Distribution and characteristic of Cd

Cr

Cu

Hg

Pb

Zn

Ni of urban dust were analyzed on regional scale coming from forty-seven cities.The results showed that heavy metal concentrations were divided into five grades

and change from one to four times standard deviation.In space scale

they were high in western and southern

and low in eastern and northern

and reduced from southwest to northeast.The order of heavy metal content in each region was Southwest ChinaNorthwest ChinaSouth ChinaEast ChinaNorth ChinaCentral ChinaNortheast China.In addition

some elements

spatial distribution was consistent with the stepped topography of China.Soil background and human activity were important factors

the former mainly influenced North China

Central China and Northeast China

the latter played an important role in Northwest

Southwest and South China.The order of disturbance on heavy metal was CdHgZnPbCuNiCr.