Atmospheric Environment: X最新文献

{"title":"Effectiveness of a low emission zone in improving air quality in Barcelona","authors":"Vanessa N. dos Santos ,&nbsp;Laia Font-Ribera ,&nbsp;Marc Rico ,&nbsp;Jordi Massagué ,&nbsp;Núria Nebra ,&nbsp;Eva Pérez ,&nbsp;Anna Gómez-Gutiérrez ,&nbsp;Ioar Rivas ,&nbsp;Xavier Querol ,&nbsp;Xavier Basagaña","doi":"10.1016/j.aeaoa.2026.100428","DOIUrl":"10.1016/j.aeaoa.2026.100428","url":null,"abstract":"<div><div>A low emission zone (LEZ) was implemented in the Barcelona metropolitan area in 2020, concurrently with the onset of the COVID-19 pandemic. We used a synthetic control method to estimate the impacts of the LEZ on NO₂, PM_2.5 and PM₁₀ concentrations in Barcelona, accounting for the effects of COVID-19 and other underlying trends, in addition to meteorology and desert dust outbreaks. Results showed that the LEZ reduced annual mean NO₂ concentrations by 7.6 μg/m³ (95% CI: 6.7, 8.5 μg/m³) at traffic stations, and by 4.5 μg/m³ (95% CI: 3.7, 5.3 μg/m³) at urban background stations. The LEZ was less effective in reducing PM_2.5 and PM₁₀ concentrations. These results indicate that the LEZ in Barcelona was effective in reducing NO₂ concentrations, while the effects on PM were more uncertain, probably due to the major secondary PM origin.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"29 ","pages":"Article 100428"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147394898","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":"In vitro toxicity of car and train brake wear emissions using Air-Liquid Interface and submerged exposure models","authors":"Ana Teresa Juárez-Facio ,&nbsp;Micol Introna ,&nbsp;Andrea Montano Montes ,&nbsp;Lucas Bard ,&nbsp;Alessandro Mancini ,&nbsp;Bozhena Tsyupa ,&nbsp;Minghui Tu ,&nbsp;N.V. Srikanth Vallabani ,&nbsp;Hanna L. Karlsson ,&nbsp;Ulf Olofsson ,&nbsp;Sarah S. Steimer ,&nbsp;Karine Elihn","doi":"10.1016/j.aeaoa.2026.100426","DOIUrl":"10.1016/j.aeaoa.2026.100426","url":null,"abstract":"","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"29 ","pages":"Article 100426"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147394902","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":"Utilization of catalytically cracked waste transformer oil in compression ignition engines: Effects of combustion chamber geometry on efficiency and emission characteristics","authors":"S. Prasanna Raj Yadav ,&nbsp;Seetharaman Sathyanarayanan ,&nbsp;C.G. Saravanan ,&nbsp;D. Damodharan ,&nbsp;S. Balasaraswathy ,&nbsp;Femilda Josephin JS ,&nbsp;Edwin Geo Varuvel ,&nbsp;Jonas Matijošius ,&nbsp;Artūras Kilikevičius ,&nbsp;Haiter Lenin Allasi","doi":"10.1016/j.aeaoa.2025.100402","DOIUrl":"10.1016/j.aeaoa.2025.100402","url":null,"abstract":"<div><div>Research on alternative fuels has received increased attention in recent years because they not only address the sustainability issues associated with fossil fuels but also mitigate the harmful gases released during combustion. This study focuses on the use of recycled transformer oil (WTO) in diesel engines, aiming to harness its energy content, which is typically discarded as waste. The WTO was recycled via catalytic cracking, and CCWTO50 (a 50 % CCWTO and 50 % neat diesel blend) was used as the test fuel. Furthermore, a re-entrant combustion chamber (RCC) and a hemispherical open-type combustion chamber (HCC) were employed to investigate the combustion and emission characteristics of WTO. The combustion characteristics, engine performance, and exhaust gas emission levels were recorded when the CCWTO50 powered the engine for both HCC and RCC geometries. The results indicate that CCWTO50 improved engine performance and reduced emissions compared to diesel fuel. Further improvements were observed when RCC was employed. A higher heat release rate of 169.3 kJ/m³/°C and a peak pressure of 61.54 bar were observed for CCWTO50-RCC. CCWTO50-RCC improved brake thermal efficiency by 3 % compared to diesel-HCC. In addition, CCWTO50-RCC reduced emissions of hydrocarbons (HC), carbon monoxide (CO), and smoke by 8 %, 6 %, and 5 %, respectively, compared to diesel-HCC. Thus, the authors suggest that CCWTO50 with RCC can be effectively used in diesel engines to enhance engine performance and reduce exhaust gas emissions.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"29 ","pages":"Article 100402"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737856","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":"Difference in ammonia air concentration at two sampling heights from ground surface: implications for deposition research","authors":"Claire Boerée-Kamphorst ,&nbsp;Serigne Lô ,&nbsp;Wietske Dohmen ,&nbsp;Huifang Deng ,&nbsp;Roel Vermeulen ,&nbsp;Gerard Hoek ,&nbsp;René Verburg ,&nbsp;Dick Heederik","doi":"10.1016/j.aeaoa.2026.100424","DOIUrl":"10.1016/j.aeaoa.2026.100424","url":null,"abstract":"<div><div>Monitoring atmospheric ammonia levels (NH₃) is essential for accurately assessing nitrogen deposition, especially in agricultural regions. Conventional dry deposition measurement techniques are costly, complex, and often sparsely deployed, especially in emission hotspots. This limits the empirical basis for evaluating spatial and temporal variability and uncertainty in dry deposition estimates. In this study, we evaluated a low-cost passive sampling approach to monitor vertical NH₃ concentration gradients between two heights (100 cm and 180 cm) across 70 locations in the Netherlands, covering rural, semi-urban, and natural areas. We assessed whether systematically observed NH₃ air concentration gradients can serve as a proxy for estimating near-surface deposition processes. Over 1600 monthly measurement sets were collected and analyzed.</div><div>We observed a consistent and statistically significant vertical concentration gradient, with higher concentrations at 1.8m height than at 1.0m height. The difference (Δ) averaged 0.49 μg/m³, about 4% of the overall sampling area average ambient ammonia concentration. This vertical gradient was detectable despite measurement uncertainty and a low signal-to-noise ratio. Total variability in Δ was only partly explained by spatial and temporal factors, but remained largely unexplained (residual variation) and thus reflected analytical and sampling errors. Spatial and temporal variables which were related to (a higher) Δ were in particular proximity to livestock farms and wind speed.</div><div>Rather than providing direct flux estimates, our findings indicate that vertical NH₃ gradients can function as a diagnostic, proxy for surface atmosphere exchange patterns at local scales. By demonstrating that statistically significant gradients can be detected using low-cost passive samplers when spatial coverage and replication are sufficient, this study extends previous NH₃ monitoring work that has largely focused on single-height concentration measurements. Our study offers a scalable approach to empirically explore spatial variability and uncertainty in dry deposition assessments, particularly in regions with high agricultural emission where conventional flux measurements remain impractical.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"29 ","pages":"Article 100424"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188046","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":"Ship fuel consumption and emissions during low load manoeuvring conditions","authors":"Mojibul Sajjad ,&nbsp;Thuy Chu-Van ,&nbsp;G.M. Hasan Shahariar ,&nbsp;Kabir Adewale Suara ,&nbsp;Nicholas Surawski ,&nbsp;Timothy A. Bodisco ,&nbsp;Zoran D Ristovski ,&nbsp;Richard J. Brown ,&nbsp;Ali Zare","doi":"10.1016/j.aeaoa.2025.100398","DOIUrl":"10.1016/j.aeaoa.2025.100398","url":null,"abstract":"<div><div>Ship engine loading typically follows the propeller law, with fuel consumption models primarily using engine load as a predictor. However, this study highlights the limitations of propeller laws in accurately representing engine behaviour in port and coastal areas under transient operational conditions (e.g. manoeuvring/running under partial loading at slower speeds). This study presents a comparative analysis of on-board ship measurements and a laboratory study using a testbed diesel engine operating under a custom-designed propeller law transient cycle. Results indicate that the test engine's measured load profile lagged during acceleration and led during deceleration, with this effect intensifying at higher ramp rates. Brake-specific fuel consumption (BSFC) peaked at low loads and decreased at higher loads in departure/arrival scenarios, highlighting the critical role of engine speed under partial loading in operational safety, asset life, and emissions. Additionally, ship EFs (g/kg of fuel) were disproportionately high at low operating loads under partial loading, reflecting increased fuel-specific emissions due to unstable operating conditions. Particle number (PN) and particulate mass (PM₁) EFs are over-estimation at loads &lt;5 % and &lt;4 % respectively, and underestimation for loads &gt;5 % and &gt;4 %, respectively. Low load (≤20 %) correction factors overestimate NO_x, CO, and PM₁ at &lt;5 % load. Above 5 % load, NO_x is underestimated but aligns during approaching to Port of Gladstone (POGL). CO is overestimated leaving Port of Brisbane (POB) but aligns during approaching to POGL. Testbed findings of emissions for different ramps match modelled low load correction factor values, though deceleration EFs (during 8–15 % load) exceed predictions. At ≤10 % load for both acceleration and deceleration states, the low load correction factors differ significantly; at higher loads, they align with the modelled predictions. Testbed engine results align with standard low load correction factors through transient cycle studies, highlighting the need to account for partial loading and dynamic conditions in emission estimates. With the aid of the propeller law drive cycle, the ship activity during the port manoeuvring demonstrated in a testbed engine. Testbed responses under acceleration-deceleration transient run, identified significance differences in specific emissions, and this study bridges a key gap in emission modelling with real-world data and empirical models.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"29 ","pages":"Article 100398"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145625000","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":"Atmospheric distribution and exposure implications of heavy metals around industrial, mining, and slum areas in Liberia","authors":"Anthony Saah Tengbeh ,&nbsp;Ismail Olawale Akande ,&nbsp;Chideraa Courage Offor ,&nbsp;Prosper Manu Abdulai ,&nbsp;John Kanayochukwu Nduka ,&nbsp;Chiara Frazzoli ,&nbsp;Orish Ebere Orisakwe","doi":"10.1016/j.aeaoa.2026.100429","DOIUrl":"10.1016/j.aeaoa.2026.100429","url":null,"abstract":"<div><div>This study evaluated the distribution, sources, and health risks of airborne As, Cd, Pb, and Hg in industrial, mining, and urban slum areas of Liberia. Eighty-one total suspended particulate samples were collected at source locations and at 100 m and 500 m distances. Metal concentrations were measured using atomic absorption spectrophotometry, with multivariate analysis, Positive Matrix Factorization (PMF), and Monte Carlo simulation applied for source apportionment and uncertainty assessment. The mining zone recorded the highest metal concentrations, including arsenic (0.102 mg/m³), lead (1.002 mg/m³), cadmium (0.016 mg/m³), and mercury (0.008 mg/m³). Metal concentrations declined significantly with distance, stabilizing at ≥100 m, where reductions of 55–80% were observed relative to the source.</div><div>Non-carcinogenic risk assessment showed that As, Cd, Pb, and Hg posed no significant health risk (HQ &lt; 1) for both adults and children, although children exhibited relatively higher HQ values, suggesting greater vulnerability. Carcinogenic risks for As, Cd, and Pb remained below the permissible threshold (CR = 1.1 × 10⁻⁶–8.4 × 10⁻⁶), while Monte Carlo simulations confirmed risk stability, with exposure following the order industrial &gt; mining &gt; slum which reflects the differences in exposure frequency, population density, and intensity of human activities rather than concentration levels alone. Although current risks are minimal, continued unregulated emissions could pose long-term health concerns. Regular air quality monitoring and enforcing ≥100-m buffer zones around mining and industrial sites are recommended, alongside further research on seasonal and cumulative exposure pathways.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"29 ","pages":"Article 100429"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147394899","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":"Sustainable Aviation Fuels and their impact in commercial airport operation","authors":"Leandro B. Magalhães ,&nbsp;Luís F.F.M. Santos ,&nbsp;Ana F. Ferreira ,&nbsp;André R. Silva","doi":"10.1016/j.aeaoa.2025.100403","DOIUrl":"10.1016/j.aeaoa.2025.100403","url":null,"abstract":"<div><div>With global air traffic projected to grow annually by approximately 3.8%, the aviation sector faces increasing pressure to implement effective strategies for mitigating its environmental impact, particularly with respect to greenhouse gas emissions. Sustainable Aviation Fuels represent a critical pathway for decarbonizing aviation by offering a lower-emission alternative to conventional jet fuels. This study evaluates the environmental impact of SAFs on specific operational phases of flight, with a focus on the landing and take-off cycle. A case study was conducted at Lisbon Airport using real aircraft movement data over a one-week period. Emissions were calculated by correlating aircraft engine types with data from the ICAO Engine Exhaust Emissions Databank. The analysis identifies the most emission-intensive flight phase, the most polluting fleet, and evaluates the potential GHG reductions achievable through the use of various SAF pathways. Additionally, operational alternatives for reducing emissions during the taxi phase, including APU management strategies, are examined. The results provide actionable insights into the role of SAFs in reducing airport-level emissions and support targeted interventions for more sustainable airport operations.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"29 ","pages":"Article 100403"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737857","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":"Physical mechanisms distinguishing severe-weather-producing and non–severe-weather-producing precipitation in Northern Thailand's pre-monsoon environment","authors":"Nattapon Mahavik","doi":"10.1016/j.aeaoa.2026.100416","DOIUrl":"10.1016/j.aeaoa.2026.100416","url":null,"abstract":"<div><div>Severe pre-monsoon convection in northern Thailand frequently produces damaging winds and hail, yet the physical mechanisms that distinguish severe-weather-producing environments from ordinary rainfall remain poorly understood. This study analyzes 222 pre-monsoon days (2015–2024) across nine provinces using 00 UTC radiosonde soundings and ERA5 synoptic composites to identify the atmospheric controls that separate Severe-Weather-Producing Events (SWPE) from non-severe counterparts (NSWPE). Among 34 thermodynamic and kinematic parameters evaluated, convective inhibition (CIN) emerges as the strongest discriminator: SWPE environments exhibit substantially stronger mixed-layer inhibition, consistent with a tropical “loaded-gun” profile in which delayed initiation allows instability to accumulate before explosive deep convection occurs. In contrast, CAPE shows limited separability between the two regimes. Storm-producing environments also feature enhanced downdraft potential (higher DCAPE) and a distinctive vertical wind-speed structure characterized by weaker low-level flow but markedly stronger upper-tropospheric winds, highlighting the importance of divergent outflow and jet coupling. ERA5 composites reveal coherent synoptic-scale differences, including strengthened circulation along the Thailand–Myanmar corridor and enhanced lower-tropospheric warming coupled with mid-tropospheric cooling during SWPE days. Together, these results demonstrate that capping strength, downdraft potential, and upper-level dynamical support—not buoyancy magnitude alone—are the key physical mechanisms distinguishing severe from non-severe pre-monsoon convection. The findings underscore the operational value of CIN- and DCAPE-based diagnostics for severe-weather forecasting in tropical Southeast Asia.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"29 ","pages":"Article 100416"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188043","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":"Atmospheric ammonia concentration measurements in Japanese laying hen buildings and modeling for emission inventory","authors":"T. Yoshida ,&nbsp;G. Katata ,&nbsp;H. Kuroda ,&nbsp;N. Tanaka","doi":"10.1016/j.aeaoa.2026.100422","DOIUrl":"10.1016/j.aeaoa.2026.100422","url":null,"abstract":"<div><div>Atmospheric ammonia (NH₃) from livestock contributes to PM2.5 formation and nitrogen loading in watersheds. Although chemical transport models often adopt the emission factor (<em>EF</em>) and monthly variation coefficient (<em>M</em>_<em>f</em>) from European NH₃ emission inventories due to the limited availability of direct measurement data worldwide, their applicability to Asian countries remains unknown. In this study, we observed the spatial distributions and diurnal changes in NH₃ concentrations within windowless laying hen buildings during May–October of 2022 and 2023. The observed spatial distribution showed that the major drivers of monthly NH₃ emissions were air temperature and ventilation rate. Moreover, NH₃ concentrations changed depending on the number of days after manure removal according to the diurnal observations. A regression analysis was conducted using observed temperature, ventilation rate, and manure removal to develop a statistical model for estimating NH₃ emission rates based on ambient temperature data. Subsequently, model application to the different climatic conditions were performed by using the typical monthly mean air temperature from the surface weather databases at several major poultry production cities in Japan. The results demonstrated that the calculated <em>EF</em> in Japan varied substantially (0.11–0.52 kgNH₃ y⁻¹ head⁻¹) depending on air temperature, whereas that in the Netherlands remained near the lowest values. The summertime <em>M</em>_<em>f</em> was higher in Japan than that in the Netherlands, suggesting differences in climate and manure management systems between Japan and Europe. To improve the accuracy of livestock emission inventories, further observations for NH₃ emission rate estimates are required for other sources, such as manure storage and land application.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"29 ","pages":"Article 100422"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187949","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":"Acute exposure to fine ambient particulate matter and pulmonary exacerbations in cystic fibrosis: A case-crossover study","authors":"Stephen P. Colegate ,&nbsp;Erika Rasnick Manning ,&nbsp;Andrew Vancil ,&nbsp;Ziyun Wang ,&nbsp;Marepalli Rao ,&nbsp;Emrah Gecili ,&nbsp;Anushka Palipana ,&nbsp;Patrick Ryan ,&nbsp;Rhonda D. Szczesniak ,&nbsp;Cole Brokamp","doi":"10.1016/j.aeaoa.2026.100414","DOIUrl":"10.1016/j.aeaoa.2026.100414","url":null,"abstract":"<div><div>In cystic fibrosis (CF) lung disease, increased exposure to PM_2.5 (particulate matter &lt;2.5 μm in diameter) has been linked to more frequent pulmonary exacerbations, yet the timing of exposure that presents the greatest exacerbation risk remains uncertain. Our study investigated whether short-term increases in ambient fine particulate matter (PM_2.5) contribute to exacerbation risk in individuals with CF. We analyzed data from 108 participants across 17 U.S. clinical sites enrolled in the Early Intervention in Cystic Fibrosis Exacerbation study (October 2011–July 2015), who recorded forced expiratory volume in 1 s (FEV₁) measurements at least twice weekly. Exacerbation cases were identified via the FEV₁ indicated exacerbation signal (FIES), defined as a ≥10 % predicted decline in FEV₁. Daily 24-h average PM_2.5 concentrations were estimated at the residential ZIP code using a high-resolution spatiotemporal exposure model. A time-stratified case-crossover design modeled exacerbation onset and PM_2.5 exposure, controlled for temperature, relative humidity, and holiday impacts. We analyzed 6936 FEV₁ observations yielding 1432 exacerbation cases, averaging 7.7 cases per person-year, matched to 4794 control dates in the same year, month, and day of the week. Increased exacerbation risk occurred one (OR: 1.18; 95 % CI: 1.02–1.36), two (OR: 1.20; 95 % CI: 1.04–1.40), and three (OR: 1.23; 95 % CI: 1.05–1.43) days after PM_2.5 exposure, but not on the day of onset (OR: 1.07; 95 % CI: 0.92–1.25). Integrating home-monitored lung function with hyperlocal exposure estimates provides improved temporal resolution for detecting acute environmental triggers and may inform early intervention strategies in CF care.</div><div>e-ICE clinical trial registered with <span><span>www.clinicaltrials.gov</span><svg><path></path></svg></span> (NCT01104402).</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"29 ","pages":"Article 100414"},"PeriodicalIF":3.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187948","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}