ACS ES&T Air最新文献

{"title":"Chemical Fate of Particulate Sulfur from Nighttime Oxidation of Thiophene","authors":"Michael Lum,&nbsp;Kunpeng Chen,&nbsp;Bradley Ries,&nbsp;Linhui Tian,&nbsp;Raphael Mayorga,&nbsp;Yumeng Cui,&nbsp;Nilofar Raeofy,&nbsp;David Cocker,&nbsp;Haofei Zhang,&nbsp;Roya Bahreini* and Ying-Hsuan Lin*,&nbsp;","doi":"10.1021/acsestair.4c0016410.1021/acsestair.4c00164","DOIUrl":"https://doi.org/10.1021/acsestair.4c00164https://doi.org/10.1021/acsestair.4c00164","url":null,"abstract":"<p >Sulfur-containing volatile organic compounds emitted during wildfire events, such as dimethyl sulfide, are known to form secondary aerosols containing inorganic sulfate (SO₄^2–) and surfactant-like organic compounds; however, little is known about the fate of sulfur in other emitted reduced organosulfur species. This study aimed to determine the sulfurous product distribution resulting from the nighttime oxidation of thiophene as a model system. Ion chromatography (IC) and aerosol mass spectrometry (a mini aerosol mass spectrometer, mAMS) were used to constrain the proportions of sulfurous compounds produced under wildfire-relevant conditions ([NO₂]/[O₃] = 0.1). With constraints from IC, results indicated that the sulfurous particle mass consisted of 30.3 ± 6.6% SO₄^2–, while mAMS fractionation attributed 24.5 ± 1.6% of total sulfate signal to SO₄^2–, 15.4 ± 1.9% to organosulfates, and 60.1 ± 0.9% to sulfonates. Empirical formulas of organosulfur products were identified as C1–C8 organosulfates and sulfonates using complementary mass spectrometry techniques. This study highlights the nighttime oxidation of thiophene and its derivatives as a source of SO₄^2– and particulate organosulfur compounds, which have important implications for the atmospheric sulfur budget and aerosol/droplet physical and chemical properties.</p><p >Little is known about the atmospheric oxidation of volatile organosulfur compounds found in biomass burning emissions. This study investigates the fate of volatile organosulfur compounds and the distribution of sulfurous products in secondary aerosols, with implications for aerosol physical and chemical properties.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"1 12","pages":"1637–1649 1637–1649"},"PeriodicalIF":0.0,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.4c00164","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142843545","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":"Wildland Urban Interface (WUI) Emissions: Laboratory Measurement of Aerosol and Trace Gas from Combustion of Manufactured Building Materials","authors":"Katherine. B. Benedict*,&nbsp;James E. Lee,&nbsp;Nitin Kumar,&nbsp;Prakash S. Badal,&nbsp;Michele Barbato,&nbsp;Manvendra K. Dubey and Allison C. Aiken,&nbsp;","doi":"10.1021/acsestair.4c0021710.1021/acsestair.4c00217","DOIUrl":"https://doi.org/10.1021/acsestair.4c00217https://doi.org/10.1021/acsestair.4c00217","url":null,"abstract":"<p >Wildfires are increasing in intensity and more often threatening the wildland urban interface (WUI) where buildings and homes coexist with the natural environment. WUI emissions have not been as well-studied as emissions from vegetation. Thus, there is a need to quantify the emissions of building materials used in home construction under flaming and smoldering conditions to study their impacts to human health, visibility, air quality, and climate. Here, in a controlled laboratory setting, we quantify emissions of aerosols and trace gases including formaldehyde, particulate matter, and black carbon. We focus on the combustion of traditional single-source wood-based construction fuels. Our results indicate that, similar to natural fuels, the aerosol optical properties were more related to combustion conditions than the fuel type. Overall, we observed significant variability in the gas and particle emissions. Consistent trends include high formaldehyde (HCHO) and carbon monoxide (CO) emissions for smoldering conditions and higher carbon dioxide (CO₂), nitrogen oxides (NO_<i>x</i>), and black carbon for flaming conditions. These observations highlight the need to better characterize emissions for materials in the built environment to assess large-scale climate and human health impacts of fires at the WUI.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"1 12","pages":"1673–1686 1673–1686"},"PeriodicalIF":0.0,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851135","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":"Encountering Prescribed Fire: Characterizing the Intersection of Prescribed Fire and Wildfire in the CONUS","authors":"James L. Beidler*,&nbsp;Kirk R. Baker,&nbsp;George Pouliot and Jason D. Sacks,&nbsp;","doi":"10.1021/acsestair.4c0022810.1021/acsestair.4c00228","DOIUrl":"https://doi.org/10.1021/acsestair.4c00228https://doi.org/10.1021/acsestair.4c00228","url":null,"abstract":"<p >Prescribed fire is applied across the United States as a fuel treatment to manage the impact of wildfires and restore ecosystems. While the recent application of prescribed fire has largely been confined to the southeastern US, the increase in catastrophic wildfires has accelerated the growth of prescribed fire more broadly. To effectively achieve wildfire risk reduction benefits, which includes reducing the amount of smoke emitted, the area treated by prescribed fire must come into contact with a subsequent wildfire. In this study, we applied timely and consistent geospatially resolved data sets of prescribed fires and wildfires to estimate the rate at which an area treated by prescribed fire encounters a subsequent wildfire. We summarize these encounter rates across time intervals, prescribed fire treatment area, and number of previous prescribed fires and by region. On all U.S. Forest Service lands across the Conterminous US (CONUS) 6.2% of prescribed fire treated area from 2003–2022 encountered a subsequent wildfire in 2004–2023. Encounter rates were highest in western US forests, which tend to be more impacted by wildfire than the eastern US, and lower in the eastern US. Encounter rates increased with treatment area in the southeastern US but were relatively flat in the northwest. For the CONUS, encounter rates increased with longer time intervals, associated with diminished potential for reducing wildfire severity, between prescribed fire and the subsequent wildfire area burned. Our results provide timely information on prescribed fire and wildfire interactions that can be leveraged to optimize analyses of the trade-offs between prescribed fire and wildfire.</p><p >To date few studies show the rate at which a wildfire encounters a previous prescribed fire. Here we show that a small fraction of prescribed fires spatially intersect with a subsequent wildfire.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"1 12","pages":"1687–1695 1687–1695"},"PeriodicalIF":0.0,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.4c00228","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142843824","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":"Emission and Formation of Aircraft Engine Oil Ultrafine Particles","authors":"Zachary C. J. Decker*,&nbsp;Peter A. Alpert,&nbsp;Markus Ammann,&nbsp;Julien G. Anet,&nbsp;Michael Bauer,&nbsp;Tianqu Cui,&nbsp;Lukas Durdina,&nbsp;Jacinta Edebeli,&nbsp;Martin Gysel-Beer,&nbsp;Andre S. H. Prévôt,&nbsp;Lu Qi,&nbsp;Jay G. Slowik,&nbsp;Curdin Spirig,&nbsp;Sarah Tinorua,&nbsp;Florian Ungeheuer,&nbsp;Alexander Vogel,&nbsp;Jun Zhang and Benjamin T. Brem*,&nbsp;","doi":"10.1021/acsestair.4c0018410.1021/acsestair.4c00184","DOIUrl":"https://doi.org/10.1021/acsestair.4c00184https://doi.org/10.1021/acsestair.4c00184","url":null,"abstract":"<p >Civil aviation gas turbine engines emit ultrafine particles (UFPs, diameter &lt; 100 nm). UFPs degrade air quality because they efficiently transport their chemical content, including engine oil, into the body. Yet, little is known about how and when oil containing UFPs are formed. Results here describe the thrust and flight phase-dependent oil emission and reveal the particle size-dependent transfer of vaporized oil to UFPs with molecular level resolution. All six engines studied emitted oil containing UFPs. Lower volatility oil molecules are enriched on particles &lt;30 nm. Further, the particulate oil mass size distribution aligns with the emitted surface area distribution, suggesting oil vapor condensation onto primary particles and the potential for oil nucleation. However, the oil gas-to-particle transfer in hot exhaust is likely incomplete at least 50 m downwind thus limiting current emission studies. The measured engine oil consumption provides an upper-limit oil emission index at idle of 240 mg oil per kg fuel. The emission index at cruise is 110 mg kg^–1, which is a factor of 10 greater than black carbon. For any flight &gt;2 h, 95% of oil emission is expected to occur at cruise altitude, highlighting the unknown effects of oil emission in the upper atmosphere.</p><p >This work provides details on when and how oil containing ultrafine particles are formed from real-world aircraft emissions. The results reveal important implications for oil particle growth and injection in the upper atmosphere.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"1 12","pages":"1662–1672 1662–1672"},"PeriodicalIF":0.0,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.4c00184","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142851176","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":"Assessment of the Statistical Performance of Chemical Transport Model Studies in India","authors":"Rishi Shandilya,&nbsp;Pranav Chaudhari and Srinidhi Balasubramanian*,&nbsp;","doi":"10.1021/acsestair.4c0007210.1021/acsestair.4c00072","DOIUrl":"https://doi.org/10.1021/acsestair.4c00072https://doi.org/10.1021/acsestair.4c00072","url":null,"abstract":"<p >India’s public health is seriously endangered by air pollution and linked to ∼0.8–0.98 million and 0.17 million premature deaths annually from chronic exposure to particulate matter (PM_2.5) and ozone, respectively. Air quality forecasting tools are needed to assess the spatiotemporal variability of air pollutants and evaluate the impact of potential mitigation measures. Gridded concentrations of PM_2.5 and ozone are typically derived from first principle models called Chemical Transport Models (CTMs). Widespread application of CTMs, particularly for regulatory purposes, requires an understanding of model performance in comparison with observation data. A landscape approach that systematically reviews CTM model predictions and proposes benchmarks for assessing model performance can offer a way forward to build confidence in CTM-backed forecasting tools. Following similar efforts in the United States and China, we systematically shortlisted and examined model performance outcomes for 46 CTM studies reporting PM_2.5 and ozone predictions in India between 2008 and 2023. The reported statistical metrics for each pollutant (normalized mean bias (NMB), normalized mean error (NME), coefficient of correlation (<i>r</i>), and index of agreement (IOA) were rank ordered to identify two types of benchmarks: “goals” (highest achievable model accuracy based on top one-third performing studies) and “criteria” (typical model accuracy based on the top two-third performing studies). The identified goal performance for PM_2.5 was 17% (NMB), 34% (NME), and 0.67 (<i>r</i>), and ozone was 14% (NMB), 43% (NME), and 0.89 (<i>r</i>). These benchmarks are less restrictive than those reported for the United States and China. This highlights the need for the CTM community to coalesce around a common set of practices in evaluating CTMs. Additionally, complementary efforts in developing representative emissions inventories and including air pollution data from the expanding observational networks are required to update such benchmarks periodically. This study seeks to advance the capabilities of CTMs as a cornerstone of air quality forecasting tools and augment air quality management frameworks in India.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"1 12","pages":"1519–1530 1519–1530"},"PeriodicalIF":0.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142850603","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":"A Nudge to the Truth: Atom Conservation as a Hard Constraint in Models of Atmospheric Composition Using a Species-Weighted Correction.","authors":"Patrick Obin Sturm, Sam J Silva","doi":"10.1021/acsestair.4c00220","DOIUrl":"10.1021/acsestair.4c00220","url":null,"abstract":"<p><p>Computational models of atmospheric composition are not always physically consistent. For example, not all models respect fundamental conservation laws such as conservation of atoms in an interconnected chemical system. In well performing models, these unphysical deviations are often ignored because they are frequently minor, and thus only need a small nudge to perfectly conserve mass. Here we introduce a method that anchors a prediction from any numerical model to physically consistent hard constraints, nudging concentrations to the nearest solution that respects the conservation laws. This closed-form model-agnostic correction uses a single matrix operation to minimally perturb the predicted concentrations to ensure that atoms are conserved to machine precision. To demonstrate this approach, we train a gradient boosting decision tree ensemble to emulate a small reference model of ozone photochemistry and test the effect of the correction on accurate but nonconservative predictions. The nudging approach minimally perturbs the already well-predicted results for most species, but decreases the accuracy of important oxidants, including radicals. We develop a weighted extension of this nudging approach that considers the uncertainty and magnitude of each species in the correction. This species-level weighting approach is essential to accurately predict important low concentration species such as radicals. We find that applying the species-weighted correction slightly improves overall accuracy by nudging unphysical predictions to a more likely mass-conserving solution.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 1","pages":"99-108"},"PeriodicalIF":0.0,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11730974/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143019501","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":"A Nudge to the Truth: Atom Conservation as a Hard Constraint in Models of Atmospheric Composition Using a Species-Weighted Correction","authors":"Patrick Obin Sturm*,&nbsp; and ,&nbsp;Sam J. Silva,&nbsp;","doi":"10.1021/acsestair.4c0022010.1021/acsestair.4c00220","DOIUrl":"https://doi.org/10.1021/acsestair.4c00220https://doi.org/10.1021/acsestair.4c00220","url":null,"abstract":"<p >Computational models of atmospheric composition are not always physically consistent. For example, not all models respect fundamental conservation laws such as conservation of atoms in an interconnected chemical system. In well performing models, these unphysical deviations are often ignored because they are frequently minor, and thus only need a small nudge to perfectly conserve mass. Here we introduce a method that anchors a prediction from any numerical model to physically consistent hard constraints, nudging concentrations to the nearest solution that respects the conservation laws. This closed-form model-agnostic correction uses a single matrix operation to minimally perturb the predicted concentrations to ensure that atoms are conserved to machine precision. To demonstrate this approach, we train a gradient boosting decision tree ensemble to emulate a small reference model of ozone photochemistry and test the effect of the correction on accurate but nonconservative predictions. The nudging approach minimally perturbs the already well-predicted results for most species, but decreases the accuracy of important oxidants, including radicals. We develop a weighted extension of this nudging approach that considers the uncertainty and magnitude of each species in the correction. This species-level weighting approach is essential to accurately predict important low concentration species such as radicals. We find that applying the species-weighted correction slightly improves overall accuracy by nudging unphysical predictions to a more likely mass-conserving solution.</p><p >Computational models of atmospheric composition do not always make scientifically trustworthy predictions. This corrective approach minimally adjusts the predicted concentrations of chemical species to guarantee conservation of mass.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 1","pages":"99–108 99–108"},"PeriodicalIF":0.0,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.4c00220","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143091690","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":"Informing Near-Airport Satellite NO2 Retrievals Using Pandora Sky-Scanning Observations","authors":"Asher P. Mouat,&nbsp;Elena Spinei and Jennifer Kaiser*,&nbsp;","doi":"10.1021/acsestair.4c0015810.1021/acsestair.4c00158","DOIUrl":"https://doi.org/10.1021/acsestair.4c00158https://doi.org/10.1021/acsestair.4c00158","url":null,"abstract":"<p >Airports are a large and growing source of NO_<i>x</i>. Tracking airport-related emissions is especially difficult, as a portion of emissions are elevated above the surface. While satellite-based NO₂ observations show hot-spots near airports, near-source retrievals often have large biases related to uncertainties in the NO₂ vertical distribution and resultant air mass factors (AMF). Here we use observations from UV–vis spectrometers (Pandora 1S, SciGlob) deployed near the Atlanta Hartsfield-Jackson International airport from April 2020–May 2021 to assess the impact of aviation on NO₂ vertical profiles. We show the first near-airport sky-scanning Pandora observations, which are used to distinguish the airport plume from the urban background. We find that increasing aviation leads to higher NO₂ over the airport, and the enhancement is distributed across the mixed layer near-equally. We compare observed profiles with those modeled by the Goddard Earth Observing System composition forecast (GEOS-CF) system. We find that modeled profiles attribute a larger portion of the column closer to the surface and underestimate the NO₂ mixing height. Observed profiles typically exhibited greater NO₂ concentrations up to 2.5 km above ground level. Air mass factors (AMF) calculated using observations (AMF_Fused) are similar over Hartsfield-Jackson to those calculated using GEOS-CF (AMF_GEOS-CF). The unexpected similarity in alternative AMFs is attributed to the altitude-dependent sensitivity of AMF_Fused to changes in NO₂ concentration. Using either AMF_Fused or AMF_GEOS-CF to evaluate TROPOMI NO₂ against independent direct-sun observations produces consistent normalized mean differences of −22% and −29%, respectively. Overall, these results demonstrate the benefits of a combined ground and satellite-based approach for probing a complex distribution of NO_<i>x</i> emissions in an urban area.</p><p >Observational constraints on airport-related emissions are limited. We use 3D observations from the Pandora instrument to map the near-airport NO₂ enhancement and discuss implications of discrepancies in measured and modeled NO₂ vertical profiles for interpretation of satellite-based observations.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"1 12","pages":"1617–1628 1617–1628"},"PeriodicalIF":0.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.4c00158","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142849895","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":"Informing Near-Airport Satellite NO₂ Retrievals Using Pandora Sky-Scanning Observations.","authors":"Asher P Mouat, Elena Spinei, Jennifer Kaiser","doi":"10.1021/acsestair.4c00158","DOIUrl":"10.1021/acsestair.4c00158","url":null,"abstract":"<p><p>Airports are a large and growing source of NO _<i>x</i> . Tracking airport-related emissions is especially difficult, as a portion of emissions are elevated above the surface. While satellite-based NO₂ observations show hot-spots near airports, near-source retrievals often have large biases related to uncertainties in the NO₂ vertical distribution and resultant air mass factors (AMF). Here we use observations from UV-vis spectrometers (Pandora 1S, SciGlob) deployed near the Atlanta Hartsfield-Jackson International airport from April 2020-May 2021 to assess the impact of aviation on NO₂ vertical profiles. We show the first near-airport sky-scanning Pandora observations, which are used to distinguish the airport plume from the urban background. We find that increasing aviation leads to higher NO₂ over the airport, and the enhancement is distributed across the mixed layer near-equally. We compare observed profiles with those modeled by the Goddard Earth Observing System composition forecast (GEOS-CF) system. We find that modeled profiles attribute a larger portion of the column closer to the surface and underestimate the NO₂ mixing height. Observed profiles typically exhibited greater NO₂ concentrations up to 2.5 km above ground level. Air mass factors (AMF) calculated using observations (AMF_Fused) are similar over Hartsfield-Jackson to those calculated using GEOS-CF (AMF_GEOS-CF). The unexpected similarity in alternative AMFs is attributed to the altitude-dependent sensitivity of AMF_Fused to changes in NO₂ concentration. Using either AMF_Fused or AMF_GEOS-CF to evaluate TROPOMI NO₂ against independent direct-sun observations produces consistent normalized mean differences of -22% and -29%, respectively. Overall, these results demonstrate the benefits of a combined ground and satellite-based approach for probing a complex distribution of NO _<i>x</i> emissions in an urban area.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"1 12","pages":"1617-1628"},"PeriodicalIF":0.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11650605/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142857500","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":"Synergistic Disinfection by 222 nm Far-UVC and Negative Air Ions of Airborne Bacteria and the Induced Oxidative Stress Responses: A Bioaerosol Chamber Study","authors":"Haoxiang Wu,&nbsp;Yuhao Lu,&nbsp;Ruixuan Wang and Alvin Chi Keung Lai*,&nbsp;","doi":"10.1021/acsestair.4c0016210.1021/acsestair.4c00162","DOIUrl":"https://doi.org/10.1021/acsestair.4c00162https://doi.org/10.1021/acsestair.4c00162","url":null,"abstract":"<p >The understanding of the mechanisms of synergistic bioaerosol disinfection using 222 nm far-UVC and negative air ions is limited. In this study, we employed a fabricated aerosol chamber to investigate the synergistic disinfection effects of these two technologies and their impact on oxidative stress responses in airborne <i>Staphylococcus epidermidis</i>, <i>Salmonella enterica</i>, and <i>Escherichia coli</i>. We measured the log reduction in airborne survival of bacteria, lipid peroxidation, and the activities of antioxidant enzymes and total antioxidants. The results show that bacterial inactivation by the simultaneous operation of both technologies was significantly greater than the sum of the inactivation values by individual treatments, demonstrating a synergistic disinfection effect. The Pearson correlation coefficient indicates a strong correlation between airborne bacterial survival and lipid peroxidation (<i>r</i> ≥ 0.83). Furthermore, 222 nm far-UVC was found to be able to inactivate the antioxidant defense in airborne bacteria. Our results together suggest that the simultaneous operation of 222 nm far-UVC and negative air ions induces oxidative stress while deactivating antioxidant defense, contributing to the observed synergistic disinfection effect. Findings from the current study contribute to the mechanistic understanding of the synergistic effect by 222 nm far-UVC and negative air ions in bioaerosol disinfection, offering a new research opportunity for system design in high-efficiency air disinfection.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"1 12","pages":"1629–1636 1629–1636"},"PeriodicalIF":0.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142850165","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}