Volume 14, No. 3, April 2014, Pages 734-743 PDF(1.18 MB)
Road Dust Emission Sources and Assessment of Street Washing Effect
Angeliki Karanasiou1,2, Fulvio Amato1,3, Teresa Moreno1, Julio Lumbreras4, Rafael Borge4, Cristina Linares5,6, Elena Boldo5,6, Andres Alastuey1, Xavier Querol1
1 Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain
2 Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
3 TNO Environment and Geosciences, Dept. of Climate, Air and Sustainability, P.O. Box 80015, 3508 TA Utrecht, The Netherlands
4 Department of Chemical & Environmental Engineering, Technical University of Madrid (UPM), Madrid, Spain
5 Cancer and Environmental Epidemiology Unit, National Center of Epidemiology, Carlos III Institute of Health, Madrid, Spain
6 CIBER Epidemiología y Salud Pública (CIBERESP), Spain
Although previous studies report on the effect of street washing on ambient particulate matter levels, there is a lack of studies investigating the results of street washing on the emission strength of road dust. A sampling campaign was conducted in Madrid urban area during July 2009 where road dust samples were collected in two sites, namely Reference site (where the road surface was not washed) and Pelayo site (where street washing was performed daily during night). Following the chemical characterization of the road dust particles the emission sources were resolved by means of Positive Matrix Factorization, PMF (Multilinear Engine scripting) and the mass contribution of each source was calculated for the two sites. Mineral dust, brake wear, tire wear, carbonaceous emissions and construction dust were the main sources of road dust with mineral and construction dust being the major contributors to inhalable road dust load. To evaluate the effectiveness of street washing on the emission sources, the sources mass contributions between the two sites were compared. Although brake wear and tire wear had lower concentrations at the site where street washing was performed, these mass differences were not statistically significant and the temporal variation did not show the expected build-up after dust removal. It was concluded that the washing activities resulted merely in a road dust moistening, without effective removal and that mobilization of particles took place in a few hours between washing and sampling. The results also indicated that it is worth paying attention to the dust dispersed from the construction sites as they affect the emission strength in nearby streets.
Road dust; Resuspension; Source apportionment; Madrid; Spain; Non-exhaust emissions.