Elemental profiles of road dust resuspension particles (Metadata RADIATE TA Proposal 20002323-ST)

Proposal title "Elemental profiles of road dust resuspension particles". Measurements carried out at the external beam set-up for atmospheric aerosol analysis of the INFN LABEC accelerator laboratory), on 11 November 2020. Hands-off mode.

Numerous studies have shown that the contribution of non-exhaust primary particles, where road dust resuspension is included, to the atmospheric levels is significant in urban areas. In Mediterranean countries and in other regions, where long periods without precipitation can be recorded, the dry weather conditions favor the resuspension of road dust. Dust loadings and the chemical source profiles vary geographically, depending on other parameters besides meteorology, such as traffic (volume and pattern, fleet characteristics), pavement type, and geology of the region. Thus, to correctly apportion the contribution of road dust to ambient particulate matter, chemical profiles for each region should be used. Region-specific emission factors are also a condition for improving the accuracy of emission inventories. There is a clear lack of data in the field of dust resuspension to conclusively assess its importance for air quality and the impact on human health.

With the aim of obtaining new emission factors and chemical profiles, twenty samples of the thoracic fraction of road dust (PM10) were collected in three Portuguese cities (Aveiro, Ílhavo and Lisbon), directly vacuumed in situ using a pump connected to a field resuspension chamber and then deposited on polytetrafluoroethylene filters. These samples were analyzed by PIXE technique using an extracted proton beam of 3.0 MeV (energy on target) to determine the elemental composition (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Pb). A set of elemental standards and an aerosol reference standard (NIST 2783) were analysed as well for quality assurance purposes and to check the accuracy of quantitative results.