Indoor air最新文献

{"title":"Comprehensive Investigation of Airborne Benzalkonium Ion Behavior Following Nebulization: Implications for Indoor Air Quality and Health Risk Assessment","authors":"Sion Lee,&nbsp;Eunwoo Choi,&nbsp;So Yeon Lee,&nbsp;Minji Kim,&nbsp;Joo Hyon Kim,&nbsp;Han Bin Oh","doi":"10.1155/ina/3951534","DOIUrl":"https://doi.org/10.1155/ina/3951534","url":null,"abstract":"<p>The COVID-19 pandemic has intensified the use of quaternary ammonium compound (QAC) disinfectants, raising concerns about potential health effects. This study investigated the airborne behavior of benzalkonium chloride (BKC), a common QAC, sprayed at 500 ppm for 4 min in a 105 m³ space using automatic and manual methods. Airborne BKC was collected via an air pump and quantified using LC-ESI-MRM/MS. Results showed that BKC concentrations peaked during spraying but rapidly decreased thereafter, becoming negligible within 8–12 min postspraying. Cumulative capture exhibited a sigmoidal trend with time, with maximum captures of 8.21 <i>μ</i>g (front) and 1.36 <i>μ</i>g (back) for automatic spraying, and 0.14 <i>μ</i>g (front) and 0.29 <i>μ</i>g (back) for manual spraying. The “exposure to spray model” was applied to determine parameters such as airborne fraction and settling velocity. Hazard quotients (HQs) were calculated based on the maximum cumulative captures, with all values remaining below 1, indicating minimal health risks. Specifically, for the automatic sprayer, HQs were 0.856 (front) and 0.142 (rear), while for the manual sprayer, they were 0.015 (front) and 0.030 (rear). The highest HQ of 0.856, observed for automatic spraying at the front location, suggests that some caution may be warranted in this scenario. The study demonstrates that while BKC concentrations can be significant during spraying, they decrease rapidly postapplication, leading to limited exposure risks. These findings provide valuable insights into the safe use of QAC disinfectants and their impact on indoor air quality, particularly relevant in the context of increased disinfectant practices during the COVID-19 pandemic.</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2025 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/ina/3951534","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143688924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing Personal PM2.5 Exposure: A Method Leveraging Movement Routes and Activity Space Information","authors":"Shin-Young Park,&nbsp;Jaymin Kwon,&nbsp;Jeong-An Gim,&nbsp;Il-Ho Park,&nbsp;Cheol-Min Lee,&nbsp;Dae-Jin Song","doi":"10.1155/ina/2412518","DOIUrl":"https://doi.org/10.1155/ina/2412518","url":null,"abstract":"<p>Previous studies have consistently shown a significant correlation between air pollution, particularly PM_2.5, and various diseases, as well as increased mortality rates. This study introduces a novel approach for predicting time-specific indoor PM_2.5 exposure by incorporating individual movement routes and activity spaces using GPS tracking data and a time–activity diary. The models were trained separately for each hour of the day (e.g., 0:00–0:59, 1:00–1:59) with a total of 24 models. Their applicability was demonstrated with data gathered from actual participants. Additionally, automated machine learning (<i>AutoML</i>) was utilized to optimize prediction performance. The results revealed that the proposed model effectively accounted for the influence of outdoor PM_2.5 concentrations and meteorological factors. The performance varied across different indoor environments, with the subway station model showing the highest prediction accuracy. Future research should address these uncertainties, adopt more advanced modeling techniques, and consider diverse indoor variables for a comprehensive understanding. The insights from this study could significantly enhance health risk assessments associated with fine particulate matter exposure.</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2025 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/ina/2412518","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating Indoor Thermal Comfort of the Elderly During Summer in the Hot-Humid and Less-Windy Climate","authors":"Li Wang,&nbsp;Xian Yang,&nbsp;Huabin Xie,&nbsp;Qi Wang,&nbsp;Jiang He","doi":"10.1155/ina/8864602","DOIUrl":"https://doi.org/10.1155/ina/8864602","url":null,"abstract":"<p>There is still a lack of research on the evaluation of summer thermal comfort for the elderly. This study conducted a questionnaire survey and indoor thermal environment measurement in Nanning, China, with a hot-humid and less-windy climate. Six hundred elderly subjects were selected to answer the thermal sensation questionnaire in the naturally ventilated residential buildings during the summer. The analysis results of the collected data show that the neutral temperature for the local elderly is 28.0°C, and the range of operative temperature for 80% thermal acceptability is 26.4°C–29.5°C. An adaptive thermal comfort model was developed using the measured data, and its predicted thermal neutral temperature is 28.1°C, nearly equal to the measured value (28.0°C). The thermal neutral temperatures for the local male and female elderly are 27.7°C and 28.2°C, respectively, which reveals that there are gender differences in the thermal comfort. It was also found that the outdoor air temperature has a significant impact on the thermal neutral temperature, and the developed adaptive thermal comfort model can more accurately predict the indoor thermal comfort of the local elderly. The findings in this study can provide theoretical support and supporting data for the indoor thermal environment design of new old-age facilities and aging-adapted renovation of existing buildings in hot and humid climates.</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2025 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/ina/8864602","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Galician Radon Map: Determining Indoor Radon Exposure Through Census Tracts","authors":"Lucia Martin-Gisbert,&nbsp;Alberto Ruano-Ravina,&nbsp;Esther López-Vízcaíno,&nbsp;Juan Barros-Dios,&nbsp;María Piñeiro-Lamas,&nbsp;Ana Teijeiro,&nbsp;Raquel Casal-Fernández,&nbsp;Karl Kelsey,&nbsp;Guadalupe García,&nbsp;Carla Guerra-Tort,&nbsp;Leonor Varela-Lema,&nbsp;Cristina Candal-Pedreira","doi":"10.1155/ina/4176561","DOIUrl":"https://doi.org/10.1155/ina/4176561","url":null,"abstract":"<p>Indoor radon is a human lung carcinogen. The objective of this research is to describe residential radon distribution in a European region with high geogenic radon potential using cross-sectional data. This study is also aimed at describing the use of census tracts as a geographical unit in radon maps and describing radon distribution according to floor level. To do this, 6080 radon measurements were carried out by the Galician Radon Laboratory (GRL, https://www.radon.gal) with alpha track detectors located at each dwelling for at least 3 months. The dwellings measured were the primary residences of volunteer participants. All participants filled out a questionnaire on the dwelling characteristics, and a follow-up call assured the appropriate return of radon devices to the GRL. A descriptive analysis was performed, including radon concentration distribution per floor level measured and a Galician map of indoor radon using both municipalities and census tracts as geographic units was made. In Galicia, a median radon concentration of 132 Bq/m³ (interquartile range: 66–239 Bq/m³) and a geometric mean (GM) of 126 Bq/m³ were observed. Eighteen percent of dwellings exceeded 300 Bq/m³. Radon levels vary widely across and within municipalities. The latter can be observed with census tract-level maps. A height gradient for radon concentration was observed from a GM of 289 Bq/m³ in cellars to a GM of 89 Bq/m³ on the fifth floor and above. Remarkably, 14% of dwellings on the second floor exceeded 300 Bq/m³, thus challenging the paradigm that indoor radon is only a priority for underground and ground levels in radon priority areas. Galicia is mostly composed of radon priority areas, with high heterogeneity in indoor radon distribution. Census tracts can be used in indoor radon maps as the smallest geographic unit to increase resolution and acknowledge variations within municipalities. In radon priority areas, radon surveillance should include second-floor levels.</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2025 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/ina/4176561","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the Fluctuation of Indoor Thermal Conditions in Naturally Ventilated Classrooms Through K-Means Clustering","authors":"Sen Miao,&nbsp;Marta Gangolells,&nbsp;Blanca Tejedor","doi":"10.1155/ina/4453536","DOIUrl":"https://doi.org/10.1155/ina/4453536","url":null,"abstract":"<p>For naturally ventilated classrooms, windows should be constantly open to maintain good indoor air quality during class times. However, it is unknown whether this would result in significant fluctuations in the indoor thermal environment, while the effects of ventilation rate and window operation are still unclear. Therefore, this study assesses the fluctuation of indoor thermal conditions under natural ventilation during class periods, based on the <i>K</i>-means clustering and statistical analysis of data collected in a large measurement campaign in Spanish schools. The results showed that regardless of the heating mode, the indoor thermal parameters remained stable in most cases. High fluctuations were observed only in a few cases: 15% for indoor temperature, 6% for relative humidity, and 3% for indoor air velocity. The variability of the indoor thermal parameters within an hour was less than 1°C for indoor temperature, 3% for relative humidity, and 0.1 m/s for indoor air velocity. Ventilation rate and window operation were found to be related to the fluctuation of the indoor temperature and air velocity, rather than the relative humidity. These findings shed light on the thermal conditions in naturally ventilated classrooms and have practical implications for the implementation of natural ventilation protocols in schools.</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2025 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/ina/4453536","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined Intervention Removes More Aerosols From the Environment—A Quantitative Assessment","authors":"Javed Akhtar,&nbsp;Abner Luna Garcia,&nbsp;Leonardo Saenz,&nbsp;Gabe Garcia,&nbsp;Sarada Kuravi,&nbsp;Fangjun Shu,&nbsp;Krishna Kota,&nbsp;Antonio Garcia","doi":"10.1155/ina/1785997","DOIUrl":"https://doi.org/10.1155/ina/1785997","url":null,"abstract":"<p>Aerosols such as dust, pollen, smoke, soot, or viruses in our environment can significantly affect air quality, impacting climate and health. For example, virus transmission through aerosols is an important mode of spread for certain respiratory viruses, including the SARS-CoV-2 virus responsible for the COVID-19 pandemic. Numerous measures were proposed for mitigating the harmful effects of aerosol transmission on health. Though these measures are effective, they were found to have intrinsic disadvantages. Combined intervention is promising, with progress being made in combining different technologies to enhance aerosol removal and improve indoor air quality. While the combined or layered intervention was previously proposed as a rational measure to overcome some of the disadvantages associated with individual approaches, there is a lack of availability of quantitative experimental data for at least some of the many possible combinations from the viewpoint of the number of aerosol particles removed from the surrounding environment. This study assesses the efficacy of one possible layered approach on aerosol removal. Particle flow visualization was employed to quantitatively investigate the combined effect of two measures—filtration and air ionization—on aerosol removal. The results of particle counting showed that for the experimental configuration studied, the combined intervention had a synergistic effect and removed 15%–85% more aerosol particles from the environment compared to a single intervention (filtration) in the same duration. It is observed that combined approaches demonstrate the potential to address the disadvantages of the constituent approaches; for example, in this case, effective aerosol removal was shown to be a possibility even with a medium-quality filter (which is economical and accessible) and a weak ionizer (with low ozone generation).</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2025 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/ina/1785997","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Assessment of Thermal and Visual Comfort in Immersive Virtual Environments Based on Varied Activity Intensity: A Pilot Experimental Study","authors":"Victor Adetunji Arowoiya,&nbsp;Robert Christian Moehler,&nbsp;Yihai Fang","doi":"10.1155/ina/2258335","DOIUrl":"https://doi.org/10.1155/ina/2258335","url":null,"abstract":"<p>Activity levels are crucial in thermal comfort (TC) studies, and specific activities determine the choice of visuals in building design for users. This research presents a pilot study for the experimental design to assess comparability between visual scenarios and TC in controlled settings under different activity intensities for an immersive virtual environment (IVE) while sampling unregulated environments. This experimental design compares two distinct metabolic activity intensities, comparing observations between unregulated and virtual thermal controlled environments. Observations were conducted in Monash University Makerspace, an unregulated environment, to understand users’ thermal and visual perceptions based on activity intensities, clothing levels, and lighting. The observations in a controlled setting were carried out in the simulated IVE where participants were exposed to 18°C, 24°C, and 30°C with cool white light simulation. Data were analyzed using interval plots and linear regression which indicates higher thermal sensations, discomfort, and heat when carrying out high-intensity activity for the same clothing level. In comparison, in the controlled setting, the same behavioral intention selected in the IVE applied to the unregulated environment. Previous studies have not explored whether TC aligns in virtual reality (VR) for different activity intensities, especially for high-intensity activity. Also, there is a need to understand how thermal and visual comfort is influenced by visual scenarios under varied activity intensity and thermal condition changes. A feasibility study using VR for low-intensity activity in a controlled climate shows changes in visual perception during different thermal conditions. The study contributes to understanding the feasibility of the experimental design of VR for the TC changes’ observations based on two activities.</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2025 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/ina/2258335","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143564847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental Mold Management in Negative-Pressure Isolation Wards During the COVID-19 Pandemic: A Potential Indicator of COVID-19-Associated Pulmonary Aspergillosis","authors":"Jin Yeong Hong,&nbsp;Jae-Hoon Ko,&nbsp;Jinyoung Yang,&nbsp;Kyungmin Huh,&nbsp;Sun Young Cho,&nbsp;Cheol-In Kang,&nbsp;Kyong Ran Peck,&nbsp;Tae Yeul Kim,&nbsp;Hee Jae Huh,&nbsp;Nam Yong Lee,&nbsp;Doo Ryeon Chung","doi":"10.1155/ina/8961340","DOIUrl":"https://doi.org/10.1155/ina/8961340","url":null,"abstract":"<p>High concentration of mold spores in inhaled air is an important risk factor for invasive mold infections. COVID-19 (coronavirus disease 2019)-associated pulmonary aspergillosis (CAPA) is a serious complication of severe COVID-19. To investigate the mold distribution in negative-pressure isolation wards and its potential association with CAPA incidence, we conducted microbiological air sampling and retrospectively analyzed CAPA cases in a tertiary care hospital in Korea during the COVID-19 pandemic. Air sampling was conducted in January 2022 at multiple sites in four negative-pressure isolation wards designated for managing severe COVID-19 patients. A portable microbial air sampler (MAS-100 NT) was used for air sampling, and Tryptic Soy Agar plates were incubated to identify mold isolates at the genus level. CAPA cases (January 2021–June 2023) were defined by antifungal treatment, mycological evidence (serum galactomannan index &gt; 0.5), and radiological findings. Immunomodulator use, including dexamethasone and tocilizumab, was analyzed to identify clinical risk factors influencing CAPA incidence. Among the isolated molds, <i>Aspergillus</i> (86.7%) was the most prevalent, followed by <i>Penicillium</i> (53.3%), <i>Mucorales</i> (20%), and <i>Paecilomyces</i> (13.3%). Mold concentrations were highest in areas adjacent to a construction site. Intervention procedures, including installing air purifiers and reinforcing seals between the adjoining construction site and isolation ward, effectively reduced mold concentrations and paralleled a decline in CAPA incidence. While increased foot traffic after the relaxation of COVID-19 restriction measures led to a rise in spore concentration, the incidence of CAPA did not increase, likely due to the decreased use of immunomodulators such as corticosteroids and tocilizumab. Construction-related mold spore increases can be mitigated with appropriate interventions, and pedestrian traffic near isolation wards may need regulation. Monitoring and mitigating environmental mold contamination are crucial to preventing opportunistic respiratory mold infections in negative-pressure isolation wards and should be interpreted in conjunction with clinical risk factors.</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2025 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/ina/8961340","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143554840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of Air Curtain Control Efficacy in Preventing Contaminant Transmission in Cleanrooms","authors":"Junzhou He,&nbsp;Hongtao Xu,&nbsp;Mingrui Cao,&nbsp;Qianshun Liang,&nbsp;Saichong Zhang,&nbsp;Miao Yu,&nbsp;Haiyang Liu,&nbsp;Zhijian Liu,&nbsp;Jingwei Liu","doi":"10.1155/ina/8831086","DOIUrl":"https://doi.org/10.1155/ina/8831086","url":null,"abstract":"<p>Maintaining high air cleanliness in cleanrooms is crucial in manufacturing processes and scientific research. However, personnel movement can breach the sealed environment, allowing contaminant to enter cleanrooms due to disturbance created. Air curtains are a traditional solution to limit air exchange, but their control efficacy in preventing contaminant transmission into cleanrooms requires careful evaluation. In this study, factors influencing the air curtain control efficacy such as the air curtain’s supply area, personnel movement speed, and temperature difference were evaluated using computational fluid dynamics with dynamic grid technology. The results indicated that increasing the air curtain’s supply area reduced contaminant concentration in cleanrooms; however, the effectiveness in blocking contaminant transport did not improve beyond a certain supply area (0.4 m²). High personnel movement increased contaminant influx, and maintaining a low speed (0.25 m/s) significantly reduced the overall influx. As the personnel movement speed increased from 0.25 to 1.50 m/s, the total amount of contaminant increased from 2.5 × 10⁻⁸ to 7 × 10⁻⁷ kg/s. When the temperature difference decreased from 7°C to 1°C, the average dimensionless concentration of contaminant in cleanrooms after personnel movement decreased from 8.5 × 10⁻³ to 1 × 10⁻⁴. Generally, air curtains perform well but require precise design. On the basis of these findings, future research can further complement overlooked factors and enable more detailed design and control, thereby improving the efficiency and sustainability of cleanroom design and control strategies.</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2025 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/ina/8831086","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of SARS-CoV-2 Virions and RNA in Aerosols From COVID-19 Environments","authors":"Consuelo Ferrer,&nbsp;Noelia Gómez-Sánchez,&nbsp;Jaime López-Botella,&nbsp;Violeta Esteban,&nbsp;Paloma Ruíz,&nbsp;Eduardo Yubero,&nbsp;Javier Crespo,&nbsp;Eusebi Chiner,&nbsp;María Francisca Colom","doi":"10.1155/ina/8861794","DOIUrl":"https://doi.org/10.1155/ina/8861794","url":null,"abstract":"<p><b>Background:</b> Characterizing aerosols produced by SARS-CoV-2 patients is crucial for understanding disease transmission. The appearance and dispersal patterns of SARS-CoV-2 viral particles in airborne samples are not yet well understood. Knowing what SARS-CoV-2 particles look like just before they pass from one person to another can provide valuable insights into the mechanism of viral transmission through the air.</p><p><b>Methods:</b> Samples from the upper respiratory tract and environmental aerosols were collected from 39 SARS-CoV-2–positive patients at different stages of symptom onset and from two distances from the source: 1 and 2 m. In addition, two nasopharyngeal samples from non-COVID-19 patients and aerosol samples from empty rooms and rooms of healthy individuals were taken as controls. Samples were analyzed by RT-PCR to detect viral RNA and by field emission scanning electron microscopy (FESEM) to visualize viral particles. Part of the nasopharyngeal and aerosol samples was studied by immunoelectron microscopy using nanogold particles against the spike protein to confirm the specific of the method.</p><p><b>Results:</b> SARS-CoV-2 RNA was detected in 59.18% of aerosols from the environments of COVID-19 patients, with no significant differences based on distance. Higher detection rates were noted when the patient’s viral load was Ct ≤ 25. Intact viral particles were observed in nasopharyngeal samples from asymptomatic patients or those early progression of disease, either as free or clumped particles with well-defined spikes. In contrast, symptomatic patients had particles in mucus without visible spikes. Virus-like particles were visualized in aerosol samples at both distances.</p><p><b>Conclusion:</b> Virions from asymptomatic patients or those in the early stages of the disease exhibited a better-conserved appearance in nasopharyngeal samples. Although RNA and virions of SARS-CoV-2 were detected in aerosol samples collected up to 2 m away from patients, only virion components, rather than complete virions, were observed. To our knowledge, this is the first report showing the appearance of three-dimensional SARS-CoV-2 particles in nasopharyngeal and air samples.</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2025 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/ina/8861794","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}