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Baroody FM, Gevaert P, Smith PK, Ziaie N, Bernstein JA. Nonallergic Rhinopathy: A Comprehensive Review of Classification, Diagnosis, and Treatment. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2024; 12:1436-1447. [PMID: 38467330 DOI: 10.1016/j.jaip.2024.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 02/29/2024] [Accepted: 03/04/2024] [Indexed: 03/13/2024]
Abstract
Chronic nonallergic rhinitis syndromes encompass various conditions, of which vasomotor rhinitis is the most common form, representing approximately 80% of patients, also referred to as nonallergic rhinopathy (NAR), nasal hyperreactivity, neurogenic rhinitis, or idiopathic rhinitis. Expert panels have recommended replacing vasomotor rhinitis terminology because it is more descriptive of this condition that is characterized by symptoms triggered by chemical irritants and weather changes through chemosensors, mechanosensors, thermosensors, and/or osmosensors activated through different transient receptor potential calcium ion channels. Elucidating the specific role of transient receptor potential vanilloid 1, triggered by capsaicin, has been an important advancement in better understanding the pathophysiology of NAR because it has now been shown that downregulation of transient receptor potential vanilloid 1 receptors by several therapeutic compounds provides symptomatic relief for this condition. The classification of NAR is further complicated by its association with allergic rhinitis referred to as mixed rhinitis, which involves both immunoglobulin E-mediated and neurogenic mechanistic pathways. Comorbidities associated with NAR, including rhinosinusitis, headaches, asthma, chronic cough, and sleep disturbances, underscore the need for comprehensive management. Treatment options for NAR include environmental interventions, pharmacotherapy, and in refractory cases, surgical options, emphasizing the need for a tailored approach for each patient. Thus, it is extremely important to accurately diagnose NAR because inappropriate therapies lead to poor clinical outcomes and unnecessary health care and economic burdens for these patients. This review provides a comprehensive overview of NAR subtypes, focusing on classification, diagnosis, and treatment approaches for NAR.
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Affiliation(s)
- Fuad M Baroody
- Section of Otolaryngology-Head and Neck Surgery, University of Chicago Medicine, Chicago, Ill
| | - Philippe Gevaert
- Upper Airways Research Laboratory, Department of Head and Skin, Ghent University, Ghent, Belgium
| | - Peter K Smith
- Department of Surgery-Otolaryngology-Head and Neck, School of Medicine, Griffith University, Southport, Queensland, Australia
| | - Navid Ziaie
- Department of Internal Medicine, Division of Rheumatology, Allergy and Immunology, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Jonathan A Bernstein
- Department of Internal Medicine, Division of Rheumatology, Allergy and Immunology, University of Cincinnati College of Medicine, Cincinnati, Ohio.
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Banholzer N, Jent P, Bittel P, Zürcher K, Furrer L, Bertschinger S, Weingartner E, Ramette A, Egger M, Hascher T, Fenner L. Air Cleaners and Respiratory Infections in Schools: A Modeling Study Based on Epidemiologic, Environmental, and Molecular Data. Open Forum Infect Dis 2024; 11:ofae169. [PMID: 38665173 PMCID: PMC11045022 DOI: 10.1093/ofid/ofae169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 03/19/2024] [Indexed: 04/28/2024] Open
Abstract
Background Using a multiple-measurement approach, we examined the real-world effectiveness of portable HEPA air filtration devices (air cleaners) in a school setting. Methods We collected data over 7 weeks during winter 2022/2023 in 2 Swiss secondary school classes: environmental (CO2, particle concentrations), epidemiologic (absences related to respiratory infections), audio (coughing), and molecular (bioaerosol and saliva samples). Using a crossover design, we compared particle concentrations, coughing, and risk of infection with and without air cleaners. Results All 38 students participated (age, 13-15 years). With air cleaners, mean particle concentration decreased by 77% (95% credible interval, 63%-86%). There were no differences in CO2 levels. Absences related to respiratory infections were 22 without air cleaners vs 13 with them. Bayesian modeling suggested a reduced risk of infection, with a posterior probability of 91% and a relative risk of 0.73 (95% credible interval, 0.44-1.18). Coughing also tended to be less frequent (posterior probability, 93%), indicating that fewer symptomatic students were in class. Molecular analysis detected mainly non-SARS-CoV-2 viruses in saliva (50/448 positive) but not in bioaerosols (2/105) or on the HEPA filters of the air cleaners (4/160). The molecular detection rate in saliva was similar with and without air cleaners. Spatiotemporal analysis of positive saliva samples identified several likely transmissions. Conclusions Air cleaners improved air quality and showed potential benefits in reducing respiratory infections. Airborne detection of non-SARS-CoV-2 viruses was rare, suggesting that these viruses may be more difficult to detect in the air. Future studies should examine the importance of close contact and long-range transmission and the cost-effectiveness of using air cleaners.
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Affiliation(s)
- Nicolas Banholzer
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Philipp Jent
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Department of Infectious Diseases, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Pascal Bittel
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Kathrin Zürcher
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Lavinia Furrer
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Simon Bertschinger
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Ernest Weingartner
- Institute for Sensors and Electronics, University of Applied Sciences and Arts Northwestern Switzerland, Windisch, Switzerland
| | - Alban Ramette
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Matthias Egger
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Population Health Sciences, University of Bristol, Bristol, UK
- Centre for Infectious Disease Epidemiology and Research, University of Cape Town, Cape Town, South Africa
| | - Tina Hascher
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Institute of Educational Science, University of Bern, Bern, Switzerland
| | - Lukas Fenner
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
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Ebrahimifakhar A, Poursadegh M, Hu Y, Yuill DP, Luo Y. A systematic review and meta-analysis of field studies of portable air cleaners: Performance, user behavior, and by-product emissions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168786. [PMID: 38008326 DOI: 10.1016/j.scitotenv.2023.168786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/08/2023] [Accepted: 11/20/2023] [Indexed: 11/28/2023]
Abstract
Indoor air quality is important for the health of building occupants, and public interest in controlling indoor airborne pathogens increased dramatically with the COVID-19 pandemic. Pollutant concentrations can be controlled locally using portable air cleaners (sometimes called air purifiers), which allow occupants to apply air cleaning technology to meet their needs in the location and times that they find appropriate. This paper provides a systematic review of scientific literature that describes field studies of the effectiveness of portable air cleaners. Over 500 papers were considered, and 148 were reviewed in detail, to extract 35 specific research results (e.g., particulate removal performance) or characteristics (e.g., type of building). These were aggregated to provide an overview of results and approaches to this type of research, and to provide meta-analyses of the results. The review includes: descriptions of the geographical location of the research; rate of publications over time; types of buildings and occupants in the field study; types of air cleaner technology being tested; pollutants being measured; resulting pollutant removal effectiveness; patterns of usage and potential barriers to usage by occupants; and the potential for by-product emissions in some air cleaner technologies. An example result is that 83 of the 148 papers measured reductions in fine particulates (PM2.5) and found a mean reduction of 49 % with standard deviation of 20 %. The aggregated results were approximately normally distributed, ranging from finding no significant reduction up to a maximum above 90 % reduction. Sixteen of the 148 papers considered gaseous pollutants, such as volatile organic compounds, nitrogen dioxide, and ozone; 36 papers considered biological pollutants, such as bacteria, viruses, pollen, fungi, etc. An important challenge, common to several studies, is that occupants run the air cleaners for shorter periods and on low airflow rate settings, because of concerns about noise, drafts, and electricity cost, which significantly reduces air cleaning effectiveness.
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Affiliation(s)
- Amir Ebrahimifakhar
- Delos Labs, Delos, New York, NY 10014, USA; Durham School of Architectural Engineering and Construction, University of Nebraska - Lincoln, 1110 S. 67th Street, Omaha, NE 68182, USA.
| | - Mehrdad Poursadegh
- Durham School of Architectural Engineering and Construction, University of Nebraska - Lincoln, 1110 S. 67th Street, Omaha, NE 68182, USA.
| | - Yifeng Hu
- Durham School of Architectural Engineering and Construction, University of Nebraska - Lincoln, 1110 S. 67th Street, Omaha, NE 68182, USA; Buildings and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
| | - David P Yuill
- Durham School of Architectural Engineering and Construction, University of Nebraska - Lincoln, 1110 S. 67th Street, Omaha, NE 68182, USA.
| | - Yu Luo
- Department of Applied Physics and Applied Mathematics, Columbia University, 500 W. 120th Street, New York, NY 10027, USA.
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Zhang R, Liu F, Wang L, Wu Z, Fan L, Liu B, Shang H. Dust-phase phthalates in university dormitories in Beijing, China: pollution characteristics, potential sources, and non-dietary oral exposure. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2024:1-19. [PMID: 38339769 DOI: 10.1080/09603123.2024.2313184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 01/27/2024] [Indexed: 02/12/2024]
Abstract
This study aimed to determine dust-phase phthalate levels in 112 dormitories of 14 universities during autumn and winter, investigate their potential sources, and estimate phthalate exposure via dust ingestion. Twelve phthalates were detected, among which di-(2-ethylhexyl) phthalate (DEHP) and dicyclohexyl phthalate (DCHP) were the most abundant, followed by di-isobutyl phthalate (DiBP) and di-n-butyl phthalate (DnBP). The median concentrations and contributions of DCHP and DEHP were the highest. The contributions of di-n-octyl phthalate and di-nonyl phthalate were higher in winter than in autumn. Potential sources included iron furniture, chemical fiber textiles, clothes, and personal care products. Medium-density fiberboard furniture is a potential sink for phthalates. In two seasons, DEHP, DCHP, DiBP, and DnBP were the main phthalates ingested by college students . The median oral exposure of ten phthalates was higher in females than in males. College students have a high risk of exposure to DEHP in dormitories.
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Affiliation(s)
- Ruixin Zhang
- School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, China
| | - Fang Liu
- School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, China
| | - Lixin Wang
- School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, China
| | - Zaixing Wu
- School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, China
| | - Liujia Fan
- School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, China
| | - Bing Liu
- Beijing Boxgo Technology Co, Ltd, Beijing, China
| | - Hong Shang
- Beijing Boxgo Technology Co, Ltd, Beijing, China
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Banholzer N, Jent P, Bittel P, Zürcher K, Furrer L, Bertschinger S, Weingartner E, Ramette A, Egger M, Hascher T, Fenner L. Air cleaners and respiratory infections in schools: A modeling study using epidemiological, environmental, and molecular data. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.12.29.23300635. [PMID: 38234723 PMCID: PMC10793541 DOI: 10.1101/2023.12.29.23300635] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Background Using a multiple-measurement approach, we examined the real-world effectiveness of portable HEPA-air filtration devices (air cleaners) in a school setting. Methods We collected environmental (CO2, particle concentrations), epidemiological (absences related to respiratory infections), audio (coughing), and molecular data (bioaerosol and saliva samples) over seven weeks during winter 2022/2023 in two Swiss secondary school classes. Using a cross-over study design, we compared particle concentrations, coughing, and the risk of infection with vs without air cleaners. Results All 38 students (age 13-15 years) participated. With air cleaners, mean particle concentration decreased by 77% (95% credible interval 63%-86%). There were no differences in CO2 levels. Absences related to respiratory infections were 22 without vs 13 with air cleaners. Bayesian modeling suggested a reduced risk of infection, with a posterior probability of 91% and a relative risk of 0.73 (95% credible interval 0.44-1.18). Coughing also tended to be less frequent (posterior probability 93%). Molecular analysis detected mainly non-SARS-CoV-2 viruses in saliva (50/448 positive), but not in bioaerosols (2/105 positive) or HEPA-filters (4/160). The detection rate was similar with vs without air cleaners. Spatiotemporal analysis of positive saliva samples identified several likely transmissions. Conclusions Air cleaners improved air quality, showed a potential benefit in reducing respiratory infections, and were associated with less coughing. Airborne detection of non-SARS-CoV-2 viruses was rare, suggesting that these viruses may be more difficult to detect in the air. Future studies should examine the importance of close contact and long-range transmission, and the cost-effectiveness of using air cleaners.
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Affiliation(s)
- Nicolas Banholzer
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Philipp Jent
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Department of Infectious Diseases, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Pascal Bittel
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Kathrin Zürcher
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Lavinia Furrer
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Simon Bertschinger
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Ernest Weingartner
- Institute for Sensors and Electronics, University of Applied Sciences and Arts Northwestern Switzerland, Windisch, Switzerland
| | - Alban Ramette
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Matthias Egger
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Population Health Sciences, University of Bristol, Bristol, UK
- Centre for Infectious Disease Epidemiology and Research, University of Cape Town, Cape Town, South Africa
| | - Tina Hascher
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Institute of Educational Science, University of Bern, Bern, Switzerland
| | - Lukas Fenner
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
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Pechter E, Lessin N. Measuring Indoor Air Quality Does Not Prevent COVID-19. New Solut 2023; 33:95-103. [PMID: 37700674 DOI: 10.1177/10482911231196883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Boston Public Schools (BPS) closed for in-person learning in March 2020 due to COVID-19 and didn't fully reopen until the 2021-2022 school year. Due to the age of schools and absent ventilation systems, coupled with decades of disinvestment in the infrastructure, BPS entered the pandemic with serious challenges impacting the health of students and staff. These challenges were magnified by an infectious airborne virus. Instead of using this opportunity to improve ventilation systems, BPS opted to invest in an air quality monitoring system. This system only confirmed what was already known-there is poor ventilation in most school buildings. It did not lead to correction of new or long-standing problems. This failure has harmed the BPS community, which includes primarily low-income Black and Brown families. This article describes Boston's school system, its track record of inadequate attention to infrastructure, and explores pitfalls of focusing on evaluation instead of correction.
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Kim J, Kim Y, Song Y, Kim TJ, Lee SH, Kim HJ. Indoor particulate matter induces epigenetic changes in companion atopic dogs. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 266:115544. [PMID: 37827097 DOI: 10.1016/j.ecoenv.2023.115544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/24/2023] [Accepted: 10/02/2023] [Indexed: 10/14/2023]
Abstract
The prevalence of atopic dermatitis (AD) is increasing and environmental factors are receiving attention as contributing causes. Indoor air pollutants (IAPs), especially particulate matter (PM) can alter epigenetic markers, DNA methylation (DNAm). Although DNAm-mediated epigenetic changes have been reported to modulate the pathogenesis of AD, their role at high risk of exposure to PM is still unclear. The study investigated the effects of exposure to IAPs in the development of AD and epigenetic changes through DNAm in companion atopic dogs that share indoor environment with their owners. Dogs were divided into two groups: AD (n = 47) and controls (n = 21). The IAPs concentration in each household was measured for 48 h, and a questionnaire on the residential environment was completed in all dogs. Eighteen dogs with AD and 12 healthy dogs were selected for DNAm analysis. In addition, clinical and immunological evaluations were conducted. The concentrations of PM2.5, PM10, and volatile organic compounds (VOCs) were significantly higher in the AD group. Moreover, there were more significant methylation differences in the LDLRAD4, KHSRP, and CTDSP2 genes in connection with PM10 in AD group compared to the controls. The degree of methylation of the LDLRAD4 and CTDSP2 genes was also correlated with related protein productions. The present study revealed that exposure to high indoor PM can cause epigenetic development of AD by methylation of the LDLRAD4, KHSRP, and CTDSP2 genes in dogs. Under the concept of "One Health," improving indoor environments should be considered to prevent the development of AD.
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Affiliation(s)
- Jihyun Kim
- Department of Internal Medicine, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, South Korea; BK 21 project team, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, South Korea
| | - Yeji Kim
- Department of Internal Medicine, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, South Korea; BK 21 project team, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, South Korea
| | - Yunji Song
- Department of Internal Medicine, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, South Korea; BK 21 project team, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, South Korea
| | - Tae Jung Kim
- College of Veterinary Medicine, Chonnam National University, Gwangju 61186, South Korea
| | - Seung-Hwa Lee
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul 05505, South Korea
| | - Ha-Jung Kim
- Department of Internal Medicine, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, South Korea; BK 21 project team, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, South Korea.
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Rawat N, Kumar P. Interventions for improving indoor and outdoor air quality in and around schools. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159813. [PMID: 36411671 DOI: 10.1016/j.scitotenv.2022.159813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 10/14/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Students spend nearly one third of their typical day in the school environment, where they may be exposed to harmful air pollutants. A consolidated knowledge base of interventions to reduce this exposure is required for making informed decisions on their implementation and wider uptake. We attempt to fill this knowledge gap by synthesising the existing scientific literature on different school-based air pollution exposure interventions, their efficiency, suitability, and limitations. We assessed technological (air purifiers, HVAC - Heating Ventilation and Air Conditioning etc.), behavioural, physical barriers, structural, school-commute and policy and regulatory interventions. Studies suggest that the removal efficiency of air purifiers for PM2.5, PM10, PM1 and BC can be up to 57 %, 34 %, 70 % and 58 %, respectively, depending on the air purification technology compared with control levels in classroom. The HVAC system combined with high efficiency filters has BC, PM10 and PM2.5 removal efficiency up to 97 %, 34 % and 30 %, respectively. Citizen science campaigns are effective in reducing the indoor air pollutants' exposure up to 94 %. The concentration of PM10, NO2, O3, BC and PNC can be reduced by up to 60 %, 59 %, 16 %, 63 % and 77 %, respectively as compared to control conditions, by installing green infrastructure (GI) as a physical barrier. School commute interventions can reduce NO2 concentration by up to 23 %. The in-cabin concentration reduction of up to 77 % for PM2.5, 43 % for PNC, 89 % for BC, 74 % for PM10 and 75 % for NO2, along with 94 % reduction in tailpipe emission of total particles, can be achieved using clean fuels and retrofits. No stand-alone method is found as the absolute solution for controlling pollutants exposure, their combined application can be effective in most of the scenarios. More research is needed on assessing combined interventions, and their operational synchronisation for getting the optimum results.
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Affiliation(s)
- Nidhi Rawat
- Global Centre for Clean Air Research (GCARE), School of Sustainability, Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - Prashant Kumar
- Global Centre for Clean Air Research (GCARE), School of Sustainability, Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom.
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Park S, Song D, Jo YM, Park JH, Lee TJ, Koo J. Development of air purifier operation guidelines using grey box models for the concentrations of particulate matter in elementary school classrooms. AEROSOL SCIENCE AND TECHNOLOGY : THE JOURNAL OF THE AMERICAN ASSOCIATION FOR AEROSOL RESEARCH 2023; 57:467-485. [PMID: 38799734 PMCID: PMC11119005 DOI: 10.1080/02786826.2023.2187691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 03/01/2023] [Indexed: 05/29/2024]
Abstract
Considering the hazardous effects of particulate matter (PM) exposure on students and teachers and the high PM concentration issue in South Korea, air purifiers have recently been installed in most classrooms to improve air quality. However, some on-site challenges, such as operational costs and noise, have been issues with the continuous operation of air purifiers. Therefore, a guideline is needed to dynamically predict the indoor PM concentration based on the changes in outdoor PM concentration and activate the air purifiers only when necessary. This study develops a grey-box model that uses measured data and physical differential equations to perform the given objective and verifies its accuracy using ASTM D5157. Modeling and analysis results have obtained information that can form the basis for developing guidelines to address PM issues in schools: The air purifier should be operated during periods where the predicted values exceed the limit in closed windows and the air purifier is not operating. It was also confirmed that the need for the operation of the air purifier varies between schools and classrooms under the same outdoor PM concentration. Indoor PM concentration increased significantly after students' simultaneous mass movement, necessitating air purifiers' operation before and after the events. The prefilter of the heater also aided in the removal of coarse PM. Additionally, the limitations and future development directions of the model were discussed.
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Affiliation(s)
- Sowoo Park
- School of Civil, Architectural Eng., and Landscape Architecture, Sungkyunkwan University, Suwon, South Korea
| | - Doosam Song
- School of Civil, Architectural Eng., and Landscape Architecture, Sungkyunkwan University, Suwon, South Korea
| | - Young Min Jo
- Department of Environmental Science and Environmental Engineering, College of Engineering, Kyung Hee University, Yong-In, Gyung-Gi Do, South Korea
| | - Ju-Hyeong Park
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Tae Jeong Lee
- Department of Environmental Science and Environmental Engineering, College of Engineering, Kyung Hee University, Yong-In, Gyung-Gi Do, South Korea
| | - Junemo Koo
- Department of Mechanical Engineering, College of Engineering, Kyung Hee University, Yong-In, Gyung-Gi Do, South Korea
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Azevedo A, Liddie J, Liu J, Schiff JE, Adamkiewicz G, Hart JE. Effects of portable air cleaners and A/C unit fans on classroom concentrations of particulate matter in a non-urban elementary school. PLoS One 2022; 17:e0278046. [PMID: 36454721 PMCID: PMC9714748 DOI: 10.1371/journal.pone.0278046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 11/08/2022] [Indexed: 12/05/2022] Open
Abstract
Given the increased use of air cleaners as a prevention measure in classrooms during the COVID-19 pandemic, this study aimed to investigate the effects of portable air cleaners with HEPA filters and window A/C fans on real-time (1 minute) concentrations of PM less than 2.5 microns (PM2.5) or less than 1 microns (PM1.0) in two classrooms in a non-urban elementary school in Rhode Island. For half of each school day, settings were randomized to "high" or "low" for the air cleaner and "on" or "off" for the fan. Descriptive statistics and linear mixed models were used to evaluate the impacts of each set of conditions on PM2.5 and PM1.0 concentrations. The mean half-day concentrations ranged from 3.4-4.1 μg/m3 for PM2.5 and 3.4-3.9 μg/m3 for PM1.0. On average, use of the fan when the air cleaner was on the low setting decreased PM2.5 by 0.53 μg/m3 [95% CI: -0.64, -0.42] and use of the filter on high (compared to low) when the fan was off decreased PM2.5 by 0.10 μg/m3 [95% CI: -0.20, 0.005]. For PM1.0, use of the fan when the air cleaner was on low decreased concentrations by 0.18 μg/m3 [95% CI: -0.36, -0.01] and use of the filter on high (compared to low) when the fan was off decreased concentrations by 0.38 μg/m3 [95% CI: -0.55, -0.21]. In general, simultaneous use of the fan and filter on high did not result in additional decreases in PM concentrations compared to the simple addition of each appliance's individual effect estimates. Our study suggests that concurrent or separate use of an A/C fan and air cleaner in non-urban classrooms with low background PM may reduce classroom PM concentrations.
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Affiliation(s)
- Alexandra Azevedo
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Jahred Liddie
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Jason Liu
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Jessica E. Schiff
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Gary Adamkiewicz
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Jaime E. Hart
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
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Zauli-Sajani S, Marchesi S, Boselli G, Broglia E, Angella A, Maestri E, Marmiroli N, Colacci A. Effectiveness of a Protocol to Reduce Children's Exposure to Particulate Matter and NO 2 in Schools during Alert Days. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:11019. [PMID: 36078735 PMCID: PMC9517784 DOI: 10.3390/ijerph191711019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/31/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
Reducing children's exposure to air pollutants should be considered a primary goal, especially for the most vulnerable subjects. The goal of this study was to test the effectiveness of applying a protocol in the event of alert days, i.e., days with forecasted PM10 levels above the EU limit value (50 µg/m3). The test was conducted, before the onset of SARS-CoV-2 restrictions, in a classroom of a primary school in Parma (Italy)-a highly polluted area in Northern Italy. The protocol included indications for the frequency of opening windows and doors, as well as the activation of an air purifier. Teachers and students were asked to apply the protocol only in the event of alert days, while no indications were provided for non-alert days. A monitoring system measuring PM1, PM2.5, PM10, CO2, and NO2 was deployed in the classroom. Measurements of the same parameters were also performed outdoors near the school. The application of the protocol reduced the indoor/outdoor (I/O) ratio for all toxic pollutants. The reduction was also remarkable for PM10-the most critical air quality parameter in the study area (1.5 and 1.1 for non-alert and alert days, respectively). Indoor concentrations of PM10-especially during non-alert days-were often higher than outdoors, showing a major contribution from resuspension due to the movement of people and personal cloud. The protocol did not cause any increase in indoor CO2 levels. Our findings showed that the application of a ventilation protocol together with the contribution of an air purifier may represent an effective way to reduce children's exposure to air pollution during severe air pollution episodes. Considering the onset of COVID-19 and the airborne transmission of pathogens, this protocol now has more meaningful implications for children's welfare, and can be integrated with protocols designed as measures against the spread of SARS-CoV-2.
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Affiliation(s)
- Stefano Zauli-Sajani
- Regional Agency for Prevention Environment and Energy of Emilia-Romagna (Arpae), 40139 Bologna, Italy
| | - Stefano Marchesi
- Regional Agency for Prevention Environment and Energy of Emilia-Romagna (Arpae), 40139 Bologna, Italy
| | - Giuseppe Boselli
- Regional Agency for Prevention Environment and Energy of Emilia-Romagna (Arpae), 40139 Bologna, Italy
| | | | | | - Elena Maestri
- Consorzio Interuniversitario Nazionale per le Scienze Ambientali (CINSA), Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Nelson Marmiroli
- Consorzio Interuniversitario Nazionale per le Scienze Ambientali (CINSA), Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Annamaria Colacci
- Regional Agency for Prevention Environment and Energy of Emilia-Romagna (Arpae), 40139 Bologna, Italy
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12
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Shan YN, Yu Y, Zhao YH, Tang LL, Chen XM. Three-dimensional psychological guidance combined with evidence-based health intervention in patients with liver abscess treated with ultrasound. World J Clin Cases 2022; 10:8196-8204. [PMID: 36159547 PMCID: PMC9403680 DOI: 10.12998/wjcc.v10.i23.8196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/23/2022] [Accepted: 06/30/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Liver abscess is a common clinical liver disease mainly caused by suppurative bacteria or amoebae, with early clinical signs of chills, high fever, jaundice, and other symptoms. Establishing its early diagnosis is difficult, which may lead to misdiagnosis.
AIM To observe the effects of psychological guidance combined with evidence-based health intervention in patients with liver abscess treated with ultrasound.
METHODS A total of 120 patients with bacterial liver abscess admitted to our hospital from May 2018 to February 2021 were selected and divided into groups according to their intervention plan.
RESULTS After the intervention, Self-Rating Depression Scale, Self-Rating Anxiety Scale, Self-Perceived Burden Scale (SPBS), and quality of life scores (physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional, mental health) were lower than before the intervention in the two groups. The observation group had lower negative sentiment, SPBS, and quality of life scores than the control group. In the observation group, 31 and 24 patients had good and general compliance, respectively, with a compliance rate of 91.67%, which was significantly higher than that in the control group. The observation group had significantly lower total incidence of incision infection, abdominal abscess, hemorrhage, and severe abdominal pain than the control group.
CONCLUSION Three-dimensional psychological guidance combined with evidence-based health intervention in treating liver abscess can reduce patients’ burden and negative emotions, improve patient compliance and quality of life, and reduce complications.
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Affiliation(s)
- Ya-Nan Shan
- Department of Infectious Diseases, First Hospital of Qinhuangdao, Qinhuangdao 066000, Hebei Province, China
| | - Ying Yu
- Department of Infectious Diseases, First Hospital of Qinhuangdao, Qinhuangdao 066000, Hebei Province, China
| | - Yi-Han Zhao
- Department of Infectious Diseases, First Hospital of Qinhuangdao, Qinhuangdao 066000, Hebei Province, China
| | - Lian-Lian Tang
- Nursing Department, First Hospital of Qinhuangdao, Qinhuangdao 066000, Hebei Province, China
| | - Xiao-Min Chen
- Nursing Department, First Hospital of Qinhuangdao, Qinhuangdao 066000, Hebei Province, China
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Fazlzadeh M, Hassanvand MS, Nabizadeh R, Shamsipour M, Salarifar M, Naddafi K. Effect of portable air purifier on indoor air quality: reduced exposure to particulate matter and health risk assessment. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:638. [PMID: 35925421 DOI: 10.1007/s10661-022-10255-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
We sought to investigate the impact of air purifiers in the removal of particular matter (PM)10, PM2.5, PM1, and particle number concentration (PNC) in the indoor air of dormitories located at Iran's largest medical university, Tehran University of Medical Sciences. Twelve rooms were selected and randomly assigned to two rooms: sham air purifier system deployed room (SR) and true air purifier system deployed room (TR). All study samples were drawn simultaneously from assigned rooms using portable GRIMM dust monitors for 24 h. The PM monitors of air were positioned in the middle of each room next to the air purifier at the height of the breathing zone (1.5 m in height). The mean PM10, PM2.5, PM1, and PNC removal efficiency in rooms with and without a smoker were measured to be 40.7 vs 83.8%, 31.2 vs 78.4%, 29.9 vs 72.3%, and 44.3 vs 75.6%, respectively. The results showed that smoking is an important influencing factor on the indoor air quality; smoking lowered the removal efficiency of PM10, PM2.5, PM1, and PNC by 43%, 47%, 43%, and 31%, respectively. An air purifier could decline the PM10 and PM2.5 even lower than the WHO 24-h guideline level in non-smoker rooms. This study revealed that using household air purifiers in rooms with smokers and non-smokers significantly reduces the non-carcinogenic risks of exposure to PM10 and PM2.5.
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Affiliation(s)
- Mehdi Fazlzadeh
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sadegh Hassanvand
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran
| | - Ramin Nabizadeh
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran
| | - Mansour Shamsipour
- Department of Research Methodology and Data Analysis, Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran
| | - Mojtaba Salarifar
- Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Kazem Naddafi
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
- Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
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14
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Bueno de Mesquita PJ, Delp WW, Chan WR, Bahnfleth WP, Singer BC. Control of airborne infectious disease in buildings: Evidence and research priorities. INDOOR AIR 2022; 32:e12965. [PMID: 34816493 DOI: 10.1111/ina.12965] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/07/2021] [Accepted: 11/11/2021] [Indexed: 06/13/2023]
Abstract
The evolution of SARS-CoV-2 virus has resulted in variants likely to be more readily transmitted through respiratory aerosols, underscoring the increased potential for indoor environmental controls to mitigate risk. Use of tight-fitting face masks to trap infectious aerosol in exhaled breath and reduce inhalation exposure to contaminated air is of critical importance for disease control. Administrative controls including the regulation of occupancy and interpersonal spacing are also important, while presenting social and economic challenges. Indoor engineering controls including ventilation, exhaust, air flow control, filtration, and disinfection by germicidal ultraviolet irradiation can reduce reliance on stringent occupancy restrictions. However, the effects of controls-individually and in combination-on reducing infectious aerosol transfer indoors remain to be clearly characterized to the extent needed to support widespread implementation by building operators. We review aerobiologic and epidemiologic evidence of indoor environmental controls against transmission and present a quantitative aerosol transfer scenario illustrating relative differences in exposure at close-interactive, room, and building scales. We identify an overarching need for investment to implement building controls and evaluate their effectiveness on infection in well-characterized and real-world settings, supported by specific, methodological advances. Improved understanding of engineering control effectiveness guides implementation at scale while considering occupant comfort, operational challenges, and energy costs.
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Affiliation(s)
| | - William W Delp
- Indoor Environment Group, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Wanyu R Chan
- Indoor Environment Group, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - William P Bahnfleth
- Department of Architectural Engineering, Pennsylvania State University, State College, Pennsylvania, USA
| | - Brett C Singer
- Indoor Environment Group, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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15
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Negative Ion Purifier Effects on Indoor Particulate Dosage to Small Airways. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 19:ijerph19010264. [PMID: 35010523 PMCID: PMC8751072 DOI: 10.3390/ijerph19010264] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 12/13/2021] [Accepted: 12/24/2021] [Indexed: 12/13/2022]
Abstract
Indoor air quality is an important health factor as we spend more than 80% of our time indoors. The primary type of indoor pollutant is particulate matter, high levels of which increase respiratory disease risk. Therefore, air purifiers are a common choice for addressing indoor air pollution. Compared with traditional filtration purifiers, negative ion air purifiers (NIAPs) have gained popularity due to their energy efficiency and lack of noise. Although some studies have shown that negative ions may offset the cardiorespiratory benefits of air purifiers, the underlying mechanism is still unclear. In this study, we conducted a full-scale experiment using an in vitro airway model connected to a breathing simulator to mimic inhalation. The model was constructed using computed tomography scans of human airways and 3D-printing technology. We then quantified the effects of NIAPs on the administered dose of 0.5-2.5 μm particles in the small airway. Compared with the filtration purifier, the NIAP had a better dilution effect after a 1-h exposure and the cumulative administered dose to the small airway was reduced by 20%. In addition, increasing the negative ion concentration helped reduce the small airway exposure risk. NIAPs were found to be an energy-efficient air purification intervention that can effectively reduce the small airway particle exposure when a sufficient negative ion concentration is maintained.
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16
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The Impact of Large Mobile Air Purifiers on Aerosol Concentration in Classrooms and the Reduction of Airborne Transmission of SARS-CoV-2. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182111523. [PMID: 34770037 PMCID: PMC8583054 DOI: 10.3390/ijerph182111523] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/20/2021] [Accepted: 10/27/2021] [Indexed: 01/09/2023]
Abstract
In the wake of the COVID-19 pandemic, an increased risk of infection by virus-containing aerosols indoors is assumed. Especially in schools, the duration of stay is long and the number of people in the rooms is large, increasing the risk of infection. This problem particularly affects schools without pre-installed ventilation systems that are equipped with filters and/or operate with fresh air. Here, the aerosol concentration is reduced by natural ventilation. In this context, we are investigating the effect of large mobile air purifiers (AP) with HEPA filters on particle concentration and their suitability for classroom use in a primary school in Germany. The three tested APs differ significantly in their air outlet characteristics. Measurements of the number of particles, the particle size distribution, and the CO2 concentration were carried out in the classroom with students (April/May 2021) and with an aerosol generator without students. In this regard, the use of APs leads to a substantial reduction of aerosol particles in the considered particle size range of 0.178-17.78 µm. At the same time, the three APs are found to have differences in their particle decay rate, noise level, and flow velocity. In addition to the measurements, the effect of various influencing parameters on the potential inhaled particle dose was investigated using a calculation model. The parameters considered include the duration of stay, particle concentration in exhaled air, respiratory flow rate, virus lifetime, ventilation interval, ventilation efficiency, AP volumetric flow, as well as room size. Based on the resulting effect diagrams, significant recommendations can be derived for reducing the risk of infection from virus-laden aerosols. Finally, the measurements were compared to computational fluid dynamics (CFD) modeling, as such tools can aid the optimal placement and configuration of APs and can be used to study the effect of the spread of aerosols from a source in the classroom.
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17
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Heo S, Kim DY, Kwoun Y, Lee TJ, Jo YM. Characterization and source identification of fine dust in Seoul elementary school classrooms. JOURNAL OF HAZARDOUS MATERIALS 2021; 414:125531. [PMID: 33676257 DOI: 10.1016/j.jhazmat.2021.125531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 09/11/2020] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
To evaluate the level of fine particulate matters in elementary schools located in a high traffic area of Seoul and verify the emission source, a field study on the classrooms was conducted under the uncontrolled condition. The indoor PM2.5 was lower than that of the outdoors as indicated by an I/O ratio of 0.52-0.92 based on mass concentration, and it was maintained below the National Guideline. Heavy metals such as Cr, Mn, Ni, Cu, Zn, As, Sn and Pb were lower in indoor PM2.5 than outdoors. On the contrary, carbons including OC and EC were higher in indoor PM2.5. As a result of source apportionment analysis, an outdoor emission source was responsible for 58.5% of the classroom PM2.5. This study can contribute to urban planning and school design to keep children safe from harmful environments.
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Affiliation(s)
- Sujeong Heo
- Department of Applied Environmental Science, Center for Environmental Fine Dust Research, Kyung Hee University, 17104, South Korea
| | - Do Yoon Kim
- Department of Applied Environmental Science, Center for Environmental Fine Dust Research, Kyung Hee University, 17104, South Korea
| | - Yerim Kwoun
- Department of Applied Environmental Science, Center for Environmental Fine Dust Research, Kyung Hee University, 17104, South Korea
| | - Tae Jung Lee
- Department of Applied Environmental Science, Center for Environmental Fine Dust Research, Kyung Hee University, 17104, South Korea
| | - Young Min Jo
- Department of Applied Environmental Science, Center for Environmental Fine Dust Research, Kyung Hee University, 17104, South Korea.
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18
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Wu Y, Wen B, Li S, Guo Y. Sand and dust storms in Asia: a call for global cooperation on climate change. Lancet Planet Health 2021; 5:e329-e330. [PMID: 33915087 DOI: 10.1016/s2542-5196(21)00082-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Affiliation(s)
- Yao Wu
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Bo Wen
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Shanshan Li
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Yuming Guo
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia.
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19
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Kim JS, Lee MH. Effect of filter collection efficiency on the clean air delivery rate in an air cleaner. INDOOR AIR 2021; 31:745-754. [PMID: 33020961 DOI: 10.1111/ina.12757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 09/17/2020] [Accepted: 09/25/2020] [Indexed: 06/11/2023]
Abstract
The performance of an air cleaner is evaluated by the clean air delivery rate (CADR), which is defined as the measure of the delivery of contaminant-free air. Herein, we conducted comparative analyses of various particulate air filters with various collection efficiencies. We installed each filter in identical commercial air cleaners to determine the effects of the collection efficiency on the CADR. Three different filters (E11, E12, and H13 classes) were prepared to determine the effects of the filter collection efficiency and pressure drop on the air cleaner performance (ie, the CADR). Based on experimental data, filters E11 and E12 had similar CADRs and flow rates. However, filter H13, which had the highest collection efficiency and the lowest flow rate, had the lowest CADR. This indicates that even if a filter with higher collection efficiency is installed in an air cleaner, the larger pressure drop causes a reduction in the air flow rate. The CADR value is widely distributed for a flow rate range for commercially available models; however, the collection efficiencies for most air cleaners on the market lie in a narrow range. Therefore, the flow rate has the most direct impact on the performance of a commercial air cleaner.
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Affiliation(s)
- Jin Sik Kim
- Educational Environment Assessment Team, Korea Educational Environments Protection Agency, Osong-eup, Heungdeok-gu, Chungbuk, South Korea
| | - Myong-Hwa Lee
- Department of Environmental Engineering, Kangwon National University, Chuncheon-si, Gangwon-do, 24341, South Korea
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20
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Wang J, Park YK, Jo YM. Sequential improvement of activated carbon fiber properties for enhanced removal efficiency of indoor CO2. J IND ENG CHEM 2020. [DOI: 10.1016/j.jiec.2020.06.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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21
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Park H, Park S, Seo J. Evaluation on Air Purifier's Performance in Reducing the Concentration of Fine Particulate Matter for Occupants according to its Operation Methods. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17155561. [PMID: 32752211 PMCID: PMC7432819 DOI: 10.3390/ijerph17155561] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/24/2022]
Abstract
Fine particulate matter entering the body through breathing cause serious damage to humans. In South Korea, filter-type air purifiers are used to eliminate indoor fine particulate matter, and there has been a broad range of studies on the spread of fine particulate matter and air purifiers. However, earlier studies have not evaluated an operating method of air purifiers considering the inflow of fine particulate matter into the body or reduction performance of the concentration of fine particulate matter. There is a limit to controlling the concentration of fine particulate matter of the overall space where an air purifier is fixed in one spot as the source of indoor fine particulate matter is varied. Accordingly, this study analyzed changes in the concentration of indoor fine particulate matter through an experiment according to the discharging method and location of a fixed air purifier considering the inflow route of fine particulate matter into the body and their harmfulness. The study evaluated the purifiers' performance in reducing the concentration of fine particulate matter in the occupants' breathing zone according to the operation method in which a movable air purifier responds to the movement of occupants. The results showed the concentration of fine particulate matter around the breathing zone of the occupants had decreased by about 51 μg/m3 compared to the surrounding concentration in terms of the operating method in which an air purifier tracks occupants in real-time, and a decrease of about 68 μg/m3 in terms of the operating method in which an air purifier controls the zone. On the other hand, a real-time occupant tracking method may face a threshold due to the moving path of an air purifier and changes in the number of occupants. A zone controlling method is deemed suitable as an operating method of a movable air purifier to reduce the concentration of fine particulate matter in the breathing zone of occupants.
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Affiliation(s)
- Hyungyu Park
- Department of Architecture, Graduated School, Kookmin University, Seoul 02707, Korea;
| | - Seonghyun Park
- Department of Industry-Academic Cooperation Foundation, Kookmin University, Seoul 02707, Korea;
| | - Janghoo Seo
- School of Architecture, Kookmin University, Seoul 02707, Korea
- Correspondence: ; Tel.: +82-02-910-4593
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