Characteristics and Mitigation of Vehicular Non-exhaust Particle Emissions in Nordic Conditions

Abstract

Assessment of air pollution health effects of road traffic should accurately characterize also the non-exhaust sources to support efficient emission mitigation. The use of the recently developed new-generation non-exhaust emission models opens new opportunities to extend and improve the traffic PM emission factors and the emission inventories. This study utilizes the non-exhaust emission model NOn-exhaust Road TRaffic Induced Particle emissions (NORTRIP) to evaluate the PM₁₀ and PM_2.5 emission factors separately for different climatic zones, road and street categories, and road maintenance practices in Finland. The non-exhaust emissions are influenced by climatic and weather factors, especially the road surface moisture, and have seasonal peaks particularly in winter and spring, due to enhanced formation of layers of street dust and their suspension to the air. The results demonstrated that changes in the selection of the types of winter tyres and their use, as well as road maintenance interventions could substantially reduce the non-exhaust emissions, especially in spring. Data gaps were identified in collecting the relevant inputs for the model. The methods presented in this study could be used at least in the whole Northern part of the world, i.e., the Nordic countries and Northern Central Europe, Northern Russia, North America, and parts of China and Japan.