Indoor Environments最新文献

{"title":"Lessons learned from developing the worldwide IEQ guidelines database","authors":"Samy Clinchard ,&nbsp;Henna Maula ,&nbsp;Piet Jacobs ,&nbsp;Amelia Staszowska ,&nbsp;Suchismita Bhattacharjee ,&nbsp;Marzenna Dudzinska ,&nbsp;Sani Dimitroulopoulou ,&nbsp;Christina Higgins ,&nbsp;Xiaojun Fan ,&nbsp;Ju-Hyeong Park ,&nbsp;Oluyemi Toyinbo ,&nbsp;Ulla Haverinen-Shaughnessy","doi":"10.1016/j.indenv.2025.100124","DOIUrl":"10.1016/j.indenv.2025.100124","url":null,"abstract":"<div><div>Indoor environmental quality (IEQ) guidelines and standards aim to ensure consistent, safe and healthy indoor spaces by providing clear benchmarks for air quality, lighting, thermal comfort and acoustics. Many countries and organizations have established their own IEQ regulations and standards or guidelines, but discrepancies in parameters, definitions, methods, and updating frequency often cause them to lag behind the latest scientific and technological advancements, potentially limiting their effectiveness. Researchers and practitioners advocate for the simplification and unification of IEQ guidelines, though risking overlooking geographical and cultural specificities. To address these challenges, and to help preserve and use current knowledge, an open database compiling worldwide IEQ guidelines was developed, ensuring equitable access to up-to-date information. The database covers four key IEQ domains, indoor air quality (IAQ), thermal comfort, acoustics, and lighting, as well as two related domains: ventilation and outdoor air quality (OAQ). Ventilation is a critical factor influencing most of the other IEQ domains, while OAQ guidelines are sometimes used in the absence of indoor-specific guidelines. Each of the six resulting tables includes both mandatory governmental regulations and voluntary guidelines, along with internationally recognized standards for broader relevance. This paper summarizes key lessons learned from database development and data collection efforts over the past five years. Practical IEQ guidelines and standards balance health and wellbeing outcomes with environmental, economic, and comfort considerations. Guidelines and standards can work best when science-based, adaptable to regional contexts, and structured with clear, measurable parameters, such as exposure limits, timeframes, and validated measurement methods. Collaboration between scientific research, technological advancements, and policy development can ensure regulations remain effective and up to date. To increase compliance and raise public awareness, the database consolidates and shares existing international guidelines and standards, supporting global alignment with best practices while accommodating resource constraints and regional specificities.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 4","pages":"Article 100124"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159723","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":"Mechanical ventilation and indoor air quality in recently constructed homes in the humid climate of the Southeast U.S.","authors":"Haoran Zhao ,&nbsp;Eric Martin ,&nbsp;Tanvir Khan ,&nbsp;David Chasar ,&nbsp;Jeffrey Sonne ,&nbsp;Charles R. Withers Jr. ,&nbsp;Marion L. Russell ,&nbsp;William W. Delp ,&nbsp;Wanyu Rengie Chan ,&nbsp;Iain S. Walker ,&nbsp;Brett C. Singer","doi":"10.1016/j.indenv.2025.100121","DOIUrl":"10.1016/j.indenv.2025.100121","url":null,"abstract":"<div><div>This study examines whole-house mechanical ventilation (WHMV) and indoor air quality (IAQ) in 51 single-family homes constructed since 2013 in the humid southeastern U.S. Homes were monitored for one or two weeks, operating with or without WHMV, or under both conditions (two-week homes, n = 11). Measurements included envelope and duct airtightness; mechanical ventilation airflows; time-resolved CO₂, PM_2.5, formaldehyde, and radon; and time-integrated gravimetric PM_2.5, NO₂, NOₓ, and formaldehyde. Participants reported on ventilation use, IAQ-related activities and perceptions. Major deficiencies were observed in WHMV installation, operation, and occupant awareness. Thirty-seven homes had controlled WHMV equipment. Twenty-one could meet the ASHRAE 62.2–2010 airflow requirement with continuous or controlled runtime, but only 11 systems were operating at the field team’s arrival (as-found condition). Performance and homeowner awareness varied by system type. Most energy recovery ventilators and ventilating dehumidifiers were functional and operating as found, with owners aware of their purpose. Fifteen homes had exhaust fans with compliant airflow and sound ratings but no labeling, and owners did consider them WHMV. Central Fan integrated supply (CFIS) systems were rarely functional. Six homes had no kitchen exhaust ventilation, and only 35 had airflow above the 50 L/s requirement of 62.2–2010 at any setting. PM_2.5 concentrations were low in most homes. WHMV operation did not discernibly lower PM_2.5 or formaldehyde but did significantly reduce CO₂ and radon in both two-week homes and all homes with/out WHMV. Occupants of homes with WHMV operating as found felt they had better control of temperature and relative humidity.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 4","pages":"Article 100121"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097817","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":"Building-related symptoms in school environment: Predictability using machine learning approach","authors":"Azimil Gani Alam ,&nbsp;Alena Bartonova ,&nbsp;Britt Ann Kåstad Høiskar ,&nbsp;Mirjam F. Fredriksen ,&nbsp;Jivitesh Sharma ,&nbsp;Hans Martin Mathisen ,&nbsp;Zhirong Yang ,&nbsp;Kai Gustavsen ,&nbsp;Tore Fredriksen ,&nbsp;Dinastry Pramadita Zakiudin ,&nbsp;Guangyu Cao","doi":"10.1016/j.indenv.2025.100140","DOIUrl":"10.1016/j.indenv.2025.100140","url":null,"abstract":"<div><div>Building-related symptoms (BRS) are commonly experienced by students in schools and are potentially affecting academic performance and health. Even though indoor environment quality (IEQ) measurements indicated fair conditions, students still perceived discomfort that led to symptoms, highlighting the necessity of collecting user-feedback about IEQ-complaints. This study aimed to predict and understand the prevalence of BRS (<em>headache, tiredness, cough, dry eyes-hands</em>) experienced by students in classrooms using machine-learning (ML) approach based on measurement data, building factors, and prevalence of IEQ-complaints. We collected measurement data (from indoor and outdoor climate), building factors, and user-feedback by students via online-platform across three sampled classrooms each campaign during three consecutive school semesters. Significant input variables for ML were pre-selected using statistical tests. ML models were evaluated based on accuracy metrics and SHAP analysis for input interpretation. Models using measurement data alone performed poorly (testing R² &lt;50 %) to predict prevalence of BRS, whereas adding building factors and prevalence of IEQ-complaints increased accuracy (R² up to 95 %) of prediction of BRS with lower RMSE. In addition, interpretation from SHAP analysis showed IEQ-complaints especially related with indoor air quality (e.g., <em>heavy air</em>, <em>dust &amp; dirt</em>, and <em>dry air</em>) as significant contributors for predicting prevalence of BRS. We conclude that the framework of combining objective measurements with occupant-reported complaints can be reliable, interpretable predictions of symptom prevalence. This study is limited by single-school setting, health confounders, and symptoms verification. Future research may contribute to exploring wider set of input variables, applicability, and variation of complaints preference.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 4","pages":"Article 100140"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145684128","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":"Quantifying the impact of workplace environment features on physical activity for hybrid workers: A wearable sensors study","authors":"Charu Srivastava ,&nbsp;Holly Samuelson","doi":"10.1016/j.indenv.2025.100138","DOIUrl":"10.1016/j.indenv.2025.100138","url":null,"abstract":"<div><div>Recent studies show that working from home has resulted in an increase in self-reported sedentary behavior; however, less is known about the contribution of workplace environment features on measured physical activity when working on a hybrid schedule (i.e., both at home and from an office). This small-scale study takes advantage of an unprecedented time to examine differences in the quantity and pattern of physical activity for hybrid workers. By pairing measured data collected from wearable activity trackers with self-reported data on work location and workday routines, we identify to what extent specific workplace environment features help promote physical activity. Results from 245 participant-days of data showed a significant 33 % increase in daily step count when working from an office compared to home, translating to an average of 2580 steps, or 25 min of additional daily physical activity. On days when participants worked either partial or full days in the office, times of increased step count aligned with reported entry and exit times from the office building. A mixed effects model further revealed that a walking commute and the presence/convenience of stairs significantly predicted increased physical activity on office days, while access to gym/exercise equipment significantly predicted higher step counts on home days. To substantiate our quantitative results, a qualitative analysis of participant responses emphasized the benefits of active commutes and walking meetings at the office, as well as access to urban amenities and walking breaks at home. This analysis serves as a strong proof of concept and could inform the design of future studies that examine the ability of work environments to promote physical activity and reduce sedentary behavior.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 4","pages":"Article 100138"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618132","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":"Development of the CoSIE Lab: An advanced laboratory for multi-domain indoor environmental quality research","authors":"Jun Jiang ,&nbsp;Tobias Maria Burgholz ,&nbsp;Kai Rewitz ,&nbsp;Rita Streblow ,&nbsp;Dirk Müller","doi":"10.1016/j.indenv.2025.100120","DOIUrl":"10.1016/j.indenv.2025.100120","url":null,"abstract":"<div><div>Laboratory studies are essential in advancing multi-domain indoor environmental quality (IEQ) research, as they provide highly controllable, precise, and reproducible conditions for investigating the effects of various IEQ factors on occupants’ health and behavior. However, many existing IEQ laboratories face significant challenges, including inadequate multi-domain control, limited participant-laboratory interaction, and incomplete performance testing. This paper presents the comprehensive development process of the Comfort Studies and Indoor Environment Laboratory (CoSIE Lab), a flexible and expandable research facility designed to control IEQ factors across thermal, indoor air quality, visual, and acoustic domains. The development process is organized into distinct phases: conceptual planning, design and construction, commissioning and performance testing, and experimental applications. Through this structured approach, we aim to share valuable insights and lessons learned from the development of the CoSIE Lab. Key findings indicate that capillary tube mat is an effective solution for radiant temperature control. In conjunction with a hydronic system, the CoSIE Lab achieves 76 zones with individual surface temperature control ranging from 15 °C to 40 °C. The surface radiant system enhances air conditioning process, enabling both homogenous and heterogenous air temperature distributions within the test rooms. Measurements of illuminance and color temperature demonstrate close alignment with design specifications for artificial lighting as simulated in software. An acoustic assessment reveals potential overestimation of effective absorption areas when applying the DIN EN 12354‐6 model for reverberation time calculations. In addition to these findings, this study contributes to enhancing clarity and consistency in research dissemination related to IEQ laboratory developments.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 4","pages":"Article 100120"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050503","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":"Investigating transport of particulate matter from cooking emissions in a multi-story house using low-cost sensor measurements and different modeling approaches","authors":"Andrew B. Martin ,&nbsp;Stephen M. Zimmerman ,&nbsp;Liora E. Mael ,&nbsp;Dustin Poppendieck ,&nbsp;Delphine K. Farmer ,&nbsp;Marina E. Vance","doi":"10.1016/j.indenv.2025.100126","DOIUrl":"10.1016/j.indenv.2025.100126","url":null,"abstract":"<div><div>This work investigates the transport of fine particulate matter (PM_2.5) in a multi-story test house using cooking emissions as a point source. The test house was instrumented with 13 PM_2.5 monitors, and the particle sources included pan cooking and air frying, as well as ambient PM_2.5 penetration during periods of no indoor activity. In the absence of indoor sources, we observed about 10 % of ambient PM_2.5 concentrations penetrating indoors with a time lag of ≈ 1 h. Similar peak PM_2.5 concentrations were observed for pan frying and air frying of the same food ingredients. A cross-correlation analysis showed that it took 2–4 min for kitchen peak concentrations to reach other sensors on the first floor and about 8 min to reach the second floor. PM_2.5 concentrations were heterogeneous on the first floor, with non-kitchen areas peaking at 45 % ± 9 % of kitchen levels. Second-floor concentrations were more homogeneous, peaking at 18 % ± 2 % of kitchen levels. Using a typical occupancy scenario, the highest estimated personal PM_2.5 exposure (44 %) was experienced in the kitchen/dining area, which accounted for 9 % of the time spent at home. We used three modeling approaches to analyze particle transport throughout the house, with increasing input requirements: a multi-box model, an empirical model, and the NIST CONTAM model. All models predicted time integrated PM_2.5 concentrations on the 1st and 2nd floors, with R² between 0.57 and 0.82 and RMSE from 6 µg m⁻³ to 11 µg m⁻³.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 4","pages":"Article 100126"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221976","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":"Advancing indoor environmental quality in African countries: A call to action for awareness, research, and policy","authors":"Oluyemi Toyinbo ,&nbsp;Jacob Mensah-Attipoe ,&nbsp;Elisephane Irankunda ,&nbsp;Ibeh Gabriel Friday ,&nbsp;Abiyu Kerebo Berekute ,&nbsp;Fabiano Gibson Daud Thulu ,&nbsp;Adeshokan Muktar Olawale ,&nbsp;Miriam Byrne ,&nbsp;Kati Huttunen ,&nbsp;Tunrayo Oluwadare ,&nbsp;Lucmane Koala ,&nbsp;Jhao-Hong Chen ,&nbsp;Xiaojun Fan ,&nbsp;James Waichoka ,&nbsp;Reginald Quansah ,&nbsp;Egide Kalisa ,&nbsp;Pawel Wargocki","doi":"10.1016/j.indenv.2025.100123","DOIUrl":"10.1016/j.indenv.2025.100123","url":null,"abstract":"<div><div>Indoor Environmental Quality (IEQ), including indoor air quality (IAQ), thermal comfort, lighting, and noise, is a critical determinant of health, well-being, and productivity. However, African countries remain underrepresented in IEQ research, policy, and advocacy, despite facing unique challenges such as energy poverty, reliance on biomass fuels, inadequate building practices, poor ventilation, overheating, inadequate lighting, and pervasive noise pollution. These conditions increase health risks and compromise learning, working, and living environments.</div><div>This paper highlights the urgent need for a comprehensive approach to IEQ in Africa, addressing not only indoor air pollution but also thermal discomfort from rising temperatures, insufficient indoor lighting, and chronic exposure to harmful noise levels. It introduces the \"Promoting IEQ and IAQ in Africa\" initiative launched by the International Society of Indoor Air Quality and Climate (ISIAQ), which aims to foster research collaboration, raise awareness, support context-specific solutions, and influence policy development tailored to Africa’s diverse climates and socio-economic realities. By aligning with the United Nations Sustainable Development Goals (SDGs), this initiative advocates healthier and more sustainable indoor environments across the continent. This paper serves as a call to action for researchers, policymakers, and practitioners to work together to advance IEQ research, innovation, and advocacy for African communities.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 4","pages":"Article 100123"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097818","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":"Beyond the metrics: The discrepancy between indoor air quality benchmarks, outdoor access, and occupant satisfaction in U.S. office buildings","authors":"Elizabeth L. McCormick ,&nbsp;Traci R. Rider ,&nbsp;Jianxin Hu","doi":"10.1016/j.indenv.2025.100133","DOIUrl":"10.1016/j.indenv.2025.100133","url":null,"abstract":"<div><div>Well-filtered air, biophilic design, and outdoor terraces are increasingly provided as workplace amenities intended to foster a connection to nature within the confines of urban infrastructure. Yet this mixed-methods study of four urban office spaces in the US Southeast and mid-Atlantic (Atlanta, Charlotte, Durham, and Washington, DC) reveals a persistent disconnect between design strategies and occupant experiences. Despite meeting or exceeding industry standards for ventilation, daylight, greenery, and access to outdoor space, study participants frequently expressed feeling “trapped,” “confined,” or “stuck in a cold box” during the workday, highlighting the gap between technical compliance and sensory satisfaction. Continuous air quality monitoring confirmed that average IAQ index values ranged from 34 to 50, CO₂ levels averaged 454–557 ppm, and PM₂.₅ concentrations rarely exceeded 15 μg/m³ . Nevertheless, behavioral and perceptual data from surveys, interviews, and QR-based tracking revealed limited terrace use and a persistent desire for “fresh air,” environmental variability, and sensory richness. When terraces were used, they functioned primarily as recreational or social spaces rather than work environments, constrained by glare, noise, poor ergonomics, and a lack of supportive infrastructure. These findings demonstrate that technical benchmarks, while necessary, are insufficient to ensure well-being. Instead, more effective workplace strategies must therefore move beyond narrowly defined performance metrics to embrace environmental diversity, occupant perception, and cultivate more porous boundaries between the indoors and nature.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 4","pages":"Article 100133"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363989","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":"Semi-outdoor workspace in the tropics: Exploring thermal comfort through field measurements and surveys","authors":"Toby Cheung ,&nbsp;Kuniaki Mihara ,&nbsp;Takamasa Hasama","doi":"10.1016/j.indenv.2025.100136","DOIUrl":"10.1016/j.indenv.2025.100136","url":null,"abstract":"<div><div>This study explores the viability of a semi-outdoor workspace in Singapore designed to promote natural ventilation as a sustainable alternative to traditional air-conditioned offices. Continuous physical measurements and voluntary occupant surveys were conducted over two months during the hottest season in Singapore to assess thermal comfort performance across different environmental settings under living workplace. Under natural ventilation, despite indoor temperatures averaging 30.4 °C and relative humidity around 70 %, occupant comfort was largely maintained through elevated air speeds up to 1.0 m/s generated by ceiling fans. At high fan speed settings, occupant thermal satisfaction reached 68 % while observed only 11 % dissatisfaction rate, effectively minimizing discomfort related to excessive warmth sensation, insufficient airflow, and limited control of the environment. Compared to air-conditioning at a 28.0 °C setpoint with medium fan speed, which recorded the highest satisfaction among the air-conditioned settings, natural ventilation achieved comparable thermal satisfaction while reducing cooling energy consumption by approximately seven times. Additional energy use was recorded at 26.0 °C with fans settings, where two-fifth of occupants preferred a warmer environment, indicating potential overcooling even in tropical climates. Standard Effective Temperature (SET) analysis further identified an optimal comfort zone between 25.0 °C and 28.0 °C, supporting at least 80 % thermal acceptability across a range of environmental conditions. This longitudinal field study in living testbed provides strong evidence that well-designed semi-outdoor workspaces can achieve high occupant satisfaction and substantial energy savings, offering a promising direction for more sustainable and resilient workplace designs in the tropics.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 4","pages":"Article 100136"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571366","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":"Comparison of two methods for evaluating the performance of particle filtration systems in underground railway stations","authors":"Valisoa M. Rakotonirinjanahary ,&nbsp;Suzanne Crumeyrolle ,&nbsp;Mateusz Bogdan ,&nbsp;Benjamin Hanoune","doi":"10.1016/j.indenv.2025.100144","DOIUrl":"10.1016/j.indenv.2025.100144","url":null,"abstract":"<div><div>Filtration is one of the strategies that can be implemented to mitigate the public health challenge due to elevated concentrations of particles in underground railway stations (URS). During a particle (PM_2.5 and PM₁₀) monitoring campaign performed in a Paris URS over more than 5 years, two filtration systems were tested. One of these systems employs positive ionization (Experiment 1), the second one is based on water filtration (Experiment 2). The present study focuses on evaluating the performance of these experiments, using two distinct methods: the daily amplitude coefficient (DAC), and a generalized additive model (GAM). The DAC method requires only particulate matter measurements, while the GAM method necessitates additional measurements (indoor CO₂ concentration, temperature and humidity, outdoor pollutant concentration) as it analyses the nonlinear relationships between all these factors. The results show that both filtration technologies are more effective at reducing PM_2.5 concentrations than PM₁₀, but Experiment 2 was less efficient than Experiment 1. Specifically, DAC analysis leads to a reduction of 17.8 ± 3.2 % for PM₁₀ and 25.9 ± 6.6 % for PM_2.5 for Experiment 1, compared to only 0.4 ± 0.1 % for PM₁₀ and 3.7 ± 1.0 % for PM_2.5 for Experiment 2. GAM analysis gives similar results, with a reduction of 13.1 ± 0.8 % for PM₁₀ and 26.0 ± 0.8 % for PM_2.5 for Experiment 1, and for Experiment 2 a reduction of 1.3 ± 2.0 % for PM₁₀ and 4.6 ± 1.3 % for PM_2.5. Yet, because of differences in the filtration setups, such as the position of the modules and the maximal air flow capacity, and of unspecified internal characteristics of the systems, no conclusion can be drawn as to whether one of the filtration techniques is more efficient than the other. The two analysis methodologies lead to similar results and allow to fully and rigorously exploit long time series. The DAC method can be applied using only PM measurements, while the GAM method requires additional measurements, but at the same time provides valuable insights about the effects of each parameter considered.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 4","pages":"Article 100144"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145736267","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}