Atmospheric Environment最新文献

{"title":"Bioaerosols and phosphorus in PM2.5 in a major Eastern Mediterranean city","authors":"Kyriaki Papoutsidaki ,&nbsp;Konstantina Oikonomou ,&nbsp;Maria Tsagkaraki ,&nbsp;Georgios Grivas ,&nbsp;Kalliopi Tavernaraki ,&nbsp;Faidra-Aikaterini Kozonaki ,&nbsp;Irini Tsiodra ,&nbsp;Aikaterini Bougiatioti ,&nbsp;Nikos Mihalopoulos ,&nbsp;Maria Kanakidou","doi":"10.1016/j.atmosenv.2026.121813","DOIUrl":"10.1016/j.atmosenv.2026.121813","url":null,"abstract":"<div><div>This study presents novel observations of phosphorus, primary sugars, sugar alcohols and anhydro saccharides in fine atmospheric aerosols (PM_2.5) in Athens, Greece, one of the largest cities in the eastern Mediterranean, obtained through multi-year sampling from Dec. 2018 to July 2021 (20 months in total). It also leverages additional aerosol composition data to identify and attribute P levels to natural and anthropogenic sources through receptor modeling. Total sugars concentrations had a median of 205 ng m⁻³ and varied from 12.6 to 3391 ng m⁻³, with primary sugars, sugar alcohols and anhydro saccharides contributing 22 %, 19 % and 59 %, respectively. The median total P (TP) concentration was 21.0 ng m⁻³ (2.64–179 ng m⁻³) during the study period. On average, sugars contributed 2.6 % to organic carbon and 4.9 % to water soluble organic carbon. Positive Matrix Factorization analysis (PMF) showed that bioaerosols were the major contributors (31 %) of TP, followed by traffic/resuspension (28 %), Sahara dust (19 %), regional transport (14 %) and sea salt (6 %). In addition, bioaerosols (fungi and pollen) contributed by ∼21 % to total PM_2.5 mass. Overall natural sources accounted for approximately 50 % of the total PM_2.5 mass, that is a notable finding highlighting the significant impact of non-anthropogenic sources on ambient PM_2.5.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121813"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075937","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":"Policy-driven emission reduction and the COVID-19 lockdown paradox: Long-term decline, short-term rebound, and regional heterogeneity of nocturnal atmospheric oxidation in the Yangtze River Delta","authors":"Luyao Chen ,&nbsp;Renzhi Hu ,&nbsp;Longsheng Wei ,&nbsp;Chuan Lin ,&nbsp;Pinhua Xie","doi":"10.1016/j.atmosenv.2026.121812","DOIUrl":"10.1016/j.atmosenv.2026.121812","url":null,"abstract":"<div><div>Nocturnal atmospheric oxidizing capacity plays a pivotal role in nitrogen oxide (NOx) transformation, ozone (O₃) lifetime regulation, and particulate matter pollution control, with the nitrate radical (NO₃) serving as the central species in nighttime oxidation processes. The spatiotemporal characteristics of nocturnal NO₃ production rate (PNO₃) and its influencing factors are investigated in the Yangtze River Delta (YRD) region based on ground-level observations and meteorological data from 2017 to 2024. The results demonstrated that the YRD region exhibited an overall declining trend in concentrations of NO₂, O₃, Ox and PNO₃ under policy-driven emission reductions. However, NO₂ and PNO₃ concentrations experienced a temporary rebound during the 2020 pandemic period, while O₃ levels showed a significant increase in 2022, revealing the nonlinear response of nocturnal oxidizing capacity to both policy interventions and pandemic restrictions. Based on the measured data of Hefei in summer from 2020 to 2022, the research identified that local high-intensity emissions can still form night-time oxidation hotspots.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121812"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075939","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":"Evaluation of the performance of receptor statistical methods for quantifying desert dust contributions to ambient particulate for health studies and policy","authors":"Xavier Querol ,&nbsp;Andrés Alastuey ,&nbsp;Jorge Pey ,&nbsp;Pedro Salvador ,&nbsp;Adolfo González-Romero ,&nbsp;Noemí Pérez","doi":"10.1016/j.atmosenv.2026.121831","DOIUrl":"10.1016/j.atmosenv.2026.121831","url":null,"abstract":"<div><div>There is a body of evidence on the risk to human health posed by the exposure to desert dust. However, results from epidemiological studies from different regions are inconsistent. Among possible causes of inconsistency is the scarcity of daily desert dust contributions to PM₁₀ and PM_2.5 levels recorded in populated areas in order to conduct rigorous epidemiological studies, but also the lack of robust and harmonized methodologies to deliver airborne desert-dust concentrations. This study evaluated the performance of the main statistical methods currently used by European countries to estimate the net load of desert dust on PM₁₀ and PM_2.5 levels during the occurrence of desert dust outbreaks. To this end, long-term data series (2010–2023) on PM₁₀ and PM_2.5 levels and composition obtained in a regional background (Montseny) and an urban background (Barcelona) monitoring site, in Northeast Spain, were used. The results identify the most appropriate method for determining the regional daily PM₁₀ background concentration, excluding dust-days. This involves applying a moving 50th percentile with a 30-day time window to data from nearby regional background environments. Such PM_{10 background} is essential for calculating the daily net dust contribution (PM_{10 net-dust}). However, applying this procedure to data from urban or industrial environments causes an overestimation of PM_{10 net-dust} values, which intensifies with higher local PM₁₀ levels. On the other hand, in the case of low PM₁₀ _net-dust values(&lt;3 μg m⁻³) the relative errors are so high that it is not advisable to use these estimates of natural PM contributions to assess compliance with air quality standards. For PM_2.5, however, the mineral dust content is much lower than for PM₁₀. Consequently, applying the same methodology results in significantly greater relative errors in the PM_{2.5 net-dust} estimates. In this case, it is also advisable to use PM_2.5 data series obtained in regional background environments. However, if nearby regional background data is not available, the method can be applied directly to the evaluated urban or industrial datasets, but excluding traffic and industrial hotspots for the calculation of the PM_net-dust. In conclusion, accurately quantifying PM_net-dust is a complex issue, and it is necessary to continue improving current methods and developing new methods that allow for the most accurate estimation possible of daily desert dust contributions, especially for the low concentration ranges and for finer PM size fractions. The methodologies reported here are applicable to all regions affected by desert dust.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121831"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075941","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":"Intrusion of Marine-continental mixed aerosols disturb cloud properties","authors":"Shuo Wang ,&nbsp;Wenqing Xu ,&nbsp;Chang Liu ,&nbsp;Jun Wang ,&nbsp;Zhiming Yi ,&nbsp;Liang Xu ,&nbsp;Jing Han ,&nbsp;Guangzhi Ren ,&nbsp;Dianguo Zhang ,&nbsp;Wenqing Wang ,&nbsp;Weijun Li","doi":"10.1016/j.atmosenv.2026.121794","DOIUrl":"10.1016/j.atmosenv.2026.121794","url":null,"abstract":"<div><div>Aerosol-cloud interactions (ACI) for marine-continental mixed aerosols (MCMA) in coastal zones remain poorly constrained in climate models. Combining aircraft observations and WRF simulations during a spring 2023 North China precipitation event, we demonstrate distinct vertical stratification: MCMA dominates below 3000 m with variable activation (4.2 %) due to compositional complexity, while continental aerosols (CA) prevail above 3000 m with lower activation (2.1 %) from homogeneous properties. MCMA's broader size distribution (enhanced giant aerosols &gt;0.5 μm), yielding higher cloud droplet concentrations (N_c) but lower spectral dispersion (ε) than CA (N_c = 96.6 cm⁻³, ε = 0.263 vs. N_c = 57.5 cm⁻³, ε = 0.375). Integrating observed aerosol data into WRF revealed that parameterizing ε-N_c relationships under MCMA improves cloud microphysics representation, capturing cloud-water mixing ratios (up to 0.44 g kg⁻¹) and precipitation patterns. Results highlight the critical role of aerosol mixing states in modulating cloud processes and necessitate refined parameterizations for coastal aerosols in climate models.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121794"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026189","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":"Do regional background sites capture changes in primary PM2.5 emissions at the national scale? Recent trends in PM2.5 in rural environments in metropolitan France","authors":"Anna Font ,&nbsp;Joel F. de Brito ,&nbsp;Véronique Riffault ,&nbsp;Sébastien Conil ,&nbsp;Jean-Luc Jaffrezo ,&nbsp;Aude Bourin","doi":"10.1016/j.atmosenv.2026.121811","DOIUrl":"10.1016/j.atmosenv.2026.121811","url":null,"abstract":"<div><div>Trends in daily PM_2.5 concentrations were assessed at 5 rural background sites in France in 2014–2021, together with major particulate components which concentrations were attributed to (i) anthropogenic emissions including fossil fuels (FF) and biomass burning (BB) from primary emissions; and (ii) secondary particulate constituents including non-sea-salt sulphate, nitrate and ammonium. Annual PM_2.5 concentrations correlated to annual emissions in both SO₂ and NO_X in France at all sites; correlations to primary PM_2.5 emissions varied depending on the site. To disentangle the influence of weather, long-range transport, and the conditions controlling for PM secondary formation on the PM_2.5 time series, boosted regression tree (BRT) models were built at each site for PM_2.5; and normalised time series calculated by randomising the value of the explanatory variables at a given time. Two BRT models with their respective normalised PM_2.5 time series were calculated: de-weathered time series (without the influence of the meteorological and long-range transport) and de-weathered &amp; de-oxidised time series (randomisation of meteorology, transport and O_X (NO₂ + O₃) concentrations). In 2014–2021, PM_2.5 decreased at −5.6 % year⁻¹, almost twice as fast as changes in primary emissions in France and neighbouring countries (about −3 % year⁻¹). Overall trends in de-weathered, and de-weathered and de-oxidised PM_2.5 were lower than that in PM_2.5 observations, at −3.9 % year⁻¹ and -3.2 % year⁻¹, respectively. Trends in de-weathered &amp; de-oxidised PM_2.5 were close to those in emissions, demonstrating the role of including variables capturing the oxidative capacity of the atmosphere in the normalising techniques to compare trends in PM_2.5 with primary emissions. Faster downward rates in PM_2.5 aerosols in rural background in mainland France were mostly associated with the decrease in gas emissions responsible for secondary particles and less sensitive to changes in primary emissions. Control of NH₃ emissions is suggested to be crucial to ensure downward trends in PM_2.5 at the regional background environments to reduce concentrations closer to WHO limits.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121811"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026108","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 new radius–time relationship for droplet evaporation revealing vapour-to-bulk diffusion transition via optical tweezers","authors":"Shuqi Guo ,&nbsp;Chengyi Fan ,&nbsp;Nan Ma ,&nbsp;Chunsheng Zhao","doi":"10.1016/j.atmosenv.2026.121829","DOIUrl":"10.1016/j.atmosenv.2026.121829","url":null,"abstract":"<div><div>Droplet evaporation is a fundamental process with broad implications for cloud microphysics and atmospheric chemistry. Solutes introduce non-ideal behaviour that alters the droplet's microphysical properties and reconfigures its evaporation dynamics, yet their influence remains insufficiently quantified. Using an optical tweezers system, we investigated the evaporation of droplets containing non-volatile solutes. The results reveal distinct stagewise variation in evaporation rate, driven by a gradual transition in the dominant microphysical mechanism from vapour diffusion across the gas–liquid interface to bulk-phase diffusion within the droplet. Once bulk-phase diffusion becomes dominant, the evaporation rate decreases significantly and the overall evaporation time increases, indicating that classical evaporation theory underestimates droplet lifetime by neglecting internal mass transport. A new radius–time relationship that better aligns with experimental observations is proposed and highlights the decisive role of solutes in both the initial conditions and the dynamic evolution of droplet evaporation. These findings advance our understanding of the microphysical evolution of droplet evaporation, providing a physical basis for improving the parameterisation of aerosol–cloud interactions and droplet lifetime in atmospheric models.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121829"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075938","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":"Effects of seed particles and relative humidity on brown carbon formation from NO3-driven oxidation of vanillin","authors":"Shixin Mai ,&nbsp;Kunpeng Chen ,&nbsp;Hengjia Ou ,&nbsp;Li Chen ,&nbsp;Dexian Chen ,&nbsp;Shengzhen Zhou","doi":"10.1016/j.atmosenv.2026.121827","DOIUrl":"10.1016/j.atmosenv.2026.121827","url":null,"abstract":"<div><div>Methoxyphenols, as emitted abundantly from biomass burning, are important precursors of brown carbon (BrC) in the atmosphere. However, the effects of environmental factors on their gas-phase oxidation by nitrate radicals (NO₃), the dominant nighttime oxidant, remain poorly understood. In this study, the reaction of vanillin, a proxy for methoxyphenols, with NO₃ was investigated in a smog chamber under six environmental conditions, varied by pre-existing seed particles levels and relative humidity (RH). The NO₃-driven oxidation under different environmental conditions consistently produced secondary BrC, with nitrogen-containing species identified as the dominant reaction products. Both seed level and RH were found to be critical environmental controls; higher seed concentrations promoted secondary organic aerosol (SOA) formation and increased mass absorption coefficient (MAC) under dry conditions but suppressed them under humid conditions. Furthermore, variations in seed concentration and RH guided the reaction pathways to distinct product distributions. Our findings also revealed that humid conditions may enhance the concentration of low-molecular-weight species regardless of seed levels. Overall, this work reveals how environmental conditions modulate secondary BrC formation from methoxyphenols oxidation with NO₃, providing critical constraints for atmospheric models of aerosol optical properties.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121827"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075940","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":"Field observations reveal biomass burning and cooking as the significant sources of PM2.5-bound organic acids in Central China","authors":"Ziyue Xiang ,&nbsp;Runqi Zhang ,&nbsp;Sheng Li ,&nbsp;Bin Xu ,&nbsp;Qiongwei Zhang ,&nbsp;Jun Wang ,&nbsp;Datong Luo ,&nbsp;Zhan Liu ,&nbsp;Xinming Wang","doi":"10.1016/j.atmosenv.2026.121858","DOIUrl":"10.1016/j.atmosenv.2026.121858","url":null,"abstract":"<div><div>Organic acids (OAs), crucial components of fine particulate matter (PM_2.5), not only influence cloud condensation nuclei but also promote particle nucleation and growth. Elucidating the chemical composition and key sources of atmospheric OAs is therefore crucial, particularly in Central China, a region with agricultural and cooking practices. This study investigated the chemical characteristics and sources of PM_2.5-bound OAs (C₉-C₃₂ monocarboxylic acids, C₄-C₁₀ dicarboxylic acids, 22 aromatic acids) in urban Changsha from August 2021 to January 2022. Results show that the quantified total OAs concentrations continuously increased from 362.2 ng/m³ in August to 894.1 ng/m³ in January. Chemically, hexadecanoic acid exhibited the highest average concentration (14.5% of quantified OAs), followed by p-Terephthalic acid (10.2%), octadecanoic acid (9.6%), succinic acid (9.1%), and azelaic acid (7.9%). Source apportionment revealed vehicle emissions as the predominant contributor (32.2% on average). Notably, biomass burning (24.8%) and cooking emissions (20.2%) also made substantial contributions. Particularly during October and November, biomass burning emission contributions surged to 32.2%, attributable to intensified open straw burning in October and residential firewood heating in surrounding suburban/rural areas in November. Even in August, with minimal agricultural burning and residential heating, biomass burning still contributed over 20%. A significant correlation (R² = 0.90) exists between biomass burning and cooking emissions tracers in August, which features prevalent charbroiling cooking and concurrently explains the marked contribution of cooking emissions (25.0% on average). This study provides critical insights into the molecular composition and potential sources of OAs in Central China, highlighting the importance of biomass burning and cooking emissions in developing air-quality management strategies for this region.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121858"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171164","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":"Geospatial patterns of concurrent thermal stress and multi-pollutant exposure in China","authors":"Fuxing Li ,&nbsp;Weimiao Li ,&nbsp;Shiyao Wang ,&nbsp;Gerrit de Leeuw ,&nbsp;Yang Wang ,&nbsp;Wei Wang ,&nbsp;Cheng Fan ,&nbsp;Zhengqiang Li","doi":"10.1016/j.atmosenv.2026.121853","DOIUrl":"10.1016/j.atmosenv.2026.121853","url":null,"abstract":"<div><div>Integrated effects of concurrent exposure to multiple air pollutants and extreme temperatures can amplify health hazards and may induce differential health impacts. However, air quality regulations do not take these combined effects into account. In this study, we assess exposure levels for combinations of different ambient air pollutants, extreme temperature, population and mortality in distinct regions of China during 2000-2019. The results show that, during this period, population exposure to PM_2.5 and PM₁₀ declined by 4.09% and 3.95% per year, respectively, within the existing regulatory framework governing Chinese national ambient air quality standards (CNAAQS). In contrast, exposure to O₃ increased notably, with 2.43% per year. Despite improvements of air quality, under the CNAAQS Level-1 framework, five out of seven climatic regions in China experienced compound pollution events involving PM₁₀-O₃, PM_2.5-PM₁₀, and PM_2.5-PM₁₀-O₃ during at least 158 days in 2019. The exposure time to extreme temperature episodes exhibited a fluctuating change pattern during the study period. However, it is worth noting that the exposure time during heat waves increased significantly since 2015, by 2.67% per year. While we highlight the improved air quality in China, we underscore the imperative for prioritized interventions targeting specific pollutants and their co-occurring phenomena for different climatic regions, particularly under climate-driven temperature escalation observed since 2015.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121853"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171160","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":"Characteristics and sources of ambient VOCs under varying PM2.5 levels in winter","authors":"Rui Sun ,&nbsp;Guiying You ,&nbsp;Danlin Song ,&nbsp;Miao Feng ,&nbsp;Hefan Liu ,&nbsp;Shaodong Xie","doi":"10.1016/j.atmosenv.2026.121826","DOIUrl":"10.1016/j.atmosenv.2026.121826","url":null,"abstract":"&lt;div&gt;&lt;div&gt;To investigate the concentration, sources of volatile organic compounds (VOCs), and their impact on the formation of secondary particulate matter under different PM&lt;sub&gt;2.5&lt;/sub&gt; concentration levels in ambient air, a one-month online observation of ambient VOCs and PM&lt;sub&gt;2.5&lt;/sub&gt; concentrations was conducted in Chengdu, China during winter. The results showed that the concentrations of most VOC species increased significantly with the rising PM&lt;sub&gt;2.5&lt;/sub&gt; concentration. The Concentration and proportions of alkenes/alkynes, halocarbons, aromatics, and oxygenated VOCs (OVOCs) all increased as PM&lt;sub&gt;2.5&lt;/sub&gt; concentrations rose, with alkenes and alkynes showing a more prominent increase. However, the proportion of alkanes decreased with increasing PM&lt;sub&gt;2.5&lt;/sub&gt; concentration, yet they still accounted for over 40 % of total VOCs concentrations. During moderately polluted period (PM&lt;sub&gt;2.5&lt;/sub&gt;&gt;115 μg/m&lt;sup&gt;3&lt;/sup&gt;), the concentrations of isopentane, ethyl acetate, trans-2-butene, o-xylene, and 3-ethyltoluene were 9.5,7.4, 6.4, 6.2 and 6 times those in the excellent air quality period (PM&lt;sub&gt;2.5&lt;/sub&gt;≤35 μg/m&lt;sup&gt;3&lt;/sup&gt;), respectively, much higher than the 1.8-fold increase of CO. In contrast, the concentrations of 1-pentene and cis-2-pentene decreased instead of increasing, dropping by 75 % and 60 %, respectively. The concentrations of typical long-lived species remained essentially stable. Source apportionment results indicated that among the 8 sources of VOCs in ambient air, the concentration contributions and proportions of 4 sources, namely vehicle emissions, gas evaporation, solvent use, and domestic sources, all increased with the elevation of PM&lt;sub&gt;2.5&lt;/sub&gt; concentrations. During moderate pollution, their concentration contributions were 22.1 ppbv (34.3 %), 13.61 ppbv (21.7 %), 8.1 ppbv (11.5 %), and 7.8 ppbv (10.1 %), respectively. Among these, the concentration contribution of solvent use source during moderate pollution was 12.6 times that in the excellent air quality period, making it the source with the largest relative concentration contribution. The concentration contributions of the other 4 sources hardly changed with PM&lt;sub&gt;2.5&lt;/sub&gt; concentration. This indicated that industrial emissions, as well as biomass/waste combustion sources were effectively controlled throughout the pollution process, and no secondary formation sources of VOCs were detected during the winter pollution episodes. A comparison of changes in VOC species concentrations and their sources revealed that the increase in concentrations of reactive species with PM&lt;sub&gt;2.5&lt;/sub&gt; concentration was much lower than the increase in their source contributions, indicating significant chemical depletion. These findings suggested that the main sources driving the synchronous increase of PM&lt;sub&gt;2.5&lt;/sub&gt; and VOC concentration in ambient air are vehicle emissions, gas evaporation, solvent use, and domestic sources. These sources not only directly emit","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121826"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026109","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}