Air pollution is associated with mortality and morbidity worldwide, and many toxic organic substances have been identified in aerosols, but their sources, atmospheric chemical processes, their distributions and bioavailability are insufficiently understood and studied. In addition, the complex aerosol chemistry of organic pollutants impacts climate change and human health. Organic pollutants (like VOCs, PAHs and their derivatives, PCBs, pesticides, PFAS, etc.) enter the atmosphere released from both natural and anthropogenic sources and affect air quality from local to global scales. These pollutants can either persist in air, surface water and soils or undergo atmospheric processes depending on their chemical composition and meteorological parameters, potentially leading to the formation of secondary aerosols/organic pollutants with increased toxicity and persistence (like, PAHs interact with VOCs, NOx, Cl·, and other atmospheric pollutants to form Nitro-, Oxy-, and Cl-PAHs via radical-initiated reactions in both the gaseous and particulate phases). Nitro-, Oxy-, and halogenated PAHs are possibly ubiquitous in the global atmosphere. These pollutants may enter the human body with fine (PM2.5) and ultra-fine particulate matter (PM0.1) or gaseous, and may induce oxidative stress due to the excess formation of reactive oxygen species (ROS). International agencies are making continuous attempts to improve air quality, and making policies for the containment of emission of pollutants from anthropogenic sources. However, these efforts are insufficient to make the inevitable effects of air pollutants and their impact on human health. In this session, we invite submissions on the latest methodological developments on emerging air pollutants, their atmospheric chemistry and their source signatures in urban environments. This session also welcomes submissions on observational and modeling analysis of atmospheric processes of pollutants and their potential health impacts on humans.