CHANEL · Household Chemicals Amplifying Urban Aerosol Pollution

Urban aerosol particles are one of the largest human health hazards globally. A significant fraction of urban aerosol is secondary, .i.e., formed via atmospheric chemical reactions of emitted trace gases, with secondary organic aerosol (SOA) driving health impacts in urban air. Decades of air quality regulations have substantially reduced the motor vehicle emissions of organic compounds that act as precursors to SOA pollution. In my recent studies, we show for the first time that volatile chemical products (VCPs) from household chemicals are becoming one of the largest sources of organic vapors in US cities. Based on their chemical properties, the potential of VCPs to form SOA is expected to be high but is as yet unknown. With chemical transport models showing a general shortfall in predicting urban SOA, VCPs are anticipated to be the missing source to bridge this long-standing knowledge gap. The aim of CHANEL is to provide unprecedented data to resolve the urban SOA pollution puzzle and identify the key VCP precursors to aerosol pollution. Using recent advances in state-of-the-art chemical ionization mass spectrometry, we will perform field measurements in European urban areas to determine the chemical composition of VCP emissions. A Zeppelin will be used as an airborne platform to probe the urban breath of European cities and quantify the chemical evolution and SOA production from VCPs downwind of urban centers. These measurements will be accompanied by controlled atmospheric simulation chamber experiments to oxidize VCP emissions and retrieve their SOA yields as a parametrization to be used by chemical transport models. In a future of electrified fleets where fossil fuel emissions are expected to further decrease and VCPs will dominate urban air pollution, CHANEL will push the frontiers of knowledge on urban SOA pollution and set the basis for future efficient adaptation policies.