Characterization of road dust and resuspended particles close to a busy road of Venice mainland (Italy)

Road traffic contributes to atmospheric particulate matter with exhaust (fuel combustion) and non-exhaust (wear of vehicle parts such as brake, tires and abrasion of the road surface) emissions. Road dust is composed of particles belonging to natural and anthropogenic sources related in large part to road traffic. To date, understanding the relative contribution of road dust resuspension and particles directly emitted by abrasion to particulate matter is still a matter of debate. In this work, road dust and resuspended particles samples are collected at different heights and with increasing sampling time near a busy road of Venice mainland. Elemental composition and morphology of particles were investigated with a combination of techniques: inductively coupled plasma optical emission spectroscopy (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), laser diffraction analysis and scanning electron microscopy-energy-dispersive X-ray spectrometry (SEM-EDX). The differences between deposited and resuspended particles were highlighted and the main pollutant sources were identified to study the resuspension process related to the traffic flow. Resuspended particles were divided into six groups related to the presence of anti-ice material, to soil resuspension and to the road surface and vehicle parts wear. The contributions of clustered particles vary with the height from the road level. This study, the first one focusing on the road traffic particles resuspension in Veneto region, will provide topical information for the identification of this source in atmospheric particulate samples.