Atmospheric Environment最新文献

{"title":"Trends of anthropogenic sources in a Southeastern Mediterranean coastal site over five years","authors":"D. Tobarra ,&nbsp;E. Yubero ,&nbsp;A. Carratala","doi":"10.1016/j.atmosenv.2025.121279","DOIUrl":"10.1016/j.atmosenv.2025.121279","url":null,"abstract":"<div><div>A five-year study of PM₁₀ concentrations was carried out from 2017 to 2021 in the port of a Mediterranean coastal city, with an annual collection rate approaching 50 % of the days. The chemical composition of the PM₁₀ dataset was analyzed to assess changes in both natural sources and the effects of regulations and mitigation measures on PM₁₀ and its precursors. While overall PM₁₀ concentrations remained stable over the study period, the analysis suggests that mitigation measures have contributed to a reduction in daily exceedances of PM₁₀ levels in the area.</div><div>Using positive matrix factorization, seven distinct PM₁₀ sources were identified and ranked by their contribution: road traffic, bulk materials + dust resuspension, aged sea salt, Saharan intrusion, fresh sea salt, shipping emissions, and ammonium sulphate. Further analysis showed decreasing trends over the five-year period for road traffic, shipping, and ammonium sulphate sources, and increasing trends for Saharan intrusion and aged sea salt sources. No significant trends were observed for the bulk materials + dust resuspension and fresh sea salt sources. Although the measures taken by the Port of Alicante did not lead to a reduction in the PM₁₀ average concentrations of this source, they did reduce the number of exceedance episodes. On the other hand, the efforts to reduce emissions from shipping and traffic succeeded in reducing the contribution of these sources.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"355 ","pages":"Article 121279"},"PeriodicalIF":4.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel approach for quantifying elongated airborne mineral particles (EMPs) using an automated scanning electron microscope (SEM)","authors":"Anushka Elangasinghe ,&nbsp;Hamesh Patel ,&nbsp;Kim N. Dirks ,&nbsp;Ayrton Hamilton ,&nbsp;Wenxia (Wendy) Fan ,&nbsp;Shuoyu Chen ,&nbsp;Nick Talbot ,&nbsp;Shanon Lim ,&nbsp;Jed Januch ,&nbsp;Martin Brook ,&nbsp;Brett Wells ,&nbsp;David E. Williams ,&nbsp;Perry Davy ,&nbsp;Woodrow Pattinson ,&nbsp;Jennifer A. Salmond","doi":"10.1016/j.atmosenv.2025.121217","DOIUrl":"10.1016/j.atmosenv.2025.121217","url":null,"abstract":"<div><div>Exposure to carcinogenic elongated mineral particles (EMPs), such as erionite, found in rocks and released into the air by construction, quarrying, or roading activities, poses a significant possible health risk due to their respirable size and potential for airborne dispersion. The detection of EMPs in the air is typically achieved by filter sampling and subsequent examination using a range of microscopic methods, including phase contrast microscopy (PCM) and scanning electron microscope (SEM). Such analyzes require the manual searching for fibers through many image fields and are both labor-intensive and time-consuming. Moreover, these methods do not result in conclusive particle identification, limiting their effectiveness in large-scale monitoring programmes. This paper introduces a novel methodology for the automated detection and quantification of EMPs using an automated SEM with energy dispersive spectroscopy (EDS) to identify fibers on pre-sampled polycarbonate (PC) filters. This method provides a streamlined workflow for fiber identification based on their size, morphology, and elemental composition. Performance evaluation (PE) standards were prepared by spiking filters with a series of known concentrations of one EMP, namely erionite, and fiber concentrations were measured using the automated SEM-EDS approach. Our results demonstrate a linear relationship (R² = 0.98∗∗∗) between the erionite mass percentage in a bulk sample and the fiber counts in an aerosolized air volume, with a detection limit of 7.4 f/cc. The approach can be optimized based on the time available for analysis and the choice of detection limit suitable for the specific site and application. Additionally, the automated SEM-EDS method has been applied to real-world air samples collected from Auckland, New Zealand, showing promising results for fiber detection in complex environmental matrices.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"354 ","pages":"Article 121217"},"PeriodicalIF":4.2,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143905924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of freshly-emitted particles from poplar wood burning: OC/EC, morphology, and elemental analysis under varying ignition temperatures","authors":"Junjie Cai ,&nbsp;Jiaming Wu ,&nbsp;Yingjun Chen","doi":"10.1016/j.atmosenv.2025.121271","DOIUrl":"10.1016/j.atmosenv.2025.121271","url":null,"abstract":"<div><div>Biomass burning is a significant source of atmospheric pollution. While existing studies have largely focused on the comprehensive analysis of biomass burning particulate matter (PM), the variations in particle size, morphology, and mixing characteristics under different burning conditions remain to be thoroughly investigated. In this study, we collected PM emitted from poplar wood burning in a quartz tube furnace at three different ignition temperatures (400, 600, and 800 °C), aiming to analyze the chemical composition and single-particle characteristics of PM under varying ignition temperatures. OC/EC analysis revealed that the OC emission factor at 400 °C (35.05 ± 2.11 g/kg) was an order of magnitude higher than those at 600 °C (1.00 ± 0.21 g/kg) and 800 °C (1.57 ± 0.93 g/kg), while the EC emission factor increased by an order of magnitude with rising temperature, from 0.41 ± 0.03 g/kg at 400 °C to 4.03 ± 0.94 g/kg at 800 °C. Further observation under TEM-EDS showed that carbonaceous particles were the predominant components of PM emitted from poplar wood burning at all temperatures. At 400 °C, over 95 % of the particles were primarily amorphous organic matter, with only a small number of EC particles formed. At 600 °C, 72.6 % of the emitted particles were aggregated black carbon particles, 17.5 % were tar-balls, and the remaining 9.9 % were monomeric organic matter particles with extremely small particle sizes. At 800 °C, 93.8 % of the particles were two types of black carbon particles with varying monomer particle sizes and nearly bare surfaces. Our experimental results indicate that burning temperature is a crucial factor leading to differences in the composition, morphology, and elemental composition of biomass-emitted particles. Furthermore, they serve as a reminder that the significant variations caused by different burning temperatures should be considered when estimating biomass burning, especially the increasingly widespread wildfire burning.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"355 ","pages":"Article 121271"},"PeriodicalIF":4.2,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143924683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of dust storm height using weak beam photons from ICESat-2 and relating with vertical wind profile","authors":"Giribabu Dandabathula ,&nbsp;Subham Roy ,&nbsp;Omkar Ghatage ,&nbsp;Apurba Kumar Bera ,&nbsp;Sushil Kumar Srivastav","doi":"10.1016/j.atmosenv.2025.121276","DOIUrl":"10.1016/j.atmosenv.2025.121276","url":null,"abstract":"<div><div>Studies related to vertical probing of dust aerosols during an active episode of a dust storm will enable quantification of the dust load and unleash the mechanics of dust transport. Space-borne sensors, especially LiDAR-based sensors, are proven to detect the vertical concentration of dust aerosols; practically, essaying the suspended aerosols in the troposphere has been well recorded by the Cloud-Aerosol LIdar and Infrared Pathfinder Satellite Observations (CALIPSO) mission, which retired in 2023. This research is motivated to utilize NASA ICESat-2's photon data as a substitute for the CALIPSO mission to study the vertical structure of an active dust storm. This research suggests using photons from ICESat-2's weak beam over the strong beam to successfully profile aerosols suspended in the atmosphere. Technical validation by comparing the heights of the dust aerosols retrieved by attenuated photons from ICESat-2 and 532 nm total attenuated backscatter of Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) sensor yielded a good agreement of the results from both sensors. Further, analyzing the vertical wind profiles from ECMWF Reanalysis v5 (ERA5) data for the ten test sites with active dust storms confirms that the lift force of wind speed is greater than 5 m/s, while the drag force of the wind speed above the vertical structure having the dust aerosols is always greater than the lift force.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"354 ","pages":"Article 121276"},"PeriodicalIF":4.2,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Litter addition potentially enhances volatile organic compound emission from a freshwater wetland","authors":"Hua Fang ,&nbsp;Ting Wu ,&nbsp;Shutan Ma ,&nbsp;Qina Jia ,&nbsp;Fengyu Zan ,&nbsp;Juan Zhao ,&nbsp;Jintao Zhang ,&nbsp;Zhi Yang ,&nbsp;Hongling Xu ,&nbsp;Han Jiang ,&nbsp;Xinming Wang","doi":"10.1016/j.atmosenv.2025.121274","DOIUrl":"10.1016/j.atmosenv.2025.121274","url":null,"abstract":"<div><div>Plant litter could be a potential source of atmospheric volatile organic compounds (VOCs). Previous studies are mostly restricted to forest litter, but VOC budget of wetlands resulting from litter decomposition remains largely unexplored. Here we performed in-situ VOC flux measurements in a freshwater wetland and three treatments including A (no litter addition), B (1.15 kg litter m⁻²) and C (2.30 kg litter m⁻²) were designed to investigate impacts of litter decomposition on wetland-atmosphere exchange of VOCs. During year-round observation, average fluxes of net VOCs for B and C were 5.14 ± 2.75 μg m⁻² h⁻¹ and 7.85 ± 3.80 μg m⁻² h⁻¹, respectively, significantly higher than that of A (2.13 ± 2.41 μg m⁻² h⁻¹). These results suggested that freshwater wetlands were potential sources of atmospheric VOCs and that litter decomposition could enhance VOC release. The net VOC flux exhibited distinct seasonal patterns and was correlated with ambient temperature (<em>p</em> &lt; 0.05). Moreover, the release or uptake of VOCs varied among different chemical groups. Specifically, non-methane hydrocarbons including alkanes, alkenes and aromatics showed positive net fluxes that increased with added litter. Halocarbons exhibited a negative net flux in A, but positive net fluxes in B and C. Oxygenated VOCs demonstrated negative net fluxes in both A and B, but switched to a positive flux in C. Positive net fluxes of volatile organic sulfide compounds were observed in three treatments. Based on the flux variations of specific VOC groups, our findings suggest that both temperature-dependent biotic and abiotic processes regulated the exchange of VOCs between freshwater wetland and atmosphere.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"354 ","pages":"Article 121274"},"PeriodicalIF":4.2,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dense and diverse regional methane sources characterized using a tiered, dual-tracer measurement strategy","authors":"Andrew B. Moyes,&nbsp;Andre L.D. dos Santos,&nbsp;Ken Reichl,&nbsp;Sebastien C. Biraud","doi":"10.1016/j.atmosenv.2025.121270","DOIUrl":"10.1016/j.atmosenv.2025.121270","url":null,"abstract":"<div><div>Methane emissions reduction has become a high priority due to its tractability relative to other greenhouse gases, and the potential for climate and air-quality benefits. However, regional methane sources have been difficult to ascertain, with discrepancies between top-down and bottom-up estimates. We combined mobile surveys with continuous atmospheric measurements at two fixed locations (one urban and one rural) in the southern San Joaquin Valley of California, USA, using ethane:methane (C2:C1) content and stable carbon isotope ratio (δ¹³CH₄) as tracers for source type. In 6483 km of road surveys conducted over five field campaigns, 108 methane source events from 74 unique locations were sampled. C2:C1 was characteristically low for dairies and wastewater facilities, but was also near zero for many oil and gas sources, notably within a northeastern arc of high-density oil and gas fields. Natural gas sources within the Bakersfield urban area fell consistently within 2.3–4.2 % C2:C1. δ¹³CH₄ was effective at separating dairy (−51.6 ± 3.1 ‰), wastewater (−45.4 ± 3.2 ‰), and thermogenic natural gas (−42.9 ± 1.8 ‰) sources. Oil and gas production sources were less consistent, with 50 % of observations within −45.8 to −42.7 ‰ (median: 43.8 ‰), but with the largest spans of δ¹³CH₄ and C2:C1. The urban location experienced frequent methane enhancements attributed to both thermogenic and biogenic origins, whereas methane enhancements at the rural location enhancements were almost exclusively attributed to biogenic sources. Our results demonstrate considerable utility of diagnostic ethane and δ¹³CH₄ measurements in partitioning several methane source types, with the caveat that oil and gas sources may contain wide-ranging C2:C1 and δ¹³CH₄ due to thermal maturities and secondary processes (microbial and oxidation).</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"354 ","pages":"Article 121270"},"PeriodicalIF":4.2,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Source apportionment of organic gaseous and particulate compounds using a combined positive matrix factorization approach in summer (2020) in the Paris region (France)","authors":"Leïla Simon ,&nbsp;Olivier Favez ,&nbsp;Jean-Eudes Petit ,&nbsp;Francesco Canonaco ,&nbsp;Jay G. Slowik ,&nbsp;Caroline Marchand ,&nbsp;Valérie Gros","doi":"10.1016/j.atmosenv.2025.121269","DOIUrl":"10.1016/j.atmosenv.2025.121269","url":null,"abstract":"<div><div>Gaseous and particulate organic compounds are key components of atmospheric chemistry and better understanding their composition, sources and processes is essential to limit their impacts. Source apportionment using positive matrix factorization (PMF) is customarily performed for such studies. Combining organic aerosol data with their gaseous precursors was shown to be a promising approach, however very rarely attempted so far, to refine their origins using PMF. In this study, co-located continuous proton-transfer-reaction mass spectrometer (PTR-MS) and aerosol chemical speciation monitor (ACSM) measurements were performed at the suburban SIRTA station located in the Paris region. A combined dataset using both instruments during summer (June–August 2020) was then used in an exploratory PMF analysis to investigate the sources and processes of organic compounds, particularly the influences of biogenic emissions and important photochemical reactions on the formation of secondary organic aerosol (SOA) in this period of the year. Specific parameters and evaluation procedures were needed to ensure an equivalent representation of both instruments in the PMF model. A weighing factor was applied to the PTR-MS uncertainties which was controlled and optimized based on the analysis of the modelled scaled residuals. Seven main factors were obtained, describing anthropogenic sources (hydrocarbon-like organics, cooking-like organics), primary biogenic volatile organics, nighttime VOC, oxidized organics, aged organics and a specific isoprene oxidation factor which contributed 11 % to VOC and 4 % to OA. Compared to single-instrument PMFs, more factors were obtained, notably including the cooking-like factor which is not usually resolved using only ACSM data. This method also showed a better mathematical performance for the PTR-MS variables (mean absolute scaled residuals lower for the combined PMF (11.2) than for the PTR-MS-only PMF (38.2)) and a better separation of the factors for the ACSM variables in the combined PMF.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"354 ","pages":"Article 121269"},"PeriodicalIF":4.2,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Will benefits of physical activity in reducing the risk of all-cause and cause-specific mortality be attenuated by exposure to air pollutant mixture? A prospective study in the UK Biobank","authors":"Hao Fu ,&nbsp;Haijuan Xiong ,&nbsp;Hao Bai ,&nbsp;Yuanliang He ,&nbsp;Zhaohui Zhang ,&nbsp;Jianhao Xu ,&nbsp;Jiayu Li ,&nbsp;Fan He ,&nbsp;Mengling Tang ,&nbsp;Jianbing Wang ,&nbsp;Kun Chen ,&nbsp;Mingjuan Jin","doi":"10.1016/j.atmosenv.2025.121262","DOIUrl":"10.1016/j.atmosenv.2025.121262","url":null,"abstract":"<div><h3>Background</h3><div>To explore whether benefits of physical activity (PA) in reducing all-cause and cause-specific [all-cancer, cardiovascular disease (CVD) and respiratory disease] mortality risk might be attenuated by air pollution from the perspective of pollutant mixture.</div></div><div><h3>Methods</h3><div>We included 381,454 participants from the UK Biobank. Self-reported information on PA was grouped according to guidelines in International Physical Activity Questionnaire. Air pollutant mixture (NO₂, NO_x, PM_2.5, PM₁₀, and PM_2.5-10) was estimated using a Land Use Regression model and converted into a joint air pollution score. Cox proportional-hazard models were used to examine their associations with death outcomes.</div></div><div><h3>Results</h3><div>During a median follow-up of 11.99 years, deaths due to all-cause, all-cancer, CVD, respiratory disease were 24,264, 12,602, 4903, and 1680, respectively. Per PA-level increment was associated with lower risk of all-cause, all-cancer, CVD, and respiratory disease death, with hazard ratios of 0.86 (0.84–0.87), 0.91 (0.89–0.93), 0.86 (0.82–0.89) and 0.70 (0.66–0.75), respectively. However, an interquartile increment in air pollutant mixture was associated with higher risk of the above death outcomes. Notably, PA's effect on decreasing mortality risk remained relatively robust across all strata of air pollutant mixture. The combination of high PA and lowest air pollutant mixture reduced mortality risk by 37%, 24%, 41% and 64% from all-cause, all-cancer, CVD, and respiratory disease, respectively.</div></div><div><h3>Conclusions</h3><div>At all levels of air pollutant mixture, PA was inversely related with mortality risk. PA might still be an appropriate strategy to lower all-cause and cause-specific mortality risk, even for individuals exposed to high-level air pollution in the UK.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"354 ","pages":"Article 121262"},"PeriodicalIF":4.2,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature dependent kinetics and insights on the gas-phase products of the reaction between prenol and hydroxyl radicals","authors":"Reem Al Mawla ,&nbsp;Cécile Cœur ,&nbsp;Nicolas Houzel ,&nbsp;Sylvain Billet ,&nbsp;Vincent Gaudion ,&nbsp;Manolis N. Romanias","doi":"10.1016/j.atmosenv.2025.121260","DOIUrl":"10.1016/j.atmosenv.2025.121260","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Unsaturated alcohols with two functional groups (C=C and OH), such as prenol, are gaining attention as potential second-generation biofuels. As demand for sustainable energy sources grows, increased use of prenol in biofuel applications could lead to additional atmospheric emissions contributing to secondary pollution and affecting air quality. As the OH radical is the major oxidant during daytime and is highly reactive toward organic compounds, the OH-initiated oxidation of prenol needs to be investigated. Therefore, the reaction of prenol with OH was studied in the atmospheric simulation chamber THALAMOS (THermally Regulated Atmospheric Simulation Chamber), under atmospheric pressure and in the temperature range 273–353 K. The temperature-dependent rate coefficient, measured by the relative method, follows the Arrhenius equation: &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;k&lt;/mi&gt;&lt;mrow&gt;&lt;mtext&gt;prenol&lt;/mtext&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mtext&gt;OH&lt;/mtext&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;273&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;353&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;1.43&lt;/mn&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;0.28&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;11&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;mi&gt;exp&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mn&gt;691&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mn&gt;59&lt;/mn&gt;&lt;/mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mfrac&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; cm&lt;sup&gt;3&lt;/sup&gt; molecule&lt;sup&gt;−1&lt;/sup&gt; s&lt;sup&gt;−1&lt;/sup&gt;. Our results were combined with literature data determined under combustion relevant temperatures, to provide the following expression: &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;k&lt;/mi&gt;&lt;mrow&gt;&lt;mtext&gt;prenol&lt;/mtext&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mtext&gt;OH&lt;/mtext&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;273&lt;/mn&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1290&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;K&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1.46&lt;/mn&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mfrac&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mn&gt;300&lt;/mn&gt;&lt;/mfrac&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;2.18&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; + 1.14 &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;mi&gt;exp&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;2961&lt;/mn&gt;&lt;/mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mfrac&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; cm&lt;sup&gt;3&lt;/sup&gt; molecule&lt;sup&gt;−1&lt;/sup&gt; s&lt;sup&gt;−1&lt;/sup&gt; which covers a wide range of temperatures under atmospheric, but also cold (273–353 K) and traditional combustion conditions (900–1290 K). In addition to kinetic measurements, the reaction mechanism was investigated through product analysis. The major oxidation products, formed predominantly via the OH addition pathway, were acetone with a yield of 97 %, glycolaldehyde, and formaldehyde, with minor traces of 2-hydroxy-2-methylpropanal. The H-atom abstraction was found to be less significant (&lt;3 %), leading primarily","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"354 ","pages":"Article 121260"},"PeriodicalIF":4.2,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143905914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-year (2015–2023) trend and key factors of bioaerosols in urban atmosphere: A case study in Xi'an","authors":"Tantan Tan ,&nbsp;Gaoshan Zhang ,&nbsp;Chao Liu ,&nbsp;Yanpeng Li","doi":"10.1016/j.atmosenv.2025.121258","DOIUrl":"10.1016/j.atmosenv.2025.121258","url":null,"abstract":"<div><div>Bioaerosols and associated health risks are increasingly scrutinized amid improving air quality and recurrent public health crises in China. However, the response of bioaerosols to the process of improving air quality remains unclear. Consequently, multi-year (2015–2023) bioaerosol samples were collected at two sampling sites (Yanta and Weishui) and analyzed using fluorescence counting combined with high-throughput sequencing to investigate long-term trends in bioaerosol concentrations and bacterial communities. Additionally, Prophet and XGBoost-SHAP models elucidated the impact of the COVID-19 pandemic on bioaerosol concentrations and identified key drivers of bioaerosol fluctuations. Results showed that, unlike the decreasing trends in PM_2.5 concentrations, bioaerosol concentrations initially decreased from (3.71 ± 0.88) × 10⁵ cells/m³ to (0.7 ± 0.36) × 10⁵ cells/m³ during 2015–2019, but rebounded to (7.54 ± 3.75) × 10⁵ cells/m³ following the COVID-19 pandemic (2020–2022), highlighting the complex interplay between policy interventions and public health disruptions. Notably, increases in bioaerosol concentrations correlated with influenza incidence rates, reflecting its potential health risks. Bacterial diversity was higher during the Blue Sky Defense War (2018–2020) than in other periods, while the dominant phylum (Proteobacteria, relative abundance range 32 %–89 %) were relatively stable. <em>Pseudomonas</em>, <em>Burkholderia</em>, and <em>Paucibacter</em> were the dominant genera during the observation period, and COVID-19 pandemic changed the structure of bacterial communities. Additionally, O₃ correlated more significantly with long-term trends of bioaerosols than SO₂ and RH. These results can provide scientific basis for comprehensive evaluation and formulation of urban air quality improvement measures and prevention policies.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"353 ","pages":"Article 121258"},"PeriodicalIF":4.2,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}