Reactive organic carbon air emissions from mobile sources in the United States DOI Creative Commons
Benjamin N. Murphy, Darrell Sonntag, Karl M. Seltzer

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(20), P. 13469 - 13483

Published: Oct. 25, 2023

Abstract. Mobile sources are responsible for a substantial controllable portion of the reactive organic carbon (ROC) emitted to atmosphere, especially in urban environments United States. We update existing methods calculating mobile source particle and vapor emissions States with over decade laboratory data that parameterize volatility aerosol (OA) potential from on-road vehicles, nonroad engines, aircraft, marine vessels, locomotives. find emission factor information Teflon filters combined quartz collapses into simple relationships can be used reconstruct complete distribution ROC emissions. This new approach consists source-specific filter artifact corrections state-of-the-science speciation including explicit intermediate-volatility compounds (IVOCs), yielding first bottom-up volatility-resolved inventory US Using Community Multiscale Air Quality model, we estimate account 20 %–25 % IVOC concentrations 4.4 %–21.4 ambient OA. The updated air quality model reduce biases predicting fine-particle winter, spring, autumn throughout (4.3 %–11.3 reduction normalized bias). identify key uncertain parameters align current state-of-the-art research measurement challenges.

Language: Английский

Full-Volatility Reactive Organic Carbon Emissions from Volatile Chemical Products in Mainland China DOI
Yangjun Wang, Jiayu Huang, Bin Zhao

et al.

ACS ES&T Air, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 29, 2024

Volatile chemical products (VCPs), including personal care products, general cleaners, architectural coatings, pesticides, adhesives, and others, are becoming increasingly significant anthropogenic sources of reactive organic carbon (ROC) in China. These ROC serve as critical precursors to ozone (O3) secondary aerosols (SOAs). Therefore, it is essential estimate emissions from VCPs China accurately. In this study, the VCPy framework developed by U.S. EPA was used simulate evaporative mainland China, its emission inventory established. The results indicate that 2019, total VCP amounted 9.4 Tg (6.9 TgC) with a 95% confidence interval 8.4–11.8 (6.2–8.7 TgC). category paints coatings emerged dominant contributor emissions, emitting 6.0 (4.4 TgC), accounting for 63.7% followed cleaning at 11.2% adhesives 10.1%. Among volatile compounds (VOCs) accounted largest proportion, intermediate-volatility (IVOCs), 23.6%. Oxygenated aromatics were components emitted VCPs, 48.0% 31.0% mass, respectively. Moreover, mass proportion oxygenated IVOC 72.0%. However, still predominantly form VOCs. Additionally, O3 formation potential (OFP) SOA (SOAFP) estimated 32.0 0.5 Tg, respectively, suggesting impact on sources. Emissions contributed significantly OFP SOAFP 33.8% 17.1%, By comparing measurement data, can reliably reproduce key species This study provides basic data more comprehensive assessment

Language: Английский

Citations

5
Atmospheric Autoxidation of Organophosphate Esters DOI

Zihao Fu,

Hong‐Bin Xie, Jonas Elm

et al.

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 56(11), P. 6944 - 6955

Published: Nov. 18, 2021

Organophosphate esters (OPEs), widely used as flame retardants and plasticizers, have frequently been identified in the atmosphere. However, their atmospheric fate toxicity associated with transformations are unclear. Here, we performed quantum chemical calculations computational toxicology to investigate reaction mechanism of peroxy radicals OPEs (OPEs-RO2•), key intermediates determining chemistry OPEs, products. TMP-RO2• (R1) TCPP-RO2• (R2) derived from trimethyl phosphate tris(2-chloroisopropyl) phosphate, respectively, selected model systems. The results indicate that R1 R2 can follow an H-shift-driven autoxidation under low NO concentration ([NO]) conditions, clarifying RO2• mechanism. unexpected be attributed distinct role ─(O)3P(═O) phosphate-ester group facilitating H-shift OPEs-RO2• commonly encountered ─OC(═O)─ ─ONO2 ester groups Under high [NO] mediate form organonitrates alkoxy radical-related products volatility aquatic compared corresponding parent compounds. proposed advances our current understanding environmental risk OPEs.

Language: Английский

Citations

31
Contrasting Chemical Complexity and the Reactive Organic Carbon Budget of Indoor and Outdoor Air DOI Creative Commons
James M. Mattila, Caleb Arata, Andrew Abeleira

et al.

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 56(1), P. 109 - 118

Published: Dec. 15, 2021

Reactive organic carbon (ROC) comprises a substantial fraction of the total atmospheric budget. Emissions ROC fuel oxidation chemistry to produce secondary pollutants including ozone, dioxide, and particulate matter. Compared outdoor atmosphere, indoor budget is comparatively understudied. We characterized in test house during unoccupied, cooking, cleaning scenarios using various online mass spectrometry gas chromatography measurements gaseous organics. Cooking greatly impacted concentrations bulk physicochemical properties (e.g., volatility state), while yielded relatively insubstantial changes. Additionally, cooking enhanced reactivities hydroxyl radicals ozone toward ROC. observed consistently higher median indoors (≥223 μg C m–3) compared outdoors (54 m–3), demonstrating that buildings can be net source reactive following its removal by ventilation. estimate unoccupied emitted 0.7 g day–1 from outdoors. Indoor emissions may thus play an important role air quality pollutant formation outdoors, particularly urban suburban areas, use oxidant-generating purifiers.

Language: Английский

Citations

28
Sensitivity of northeastern US surface ozone predictions to the representation of atmospheric chemistry in the Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMMv1.0) DOI Creative Commons
Bryan K. Place,

William T. Hutzell,

K. Wyat Appel

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(16), P. 9173 - 9190

Published: Aug. 21, 2023

Chemical mechanisms describe how emissions of gases and particles evolve in the atmosphere are used within chemical transport models to evaluate past, current, future air quality. Thus, a mechanism must provide robust accurate predictions pollutants if it is be considered for use by regulatory bodies. In this work, we an initial evaluation Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMMv1.0) assessing CRACMMv1.0 surface ozone (O3) across northeastern US during summer 2018 Multiscale Air Quality (CMAQ) modeling system. O3 hourly maximum daily 8 h average (MDA8) were lower than those estimated with aerosol module 6 (RACM2_ae6), which better matched network observations (RACM2_ae6 mean bias +4.2 ppb all hours +4.3 MDA8; +2.1 +2.7 MDA8). Box model calculations combined results from CMAQ emission reduction simulations indicated high sensitivity compounds biogenic sources. addition, these differences between RACM2_ae6 largely explained updates inorganic rate constants (reflecting latest assessment values) representation monoterpene chemistry. Updates other reactive organic carbon systems also affected their emissions. Specifically, benzene, toluene, xylene chemistry led efficient NO x cycling such that predicted controlling aromatics reduces without rural disbenefits. contrast, semivolatile intermediate-volatility alkanes introduced acted suppress formation regional background through sequestration nitrogen oxides (NO ) nitrates. Overall, analyses showed was able reasonably simulate concentrations similar magnitude diurnal variation as current operational Carbon Bond (CB6r3_ae7) good performance compared recent studies literature.

Language: Английский

Citations

11
Reactive organic carbon air emissions from mobile sources in the United States DOI Creative Commons
Benjamin N. Murphy, Darrell Sonntag, Karl M. Seltzer

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(20), P. 13469 - 13483

Published: Oct. 25, 2023

Abstract. Mobile sources are responsible for a substantial controllable portion of the reactive organic carbon (ROC) emitted to atmosphere, especially in urban environments United States. We update existing methods calculating mobile source particle and vapor emissions States with over decade laboratory data that parameterize volatility aerosol (OA) potential from on-road vehicles, nonroad engines, aircraft, marine vessels, locomotives. find emission factor information Teflon filters combined quartz collapses into simple relationships can be used reconstruct complete distribution ROC emissions. This new approach consists source-specific filter artifact corrections state-of-the-science speciation including explicit intermediate-volatility compounds (IVOCs), yielding first bottom-up volatility-resolved inventory US Using Community Multiscale Air Quality model, we estimate account 20 %–25 % IVOC concentrations 4.4 %–21.4 ambient OA. The updated air quality model reduce biases predicting fine-particle winter, spring, autumn throughout (4.3 %–11.3 reduction normalized bias). identify key uncertain parameters align current state-of-the-art research measurement challenges.

Language: Английский

Citations

11