Опубликована: Янв. 1, 2023
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Язык: Английский
ACS Earth and Space Chemistry, Год журнала: 2023, Номер 7(1), С. 218 - 229
Опубликована: Янв. 5, 2023
Cyclic volatile methyl siloxanes (cVMS) that are emitted from industrial processes and consumer products often dominate the burden of organic compounds (VOCs) in occupied spaces. cVMS may contribute to oxygenated VOC secondary aerosol (SOA) formation following oxidation by gas-phase radicals both indoor outdoor source regions. Several recent studies examined SOA potential decamethylcyclopentasiloxane (D5) exposure hydroxyl (OH) found this reaction generates high yield multiple days oxidative aging. Chlorine atoms (Cl) compete with OH for loss D5 regions active chlorine chemistry, but + Cl reactions has not been studied. Here, we characterized chemical composition generated an flow reactor (OFR) under dry [relative humidity (RH) < 5%] humid (RH = 40%) conditions compared results D5. was oxidized using integrated exposures (OHexp Clexp) ranging 1.1 × 1012 8.2 cm–3 s 1.6 1010 s, respectively. Like OH, facilitated multistep aging over range OFR were studied, maximum mass yields 1.5 1.3 obtained conditions. These suggest significantly influenced chemistry enhance atmospheric
Язык: Английский
Процитировано
20
The Science of The Total Environment, Год журнала: 2023, Номер 892, С. 164702 - 164702
Опубликована: Июнь 9, 2023
Язык: Английский
Процитировано
14
TrAC Trends in Analytical Chemistry, Год журнала: 2023, Номер 168, С. 117353 - 117353
Опубликована: Окт. 11, 2023
Язык: Английский
Процитировано
14
Current Pollution Reports, Год журнала: 2024, Номер 10(3), С. 387 - 400
Опубликована: Апрель 16, 2024
Язык: Английский
Процитировано
4
ACS Earth and Space Chemistry, Год журнала: 2025, Номер unknown
Опубликована: Фев. 19, 2025
The importance of nitrate radicals (NO3) as an atmospheric oxidant is well-established. For decades, laboratory studies multiphase NO3 chemistry have used the same methods – either NO2 + O3 reactions or N2O5 thermal decomposition to generate it occurs in atmosphere. These methods, however, come with limitations, especially for N2O5, which must be produced and stored under cold dry conditions until its use. Recently, we developed a new photolytic source gas-phase by irradiating aqueous solutions ceric ammonium nitric acid. In this study, adapted method maintain stable concentrations over 24 h. We applied oxidation flow reactor (OFR) experiments measure yield chemical composition oxygenated volatile organic compounds (OVOCs) secondary aerosol (SOA) formed from (VOCs) emitted biogenic sources (isoprene, β-pinene, limonene, β-caryophyllene) biomass burning (phenol, guaiacol, syringol). SOA yields elemental ratios were typically within factor 2 10%, respectively, those obtained using conventional sources. Maximum our ranged 0.02 (isoprene/NO3) 0.96 (β-caryophyllene/NO3). highest oxygen-to-carbon (O/C) 0.48 (β-caryophyllene/NO3) 1.61 (syringol/NO3). Additionally, characterized novel condensed-phase products syringol/NO3 reactions. Overall, use irradiated cerium may enable more widespread NO3-initiated oxidative aging, has been less explored compared that hydroxyl radical chemistry.
Язык: Английский
Процитировано
0
Environmental Science & Technology, Год журнала: 2023, Номер 57(41), С. 15454 - 15464
Опубликована: Окт. 2, 2023
Growth in unconventional oil and gas development (UOGD) the United States has increased airborne emissions, raising environmental human health concerns. To assess potential impacts on air quality, we deployed instrumentation Karnes City, Texas, a rural area middle of Eagle Ford Shale. We measured several episodes elevated Cl2 levels, reaching maximum hourly averages 800 ppt, highest inland concentration reported to date. Concentrations peak during day, suggesting strong local source (given short photolysis lifetime Cl2) and/or photoinitiated production mechanism. Well preproduction activity near measurement site is plausible these high levels via direct emission photoactive chemistry. ClNO2 also observed, but it peaks overnight, consistent with well-known nocturnal formation processes. Observations organochlorines particle phases reflect contribution chlorine chemistry secondary pollutants area. Box modeling results suggest that ozone at this location influenced by These UOGD can be an important reactive atmosphere, impacting radical budgets regions.
Язык: Английский
Процитировано
8
Ecotoxicology and Environmental Safety, Год журнала: 2023, Номер 265, С. 115497 - 115497
Опубликована: Сен. 18, 2023
Ultrafine particles (UFP) of Secondary Organic Aerosol (SOA) penetrate deep into the human respiratory system and exert fatal effects on health. However, there is little data potential deposited doses UFP-generated SOA in tract. This study to estimate fraction aerosol deposition using a multiple-path-particle-dosimetry (MPPD) model. For relevancy real life, model employed measured concentrations toluene-derived fresh aged produced within serially connected smog chamber PAM-OFR (Potential Mass-Oxidation Flow Reactor) under atmospheric environmental conditions (NOx relative humidity). The number chemical composition aerosols chambers were Scanning Mobility Particle Sizer (SMPS) High-Resolution Time-of-Flight Mass Spectrometer (HR-ToF-AMS), while morphology individual was analyzed Electron Microscopy (SEM). concentration SOA-w/s more than double compared that (maximum reached after 10 h) with its size less 100 nm. O:C ratio for 0.96 1.15 depending RH (0.96 at 3% 50% RH), spherical containing water present agglomerates 1 µm. In all inhalable two chambers, 5-22% Head airways, 4-8% tracheobronchial, 8-34% alveolar regions. predominant occurred alveoli (in generation 20th lobe), faction 2-3 times higher children group adults group. presented quantitative exposure assessment generated realistic simulation suggested possibility evaluating long-term health by determining system.
Язык: Английский
Процитировано
7
The Science of The Total Environment, Год журнала: 2024, Номер 918, С. 170379 - 170379
Опубликована: Янв. 26, 2024
Язык: Английский
Процитировано
2
Environmental Science & Technology, Год журнала: 2024, Номер unknown
Опубликована: Дек. 18, 2024
Simulation of secondary organic aerosol (SOA) in models has been an uncertain component determining the impacts atmospheric aerosols on air quality and climate. Recent studies have shown that reactive chlorine can rapidly oxidize volatile compounds (VOCs), trigger SOA formation, alter other oxidants, thus having a potentially significant effect SOA, which not thoroughly investigated at global scale. Here, we developed chlorine-SOA simulation within chemical transport model along with updated anthropogenic continental emissions. Our simulations demonstrate chemistry increases annual mean boundary layer by 5–12% over most continents while decreasing 5–11% northern Atlantic Pacific oceans, are right direction to narrow existing discrepancies between observations. Notably, sensitivity China observed high levels capture temporal variations both fine Cl– aerosol, showing increase more than 100%. study also reveals polluted regions, ample emissions species VOCs, exhibit potential chlorinated commonly toxic, contributing up 15% total SOA.
Язык: Английский
Процитировано
1
Опубликована: Янв. 1, 2023
Download This Paper Open PDF in Browser Add to My Library Share: Permalink Using these links will ensure access this page indefinitely Copy URL DOI
Язык: Английский
Процитировано
0