Indoor Environments最新文献

{"title":"CO2 levels and SARS-CoV-2 transmission in public schools: A retrospective cohort study in Montreal (Canada)","authors":"Olivier Séguin ,&nbsp;Dorra Ghorbal ,&nbsp;Gabrielle Denault ,&nbsp;Karine Trudeau ,&nbsp;Patrick Poulin ,&nbsp;Catherine Dea ,&nbsp;Stéphane Perron","doi":"10.1016/j.indenv.2025.100077","DOIUrl":"10.1016/j.indenv.2025.100077","url":null,"abstract":"<div><div>Scientific evidence suggests that SARS-CoV-2 is transmitted primarily through close contact with susceptible individuals and that the risk of transmission increases during prolonged exposure in confined, inadequately ventilated and densely occupied spaces. In response to concerns related to inadequate ventilation for students and staff, CO₂ concentrations were measured in all of Montreal’s public elementary and high schools during winter of 2020–21. This study aims to evaluate the associations between ventilation system types, mid-class CO₂ concentrations and SARS-CoV-2 transmission amongst Montreal's public school’s attendees during the 2020–2021 school year. Data on building ventilation types, CO₂ measurements and school characteristics such as total enrollment and socioeconomic status (SES), were sourced from Ministry of Education’s administrative data for the 2020–2021 school year. During this pandemic period, the Montreal Public Health Department investigated COVID-19 cases among students and staff in public elementary and high schools, gradually developing a regional database of school cases and outbreaks from intervention files. Negative binomial regression models were employed to examine associations between mid-class CO₂ concentrations and COVID-19 incidence rates for both total cases and those acquired within schools. Regression models were adjusted for school types, neighborhood COVID-19 incidence rates and school SES. The mid-class CO₂ concentration<del>s</del> median was 1050 ppm in the 384 school buildings. CO₂ concentrations were associated with ventilation systems, with schools using natural ventilation exhibiting higher concentrations compared to three other types of mechanical ventilation. No positive association was observed between the incidence rates of school-acquired cases and higher mid-class CO₂ concentrations in both unadjusted and adjusted models.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 1","pages":"Article 100077"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Demonstration of a novel tracer gas method to investigate indoor air mixing and movement","authors":"Chai Yoon Um ,&nbsp;William W. Delp ,&nbsp;Rowan C. Blacklock ,&nbsp;Brett C. Singer","doi":"10.1016/j.indenv.2025.100081","DOIUrl":"10.1016/j.indenv.2025.100081","url":null,"abstract":"<div><div>This paper reports on equipment and procedures that enable the application of the pulsed tracer method to study air movement, contaminant transport, and mixing in rooms. We use ethanol as a non-toxic tracer and a network of low-cost, fast response (2 s) metal oxide sensors to measure airborne concentrations at high frequency. The method was demonstrated in a 158 m³ room of the FLEXLAB facility at Lawrence Berkeley National Laboratory, with an overhead HVAC system with controllable supply airflow and temperature. The room was configured as a meeting space with 8 simulated occupants. The sensors were mounted in a 3 × 4 grid in the upper room (0.3 m from the 2.74 m ceiling), in the middle height of the room at 1.1–1.4 m, and at several locations 0.1–0.4 m from the floor. Vaporized ethanol was released in pulses of 20 s. Sensors were cross-calibrated in-situ to provide quantitative information about relative concentrations and exposures. Results show that the method provides quantitative information about air movement patterns and mixing. For example, mixing throughout the room took 3–4 min with high supply airflow at neutral temperature and 7.5–9 min with heated supply air provided at a lower rate. The test can be used to evaluate whether air movement from the occupied zone to the upper room is fast enough to achieve the extremely high air cleaning rates that are possible with upper room germicidal ultraviolet disinfection (GUV) systems under ideal mixing conditions.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 1","pages":"Article 100081"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymmetries in global building envelope air infiltration and tightness data: Exploring knowledge gaps for accurate energy analyses","authors":"Rana Raafat ,&nbsp;Sherif Goubran ,&nbsp;Nahla N. Makhlouf ,&nbsp;Mohsen Aboulnaga","doi":"10.1016/j.indenv.2024.100071","DOIUrl":"10.1016/j.indenv.2024.100071","url":null,"abstract":"<div><div>Air infiltration is one of the leading causes of energy loss and heat gain in indoor building spaces. It significantly burdens energy use for heating and cooling, affects indoor comfort and air quality, and increases CO2 emissions, intensifying climate change. While extensive field test results have been reported in the literature, this paper aims to investigate the comprehensiveness of this published data. The research synthesizes published field test data from more than 60 sources to provide benchmark infiltration values for different building typologies, construction methods, and climate zones. Additionally, climate data estimates the average energy burden of infiltration across various climate zones. The analysis highlights critical gaps in envelope infiltration data collection for non-residential buildings and significant gaps in geographic regions outside Europe, the U.S.A., and Canada. This paper presents three main guiding questions addressing key research gaps related to air infiltration in buildings and its impact on energy performance and indoor comfort. The proposed questions and answers aim to build upon existing knowledge, provide valuable insights for ongoing and future research, and inspire exploration into innovative strategies for improving building energy efficiency and occupant well-being. It also provides a list of actionable recommendations for air infiltration testing and research to address the now-apparent gaps.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 1","pages":"Article 100071"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exposure of children and adolescents to volatile organic compounds in indoor air: Results from the German Environmental Survey 2014–2017 (GerES V)","authors":"Annika Fernandez Lahore ,&nbsp;Robert Bethke ,&nbsp;Anja Daniels ,&nbsp;Konrad Neumann ,&nbsp;Stefan Ackermann ,&nbsp;Nadine Schechner ,&nbsp;Klaus-Reinhardt Brenske ,&nbsp;Enrico Rucic ,&nbsp;Aline Murawski ,&nbsp;Marike Kolossa-Gehring ,&nbsp;Wolfram Birmili","doi":"10.1016/j.indenv.2025.100082","DOIUrl":"10.1016/j.indenv.2025.100082","url":null,"abstract":"<div><div>Indoor air concentrations of volatile organic compounds (VOC) were determined in the living environments of German children and adolescents between 2014 and 2017 during the German Environmental Survey (GerES) V. Passive sampling on Tenax TA tubes over 7 days and subsequent thermodesorption/gas chromatographic analysis yielded concentrations of 61 compounds from the groups of alcohols, alkanes, aromatics, carboxylic acid esters, glycol ethers, halogenated hydrocarbons, siloxanes, and terpenes as well as a value for total VOC (TVOC). The most abundant single compounds were decamethylcyclopentasiloxane (D5), limonene, α-pinene, butyl acetate, toluene, and 2-ethylhexanol, with geometric mean concentrations ranging between 12 and 4.5 µg/m³ . The guideline values established by the German Committee on Indoor Guidance Values (AIR) were exceeded in less than 1.3 % of participants when considered as a sum parameter for cyclic dimethylsiloxanes, monocyclic monoterpenes, bicyclic terpenes, C9-C14 alkanes, and xylenes. The concentrations of most compounds were lower in GerES V (2014/17) compared to the previous cycle GerES IV (2003/06). The concentrations of individual compounds showed moderate associations with exposure factors as identified from questionnaire data including the socio-economic status of the household, migration background, smoking status, the presence of wooden furniture, renovations in the test room, the age of the house, outdoor pollution (proximity to road traffic), as well as the age and sex of the participants.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 1","pages":"Article 100082"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Ventilation characteristics in a hospital where a COVID-19 outbreak occurred in the winter of 2020” [Indoor Environ. 2 (2025) 100065]","authors":"Motoya Hayashi ,&nbsp;Sayaka Murata ,&nbsp;Koki Kikuta","doi":"10.1016/j.indenv.2025.100076","DOIUrl":"10.1016/j.indenv.2025.100076","url":null,"abstract":"","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 1","pages":"Article 100076"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cyclone negative pressure pump for efficient purification of airborne contaminants","authors":"Gihyun Song ,&nbsp;Kyungcheol Jang ,&nbsp;Woobin Song ,&nbsp;Wonchul Choi ,&nbsp;Simon Song ,&nbsp;Hyoungsoo Kim","doi":"10.1016/j.indenv.2025.100073","DOIUrl":"10.1016/j.indenv.2025.100073","url":null,"abstract":"<div><div>Maintaining an isolation room with negative pressure is crucial in medical facilities to prevent the spread of airborne infections, especially during the COVID-19 pandemic. However, conventional negative pressure pumps have limitations in gathering suspended particles and controlling the airflow effectively. To resolve this issue, we developed a novel class of negative pressure pump that creates a swirling cyclone flow at the front to efficiently collect pollutants and particles, which was confirmed by a smoke visualization experiment. Based on the prototype pump, we conducted a numerical analysis to evaluate the particle collection performance of the cyclone pump in various scenarios, including patients covered with contaminants, and coughing or breathing. Our results demonstrate that the cyclone pump can purify airborne pollutants by up to 80%, offering superior performance over conventional pumps. We also identified optimal pump placement for effective particle purification. This research provides an innovative solution for improving the efficiency of negative pressure pumps and ventilation systems in medical settings, contributing to better control of airborne infections.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 1","pages":"Article 100073"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Quantitative Microbial Risk Assessment (QMRA) framework for exposure from toilet flushing using experimental aerosol concentration measurements","authors":"Ciara A. Higham ,&nbsp;Martín López-García ,&nbsp;Catherine J. Noakes ,&nbsp;Emma Tidswell ,&nbsp;Louise Fletcher","doi":"10.1016/j.indenv.2024.100069","DOIUrl":"10.1016/j.indenv.2024.100069","url":null,"abstract":"<div><h3>Background</h3><div>Flushing a toilet generates aerosols potentially containing microorganisms, serving as a transmission route for pathogens, notably gastrointestinal and respiratory infections. Despite identification of aerosols and positive microbial sampling, there is a lack of quantitative assessments linking aerosol generation to infection risk in toilet settings.</div></div><div><h3>Methods</h3><div>We develop a framework to evaluate the infection risk to a second susceptible individual using a shared toilet following faecal shedding and flush aerosolisation by an infected individual. Experimental measurements of particle concentrations from a toilet flush in a controlled chamber are combined with a model using Quantitative Microbial Risk Assessment (QMRA) methods. We demonstrate the approach for SARS-CoV-2 and norovirus, examining model sensitivity and how adding cubicle space and varying occupancy times affect risk.</div></div><div><h3>Results</h3><div>The model suggests non-negligible infection risk from the toilet plume, particularly for pathogens with higher concentrations in faeces. The model suggests norovirus could have a 2 times greater maximum infection risk than SARS-CoV-2. Mean and median risks for all scenarios decreased when the second individual entered 60 s post-flush compared to 0 s. Occupancy times had less impact on risk compared to the timing of entry post-flush.</div></div><div><h3>Conclusion</h3><div>To mitigate infection risk from shared toilets, ventilating the room before entering is crucial. Allowing time between toilet usages may be more effective compared to reducing occupancy times. Models provide valuable insights into relative impacts of measures and comparison between pathogens, but improved quantitative data is needed, particularly in higher risk scenarios (e.g. hospitals, public events), to quantify absolute risks.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 1","pages":"Article 100069"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cognition, economic decision-making, and physiological response to carbon dioxide","authors":"Stefan Flagner ,&nbsp;Thomas Meissner ,&nbsp;Steffen Künn ,&nbsp;Piet Eichholtz ,&nbsp;Nils Kok ,&nbsp;Rick Kramer ,&nbsp;Wouter van Marken-Lichtenbelt ,&nbsp;Cynthia Ly ,&nbsp;Guy Plasqui","doi":"10.1016/j.indenv.2025.100074","DOIUrl":"10.1016/j.indenv.2025.100074","url":null,"abstract":"<div><div>This study examines the isolated effect of carbon dioxide on cognition, economic decision-making, and the physiological response in healthy adults. The experiment took place in an air-tight respiration chamber controlling the environmental conditions. In a single-blind, within-subject study design, 20 healthy participants were exposed to artificially induced carbon dioxide concentrations of 3,000 ppm and 900 ppm in randomized order, with each exposure lasting for 8 h. A high ventilation rate and an air pollutant filter were used to keep concentrations of volatile organic compounds and fine particles equally low in both conditions. Cognition tests were conducted twice during the 8 h and physiological parameters were measured continuously over the 8 h. No evidence on a robust statistically significant effect of carbon dioxide on either cognitive or physiological outcome variables were found. These findings imply that the human body is able to deal with exposure to indoor carbon dioxide concentration of 3,000 ppm for a limited time without suffering significant cognitive decline, changes in decision-making or showing any physiological response.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 1","pages":"Article 100074"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Towards equitable and sustainable indoor air quality guidelines – A perspective on mandating indoor air quality for public buildings” [Indoor Environ. 2 1 (2025) 100070]","authors":"Ulla Haverinen-Shaughnessy ,&nbsp;Marzenna R. Dudzinska ,&nbsp;Samy Clinchard ,&nbsp;Sani Dimitroulopoulou ,&nbsp;Xiaojun Fan ,&nbsp;Piet Jacobs ,&nbsp;Henna Maula ,&nbsp;Amelia Staszowska ,&nbsp;Oluyemi Toyinbo ,&nbsp;Ju-Hyeong Park","doi":"10.1016/j.indenv.2025.100075","DOIUrl":"10.1016/j.indenv.2025.100075","url":null,"abstract":"","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 1","pages":"Article 100075"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ventilation characteristics in a hospital where a COVID-19 outbreak occurred in the winter of 2020","authors":"Motoya. Hayashi,&nbsp;Sayaka. Murata,&nbsp;Koki. Kikuta","doi":"10.1016/j.indenv.2024.100065","DOIUrl":"10.1016/j.indenv.2024.100065","url":null,"abstract":"<div><div>To clear the influences of ventilation performance on COVID-19 outbreaks in hospitals, the ventilation characteristics were investigated in a ward of an over-30-year-old hospital where a large outbreak occurred in the winter of 2020. At the early stage of the outbreak, nasal high-flow (NHF) was used in a treatment room for a week, and many patients stayed in multi-bed rooms during the outbreak. The viruses could expand not only with the infected staff or patients but also with the virus-contained air. To make an emergent ventilation measure plan, which the hospital requested, the actual performance of the air-conditioning and ventilation system and the ventilation characteristics were investigated using airflow volume meters, smoke testers, and a tracer gas CO₂. The results of the measurements and the analysis showed the following. The ventilation rates had decreased to 30 % of the design value in the ward. The ventilation rate was decreased to 10 % in the treatment room where NHF was used, and the ventilation rates were decreased to 4–31 % in the rooms with six beds. The room doors were usually opened, and the opening had the effect of increasing the ventilation rate of the room. However, the virus-contained air could expand to the corridor and the other spaces. The air supply is stopped to keep room temperature at night, and the ventilation is thought to be very poor, especially if the doors are closed. Inadequate ventilation in the old buildings may have affected the hospital outbreak cases. It is essential to check the ventilation characteristics regularly, especially in old buildings. The result contributed to the administrative notice “The Emergent Ventilation Measures to Control COVID-19 in Hospitals” in April 2021 in Japan.</div></div>","PeriodicalId":100665,"journal":{"name":"Indoor Environments","volume":"2 1","pages":"Article 100065"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}