National Facilities
03
Sep
2024
Urban aerosol particles are one of the largest human health hazards globally. A significant fraction of urban aerosol is secondary (SOA), .i.e., formed via chemical reactions of emitted trace gases. Decades of air quality regulations have substantially reduced vehicle emissions of organic compounds.
Recent studies show that volatile chemical products (VCPs) from household chemicals are becoming the largest source of organic vapors in US cities. Their potential to form SOA, however, remains largely unknown. With chemical transport models falling short in predicting urban SOA, VCPs are anticipated to fill this knowledge gap.
In the ATMO-ACCESS funded transnational access project “SAPHURBAN” led by the University of Eastern Finland, cutting-edge advancements in chemical ionization mass spectrometry were utilized in controlled chamber experiments in the simulation chamber SAPHIR at Forschungszentrum Jülich. This involves oxidizing atmospheric mixtures of urban emissions, including VCPs, and emissions from traffic and cooking. The main scientific objectives were to:
- Characterize SOA composition resulting from oxidation experiments, using atmospheric mixtures of compounds from VCPs, cooking, and traffic emissions and compare with field measurements.
- Determine SOA yields from the various precursor mixtures’ under atmospherically relevant conditions.
The outcomes of this project will provide novel insights into SOA formation pathways and yields, shedding light on the impact of precursor mixtures from VCPs, cooking, and traffic on urban air quality. The SOA yields obtained from this research will serve as inputs for chemical transport models, enhancing their precision in forecasting urban SOA formation. Finally, results will be tailored to the findings from recent field campaigns, where VCPs were identified, and provide thereby novel, innovative access to the SAPHIR chamber.