粤港澳大湾区某地天然放射性环境调查与评价  

Investigation and appraisals of urban natural radioactivity environment in Guangdong-Hong Kong-Macao Bay area

作　　者：赵迷迷 ZHAO Mimi(brigade,Guangdong Nuclear Industry Geology Bureau,Guangzhou 510800,Guangdong,China)

机构地区：[1]广东省核工业地质局二九二大队,广东广州510800

出　　处：《城市地质》2021年第4期432-438,共7页Urban Geology

摘　　要：天然放射性辐射是衡量优质人居环境的一项重要指标,在城市建设中开展放射性环境调查必不可少。2020年5月-10月,以(250~500)m×(50~100)m的网度布设测量点,在粤港澳大湾区某地开展1∶25000环境地表γ辐射剂量率测量。结果表明,区内整体辐射环境未发生明显变化,且处于正常水平。区内环境地表γ辐射水平可分为城镇人口密集区、基岩出露区和原野区3类,其中人口密集区的环境地表γ辐射水平略高于天然本底值2.48%~13.73%;基岩出露区环境地表γ辐射水平普遍高于天然本底值3.92%~65.29%;原野区环境地表γ辐射水平普遍低于天然本底值17.65%~40.20%,共发现10处异常高数值区(点),均与区内裸露的花岗岩及断裂构造带密切相关。居民所受环境地表γ辐射所致公众人均年有效剂量平均值为0.693 mSv·a^(-1),与全国辐射环境质量水平相当。圈定异常区4处,区内常驻人员需做好防护措施,或减少停留时间。Natural Radioactive Radiation is an important index to measure the quality of human settlements,and it is necessary to carry out radioactive environment investigations in urban construction.From May to October 2020,the environmental surfaceγradiation dose rate of 1:25,000 was measured in a city in the Guangdong-Hong Kong-Macao Greater Bay Area by setting up measuring points at a network size of(250-500)m×(50-100)m.The results show that the radiation environment of the whole area has no obvious changes and is at the normal level.The environmental surface radiation level in the region can be divided into three types:that of the urban densely populated area,of the bedrock exposed area and of the field area.The environmental surface radiation level in the densely populated area is slightly higher than the natural background value of the working area by 2.48%-13.73%;the environmental surface radiation level in the bedrock exposed area is generally higher than the natural background value by 3.92%-65.29%;and the environmental surface radiation level in the field area is generally lower than the natural background value by 17.65%-40.20%.A total of 10 abnormal high value areas(points)are found,which are closely related to the exposed granite and fault structural belt in the area.The average annual effective dose to the public caused by environmental surface radiation to the residents in the working area is 0.693 mSv·a^(-1),which is equivalent to the national level of radiation environmental quality.Four abnormal areas have been delineated and residents living in the areas should take protective measures,or reduce the length of stay.

关 键 词：粤港澳大湾区 天然放射性 公众剂量 

分 类 号：X837[环境科学与工程—环境工程]