城市道路尘埃的磁性特征及其环境意义  

Magnetic Properties of Urban Street Dust and Its Environmental Implication

作　　者：刘振东[1] 杨凌[2] 

机构地区：[1]中国科学院测量与地球物理研究所,武汉430077 [2]中国地震应急搜救中心,北京100049

出　　处：《地质科技情报》2005年第3期93-98,共6页Geological Science and Technology Information

基　　金：国家自然科学重点基金资助项目(40474025)

摘　　要：城市环境磁性研究表明,道路尘埃中的粗颗粒磁性载体(频率磁化率系数χ′FD＜5%)多为人为源,磁性矿物以单畴和多畴状态的磁铁矿为主,同时含有少量的赤铁矿和其他磁性矿物;细颗粒磁性载体(χ′FD为7%～11%)多为自然源,磁化率较低(小于100×10-8 m3/kg).磁性物质在迁移时往往与粗一级粒径的尘埃颗粒相伴生,磁性参数(如磁化率)和重金属元素(如铅、锌)质量分数之间呈相关关系,它们之间的关系可以用回归分析方法确定.利用电镜分析、因子分析和聚类分析方法可以识别道路尘埃物质的污染源.因此,道路尘埃的磁性特征研究在城市环境评价中具有潜在的重要意义.The studies of magnetism of city environment show that coarse magnetic carrier of city street dust, whose frequency-dependent susceptibility is less than 5%, commonly comes from artificial sources. The magnetic material of the carrier is mainly composed by single-domain and multi-domain magnetite, containing a bit of hematite as well as other magnetic material. Fine magnetic carrier, whose frequency-dependent susceptibility is 7%-11% and susceptibility is lower than 100×10^-8m^3/kg, mostly origins from natural sources. Magnetic materials often company with the dust of little bigger size when transferred, whose magnetic parameters （magnetic susceptibility） have correlated relation with heavy metals（e, g. lead, zinc）. The relation can be determined by regression analysis. Pollution sources of road dust may be identified by means of electron microscope, factor analysis and cluster analysis. Therefore, the study of magnetic properties of street dust possesses potential important meaning for appraising urban environment.

关 键 词：道路尘埃 重金属 相关分析 环境磁学 城市污染 

分 类 号：P574.19[天文地球—矿物学]