates of portable gamma (X) detectors carried out all the measurements.
UNASSIGNED: Approximately 4,000 measurements have been performed. They are distributed across 2,901 Italian municipalities, accounting for 75% of the Italian population. The national population-weighted mean of the gamma ambient dose equivalent rate (ADER) is 117 nSv h-1, and it ranges from 62 to 208 nSv h-1 and from 40 to 227 nSv h-1 for 21 regions and 107 provinces, respectively. The average variability at the municipal level, in terms of the coefficient of variation (CV) is 21%, ranging from 3 to 84%. The impact of land coverage and the distance from a building on the outdoor gamma radiation level was assessed with complementary measurements, leading to differences ranging from -40 to 50% and to 50%, respectively.
UNASSIGNED: A representative campaign of outdoor gamma dose rate measurements has been performed in Italy, only in urban areas, to assess the exposure effect due to outdoor gamma radiation on the population. It is the largest national campaign in urban areas worldwide, with a total of 3,876 on-site measurements. The land coverage and the distance from surrounding buildings were recognized to strongly affect outdoor gamma radiation levels, leading to high variability within small areas. The collaboration with a company that owns a network of facilities on a national territory as dense as the residing population made this survey feasible and affordable. Other countries might adopt this methodology to conduct national surveys in urban environments.