European emission inventories and projections for road transport non-exhaust emissions

The relative contribution of wear emissionsto urban road transport PM10 emissionshas steadily grown and reaches more than 50% in many countries. Based on reported emissionsby European countries for brake and tire wear and road abrasion, an overview of the emissionsfor Europe is presented and further analyzed for gaps and consistency. Implied emissionfactors per vehicle kilometer are calculated to facilitate country intercomparison, showing that differences up to a factor of 2–4 persist even if the extremes are excluded. If the current trends continue, wear emissionsare predicted to grow to about 80%–90% of the direct PM10 emissionsfrom road transport after 2020. Resuspension of road dust PM10 is currently excluded from official emissionreporting. A model-based estimate of resuspension emissionsis used to assess its importance in comparison with wear emissions, suggesting that resuspension of road dust may be the dominant source of road transport particulate matter (PM) emissionsin many cities. It is recommended to include road resuspension in the emissionreporting to obtain a more transparent and complete overview of all road transport contributions to urban PM concentrations