|
|
Vertical characteristics of deposition fluxes of dust and heavy metals of Guiyang City |
|
|
Abstract Dust was an important pathway of human heavy metal exposure. With the emergence of urban high-rise building, the vertical space of human daily life gradually extended upward. Dust and its heavy metal located on the windowsill and other platform at different height of the building was remarkable. In this study, dust deposition on the windowsill at different height (1th-8th floor) from three buildings in Guiyang city was collected and the deposition fluxes of dust and elements including Ca, Fe, Cd, Cr, Cu, Ni, Pb and Zn was analyzed. Further, the environmental risk due to heavy metals based on loadings per day was assessed by the single-factor contaminant index and Nemerow multi-factor index method. The results showed that: the deposition fluxes of dust decreased with the increases of the height of the ground. The content of elements showed small changes in dust at different height: the contents of Fe, Cd, Cu, Ni, and Pb increased with the height, while the contents of Cr and Zn in dust decreased with the height. In general, the element deposition fluxes decreased as the height of the ground increase, especially Ca, Cr and Zn. The risk assessment based on the deposition fluxes of heavy metals showed that the 1th-3th floor and 7th floor were in higher risk condition, while the 4th-6th floors were in lower risk condition, and Cd, Pb, Cu, and Zn were the main risk elements.
|
Received: 27 October 2014
|
|
|
|
|
|
|