北京市重点地区γ辐射水平监测与评价

Monitoring and assessment of environmental γ radiation in the principal areas of Beijing

北京市在奥运行动规划中,明确将放射性辐射作为环境治理的重点。在野外数据采集的基础上,运用地理信息系统(GIS)技术,对北京市重点地区(重点居民区、文物保护区、风景旅游区、奥运场馆区)环境的γ辐射水平进行了监测与评价。结果表明,所调查的4个地区,在总体上放射性辐射水平都不高,其人均年有效剂量当量最高为0.595 mSv,与国家对公众个人的标准(GB 8703—88)剂量值1 mSv比较,仅为限制剂量当量值的60%,均属于环境本底水平。

As is known, Beijing Municipal Government has taken radioactive pollution as one of the focal points of its environmental improvement policy in its action plan fbr successful holding of the 2008 Olympic Games. Applying the Geographic Information Systems （GIS） technology on the basis of data gathering in the fields, the present paper has made an analysis and evaluation over the situation of environmental γ radiation over the principal areas, including key residential blocks, protection zones of the historical relics, scenic spots and, particularly, the Olympic venue district of the city. The investigation of the paper indicates that the environmental radiation level is not high overall, with the maximum effective dose equivalent being only 0.595 mSv against the state standard （GB 8703--88）, which is just 60% of the lintit. Therefore, the radiation fails within the normal level. In our assessment, we have found that the environmental 7 γ radiation level is influenced by the characteristics of the ground under the monitored spots. Therefore, it is necessary to strengthen monitoring and defending the materials of construction in the future, especially, the building materials for residential houses, roads, plazas, and so on, because these above - said areas are the central areas for human activities. And in turn it is of great significance to maintain strict enviromuental radiation levels of such materials through control of the radioactivity pollution from thcir sources.