ACS ES&T AirPub Date : 2026-09-11Epub Date: 2026-08-21DOI: 10.1021/acsestair.6c00145
Steven A. Hawks, Jaisree Iyer, Brandon L. Foley, Benjamin M. Gordon, Cody B. Cockreham, Sarah C. Chinn, Susan A. Carroll
{"title":"A Flexible Open-Source Mass Transport Framework for Analyzing Dynamic Outgassing Experiments","authors":"Steven A. Hawks, Jaisree Iyer, Brandon L. Foley, Benjamin M. Gordon, Cody B. Cockreham, Sarah C. Chinn, Susan A. Carroll","doi":"10.1021/acsestair.6c00145","DOIUrl":"https://doi.org/10.1021/acsestair.6c00145","url":null,"abstract":"<p>Mass transport modelingplays a critical role in characterizingvolatile organic compound (VOC) emissions from materials in applicationsranging from indoor air quality to food packaging. Despite their widespreaduse, existing models often lack accessibility because source codeis not provided or lack flexibility due to the reliance on Laplacetransform methods that cannot accommodate complex experimental conditions.Here, we present a versatile open-source framework in Python thataddresses these limitations. The framework employs a mass-conservativefinite-volume formulation of the method of lines (MOL) with efficientODE solvers to model diffusion and mass transport in slab, rod, andspherical geometries with arbitrarily time-varying temperature, flow,feed concentration, and chemical generation. We validate the frameworkagainst analytical solutions and reproduce prior literature results,demonstrating that extending the model to include a finite interfacialtransfer coefficient can meaningfully improve fits to experimentalsorption data. We further illustrate the framework’s utilitythrough comprehensive analysis of multiple headspace extraction (MHE)and temperature-programmed desorption (TPD) experiments, leveragingits computational efficiency to perform high-resolution parametersweeps and global multi-temperature fitting. Together, these capabilitiesmake the framework an adaptable open-source tool for designing experimentsand interpreting material emission and sorption data.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"3 9","pages":"2315–2327"},"PeriodicalIF":0.0,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148950636","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}
ACS ES&T AirPub Date : 2026-09-11Epub Date: 2026-08-19DOI: 10.1021/acsestair.6c00137
Nathan M. Lima, Aika Y. Davis, Michael F. Link, Thomas G. Cleary, Ryan L. Falkenstein-Smith, Rileigh L. Robertson, Steven J. Emmerich, Benjamin Werden, Peter DeCarlo, Dustin G. Poppendieck
{"title":"Implications and Impacts of Mitigation Strategies for Wildland–Urban Interface Fire Smoke Exposure in Residential Environments","authors":"Nathan M. Lima, Aika Y. Davis, Michael F. Link, Thomas G. Cleary, Ryan L. Falkenstein-Smith, Rileigh L. Robertson, Steven J. Emmerich, Benjamin Werden, Peter DeCarlo, Dustin G. Poppendieck","doi":"10.1021/acsestair.6c00137","DOIUrl":"https://doi.org/10.1021/acsestair.6c00137","url":null,"abstract":"<p>This study examines the effectiveness of various indoorair qualitypollutant mitigation strategies during Wildland–Urban Interface(WUI) fire smoke events. We simulated WUI fire smoke conditions inthe field by burning mixed-fuel cribs designed as surrogates outsidea test house and measured particle concentrations using multiple instrumentsinside the house. Increasing the number of deployed portable air cleanersprovided a nonlinear benefit in particle removal effectiveness, withper-unit effectiveness increasing significantly when multiple unitswere operated simultaneously. Filters exposed to a single heavy smoke(C<sub>peak</sub> of 210 μg m<sup>–3</sup> to 1300 μgm<sup>–3</sup>) loading showed no significant degradation inparticle removal performance compared to new filters. The effectivenessof creating a “cleaner air space” within the test housewas also evaluated, demonstrating substantial reductions in peak particleconcentrations. Our findings emphasize the importance of accountingfor air movement and mixing throughout a home when sizing and positioningair cleaners to ensure optimal performance. If internal doors areopen and a central heating and cooling system is operating, air cleanersmust be sized to the entire house volume, rather than just the roomin which they are located. In contrast, if internal doors are closedand heating and cooling vents are sealed, a single properly sizedair cleaner can provide a “cleaner air space” duringWUI fire events.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"3 9","pages":"2302–2314"},"PeriodicalIF":0.0,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148950711","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}
ACS ES&T AirPub Date : 2026-09-11Epub Date: 2026-08-09DOI: 10.1021/acsestair.6c00106
Kouji Adachi, Jack E. Dibb, Meehye Lee, Guy Symonds, Dongwook Kim, Pedro Campuzano-Jost, Jose L. Jimenez, James Crawford
{"title":"Regional Fireworks Pollution over East and Southeast Asia from Airborne Observations around the Spring Festival Period","authors":"Kouji Adachi, Jack E. Dibb, Meehye Lee, Guy Symonds, Dongwook Kim, Pedro Campuzano-Jost, Jose L. Jimenez, James Crawford","doi":"10.1021/acsestair.6c00106","DOIUrl":"https://doi.org/10.1021/acsestair.6c00106","url":null,"abstract":"<p>Fireworks are spectacular, but they also pollute theatmosphere.While fireworks are known to rapidly increase local pollution levels,the regional influences and nanosized appearance of fireworks-relatedparticles are poorly understood. This study collected aerosol particlesover East and Southeast Asia during an airborne campaign and observedthe shapes and compositions of individual particles using transmissionelectron microscopy. We found significant amounts of fireworks-relatedparticles (FWPs), which were characterized by the presence of Ba,Sr, or Bi, during four flights over or near the Philippines, Taiwan,and Korea in February 2024, around the Spring Festival period. Thesecharacteristic elements were found to be nano- to submicron-sizedgrains embedded mainly within Mg-sulfates and coexisted with F, Al,K, Cr, and other trace components. Our airborne measurements showedthat the FWPs were detected at altitudes ranging from several hundredm to 3000 m, covering areas of several hundred km for each flight.The highest number fraction (75%) and estimated mass concentration(10 ± 1 μg m<sup>–3</sup>) of FWPs were observedover the Yellow Sea. These results suggest that these particles travelacross large areas, contributing to regional pollution and potentiallyhaving adverse effects on human health due to their small size andspecific composition.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"3 9","pages":"2270–2278"},"PeriodicalIF":0.0,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148950861","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}
ACS ES&T AirPub Date : 2026-09-11Epub Date: 2026-08-18DOI: 10.1021/acsestair.6c00207
Adebola Odu-Onikosi, Philip K. Hopke, Ivana Stanimirova, Paul A. Solomon
{"title":"Characterization and Source Apportionment of Ambient Particulate Matter (PM2.5) across Lagos, Nigeria on High Pollution Days","authors":"Adebola Odu-Onikosi, Philip K. Hopke, Ivana Stanimirova, Paul A. Solomon","doi":"10.1021/acsestair.6c00207","DOIUrl":"https://doi.org/10.1021/acsestair.6c00207","url":null,"abstract":"<p>Ambient particulate matter ≤2.5 μm (PM<sub>2.5</sub>) is a major public health concern in rapidly urbanizingcities suchas Lagos, Nigeria, where emissions from diverse anthropogenic sourcescontribute to poor air quality. However, source-specific informationfor Lagos remains limited. PM<sub>2.5</sub> sources were apportionedusing EPA-PMF applied to a 12-month data set (August 2020–July2021) of 24-h samples collected every third day at six sites. Thetop 30% of filters by mass concentration were chemically speciated.Mean PM<sub>2.5</sub> concentration was 68 μg/m<sup>3</sup>.Eleven factors were resolved: Dust (27.86%) the dominant source; DieselExhaust (16.98%), Pb-Battery Recycling (12.74%), Sulfate (8.70%),Open Waste Burning (8.30%), 2-Stroke Exhaust (7.25%), and Galvanizing(6.13%). Small contributors were E-Waste Processing (3.58%), CookingAerosol (3.34%), Gasoline Exhaust (2.63%), and Secondary Nitrate (2.48%).Integrated statistical modeling and meteorological analyses showedthat PM<sub>2.5</sub> variation was governed by source-specific meteorologicalcontrols. Four factors─Dust, Open Waste Burning, Sulfate, andSecondary Nitrate─were directly influenced by meteorology throughtransport, scavenging, dispersion, and gas–particle chemistry,respectively. Diesel Exhaust was the largest local source and independentof meteorology. These findings highlight that effective PM<sub>2.5</sub> mitigation in Lagos requires source-specific control strategies.Priority actions include reducing fossil-fuel generator use, enforcingindustrial emissions controls, and upgrading vehicles.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"3 9","pages":"2396–2413"},"PeriodicalIF":0.0,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148950909","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}
ACS ES&T AirPub Date : 2026-09-11Epub Date: 2026-08-17DOI: 10.1021/acsestair.6c00158
Thomas Karl, Werner Jud, Christian Lamprecht, Martin Graus, Stanislav Juran, Arianna Peron, Thilo Zürrlein, Michael Stichaner, Helen Ward, Bin Yuan, Martin Tiefengraber, Alexander Cede
{"title":"Rapid Declines in European Traffic NOx and NMVOC Emissions Revealed by Eddy-Covariance and Remote Sensing","authors":"Thomas Karl, Werner Jud, Christian Lamprecht, Martin Graus, Stanislav Juran, Arianna Peron, Thilo Zürrlein, Michael Stichaner, Helen Ward, Bin Yuan, Martin Tiefengraber, Alexander Cede","doi":"10.1021/acsestair.6c00158","DOIUrl":"https://doi.org/10.1021/acsestair.6c00158","url":null,"abstract":"<p>Reliable quantificationof anthropogenic emission trends remainsa major uncertainty in air-quality and climate assessments. Here wepresent nearly a decade of eddy-covariance flux measurements of NO<sub><em>x</em></sub>, nonmethane volatile organic compounds (NMVOCs),and CO<sub>2</sub> in the Alpine city of Innsbruck, providing directtop-down constraints on real-world traffic emissions and their long-termevolution. Combining surface fluxes with in situ concentrations, satelliteNO<sub>2</sub> observations, and emission inventories, we show thattraffic-dominated NO<sub><em>x</em></sub> fluxes declinedby approximately 70% between 2018 and 2024, corresponding to reductionsof up to 17% yr<sup>–1</sup>. Normalizing NO<sub><em>x</em></sub> by CO<sub>2</sub> reveals a strong decrease in fleet-averageemission factors, demonstrating that the observed trends reflect technologicalimprovements rather than reduced traffic activity alone. AromaticNMVOC fluxes (benzene, toluene, and higher benzenes) exhibit comparabledeclines, independently confirming reductions in combustion-relatedemissions. Older European emission inventories underestimated real-worldNO<sub><em>x</em></sub> emissions by up to a factor of 3,whereas recent updates partially overcorrect, indicating persistentstructural uncertainties. Satellite NO<sub>2</sub> columns confirmregional emission reductions but show weaker trends because of spatialaveraging in complex terrain. These results provide the first long-term,flux-based observational benchmark for evaluating European trafficemission inventories and policies.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"3 9","pages":"2366–2377"},"PeriodicalIF":0.0,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148950894","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}
ACS ES&T AirPub Date : 2026-09-11Epub Date: 2026-08-05DOI: 10.1021/acsestair.6c00143
Sharmin Akter, Misti Levy Zamora, William Gasparrini, Lixing Counsilman, Liam Curtin, Katelyn Honegger, Fayekah Assanah, Doug Brugge, Marina A. Creed, Jessica P. Hollenbach, Sarah Laskowski, Angela Starkweather, Daniel Volovski, Kristina Wagstrom
{"title":"Performance and Practical Considerations of Deploying Do-It-Yourself (DIY) Air Purifiers in Occupied Classrooms","authors":"Sharmin Akter, Misti Levy Zamora, William Gasparrini, Lixing Counsilman, Liam Curtin, Katelyn Honegger, Fayekah Assanah, Doug Brugge, Marina A. Creed, Jessica P. Hollenbach, Sarah Laskowski, Angela Starkweather, Daniel Volovski, Kristina Wagstrom","doi":"10.1021/acsestair.6c00143","DOIUrl":"https://doi.org/10.1021/acsestair.6c00143","url":null,"abstract":"<p>Poor classroom ventilation allows airborne particlesto build up,leading to suboptimal indoor air quality (IAQ) and increased riskof airborne viral transmission. While commercial portable air cleanersare effective, their high price and maintenance costs often limitwidespread deployment. This study evaluates the real-world performanceof Corsi-Rosenthal (C-R) Boxes, a low-cost, DIY air cleaner, withinoccupied university classrooms without central ventilation, whilealso considering practical aspects such as noise levels, fire safety,and air movement. We utilized a within-session pre-post design tocontrol for variables such as occupancy and outdoor conditions. Byestablishing baseline PM<sub>1</sub>, PM<sub>2.5</sub>, and PM<sub>10</sub> mass and particle number concentrations at the start ofclass before automatically activating the C-R Boxes, each sessionserved as its own control. Across 59 class sessions, the C-R Boxesreduced PM<sub>2.5</sub> mass concentrations by an average of 61%[IQR 48%–80.5%]. Multipoint sensor monitoring confirmed thatthe C-R Boxes provide air mixing. The C-R Boxes maintained an acceptablenoise level (52 dBA at 2 m) and presented no elevated fire safetyrisks even in high-temperature conditions (30 °C/86 °F).These findings demonstrate that C-R Boxes are a safe, effective, andscalable solution for improving classroom IAQ without degrading thelearning environment.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"3 9","pages":"2328–2337"},"PeriodicalIF":0.0,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148950615","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}
ACS ES&T AirPub Date : 2026-09-11Epub Date: 2026-08-07DOI: 10.1021/acsestair.6c00159
Andrey Marsavin, Da Pan, Yong Zhou, Ilana B. Pollack, Amy P. Sullivan, Barkley C. Sive, Anthony J. Prenni, Bret Schichtel, Emily V. Fischer, Jeffrey L. Collett, Jr
{"title":"Examining Ozone Production in the Permian Oil and Gas Basin Using Carlsbad Caverns National Park Measurements and Satellite Data","authors":"Andrey Marsavin, Da Pan, Yong Zhou, Ilana B. Pollack, Amy P. Sullivan, Barkley C. Sive, Anthony J. Prenni, Bret Schichtel, Emily V. Fischer, Jeffrey L. Collett, Jr","doi":"10.1021/acsestair.6c00159","DOIUrl":"https://doi.org/10.1021/acsestair.6c00159","url":null,"abstract":"<p>Air pollutant emissions from oil and gas (O&G) activityinthe Permian Basin of southeastern New Mexico and western Texas havesubstantially altered the atmospheric composition of this otherwiselargely rural region. Increasing trends in summertime surface ozone(O<sub>3</sub>) are observed at sites downwind of the Permian, includingCarlsbad Caverns National Park (CAVE), where >100 exceedances oftheO<sub>3</sub> National Ambient Air Quality Standard (NAAQS) have occurredsince 2018. We investigate the drivers of high O<sub>3</sub> at CAVEusing summer 2021 measurements of nitrogen oxides (NO<sub><em>x</em></sub>) and volatile organic compounds (VOCs), and compareour findings with a 2019 study. VOC source apportionment using positivematrix factorization showed a dominant influence from O&G emissionsduring both studies, with an additional aged biomass burning smokefactor present in 2021. Observationally constrained F0AM box modelingrevealed NO<sub><em>x</em></sub>-sensitive conditions at CAVE,with smoke exerting only a small effect on local O<sub>3</sub> productionbut contributing approximately 10 ppbv to background O<sub>3</sub> levels. O<sub>3</sub> was more responsive to simulated NO<sub><em>x</em></sub> reductions than VOC reductions, though both ledto O<sub>3</sub> decreases. Observations from the Ozone MonitoringInstrument (OMI) and the TROPOspheric Monitoring Instrument (TROPOMI)show that regional nitrogen dioxide (NO<sub>2</sub>) has increasedin parallel with surface O<sub>3</sub> and without a correspondingtrend in formaldehyde (HCHO), reflecting NO<sub><em>x</em></sub>-sensitive O<sub>3</sub> production under increasing O&G-relatedNO<sub><em>x</em></sub> emissions. CAVE O<sub>3</sub> exceedancedays are associated with elevated TROPOMI NO<sub>2</sub> (+8%) andHCHO (+5%) but a lower HCHO/NO<sub>2</sub> ratio (−3%) acrossthe Permian Basin relative to the July–August 2018–2024mean.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"3 9","pages":"2348–2365"},"PeriodicalIF":0.0,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148950675","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}
ACS ES&T AirPub Date : 2026-09-11Epub Date: 2026-08-25DOI: 10.1021/acsestair.6c00150
Yiqun Wang, Lanxiadi Chen, Sasho Gligorovski, Xinming Wang
{"title":"Ice-Nucleating Particles in the Pearl River Surface Microlayer and Bulk Water: Evidence for In-River Biological Sources","authors":"Yiqun Wang, Lanxiadi Chen, Sasho Gligorovski, Xinming Wang","doi":"10.1021/acsestair.6c00150","DOIUrl":"https://doi.org/10.1021/acsestair.6c00150","url":null,"abstract":"<p>Ice-nucleating particles (INPs) in ocean surface waterscan betransferred to the atmosphere through bubble bursting, thereby influencingcloud formation and climate. Rivers transport large amounts of biologicalmaterial and particulate matter from terrestrial ecosystems to theocean, yet the properties and sources of riverine INPs remain poorlyconstrained. Here, we investigated the properties of INPs in foursurface microlayer (SML) samples and the corresponding four bulk water(BW) samples collected during a single sampling campaign at four sitesalong the Pearl River in the Great Bay Area, China, one of the mosthighly urbanized regions in the world. INPs were detected in all samples,and no significant enrichment was observed in the SML relative tothe underlying BW. Freezing spectra were obtained between −19and −10 °C across all samples, with <em>T</em><sub>50</sub> values of −12.5 ± 0.51 °C, and concentrationat <em>T</em><sub>50</sub> ranged from 10<sup>5</sup> to10<sup>6</sup> L<sup>–1</sup>. Filtration, heating (95 °C),and NH<sub>4</sub>Cl treatment collectively indicated that most ofthe observed ice-nucleating activity (INA) was associated with heat-sensitiveparticles larger than 0.22 μm, suggesting an important contributionfrom biological or biogenic particles; mineral-related INPs were notclearly resolved within the measured temperature range. Although surroundingland use differed substantially among sites, freezing spectra and <em>T</em><sub>50</sub> values were broadly similar among sites,suggesting that local land-use differences might not exert an obviouscontrol on riverine INA during this campaign. These findings providean initial characterization of INPs in a highly urbanized subtropicalriver system and establish a basis for future studies of their transportfrom rivers to coastal waters.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"3 9","pages":"2338–2347"},"PeriodicalIF":0.0,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148950676","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}
ACS ES&T AirPub Date : 2026-08-14Epub Date: 2026-07-01DOI: 10.1021/acsestair.6c00018
Micol Introna, Ana Teresa Juárez-Facio, Naga Veera Srikanth Vallabani, Minghui Tu, Michael Norman, Sanna Silvergren, Andrea Colombo, Valentina Liboni, Bozhena Tsyupa, Alessandro Mancini, Ulf Olofsson, Sarah Sulamith Steimer, Hanna Lovisa Karlsson, Karine Elihn
{"title":"Novel Approach to Assess the Toxicity of PM2.5 on a Subway Platform Using a Mobile Air–Liquid Interface System and Submerged Exposure","authors":"Micol Introna, Ana Teresa Juárez-Facio, Naga Veera Srikanth Vallabani, Minghui Tu, Michael Norman, Sanna Silvergren, Andrea Colombo, Valentina Liboni, Bozhena Tsyupa, Alessandro Mancini, Ulf Olofsson, Sarah Sulamith Steimer, Hanna Lovisa Karlsson, Karine Elihn","doi":"10.1021/acsestair.6c00018","DOIUrl":"https://doi.org/10.1021/acsestair.6c00018","url":null,"abstract":"<p>Subway stations areenclosed environments that can have elevatedconcentrations of PM<sub>2.5</sub> (particulate matter with an aerodynamicdiameter of <2.5 μm). These particles are primarily generatedby mechanical wear from trains and are therefore rich in transitionmetals and suspected to affect health upon inhalation. To simulatereal-world inhalation scenarios, this study aimed to assess the toxicityof airborne subway PM<sub>2.5</sub> using a mobile air–liquidinterface (ALI) exposure system directly on the platform, using monoculture(A549) and coculture (A549 + dTHP-1) cell models, alongside laboratorysubmerged exposures. In ALI exposures, a dose of 0.12 ± 0.07μg/cm<sup>2</sup> could not induce any change in cell viabilityor inflammatory markers after 24 h of incubation. In submerged experiments,a higher dose was applied than in ALI, inducing a decrease in cellviability in both A549 and dTHP-1 cells. A549 cells exhibited increasedIL-6 and TNF-α release at the highest dose (100 μg/mL).In dTHP-1 cells, IL-8 release was significantly elevated even at thelowest dose (10 μg/mL), and all four cytokines (IL-8, IL-6,IL-1β, and TNF-α) were significantly increased at 100μg/mL. These findings highlight the critical role of exposureconditions in toxicological studies and support the use of both <em>in situ</em> and laboratory-based approaches. Moreover, longer <em>in situ</em> exposures may be necessary to achieve doses comparableto those in a laboratory setup for comparison.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"3 8","pages":"1976–1987"},"PeriodicalIF":0.0,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148729406","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}