Wear particles from road traffic - a field, laboratory and modelling study. Final report

The present report forms the final report from a major research project within the Swedish National Road Vehicle Emission Research Programme EMFO, carried out during the period 2005-2008. The project was carried out in collaboration between IVL, Lund University, SLB analys and VTI. Within the project extensive data have been collected by a variety of methods for measuring, sampling and analysing the chemical composition of different fractions of airborne particulate matter, with emphasis on the PM10 fraction. Collected data originate from indoor measurements in controlled runs with a circular road simulator as well as ambient air measurements at both street and roof level in a variety of Swedish cities. Based on elemental (metals etc.) source profiles of various sources to the different particle fractions, derived from the literature or from measurements carried out within the project, several different receptor models (e.g. COPREM, PMF) were applied to the collected data to derive the contribution from exhaust, brake wear, tyre wear, road surface wear, long-range transport etc., to the measured concentrations of PM10 and other particle fractions in urban environments. An important result of the project is the evidence for the great importance of studded tyres for the high PM10 concentration levels that occur in many Swedish cities during winter and early spring. According to the controlled indoor experiments with the road simulator studded tyres give rise to ten times higher emissions of PM10 than non-studded (friction) winter tyres, while PM10 emissions caused by summer tyres is almost negligibleThe present report forms the final report from a major research project within the Swedish National Road Vehicle Emission Research Programme EMFO, carried out during the period 2005-2008. The project was carried out in collaboration between IVL, Lund University, SLB analys and VTI. Within the project extensive data have been collected by a variety of methods for measuring, sampling and analysing the chemical composition of different fractions of airborne particulate matter, with emphasis on the PM10 fraction. Collected data originate from indoor measurements in controlled runs with a circular road simulator as well as ambient air measurements at both street and roof level in a variety of Swedish cities. Based on elemental (metals etc.) source profiles of various sources to the different particle fractions, derived from the literature or from measurements carried out within the project, several different receptor models (e.g. COPREM, PMF) were applied to the collected data to derive the contribution from exhaust, brake wear, tyre wear, road surface wear, long-range transport etc., to the measured concentrations of PM10 and other particle fractions in urban environments. An important result of the project is the evidence for the great importance of studded tyres for the high PM10 concentration levels that occur in many Swedish cities during winter and early spring. According to the controlled indoor experiments with the road simulator studded tyres give rise to ten times higher emissions of PM10 than non-studded (friction) winter tyres, while PM10 emissions caused by summer tyres is almost negligibl