Nationwide Trends of Reactive Organic Carbon Emissions from Volatile Chemical Products

Abstract:

Volatile chemical products (VCPs) are an increasingly important source of anthropogenic reactive organic carbon (ROC) emissions. Among these sources are everyday items, such as personal care products, general cleaners, architectural coatings, pesticides, adhesives, and printing inks. While these emissions have long been accounted for in the US EPA’s National Emission Inventory (NEI) as the solvent sector, the methods employed to quantify emissions for the NEI have changed over time and inventories are provided in 3-year increments. Here, we present VCPy, a new framework to model ROC emissions from VCPs throughout the United States. In this framework, fate and transport assumptions are a function of the use timescale for product-use categories and the evaporation timescales of individual compounds within these categories, which are a function of their physiochemical properties. We then apply this framework to explore how United States emissions from various VCP categories have changed in both time and space between 2002-2017. In addition, we investigate how these trends can influence the potential for secondary organic aerosol and ozone formation. Overall, we find National-level emissions of ROC from VCPs have decreased over this 16-year period, even as the population has increased, and discuss how these changes may manifest in resulting air quality changes.