Establishment and Comparison of Evaluation Methods for Fugitive Road Dust

In this article,we set up two methods for evaluation of fugitive road dust: the dust fall method and the AP-42 method.The two methods use relative road dust fall after subtracting background dust fall(ΔDFr) and the emission intensity of fugitive road dust(EIr) as the evaluation indices.Three conclusions have been drawn through comparing evaluation results of these two methods.First,ΔDFr and EIr are positively correlated,with a correlation coefficient R2 of 0.708.Second,ΔDFr can simultaneously measure the fugitive dust generated by vehicles and wind erosion of the road surface silt,while EIr can only measure fugitive dust generated by vehicles.Third,the single index of silt loading(sL) does not reflect the degree of pollution from fugitive road dust,but can be applied to quantitatively evaluate the quality of city road sweeping and cleaning.Compared with the AP-42 method,the dust fall method is safer and easier to use with only small errors,but it does not provide fast results and has slightly higher costs.The two methods both indicate that the policies of Guaranteeing Measures of the 2008 Olympic Games had an obvious effect on controlling fugitive road dust.Comparing the period of the 2008 Olympic Games with the same period in 2007 shows that ΔDFr on freeways,major arterial,minor arterial and collector roads was reduced by 65%,55%,65% and 84%,respectively.