ACS ES&T Air最新文献

{"title":"Gaseous and Particulate Emissions from a Small Business Jet Using Conventional Jet A-1 and a 30% SAF Blend","authors":"Lukas Durdina*,&nbsp;Zachary C. J. Decker,&nbsp;Jacinta Edebeli,&nbsp;Curdin Spirig,&nbsp;Tobias Frischknecht,&nbsp;Julien G. Anet,&nbsp;Benjamin T. Brem,&nbsp;Frithjof Siegerist and Theo Rindlisbacher,&nbsp;","doi":"10.1021/acsestair.5c0005310.1021/acsestair.5c00053","DOIUrl":"https://doi.org/10.1021/acsestair.5c00053https://doi.org/10.1021/acsestair.5c00053","url":null,"abstract":"<p >Small turbofan engines (&lt;26.7 kN thrust) are unregulated for gaseous and particulate emissions, with emissions data largely absent from public databases. Yet, their environmental impact is likely increasing. This study examines emissions from a representative small turbofan engine on a Cessna Citation 560XL. It focuses on nonvolatile particulate matter (nvPM), gaseous pollutants, and volatile organic compounds (VOCs). Ground-level measurements were conducted using a standardized system with conventional Jet A-1 and a 30% blend of synthesized paraffinic kerosene from hydroprocessed esters and fatty acids (HEFA-SPK). This sustainable aviation fuel (SAF) blend reduced the nvPM mass and number emission indices (EIs) by ∼35% and ∼20% at idle, with diminishing effects at higher thrust. Estimated nvPM number EIs at cruise decreased by ∼10%, suggesting a similar reduction in contrail ice particle concentrations at the predicted nvPM number EIs. While CO, HC, and NO_<i>x</i> emissions remained unchanged, SO₂ emissions decreased proportionally to the fuel sulfur content. VOC analysis showed lower emissions of complex unsaturated hydrocarbons. These findings highlight SAF’s potential to mitigate climate and air quality impacts. They also reveal discrepancies in estimated emissions from small turbofan engines and underscore limitations in existing models that predict fuel composition effects on nvPM emissions.</p><p >This study reports gaseous and nonvolatile particulate emissions of a popular small jet aircraft fueled with fossil Jet A-1 and a 30% biofuel blend. The findings highlight the potential of sustainable aviation fuels to reduce harmful emissions and inform future predictive models for small, unregulated turbofan engines.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"967–978 967–978"},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.5c00053","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921388","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":"Bioaerosol Emission Characteristics from Laboratory Burns","authors":"Abu Sayeed Md Shawon,&nbsp;Alejandro Gutierrez and Katherine B. Benedict*,&nbsp;","doi":"10.1021/acsestair.4c0031010.1021/acsestair.4c00310","DOIUrl":"https://doi.org/10.1021/acsestair.4c00310https://doi.org/10.1021/acsestair.4c00310","url":null,"abstract":"<p >Combustion processes can aerosolize and transport particles both from nonbiological and biological origin, with the latter termed bioaerosol particle (BAP). Previous work has shown an increase in the level of BAP in smoke plumes. The mechanism of their emission, whether from combustion of biological material or coemission with dust and soil from fire-driven winds, has yet to be examined. We carried out a series of controlled combustion experiments to understand the role of vegetation type and combustion conditions in the direct emission of BAP. The fuels we used included broadleaf, evergreen, and grass. We measured the emitted fluorescent BAP using a wideband integrated bioaerosol system (WIBS), and we measured the viability of filter-collected BAP using flow cytometry. Our measurements showed that the size and absolute concentration of the fluorescent BAP, and the viability of the BAP emitted during combustion, depend on the combustion conditions. In addition, the type of fuel impacted the type of emitted fluorescent BAP fraction relative to the total concentration of the emitted aerosol.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"857–867 857–867"},"PeriodicalIF":0.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921187","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":"The Invisible Footprint of Climbing Shoes: High Exposure to Rubber Additives in Indoor Facilities","authors":"Anya Sherman,&nbsp;Thibault Masset,&nbsp;Lukas Wimmer,&nbsp;Leah K. Maruschka,&nbsp;Lea Ann Dailey,&nbsp;Thorsten Hüffer,&nbsp;Florian Breider and Thilo Hofmann*,&nbsp;","doi":"10.1021/acsestair.5c0001710.1021/acsestair.5c00017","DOIUrl":"https://doi.org/10.1021/acsestair.5c00017https://doi.org/10.1021/acsestair.5c00017","url":null,"abstract":"<p >There is growing concern about rubber-derived compounds (RDCs), predominantly originating from tire and road wear particles. Other consumer products, including sports equipment, also contain RDCs, and human exposure to these compounds is of particular interest due to demonstrated toxicity to animal species. In this study, we investigated RDCs intentionally incorporated into climbing shoes for enhanced performance. We found high concentrations of 15 RDCs in shoe sole samples (Σ₁₅ RDCs: 25–3405 μg/g), aerosol particulate matter (Σ₁₅ RDCs: 2.6–37 μg/g), and settled dust (Σ₁₅ RDCs: 1.5–55 μg/g) in indoor climbing halls. The estimated daily intake via inhalation/ingestion of Σ₁₅ RDCs for climbers and employees in some of these facilities ranged from 1.7 to 48 ng/kg/day, exceeding known intake levels of RDCs from other sources. Abrasion powder resulting from friction between climbing shoes and footholds is the likeliest source of high concentrations of RDCs observed in aerosol particulate matter and settled dust. These findings reveal a previously unknown human exposure route of RDCs.</p><p >This work demonstrates how rubber abrasion from climbing shoes leads to the release of potentially toxic additives in indoor air.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"930–942 930–942"},"PeriodicalIF":0.0,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.5c00017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921398","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":"Haloacetic Acids as Contaminants of Emerging Concern in Arctic Aerosol","authors":"Beatrice Ulgelmo,&nbsp;Matteo Feltracco*,&nbsp;Simone Pulimeno,&nbsp;Elisa Scalabrin,&nbsp;Carlo Barbante,&nbsp;Andrea Gambaro and Elena Barbaro,&nbsp;","doi":"10.1021/acsestair.4c0031810.1021/acsestair.4c00318","DOIUrl":"https://doi.org/10.1021/acsestair.4c00318https://doi.org/10.1021/acsestair.4c00318","url":null,"abstract":"<p >Haloacetic acids are concerning emerging contaminants defined mainly as disinfection byproducts. Extensively studied in water environments, they are still poorly investigated in atmospheric aerosols and only in midlatitude anthropized countries. To our knowledge, this is the first study reporting the evidence of 12 brominated, chlorinated, and iodinated-acetic acids in the Arctic particulate matter. This paper had three main goals: 1) to evaluate the occurrence of the 12 haloacetic acids in the Arctic atmospheric aerosol, 2) to identify their possible sources, and 3) to understand their transport patterns. Samples were collected in Ny-Ålesund (Svalbard Islands, Norwegian Arctic) during an entire sampling year, starting from February 2022 to March 2023. Trace concentrations of these species were determined using a high pressure anion exchange coupled with a triple quadrupole, defining the monohaloacetic acids as the most ubiquitous compounds. In particular, the most abundant species was monochloroacetic acid with a mean concentration of 35 ± 32 pg m^–3. The statistical approach was applied to accomplish our goals: it highlighted the long-range transports and therefore anthropogenic input as the most important contribution for the investigated species. Considering their photosensitivity, future studies will be addressed to investigate the photochemical reactions of haloacetic acids in the complex polar atmosphere.</p><p >This study researches the concentrations and annual presence of haloacetic acids extracted from the atmospheric particulate matter of the Arctic. The chemometrics analysis highlighted their nonlocal sources and long-range transports.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"868–876 868–876"},"PeriodicalIF":0.0,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.4c00318","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921397","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":"The Invisible Footprint of Climbing Shoes: High Exposure to Rubber Additives in Indoor Facilities.","authors":"Anya Sherman, Thibault Masset, Lukas Wimmer, Leah K Maruschka, Lea Ann Dailey, Thorsten Hüffer, Florian Breider, Thilo Hofmann","doi":"10.1021/acsestair.5c00017","DOIUrl":"https://doi.org/10.1021/acsestair.5c00017","url":null,"abstract":"<p><p>There is growing concern about rubber-derived compounds (RDCs), predominantly originating from tire and road wear particles. Other consumer products, including sports equipment, also contain RDCs, and human exposure to these compounds is of particular interest due to demonstrated toxicity to animal species. In this study, we investigated RDCs intentionally incorporated into climbing shoes for enhanced performance. We found high concentrations of 15 RDCs in shoe sole samples (Σ₁₅ RDCs: 25-3405 μg/g), aerosol particulate matter (Σ₁₅ RDCs: 2.6-37 μg/g), and settled dust (Σ₁₅ RDCs: 1.5-55 μg/g) in indoor climbing halls. The estimated daily intake via inhalation/ingestion of Σ₁₅ RDCs for climbers and employees in some of these facilities ranged from 1.7 to 48 ng/kg/day, exceeding known intake levels of RDCs from other sources. Abrasion powder resulting from friction between climbing shoes and footholds is the likeliest source of high concentrations of RDCs observed in aerosol particulate matter and settled dust. These findings reveal a previously unknown human exposure route of RDCs.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"930-942"},"PeriodicalIF":0.0,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12070412/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144082311","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":"Indoor Surface Emissions of Volatile Organic Compounds Induced by Germicidal UV (222 and 254 nm) Illumination","authors":"Sara Bjerre Sørensen,&nbsp; and ,&nbsp;Kasper Kristensen*,&nbsp;","doi":"10.1021/acsestair.5c0000510.1021/acsestair.5c00005","DOIUrl":"https://doi.org/10.1021/acsestair.5c00005https://doi.org/10.1021/acsestair.5c00005","url":null,"abstract":"<p >The application of germicidal ultraviolet (GUV) lamps has recently attracted increased attention as a measure to mitigate indoor disease transmission. Among the most commonly employed are traditional mercury lamps and krypton–chloride excimer lamps, which emit UV-C light with peak wavelengths of 254 nm (GUV254) and 222 nm (GUV222), respectively. This study investigates volatile organic compound (VOC) surface emissions induced by GUV254 and GUV222 lamps across various surface materials. Near-surface proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOF-MS) measurements revealed significantly increased surface emissions during GUV illumination. In addition to compounds intrinsic to the illuminated surface, GUV light also increased surface off-gassing of externally applied compounds, including limonene and 4-oxopentanal (4-OPA). The magnitude of the enhanced surface emissions was found to decrease with increasing GUV path length resembling the expected decrease of the irradiance. Overall, greater surface emissions were induced by the GUV222 lamp compared with the GUV254 lamp. Conclusively, this study identifies UV-induced surface emissions as a potential source of indoor VOCs during the GUV lamp application.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"911–916 911–916"},"PeriodicalIF":0.0,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921409","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":"Theoretical Insights into the Atmospheric Chemistry of 1,1-Difluoroacetone: Reactions with OH Radicals and Cl Atoms and Its Further Degradation","authors":"Shemphang Hynniewta*,&nbsp; and ,&nbsp;Asit K. Chandra,&nbsp;","doi":"10.1021/acsestair.5c0004110.1021/acsestair.5c00041","DOIUrl":"https://doi.org/10.1021/acsestair.5c00041https://doi.org/10.1021/acsestair.5c00041","url":null,"abstract":"<p >This study investigates the atmospheric chemistry of 1,1-difluoroacetone (DFA), a potential alternative to harmful halogenated compounds. Using high-level computational methods, CCSD(T)/aug-cc-pVTZ//M06-2X/6-311++G(d,p), we explored the reaction mechanisms, rate coefficients, atmospheric lifetime, and global warming potential (GWP) of DFA. DFA primarily undergoes H-abstraction reactions with OH radicals and Cl atoms, with rate coefficients values of 1.04 × 10^–13 and 3.45 × 10^–13 cm³ molecule^–1 s^–1, respectively, at 298 K. Its atmospheric lifetime is estimated to be 0.30 years. GWP values are 37.7, 10.7, and 3.25 over 20-, 100-, and 500-year horizons. The COF₂, CO, CO₂, and HCOH are key degradation products. Notably, difluoromethylglyoxal (DMGLY) was identified as one of the possible degradation products, with a calculated rate coefficient for the reaction with OH radicals amounting to 0.54 × 10^–11 cm³ molecule^–1 s^–1. These findings offer insights into DFA’s atmospheric behavior and environmental impact, supporting its consideration as an alternative to more harmful compounds.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"957–966 957–966"},"PeriodicalIF":0.0,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921346","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":"Estimating Power Plant Contributions to Surface Pollution in a Wintertime Arctic Environment","authors":"Natalie Brett*,&nbsp;Steve R. Arnold,&nbsp;Kathy S. Law,&nbsp;Jean-Christophe Raut,&nbsp;Tatsuo Onishi,&nbsp;Brice Barret,&nbsp;Elsa Dieudonné,&nbsp;Meeta Cesler-Maloney,&nbsp;William Simpson,&nbsp;Slimane Bekki,&nbsp;Joel Savarino,&nbsp;Sarah Albertin,&nbsp;Robert Gilliam,&nbsp;Kathleen Fahey,&nbsp;George Pouliot,&nbsp;Deanna Huff and Barbara D’Anna,&nbsp;","doi":"10.1021/acsestair.5c0003010.1021/acsestair.5c00030","DOIUrl":"https://doi.org/10.1021/acsestair.5c00030https://doi.org/10.1021/acsestair.5c00030","url":null,"abstract":"<p >Arctic winter meteorology and orography in the Fairbanks North Star Borough (FNSB, interior Alaska) promote stably stratified boundary layers, often causing acute pollution episodes that exceed the US-EPA National Ambient Air Quality Standards. Power plant emission contributions to breathing level (0–10 m) pollution are estimated over the FNSB using high-resolution Lagrangian tracer simulations run with temporally varying emissions and power plant plume rise accounting for atmospheric boundary layer stability and validated against comprehensive ALPACA-2022 observations. Average relative power plant contributions of 5–23% and 4–28% are diagnosed for SO₂ and NO_<i>x</i>, respectively, with lower relative contributions in polluted conditions due to larger surface emissions. Highest population-weighted contributions are found in central and eastern (residential) areas of Fairbanks. Significant temporal variability in power plant contributions is revealed, depending on power plant operations and Arctic boundary layer stability. Vertical transport of power plant tracers to the surface depends on the interplay between the presence of temperature inversion layers and power plant stack heights as well as prevailing large-scale or local winds. Notably, power plant emissions can be transported to the surface even under strongly stable conditions, especially from shorter stacks, whereas down mixing from tall stacks mainly occurs under weakly stable conditions.</p><p >Model-based estimates of power plant contributions to wintertime Arctic air pollution at breathing level (0–10 m) depend on Arctic boundary layer stability, power plant stack height and temporal variability in the power plant emissions.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"943–956 943–956"},"PeriodicalIF":0.0,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.5c00030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921235","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":"Estimating Power Plant Contributions to Surface Pollution in a Wintertime Arctic Environment.","authors":"Natalie Brett, Steve R Arnold, Kathy S Law, Jean-Christophe Raut, Tatsuo Onishi, Brice Barret, Elsa Dieudonné, Meeta Cesler-Maloney, William Simpson, Slimane Bekki, Joel Savarino, Sarah Albertin, Robert Gilliam, Kathleen Fahey, George Pouliot, Deanna Huff, Barbara D'Anna","doi":"10.1021/acsestair.5c00030","DOIUrl":"https://doi.org/10.1021/acsestair.5c00030","url":null,"abstract":"<p><p>Arctic winter meteorology and orography in the Fairbanks North Star Borough (FNSB, interior Alaska) promote stably stratified boundary layers, often causing acute pollution episodes that exceed the US-EPA National Ambient Air Quality Standards. Power plant emission contributions to breathing level (0-10 m) pollution are estimated over the FNSB using high-resolution Lagrangian tracer simulations run with temporally varying emissions and power plant plume rise accounting for atmospheric boundary layer stability and validated against comprehensive ALPACA-2022 observations. Average relative power plant contributions of 5-23% and 4-28% are diagnosed for SO₂ and NO _<i>x</i> , respectively, with lower relative contributions in polluted conditions due to larger surface emissions. Highest population-weighted contributions are found in central and eastern (residential) areas of Fairbanks. Significant temporal variability in power plant contributions is revealed, depending on power plant operations and Arctic boundary layer stability. Vertical transport of power plant tracers to the surface depends on the interplay between the presence of temperature inversion layers and power plant stack heights as well as prevailing large-scale or local winds. Notably, power plant emissions can be transported to the surface even under strongly stable conditions, especially from shorter stacks, whereas down mixing from tall stacks mainly occurs under weakly stable conditions.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"943-956"},"PeriodicalIF":0.0,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12070414/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144083137","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":"Tracking Variations in Heatwave-Induced Aerosol Concentration and Chemical Composition Following Emission Reductions in NYC’s Downwind Region","authors":"Jie Zhang*,&nbsp;Tianyu Zhu,&nbsp;Qi Zhang,&nbsp;Nga L. Ng,&nbsp;Alexandra Catena,&nbsp;Margaret J. Schwab,&nbsp;Jorge Gonzalez-Cruz,&nbsp;Shan Zhou,&nbsp;Jianzhong Xu,&nbsp;Julia Stuart,&nbsp;Amanda Teora,&nbsp;Dirk Felton and James J. Schwab,&nbsp;","doi":"10.1021/acsestair.4c0026010.1021/acsestair.4c00260","DOIUrl":"https://doi.org/10.1021/acsestair.4c00260https://doi.org/10.1021/acsestair.4c00260","url":null,"abstract":"<p >While emission reductions from energy market shifts and regulatory controls have lowered primary fine particulate matter (PM_2.5) concentrations over the past decade, heatwaves can amplify PM_2.5 and potentially reverse these gains, a phenomenon not fully tracked. This study examines the heatwave-induced aerosol variations using aerosol chemical component measurements (2011, 2018, and 2023) and routine PM_2.5 mass concentrations in New York City’s downwind region. Results indicate that, under current emission reductions, heatwave PM_2.5 concentrations decreased by 41% (daytime), 30% (nighttime), and 26% (rush hour), significantly greater than nonheatwave reductions (∼20%), highlighting enhanced PM_2.5 mitigation effects during heatwaves. Particle sulfate, ammonium, and locally formed secondary organic aerosol (SOA) were the dominant contributors to heatwave aerosol reductions, closely tracking precursor emission changes. Additionally, sulfate and local SOA showed similar reduction rates (∼0.2 μg m^–3 per year), while regional SOA remained independent of volatile organic compound (VOC) emission reductions, suggesting a more complex formation process. Further reductions in local SOA concentrations are expected with ongoing emission controls, although continuous monitoring remains crucial. These findings will also offer valuable insights and serve as a reference for similar research in other regions.</p><p >Limited information exists on long-term heatwave-induced primary fine particulate matter (PM_2.5) variations. This study shows enhanced PM_2.5 mitigation effects, primarily from sulfate aerosols and locally formed secondary organic aerosol, during heatwaves compared to nonheatwave periods.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 5","pages":"797–807 797–807"},"PeriodicalIF":0.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.4c00260","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143921361","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}