Emissions of Secondary Organic Aerosol Precursors from Volatile Chemical Products

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

Particulate matter (PM) is directly linked to the important societal problems of public health and climate. Improving our understanding of the emissions and sources of PM addresses both problems. A large fraction of ambient PM is formed via atmospheric oxidation of organic precursor molecules. This project will quantify the emissions of organic precursors and subsequent PM formation from volatile chemical products (VCPs), a largely overlooked class of sources. VCPs include a wide range of non-combustion products including personal care products, fragrances, paints and coatings, and cleaning products, as well as other non-combustion industrial processes. The research results from this project will improve our understanding of the ambient PM burden with a focus on urban areas and will contribute to improved accuracy of PM formation in models. Crucially, this proposal directly addresses PM formation from a previously neglected source class that appears to be increasing in importance. Successful completion of this research will lead to a better characterize potential risks to human and ecological health. Both graduate and undergraduate researchers will participate in the research, and the training they receive will prepare them for successful careers in STEM fields, thus improving the scientific literacy and science preparedness of the Nation. The goal of this project is to quantify the emissions and potential formation of secondary organic aerosol (SOA) from volatile chemical products (VCPs). VCPs are non-combustion organic compounds associated with personal care products, fragrances, paints and coatings, cleaning products, and other non-combustion industrial uses. Recent research suggests that VCPs are an important source of urban SOA. However, there is uncertainty regarding the validity of the hypothesis because it is based upon emissions data that are focused on ozone formation rather than SOA formation potential. This project will address this address this uncertainty through a systematic study of SOA-forming emissions from VCPs under varying conditions. The underlying hypothesis of this research is that VCPs slowly emit low-volatility SOA precursors and that the volatility distribution and SOA formation potential of these emissions evolve over time. The specific objectives of the proposed research are to 1) measure VCP emission rates with a specific focus on SOA precursors as a function of humidity, air exchange rate, and substrate; 2) measure changes in emissions rate, composition, and SOA formation potential from VCPs as a function of time; 3) parameterize VCP emissions of both resolved and unresolved species for use in chemical transport models; and 4) quantify SOA production and composition from VCPs as a function of time and changing emissions. Successful completion of the research will increase our understanding of the contribution of VCPs to ambient SOA formation and address two key knowledge gaps regarding the emission rates and composition of organic vapors from two common VCPs (paints/coatings and adhesives/sealants) and the contribution of these VCP classes to ambient SOA loading. This research will also enable better quantification of the burden of anthropogenic SOAs and subsequent assessment of impacts on climate and human health. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.