. 2005, 23(0509): 26-30.
Heavy metals in urban topsoil have been shown to be very useful tracers of environmental pollution because urban topsoil is the "recipients" of large amounts of heavy metals from a variety of sources including industrial wastes, vehicle emissions, coal burning waste, and other activities. Dust from the ground because of wind erosion may have toxic effects as a consequence of inhalation or ingestion by humans, particularly children, which poses major health hazard. Furthermore, any contamination of urban topsoil could cause in turn surface water/groundwater contamination because metals of the polluted topsoil tend to be more mobile than those of unpolluted ones. In this paper, we firstly probe into the connotation of carrying capacity of heavy metals in urban topsoil, analyze the mechanism and inhabiting factors of heavy metals in urban topsoil, differentiate "absolute carrying capacity" and "relative carrying capacity" and put forward the computing model of relative carrying capacity for heavy metals in urban topsoil. Secondly, the preliminary assessment index (FD) and sustainable development index (FS) are discussed. Lastly the controlling measures on the emissions of heavy metals are discussed.