ACS ES&T Air最新文献

{"title":"Factors Affecting Reduction of Infectious Aerosols by Far-UVC and Portable HEPA Air Cleaners","authors":"Katherine M. Ratliff*,&nbsp;Lukas Oudejans,&nbsp;M. Worth Calfee,&nbsp;John Archer,&nbsp;Jerome U. Gilberry,&nbsp;David Adam Hook,&nbsp;William E. Schoppman and Robert W. Yaga,&nbsp;","doi":"10.1021/acsestair.4c0024710.1021/acsestair.4c00247","DOIUrl":"https://doi.org/10.1021/acsestair.4c00247https://doi.org/10.1021/acsestair.4c00247","url":null,"abstract":"<p >Technologies that can reduce concentrations of airborne microorganisms through either particle capture or inactivation are important tools for reducing the risk of disease transmission and improving overall indoor air quality. The effectiveness of these technologies is tested in different ways, and as a result, it is challenging to compare results and optimize their use in applied settings. In this study, experiments were conducted in a large bioaerosol chamber to evaluate the efficacy of far-UVC and portable HEPA air cleaners against the bacteriophage MS2 as a surrogate for human viral pathogens. For both technologies, changing the media used to aerosolize the microorganism from deionized water to a simulated saliva doubled effectiveness metrics (both log₁₀ reductions and clean air delivery rates). Because reductions did not follow first order, log–linear dynamics, using different segments of the test period to calculate efficacy also significantly impacted reported performance. Evidence shown here indicates that both microbiological and particle dynamics likely play a role in impacting test outcomes under current methods, and more research is needed to improve repeatable and reliable standardized approaches for determining technology performance against infectious aerosols.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 3","pages":"368–377 368–377"},"PeriodicalIF":0.0,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609114","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":"Volatile Organic Compound Emissions from Polluted and Natural Soils: Influences of Environmental Factors","authors":"Yaxi Liu,&nbsp;Jianhuai Ye*,&nbsp;Yan Yang,&nbsp;Chen Yu,&nbsp;Fan Yang,&nbsp;Bi Chen,&nbsp;Jianguo Zhou,&nbsp;Gan Yang,&nbsp;Xinning Wang,&nbsp;Xiaohui Lu,&nbsp;Jianmin Chen,&nbsp;Zimeng Wang,&nbsp;Lin Wang,&nbsp;Xiaofei Wang* and Xin Yang*,&nbsp;","doi":"10.1021/acsestair.4c0028210.1021/acsestair.4c00282","DOIUrl":"https://doi.org/10.1021/acsestair.4c00282https://doi.org/10.1021/acsestair.4c00282","url":null,"abstract":"<p >Volatile organic compounds (VOCs) impact urban air quality and human health. Soil represents a potentially important source of VOCs. However, the VOC emission characteristics of soils from different urban and natural environments remain unclear. In this study, the composition and flux of VOCs emitted from various soil types were examined. Results reveal significantly elevated VOC emissions from polluted soils, with levels 2 orders of magnitude higher than those from their natural counterparts. Influences of light, soil water content, and temperature on VOC emissions were explored. Light exposure notably enhanced the emissions of certain VOCs, such as acetonitrile, from highly polluted industrial soils. Simultaneously, reductions in VOCs such as terpenes were observed, possibly driven by photochemical degradation processes. By comparison, soils from less polluted environments exhibited minimal changes in VOC emissions under light exposure, emphasizing the distinct behaviors of different soil types. Soil water content was inversely correlated with VOC emission rates, likely due to reduced soil porosity and permeability at higher moisture levels, whereas temperature exhibited intricate effects on soil emissions that varied with VOC species. Factors such as soil VOC storage, VOC “affinity” to soil, and microbial activities may play roles and warrant future investigation. Results from this study highlight soil emissions as non-negligible contributors to ambient VOC levels and underscore the crucial impacts of environmental factors in modulating these emissions.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 3","pages":"386–395 386–395"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609040","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":"Real-World Asphalt Pavement Emissions: Combining Simulation Chamber Measurements and City Scale Modeling to Elucidate the Impacts on Air Quality","authors":"Anais Lostier,&nbsp;Thibaud Sarica,&nbsp;Jerome Lasne,&nbsp;Antoine Roose,&nbsp;Karine Sartelet,&nbsp;Marina Jamar,&nbsp;Vincent Gaudion,&nbsp;Sebastien Dusanter,&nbsp;Didier Lesueur,&nbsp;Hui Chen,&nbsp;Therese Salameh* and Manolis N. Romanias*,&nbsp;","doi":"10.1021/acsestair.4c0032310.1021/acsestair.4c00323","DOIUrl":"https://doi.org/10.1021/acsestair.4c00323https://doi.org/10.1021/acsestair.4c00323","url":null,"abstract":"<p >In this paper, the role of asphalt pavement emissions in urban air quality was assessed combining laboratory experiments and city-scale air-quality modeling. In particular, the emission factors (EFs) of volatile and intermediate volatility organic compounds (VOCs and IVOCs) of asphalt pavements were determined in an atmospheric simulation chamber. Relative humidity (RH) and simulated solar light UV-A radiation were found to play a key role in the emission of VOCs and IVOCs. RH significantly increased the EFs, and predominantly those of oxygenated VOCs, due to changes in the microphysical properties of the materials. Under UV-A radiation, EFs were enhanced, due to the photochemical process induced on the asphalt–air interface. IVOCs were found to account for up to 30% of the Total EFs measured. Considering Paris as a case study, asphalt emissions in air-quality simulations lead to an increase in organic aerosol concentrations of at least 3%, during average summer daytime conditions. We estimate this impact significantly higher, in case all the IVOCs emissions are included in the model. This highlights the significant influence of solar radiation on emissions from old asphalt when exposed to UV radiation and the impact on air quality during the summer.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 3","pages":"426–435 426–435"},"PeriodicalIF":0.0,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609013","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":"Shifting the Conversation on Wildland Fire Smoke Exposures: More Smoke Within and Across Years Requires a New Approach to Inform Public Health Action.","authors":"Jason D Sacks, Christopher T Migliaccio, Colleen E Reid, Luke Montrose","doi":"10.1021/acsestair.4c00236","DOIUrl":"10.1021/acsestair.4c00236","url":null,"abstract":"<p><p>With the increase in acres burned from wildfire over the last few decades, wildfire smoke is an increasing global public health threat. To date, wildfire smoke research, risk communication, and public health action has focused on short-term (or daily) smoke exposures. However, the patterns of wildfire smoke exposure are transitioning to include longer duration and repeated exposures occurring within and across years. Epidemiologic and experimental studies represent important lines of evidence that have informed risk communication and public health actions for short-term smoke exposures; however, they have yet to provide the science needed to refine public health approaches to include other dynamic exposure durations such as repeated, episodic, or cumulative. This commentary provides an overview of methodological approaches used and recent findings from epidemiologic and experimental studies that examined longer duration, repeated smoke exposures. Based on the current science, we recommend that future epidemiologic and experimental studies of wildfire smoke examine multiple exposure metrics to capture the duration, frequency, and intensity of exposures. Such studies would improve the science produced to best support the needs of the public as we strive to further protect public health in a world projected to have more smoke.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 2","pages":"122-129"},"PeriodicalIF":0.0,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11964113/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782065","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":"Comparing Short-Term Volatile Organic Compound Measurements in Fenceline Environments Using Multiple Mobile Air Monitoring Platforms and Methods","authors":"Justin G. Coughlin*,&nbsp;Antonios Tasoglou,&nbsp;Katherine Haile,&nbsp;Leslie P. Silva,&nbsp;Scott Hamilton,&nbsp;Marta Fuoco,&nbsp;Samuel Porter,&nbsp;Aikaterini Liangou and Eben Thoma,&nbsp;","doi":"10.1021/acsestair.4c0016910.1021/acsestair.4c00169","DOIUrl":"https://doi.org/10.1021/acsestair.4c00169https://doi.org/10.1021/acsestair.4c00169","url":null,"abstract":"<p >The presence of volatile organic compounds (VOCs) can increase the air pollution burden in fenceline communities. Technological advancements have made mobile air toxic monitoring a useful and attractive approach to spatially quantify VOC concentrations in real-time, but there is a need to evaluate the accuracy of these measurements in real-world applications using intercomparison techniques. Here, we conducted a two-week field campaign near different VOC-emitting facilities using three different mobile monitoring platforms and four different ambient VOC-measurement technologies. Our primary focus was the intercomparison of a proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS) and canister samples analyzed by an offline gas chromatograph mass spectrometer (GC-MS), but we also collected measurements using a closed-path ultraviolet differential optical absorption spectrometer (UV-DOAS) and a selected ion flow tube mass spectrometer (SIFT-MS). The PTR-ToF-MS and offline GC-MS analyses show strong agreement in stationary settings (all targeted VOCs <i>R</i>² = 0.92, slope = 1.1) for aromatic compounds including benzene (<i>R</i>² = 0.95, <i>p</i> &lt; 0.001), naphthalene (<i>R</i>² = 0.84, <i>p</i> &lt; 0.01), and xylenes + ethylbenzene (<i>R</i>² = 0.93, <i>p</i> &lt; 0.01). PTR-ToF-MS and UV-DOAS comparisons have varied results. The UV-DOAS compared well at some monitoring locations but had poor agreement in ambient air matrices containing naphthalene, which caused uncorrectable interferences for measurements of benzene, toluene, and xylenes. Lastly, the PTR-ToF-MS and SIFT-MS showed strong agreement (all targeted VOCs <i>R</i>² = 0.68, slope = 0.85) in mobile format comparisons but only when aldehyde compounds with high background noise were removed. Our results highlight some potential interferences that should be accounted for when performing monitoring of mobile air toxics and demonstrate multi-instrument comparison techniques that can be used to ensure robust data collection.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 3","pages":"295–308 295–308"},"PeriodicalIF":0.0,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143608879","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 Co-occurrence of Wildfire Smoke and Extreme Heat Events in British Columbia, 2010–2022: Evaluating Spatiotemporal Trends and Inequities in Exposure Burden","authors":"Stephanie E. Cleland*,&nbsp;Naman Paul,&nbsp;Eric S. Coker and Sarah B. Henderson,&nbsp;","doi":"10.1021/acsestair.4c0021910.1021/acsestair.4c00219","DOIUrl":"https://doi.org/10.1021/acsestair.4c00219https://doi.org/10.1021/acsestair.4c00219","url":null,"abstract":"<p >Climate change is fueling more frequent and severe wildfire smoke (WFS) and extreme heat events (EHEs), and co-exposure may have synergistic adverse health effects. We evaluated the spatiotemporal trends in population exposure to co-occurring WFS and EHEs (WFS-EHEs) in British Columbia (BC). We calculated the frequency, intensity, and trends in WFS-EHEs in each census dissemination area (DA) in BC between 2010 and 2022. WFS-EHEs were identified using established exceedance thresholds and daily data on fine particulate matter, smoke plumes, and meteorological conditions. Trends were identified using the Mann–Kendall and Theil–Sen approaches. Census data was used to identify the characteristics of the most exposed communities. Over 13 years, there were 276,666 DA-level WFS-EHEs, impacting all BC residents and leading to a cumulative 170.8 million person-days of exposure. Although there was substantial year-to-year variability, the frequency and intensity of WFS-EHEs increased over time, with 60.8% of co-occurrences between 2018 and 2022. 42.5% of DAs (∼1.9 million people) experienced significant increases in exposure. The highest co-exposure burden occurred in rural communities with lower adaptive capacity. Our findings demonstrate the need for public health guidance on these increasingly frequent and intense compound hazards and can inform climate change adaptation and mitigation efforts in BC and elsewhere.</p><p >Wildfire smoke and extreme heat are increasing with climate change, but it is unknown how often these health-damaging exposures co-occur in British Columbia. We identify highly exposed communities and changes in co-exposure burden over time.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 3","pages":"319–330 319–330"},"PeriodicalIF":0.0,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsestair.4c00219","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143608851","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":"Daytime Ozone Production Determined by Ratios of Total Volatile Organic Compound Consumption to Nitrogen Oxide Concentrations","authors":"Xudong Zheng,&nbsp;Qinwen Tan,&nbsp;Jie Ren,&nbsp;Bin Luo,&nbsp;Danlin Song,&nbsp;Miao Feng,&nbsp;Hefan Liu,&nbsp;Yue Qin*,&nbsp;Yufang Hao,&nbsp;Liming Zeng,&nbsp;Xin Li,&nbsp;Sihua Lu,&nbsp;Huabin Dong and Shaodong Xie*,&nbsp;","doi":"10.1021/acsestair.4c0020010.1021/acsestair.4c00200","DOIUrl":"https://doi.org/10.1021/acsestair.4c00200https://doi.org/10.1021/acsestair.4c00200","url":null,"abstract":"<p >To reduce the uncertainty in analyzing ozone (O₃) sensitivities based on observed concentrations of volatile organic compounds (VOCs) and nitrogen dioxide, this study proposed the application of consumed VOC concentrations to establish their nonlinear relationship in the actual atmosphere. These parameters were calculated based on the reaction rates and online observations of VOCs, nitrogen dioxide, and O₃ concentrations at Deyang, Chengdu, and Meishan in the Chengdu Plain, China, during summer 2019. The nighttime isoprene consumption was maximum at 2.03 ppbv at Meishan. The daytime acetaldehyde consumption was a maximum at 2.68 ppbv at Deyang, possibly due to its higher primary emissions and secondary production and its consumption by both OH radicals and photolysis. When the ratios of the total consumed VOC concentrations to the observed or initial NO_<i>x</i> (NO_<i>x</i> = NO + NO₂) concentrations were 3.51 ppbv ppbv^–1 or 2.22 ppbv ppbv^–1, daytime O₃ variations reached a maximum of 8.45 ppbv or 7.52 ppbv, respectively. The ratios delineated the VOC-sensitive and NO_<i>x</i>-sensitive areas. Over 98% of hourly data were in VOC-sensitive areas at both Chengdu and Meishan, respectively, while over 14% of hourly data belonged to NO_<i>x</i>-sensitive areas at Deyang. This provided a more accurate method for assessing real-time O₃ sensitivity and thus implementing dynamic hierarchical control strategies.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 3","pages":"331–342 331–342"},"PeriodicalIF":0.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143608883","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":"An Ensemble Machine Learning Approach for Predicting Sources of Organic Aerosols Measured by Aerosol Mass Spectrometry","authors":"Yunjiang Zhang*,&nbsp;Jie Fang,&nbsp;Qingxiao Meng,&nbsp;Xinlei Ge,&nbsp;Hasna Chebaicheb,&nbsp;Olivier Favez and Jean-Eudes Petit*,&nbsp;","doi":"10.1021/acsestair.4c0026210.1021/acsestair.4c00262","DOIUrl":"https://doi.org/10.1021/acsestair.4c00262https://doi.org/10.1021/acsestair.4c00262","url":null,"abstract":"<p >Long-term source apportionment of atmospheric organic aerosols (OA) is essential for supporting air pollution management strategies. While aerosol mass spectrometry (AMS) combined with traditional source apportionment tools can accurately identify various OA sources, they face efficiency challenges when processing large volumes of long-term data. This study proposes an ensemble machine learning approach to efficiently apportion OA sources from long-term AMS measurements. Using six-year observation of a simplified version of AMS (i.e., ACSM) in the Paris region along with OA factor data derived from positive matrix factorization analysis, we developed an ensemble machine learning source apportionment model. Compared to individual machine learning algorithms, the ensemble model substantially reduced the root-mean-square error (RMSE) and increased the correlation coefficient in predicting OA sources by approximately 30% and 5%, respectively. Sensitivity analysis with five years of baseline data revealed that model performance relatively stabilizes when the training data exceeds two years, with RMSE values for primary and secondary OA factors at 0.31–0.45 μg/m³ and 0.69–0.84 μg/m³, respectively. This ensemble model not only enhances the efficiency of long-term OA source apportionment but also holds potential for near-real-time online applications.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 3","pages":"378–385 378–385"},"PeriodicalIF":0.0,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609019","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":"Significant Changes of δ15N-NOx in Diesel Vehicle Emissions with Emission Standards and Cumulative Mileage: Insight into Isotope-Based NOx Source Analysis","authors":"Weijie Huang,&nbsp;Xingnan Ye*,&nbsp;Xiaofei Wang,&nbsp;Cheng Huang,&nbsp;Bingyue Fu,&nbsp;Yinghui Yao,&nbsp;Yuanqiao Zhou and Jianmin Chen,&nbsp;","doi":"10.1021/acsestair.4c0028910.1021/acsestair.4c00289","DOIUrl":"https://doi.org/10.1021/acsestair.4c00289https://doi.org/10.1021/acsestair.4c00289","url":null,"abstract":"<p >Nitrogen isotope (δ¹⁵N) analysis is a robust method for tracing atmospheric NO_<i>x</i> and nitrate. However, the isotopic signatures of NO_<i>x</i> emissions from heavy-duty diesel vehicles (HDDVs) remain poorly characterized. In this study, we conducted on-site tests on 18 on-road HDDVs with different emission standards in Shanghai under the condition of China World Transient Vehicle Cycle for trucks (C-WTVC). The average δ¹⁵N value under C-WTVC (−5.71 ± 2.60‰) was significantly higher than that in idle mode (−13.85 ± 1.97‰), which is attributed to the lower temperatures in the combustion chamber due to the lower engine output in idle mode, favoring the breakage of the lighter ¹⁴N¹⁴N molecules. The δ¹⁵N-NO_<i>x</i> values under C-WTVC were significantly lower than those in driving mode in the United States, suggesting that δ¹⁵N values may be localized in isotope-based NO_<i>x</i> source analysis. NO_<i>x</i> emissions were reduced considerably with the upgrade of emission standards while δ¹⁵N-NO_<i>x</i> levels showed an opposite trend. The NH₃-selective catalytic reduction (SCR) reduced automobile NO_<i>x</i> emissions by more than 50% and significantly enriched ¹⁵N relative to diesel-generated NO_<i>x</i>. Indicated by the correlations between NO_<i>x</i> emissions, δ¹⁵N-NO_<i>x</i>, and cumulative mileage, the SCR de-NO_<i>x</i> efficiency decreased linearly with the increase of cumulative mileage. Our results suggest that the routine maintenance and mandatory inspection of aged SCR systems should be strengthened. The distribution of provincial δ¹⁵N-NO_<i>x</i> values of diesel vehicle emissions was established based on a weighted average model. The contribution of vehicle NO_<i>x</i> emissions in typical megacities in China has been revisited by upgrading the δ¹⁵N-NO_<i>x</i> values of diesel vehicles, demonstrating that the application of regional δ¹⁵N-NO_<i>x</i> values of diesel vehicles can narrow the gap between isotope-based analysis and emission inventory. This study will enrich the NO_<i>x</i> isotopic fingerprint database in China and minimize the uncertainty in isotope-based NO_<i>x</i> source apportionment, helping to formulate air pollution prevention and control strategies.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 3","pages":"396–405 396–405"},"PeriodicalIF":0.0,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609018","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":"Cross-Reactions of Glyoxal and Glycolaldehyde in Aqueous Aerosol Mimics: Implications for Brown Carbon Product Formation","authors":"Brian P. Henesey,&nbsp;Stephanie M. Ingwer,&nbsp;Hope S. Tracey,&nbsp;Elizabeth G. Obarow,&nbsp;Rachael E. Holappa,&nbsp;Adelaide M. King,&nbsp;Heidi P. Hendrickson,&nbsp;Daniel R. Griffith and Melissa M. Galloway*,&nbsp;","doi":"10.1021/acsestair.4c0019210.1021/acsestair.4c00192","DOIUrl":"https://doi.org/10.1021/acsestair.4c00192https://doi.org/10.1021/acsestair.4c00192","url":null,"abstract":"<p >The formation of brown carbon (BrC) in aqueous atmospheric aerosols is well-documented and often attributed to aldehyde-ammonia reactions. However, many studies have focused on individual aldehyde precursors, overlooking the complex composition of organic aerosols, which comprise a diverse mix of organic and inorganic compounds. To address this, a complex BrC system was investigated by generating aqueous atmospheric aerosol mimics containing glyoxal (Gly), glycolaldehyde (GAld), and ammonium sulfate. Structural analysis using supercritical fluid chromatography–mass spectrometry (SFC-MS) showed that adjusting the Gly:GAld mole ratio leads to variations in the composition and abundance of BrC products formed. Notably, aromatic heterocycles (e.g., imidazoles and pyrazines) as well as acyclic carbonyl oligomers were identified to form at different concentrations depending on the Gly:GAld mole ratio. UV–visible spectroscopy analysis demonstrated that light absorption in these mixed Gly + GAld + AS systems cannot be modeled as a simple weighted average of the Gly:GAld mole ratio; observed changes in light absorbance can be explained by compositional changes in solution. These observations indicate that cross-reactions are occurring between the Gly and GAld in solution, potentially leading to changes in the physical properties of the aerosol. Given the thousands of reactive compounds found in atmospheric aerosol, these findings could have important implications for our understanding of organic reactions within the aerosol.</p>","PeriodicalId":100014,"journal":{"name":"ACS ES&T Air","volume":"2 3","pages":"309–318 309–318"},"PeriodicalIF":0.0,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609017","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}