Identifying Volatile Chemical Product Tracer Compounds in U.S. Cities

• DOI: 10.1021/acs.est.0c05467
• Publication Date: 2020-12-17T15:49:02Z
• Authors: Georgios I. Gkatz...; Matthew M. Coggon; Brian C. McDonald; Jeff Peischl; Kenneth C. Aikin; Jessica B. Gilman; Michael Trainer; Carsten Warneke
• Keywords: Octamethylcyclotetrasiloxane; Volatile organic compound; TRACER; Population density

With traffic emissions of volatile organic compounds (VOCs) decreasing rapidly over the last decades, contributions from other source categories, such as chemical products (VCPs), have become more apparent in urban air. In this work, situ measurements various VOCs are reported for New York City, Pittsburgh, Chicago, and Denver. The magnitude different emission sources relative to is determined by measuring enhancement individual benzene, a known tracer fossil fuel United States. ratios several VCP benzene correlate well with population density (R2 ∼ 0.6–0.8). These observations consistent expectation that some human activity should better than transportation emissions, due lower per capita rate driving denser cities. Using these data, together bottom-up fuel-based inventory vehicle (FIVE-VCP) inventory, we identify categories: decamethylcyclopentasiloxane (D5-siloxane) personal care products, monoterpenes fragrances, p-dichlorobenzene insecticides, D4-siloxane adhesives, para-chlorobenzotrifluoride (PCBTF) solvent-based coatings, Texanol water-based coatings. Furthermore, identified (e.g., ethanol) originate multiple sources. Ethanol fragrances among most abundant reactive associated emissions.