ACS ES&T Air最新文献

{"title":"Multiphase Processing of the Water-Soluble and Insoluble Phases of Biomass Burning Organic Aerosol","authors":"Habeeb H. Al-Mashala,&nbsp;Meredith Schervish,&nbsp;Sithumi M. Liyanage,&nbsp;Jace A. Barton,&nbsp;Manabu Shiraiwa and Elijah G. Schnitzler*,&nbsp;","doi":"10.1021/acsestair.4c0034510.1021/acsestair.4c00345","DOIUrl":"https://doi.org/10.1021/acsestair.4c00345https://doi.org/10.1021/acsestair.4c00345","url":null,"abstract":"<p >Biomass burning is one of the most significant sources of organic aerosol in the atmosphere. Biomass burning organic aerosol (BBOA) has been observed to undergo liquid–liquid phase separation (LLPS) to give core–shell morphology with the hydrophobic phase encapsulating the hydrophilic phase, potentially impacting the evolution of light-absorbing components, i.e., brown carbon (BrC), through multiphase processes. Here, we demonstrate how multiphase processing differs between the water-soluble (i.e., hydrophilic) and insoluble (i.e., hydrophobic) phases of BBOA in terms of reactive uptake of ozone in a coated-wall flow tube. Effects of relative humidity (RH) and ultraviolet (UV) irradiation were investigated. Experimental timeseries were used to inform simulations using multilayer kinetic modeling. Among non-irradiated thin films, the uptake coefficient was greatest for the water-soluble phase at 75% RH (3 × 10^–5, corresponding to a diffusion coefficient of BrC, <i>D</i>_BrC, of 3 × 10^–9 cm² s^–1) and least for the same phase at 0% RH (1 × 10^–5, corresponding to <i>D</i>_BrC of 1 × 10^–10 cm² s^–1). The uptake coefficient for the water-insoluble phase fell between these two (about 1.5 × 10^–5), regardless of RH, and the corresponding <i>D</i>_BrC increased only slightly (8 × 10^–10 cm² s^–1 at 0% RH to 9 × 10^–10 cm² s^–1 at 75% RH). The uptake coefficients of both phases at 0% RH decreased significantly after UV irradiation, consistent with a transition from viscous liquid to solid and supported by qualitative microscopy observations. Modeling multiphase ozone oxidation of primary BrC components in the atmosphere demonstrated, first, that LLPS may extend the lifetime of water-soluble BBOA encapsulated by water-insoluble species by a factor of 1.5 at moderate to high RH and, also, that UV irradiation may extend the lifetime of both phases by more than a factor of 2.5.</p><p >Liquid−liquid phase separation and ultraviolet irradiation may restrict the multiphase processing of biomass burning organic aerosol governing its climate effects.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 4","pages":"637–647 637–647"},"PeriodicalIF":0.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.4c00345","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiphase Processing of the Water-Soluble and Insoluble Phases of Biomass Burning Organic Aerosol.","authors":"Habeeb H Al-Mashala, Meredith Schervish, Sithumi M Liyanage, Jace A Barton, Manabu Shiraiwa, Elijah G Schnitzler","doi":"10.1021/acsestair.4c00345","DOIUrl":"https://doi.org/10.1021/acsestair.4c00345","url":null,"abstract":"<p><p>Biomass burning is one of the most significant sources of organic aerosol in the atmosphere. Biomass burning organic aerosol (BBOA) has been observed to undergo liquid-liquid phase separation (LLPS) to give core-shell morphology with the hydrophobic phase encapsulating the hydrophilic phase, potentially impacting the evolution of light-absorbing components, i.e., brown carbon (BrC), through multiphase processes. Here, we demonstrate how multiphase processing differs between the water-soluble (i.e., hydrophilic) and insoluble (i.e., hydrophobic) phases of BBOA in terms of reactive uptake of ozone in a coated-wall flow tube. Effects of relative humidity (RH) and ultraviolet (UV) irradiation were investigated. Experimental timeseries were used to inform simulations using multilayer kinetic modeling. Among non-irradiated thin films, the uptake coefficient was greatest for the water-soluble phase at 75% RH (3 × 10^-5, corresponding to a diffusion coefficient of BrC, <i>D</i> _BrC, of 3 × 10^-9 cm² s^-1) and least for the same phase at 0% RH (1 × 10^-5, corresponding to <i>D</i> _BrC of 1 × 10^-10 cm² s^-1). The uptake coefficient for the water-insoluble phase fell between these two (about 1.5 × 10^-5), regardless of RH, and the corresponding <i>D</i> _BrC increased only slightly (8 × 10^-10 cm² s^-1 at 0% RH to 9 × 10^-10 cm² s^-1 at 75% RH). The uptake coefficients of both phases at 0% RH decreased significantly after UV irradiation, consistent with a transition from viscous liquid to solid and supported by qualitative microscopy observations. Modeling multiphase ozone oxidation of primary BrC components in the atmosphere demonstrated, first, that LLPS may extend the lifetime of water-soluble BBOA encapsulated by water-insoluble species by a factor of 1.5 at moderate to high RH and, also, that UV irradiation may extend the lifetime of both phases by more than a factor of 2.5.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 4","pages":"637-647"},"PeriodicalIF":0.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11997950/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144048526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organic Fingerprints of Condensable Particulate Matter from Ultralow Emission Stationary Sources in China","authors":"Zhaojin An,&nbsp;Dongbin Wang*,&nbsp;Shuwen Yang,&nbsp;Jianguo Deng,&nbsp;Xue Li,&nbsp;Yaowei Li and Jingkun Jiang*,&nbsp;","doi":"10.1021/acsestair.5c0000610.1021/acsestair.5c00006","DOIUrl":"https://doi.org/10.1021/acsestair.5c00006https://doi.org/10.1021/acsestair.5c00006","url":null,"abstract":"<p >Understanding organics in condensable particulate matter (CPM) from stationary sources is crucial for assessing air quality impacts, especially as CPM gains significance due to reductions in regulated PM and the implementation of ultralow emission standards in China. Knowledge of these organics remains limited as traditional targeted analyses potentially overlook important molecules and their atmospheric impacts. Here, we employed comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOFMS) to analyze the molecular compositions of organics in CPM from typical ultralow emission coal-fired power plants and iron and steel sintering plants in China. We established a nontargeted screening approach to obtain molecular fingerprints of these organics, identifying more than 180 and 200 compounds from over 1000 peaks from the two types of plants. Key contributors to CPM organics include substituted benzenes, polyfunctional aliphatic compounds, alkanes, and cycloalkanes, differing from the previously reported alkane dominance observed using traditional one-dimensional GC analysis. Intermediate/semivolatile organic compounds (I/SVOCs) dominate organics in CPM, with a significant fraction of low volatile organic compounds detected especially in iron and steel sintering plant emissions. Iron and steel sintering plants emit higher concentrations of organics in CPM, particularly aromatics, due to their lower combustion efficiency in the sintering processes. These findings enhance our understanding of the atmospheric behavior of organics in CPM and their impacts on air quality.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 4","pages":"692–699 692–699"},"PeriodicalIF":0.0,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dominant Role of NO2 Oxidation in SO2 Conversion to Sulfate Revealed by Synchronous Measurements of Gas and Particle Sulfur Isotopes in Haze Episodes","authors":"Xinxin Feng,&nbsp;Yingjun Chen*,&nbsp;Zeyu Liu,&nbsp;Hongxing Jiang,&nbsp;Yanli Feng and Tian Chen*,&nbsp;","doi":"10.1021/acsestair.4c0023910.1021/acsestair.4c00239","DOIUrl":"https://doi.org/10.1021/acsestair.4c00239https://doi.org/10.1021/acsestair.4c00239","url":null,"abstract":"<p >The oxidation pathways of SO₂ conversion to sulfate remain controversial. Sulfur isotope (δ³⁴S) has been used to trace the SO₄^2– formation pathways based on sulfur fractionation. Accurately assessing δ³⁴S fractionation is crucial to quantify SO₄^2– formation pathways. However, previous studies have used particle-phase δ³⁴S to estimate δ³⁴S fractionation (α³⁴S_g→p-estimated) in SO₄^2– formation, leading to significant uncertainties. δ³⁴S values of gas-to-particle (δ³⁴SO₂ and δ³⁴SO₄^2–) were synchronously measured to uncover isotope fractionation (α³⁴S_g→p). Results found that α³⁴S_g→p (−3.7‰ to +9.9‰) obtained by gas-to-particle δ³⁴S showed a significant difference with α³⁴S_g→p-estimated(−6.4‰ to +1.4‰) obtained by δ³⁴SO₄^2–, implying different results for SO₄^2– formation using the two methods. Among them, α³⁴S_g→p results indicated the prominent pathway of NO₂ oxidation (48–56%), while α³⁴S_g→p-estimated suggested the dominant role of transition metal ion (TMI)-catalyzed O₂ (54–80%). Additionally, α³⁴S_g→p results show a more reasonable response to SO₄^2– formation and consistent trends with oxidant concentrations. α³⁴S_g→p-estimated overestimated the TMI-catalyzed O₂ pathway contribution (38–47%) to SO₄^2– formation. This is the first study to employ gas-to-particle δ³⁴S to demonstrate the dominant role of NO₂ oxidation in SO₄^2– formation. This approach provides new insight into using δ³⁴SO₄^2– for the analysis of SO₄^2– formation.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 4","pages":"498–507 498–507"},"PeriodicalIF":0.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical Evolution of Biomass Burning Aerosols across Wildfire Plumes in the Western U.S.: From Near-Source to Regional Scales.","authors":"Ryan Farley, Shan Zhou, Sonya Collier, Wenqing Jiang, Timothy B Onasch, John E Shilling, Lawrence Kleinman, Arthur J Sedlacek Iii, Qi Zhang","doi":"10.1021/acsestair.5c00002","DOIUrl":"https://doi.org/10.1021/acsestair.5c00002","url":null,"abstract":"<p><p>The atmospheric processing of biomass burning organic aerosol (BBOA) and its implications for tropospheric aerosol physicochemical properties remain uncertain. To address this gap, we investigate the chemical transformation of BBOA from wildfire events in the western U.S., using data from aerosol mass spectrometers aboard the DOE G-1 aircraft and at the Mt. Bachelor Observatory (∼2800 m a.s.l.) during the summers of 2013 and 2019. This study captures dynamic changes in submicron particulate matter (PM₁) concentrations and chemical profiles within wildfire plumes that span a broad range of atmospheric ages, from fresh emissions (<30 min) to plumes transported for several days. As plumes age, the oxidation state of organic aerosols (OA) increases, accompanied by the formation of secondary aerosol components such as phenolic secondary OA (SOA) species, carboxylic acids, and potassium sulfate. Early plume evolution is marked by the evaporation of semivolatile components and the formation of alcohol and peroxide functional groups, while extended aging produces more oxidized species, including carboxylic acids and carbonyl compounds. Normalized excess mixing ratios (NEMRs) of OA to CO demonstrate a complex interplay between evaporation, SOA formation, and oxidative loss. Using positive matrix factorization (PMF), we identify distinct BBOA types representing various stages of atmospheric processing and assess the contributions of primary BBOA and secondary BBOA formed through atmospheric reactions. These findings shed light on the intricate mechanisms governing the evolution of BBOA characteristics within wildfire plumes, providing critical insights to improve atmospheric modeling of BBOA and better assess the environmental and climatic impacts of wildfire emissions.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 4","pages":"677-691"},"PeriodicalIF":0.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11997948/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144030685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tire-Derived Organic Chemicals in Urban Air at the Source-Sector Scale and Guidance on the Application of Polyurethane Foam Disk Passive Air Samplers.","authors":"Cassandra Johannessen, Amandeep Saini, Xianming Zhang, Tom Harner","doi":"10.1021/acsestair.5c00013","DOIUrl":"https://doi.org/10.1021/acsestair.5c00013","url":null,"abstract":"<p><p>Tire-derived chemicals (TDCs) are shown to be elevated in urban environments. In this study, we analyzed 6PPD-quinone, 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), hexa(methoxy)methylmelamine (HMMM), as well as selected benzothiazoles and benzotriazoles, in different urban source-sectors. The chemical analyses were conducted on archived extracts of polyurethane foam (PUF) disk passive air samplers deployed across eight locations (including residential, industrial, semiurban, and traffic areas) over successive 2-month periods in the Greater Toronto Area, Canada. Principal component analysis showed distinct profiles in traffic-heavy locations, where benzothiazole and 6PPD-quinone had maximal concentrations of 2100 pg/m³ and 3.4 pg/m³, and where several TDCs including 6PPD-quinone, benzotriazoles, and some benzothiazoles were elevated during winter months. HMMM had elevated concentrations in nontraffic sectors, suggesting anthropogenic sources other than tires. This study recognizes the unique challenges to accurately quantifying TDCs in ambient air and that results presented here should be considered semiquantitative. To reduce uncertainty, temperature-dependent PUF disk-air partition coefficients (K_PUF-AIR) and gas-particle partitioning fractions of TDCs in ambient air are presented. These are calculated from K_OA values derived from quantum chemical methods using COSMOtherm and show that TDCs span a wide range of volatilities and gas-particle partitioning behavior, with implications for atmospheric fate and exposure. Lastly, guidance is provided on future measures to evaluate and minimize degradation losses of TDCs during sampling, extraction, and storage.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"917-929"},"PeriodicalIF":0.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12070413/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144082457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tire-Derived Organic Chemicals in Urban Air at the Source-Sector Scale and Guidance on the Application of Polyurethane Foam Disk Passive Air Samplers","authors":"Cassandra Johannessen*,&nbsp;Amandeep Saini,&nbsp;Xianming Zhang and Tom Harner*,&nbsp;","doi":"10.1021/acsestair.5c0001310.1021/acsestair.5c00013","DOIUrl":"https://doi.org/10.1021/acsestair.5c00013https://doi.org/10.1021/acsestair.5c00013","url":null,"abstract":"<p >Tire-derived chemicals (TDCs) are shown to be elevated in urban environments. In this study, we analyzed 6PPD-quinone, 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), hexa(methoxy)methylmelamine (HMMM), as well as selected benzothiazoles and benzotriazoles, in different urban source-sectors. The chemical analyses were conducted on archived extracts of polyurethane foam (PUF) disk passive air samplers deployed across eight locations (including residential, industrial, semiurban, and traffic areas) over successive 2-month periods in the Greater Toronto Area, Canada. Principal component analysis showed distinct profiles in traffic-heavy locations, where benzothiazole and 6PPD-quinone had maximal concentrations of 2100 pg/m³ and 3.4 pg/m³, and where several TDCs including 6PPD-quinone, benzotriazoles, and some benzothiazoles were elevated during winter months. HMMM had elevated concentrations in nontraffic sectors, suggesting anthropogenic sources other than tires. This study recognizes the unique challenges to accurately quantifying TDCs in ambient air and that results presented here should be considered semiquantitative. To reduce uncertainty, temperature-dependent PUF disk-air partition coefficients (K_PUF-AIR) and gas-particle partitioning fractions of TDCs in ambient air are presented. These are calculated from K_OA values derived from quantum chemical methods using COSMOtherm and show that TDCs span a wide range of volatilities and gas-particle partitioning behavior, with implications for atmospheric fate and exposure. Lastly, guidance is provided on future measures to evaluate and minimize degradation losses of TDCs during sampling, extraction, and storage.</p><p >Partitioning of tire-derived chemicals to PUF disk and ambient particles is predicted and used to improve measurements in urban air across different source areas. Guidance is provided for future studies.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"917–929 917–929"},"PeriodicalIF":0.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.5c00013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical Evolution of Biomass Burning Aerosols across Wildfire Plumes in the Western U.S.: From Near-Source to Regional Scales","authors":"Ryan Farley,&nbsp;Shan Zhou,&nbsp;Sonya Collier,&nbsp;Wenqing Jiang,&nbsp;Timothy B. Onasch,&nbsp;John E. Shilling,&nbsp;Lawrence Kleinman,&nbsp;Arthur J. Sedlacek III and Qi Zhang*,&nbsp;","doi":"10.1021/acsestair.5c0000210.1021/acsestair.5c00002","DOIUrl":"https://doi.org/10.1021/acsestair.5c00002https://doi.org/10.1021/acsestair.5c00002","url":null,"abstract":"<p >The atmospheric processing of biomass burning organic aerosol (BBOA) and its implications for tropospheric aerosol physicochemical properties remain uncertain. To address this gap, we investigate the chemical transformation of BBOA from wildfire events in the western U.S., using data from aerosol mass spectrometers aboard the DOE G-1 aircraft and at the Mt. Bachelor Observatory (∼2800 m a.s.l.) during the summers of 2013 and 2019. This study captures dynamic changes in submicron particulate matter (PM₁) concentrations and chemical profiles within wildfire plumes that span a broad range of atmospheric ages, from fresh emissions (&lt;30 min) to plumes transported for several days. As plumes age, the oxidation state of organic aerosols (OA) increases, accompanied by the formation of secondary aerosol components such as phenolic secondary OA (SOA) species, carboxylic acids, and potassium sulfate. Early plume evolution is marked by the evaporation of semivolatile components and the formation of alcohol and peroxide functional groups, while extended aging produces more oxidized species, including carboxylic acids and carbonyl compounds. Normalized excess mixing ratios (NEMRs) of OA to CO demonstrate a complex interplay between evaporation, SOA formation, and oxidative loss. Using positive matrix factorization (PMF), we identify distinct BBOA types representing various stages of atmospheric processing and assess the contributions of primary BBOA and secondary BBOA formed through atmospheric reactions. These findings shed light on the intricate mechanisms governing the evolution of BBOA characteristics within wildfire plumes, providing critical insights to improve atmospheric modeling of BBOA and better assess the environmental and climatic impacts of wildfire emissions.</p><p >This study integrates aircraft and mountaintop observatory measurements of wildfire emissions to analyze the chemical characteristics of aerosols and their transformation processes across a wide range of atmospheric ages.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 4","pages":"677–691 677–691"},"PeriodicalIF":0.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.5c00002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ethanol and Methanol in South Korea and China: Evidence for Large Anthropogenic Emissions Missing from Current Inventories","authors":"Ellie Beaudry*,&nbsp;Daniel J. Jacob,&nbsp;Kelvin H. Bates,&nbsp;Shixian Zhai,&nbsp;Laura H. Yang,&nbsp;Drew C. Pendergrass,&nbsp;Nadia Colombi,&nbsp;Isobel J. Simpson,&nbsp;Armin Wisthaler,&nbsp;James R. Hopkins,&nbsp;Ke Li and Hong Liao,&nbsp;","doi":"10.1021/acsestair.4c0021010.1021/acsestair.4c00210","DOIUrl":"https://doi.org/10.1021/acsestair.4c00210https://doi.org/10.1021/acsestair.4c00210","url":null,"abstract":"<p >Observations during the KORUS-AQ, MAPS-Seoul, and APHH-Beijing field campaigns of 2015–2017 reveal high concentrations of ethanol and methanol in urban air over South Korea and China, with median concentrations of 2–4 ppb for ethanol and 12–18 ppb for methanol. Simulations with the GEOS-Chem model show that these values cannot be captured by current emission inventories. They could originate from volatile chemical products (VCPs). Fitting observed ethanol concentrations with GEOS-Chem would imply per capita VCP emissions 2.4 times higher in South Korea and 1.5 times higher in China than in the U.S. The strong ethanol–methanol correlation suggests a major methanol component in VCP emissions, unlike in the U.S. where methanol use is largely banned. Including these emissions in GEOS-Chem increases the level of surface ozone over South Korea and China by 1–3 ppb. KORUS-AQ aircraft profiles also indicate a high free tropospheric methanol background of 3.2 ppb, which appears to be of terrestrial biospheric origin but cannot be reproduced by GEOS-Chem.</p><p >Atmospheric measurements of ethanol and methanol in South Korea and China indicate large emissions of these species from volatile chemical products.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 4","pages":"456–465 456–465"},"PeriodicalIF":0.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.4c00210","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ethanol and Methanol in South Korea and China: Evidence for Large Anthropogenic Emissions Missing from Current Inventories.","authors":"Ellie Beaudry, Daniel J Jacob, Kelvin H Bates, Shixian Zhai, Laura H Yang, Drew C Pendergrass, Nadia Colombi, Isobel J Simpson, Armin Wisthaler, James R Hopkins, Ke Li, Hong Liao","doi":"10.1021/acsestair.4c00210","DOIUrl":"https://doi.org/10.1021/acsestair.4c00210","url":null,"abstract":"<p><p>Observations during the KORUS-AQ, MAPS-Seoul, and APHH-Beijing field campaigns of 2015-2017 reveal high concentrations of ethanol and methanol in urban air over South Korea and China, with median concentrations of 2-4 ppb for ethanol and 12-18 ppb for methanol. Simulations with the GEOS-Chem model show that these values cannot be captured by current emission inventories. They could originate from volatile chemical products (VCPs). Fitting observed ethanol concentrations with GEOS-Chem would imply per capita VCP emissions 2.4 times higher in South Korea and 1.5 times higher in China than in the U.S. The strong ethanol-methanol correlation suggests a major methanol component in VCP emissions, unlike in the U.S. where methanol use is largely banned. Including these emissions in GEOS-Chem increases the level of surface ozone over South Korea and China by 1-3 ppb. KORUS-AQ aircraft profiles also indicate a high free tropospheric methanol background of 3.2 ppb, which appears to be of terrestrial biospheric origin but cannot be reproduced by GEOS-Chem.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 4","pages":"456-465"},"PeriodicalIF":0.0,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11997956/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144056735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}