Street dust has frequently been used as a material for the monitoring of trace element pollution, and in particular for the metal lead. The value of the analytical data, as a measure of pollution, depends on understanding the spatial, temporal, and bulk characteristics of the dust. The influence of each of these factors on the variability of trace element analytical results has been investigated in order to determine whether or not the variations reflect differing pollution levels. The concentrations of the four metals Pb, Cu, Ni, and Zn have been measured in street dust collected from a variety of situations. Coefficients of variation > 20% (particularly for lead) for a series of samples have been taken as a guide to real differences in lead levels between samples in the series. An important factor in the variability of heavy metal levels in dust is the distribution of particle size within a sample. Concentrations of the trace metals fall and then rise as the particle size decreases from 1000 μm down to silt sized particles.
Potentially toxic trace element pollution in long-term fertilized agricultural soils in China: a meta-analysis
