摘要
城市土壤中的氡和γ辐射对人体具有较强的内辐射和外辐射,危害人类健康。本文以金华市为例,通过不同功能区城市土壤氡浓度和γ辐射的调查与监测,探讨城市土壤氡浓度和γ辐射剂量率及其分异特征。结果表明,金华城市土壤氡浓度较低,平均值为6789 Bq m-3,低于世界土壤氡浓度平均值。高值区主要分布在城市绿地、硬盖层边缘及市中心地带,主要与城市绿地、硬盖层边缘氡较易析出和人为污染有关。γ辐射剂量率介于0.09~0.21μSv h-1之间,明显高于中国平均值,这与金华市区北部的江绍深断裂带造成该区γ辐射剂量率整体偏高有关。而在发展历史较早、受人为影响较大的金华江南部城区,人为因素对土壤γ辐射起着主导作用。另外,水域对γ辐射有一定的屏蔽作用。
Urban soils have a significant effect on water,atmosphere,biological activity and human health.However,radon and gamma radiation of urban soils have great internal and external radiation on human beings.Based on the measures of urban soils,the radon concentration and γ-dose rate in different domains and their characteristics are analyzed.The results show that urban soil＇s radon concentration in Jinhua City is relatively low,and its average value is 6789 Bq m-3,which is lower than the mean of the world.The high-concentration areas are mainly located in marginal areas of hard layers,greenbelts and urban centre because of radon being liable to emission in marginal areas of hard layers and greenbelts,as well as the man-made contamination.γ-dose rate in Jinhua City varies from 0.09 μSv h-1 to 0.21 μSv h-1,which is much higher than the mean of China.It results from the fracture zone to the north of Jinhua City.However,anthropogenic factors play a predominant part in the regions south of the Jinhua River which has a long history and profound human effects over the geologic factors.In addition,water has a shielding effect on gamma radiation.
出处
《土壤通报》
CAS
CSCD
北大核心
2012年第2期396-401,共6页
Chinese Journal of Soil Science
基金
中国科学院知识创新工程重要方向项目(KZCX2-YW-406)
国家自然科学基金(50909090)共同资助
关键词
城市土壤
金华
土壤氡
Γ辐射
Urban soils
Jinhua City
Soil radon
Gamma radiation
