Over the last twenty years, a significant portion of the global urban population, including Europeans, has lived in areas with consistently unhealthy levels of particulate matter (PM10, PM2.5, ultrafine particles). Despite the reduction of many air pollutants due to earlier policies, air pollution remains associated with millions of premature deaths worldwide, including in Europe.
Transportation plays a crucial role in the global distribution of food, materials, energy, and more. However, all transport sectors are substantial emitters of air pollutants. The influence of transport sectors on harmful ambient PM is not well understood, necessitating increased scientific understanding and evidence to justify policies and develop tools for policy implementation. Addressing key questions requires extensive emissions studies under real-world conditions, far beyond current emission standard protocols. Additionally, emerging sources like non-exhaust emissions and microplastics present new challenges.
The previously simple view of chemically inert primary organic aerosol (POA) has dramatically changed in the last decade. It is now clear that large fractions of volatile organic compounds (VOCs) have been neglected in most past emission studies and are not explicitly included in current emission inventories. Evidence shows that both gases and particles continuously react in the atmosphere, creating complex chemical mixtures that are just beginning to be analyzed with new analytical tools.

This session invites interdisciplinary contributions, both experimental and theoretical, ranging from real-world emissions related to various transport sectors, including new sources like non-exhaust emissions and microplastics, to their chemical transformations in the air and potential impacts on climate and health. Contributions are expected from fundamental studies to the evaluation and mitigation of these pollution sources, aiming for a better description of air quality in different regions, particularly in high-impact zones.