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Rocha-Melogno L, Xi J, Deshusses MA. Experimental evaluation of a full-scale in-duct UV germicidal irradiation system for bioaerosols inactivation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 947:174432. [PMID: 38960181 DOI: 10.1016/j.scitotenv.2024.174432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 06/03/2024] [Accepted: 06/30/2024] [Indexed: 07/05/2024]
Abstract
Bioaerosols control techniques, especially ultraviolet germicidal irradiation (UVGI) are gaining attention due to increasing needs for controlling of health risk caused by airborne biocontaminants. The effectiveness of a full-scale in-duct UVGI air disinfection system was investigated. One bacterium, a wild type Escherichia coli, and three fungal spores, Penicillium aragonense, Rhodotorula glutinis, and Cladosporium sp., were selected as test organisms and their inactivation under different conditions representative of a real application in HVAC systems were investigated. The results demonstrated that inactivation of airborne E. coli by the UVGI system was extremely effective, with >99.5 % of the input E. coli inactivated at a residence time lower than 0.36 s in the disinfection section. Airborne fungal spores were less susceptible to UV irradiation than E. coli. Under same conditions, viable counts reduction of P. aragonense, R. glutinis, and Cladosporium sp. spores were 53 %, 63 % and 73 %, respectively. The effect of UV light intensity, air flowrate and relative humidity were analyzed separately. A simplified model based on redefinition of the parameters in the classical inactivation kinetic equation was used to simulate the inactivation of airborne contaminants in the in-duct system under different conditions. The results showed that the simplified model was adequate to estimate disinfection efficacy of different bioaerosols by the UVGI system which could be useful for system design. Overall, this study shows that such in-duct UVGI systems can provide significant control of bioaerosols.
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Affiliation(s)
| | - Jinying Xi
- Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084, China
| | - Marc A Deshusses
- Department of Civil and Environmental Engineering, Box 90287, Duke University, Durham, NC 27708, USA.
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2
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Ryzhakova NK, Rogova NS, Borisenko AL, Tailasheva KA, Pokrovskaya EA. Vertical transport velocity of fine particles of aluminum smelter emissions. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2024; 59:223-230. [PMID: 38903021 DOI: 10.1080/10934529.2024.2366084] [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: 02/08/2024] [Accepted: 06/05/2024] [Indexed: 06/22/2024]
Abstract
In this study, the average values of vertical velocity of particles emitted from an aluminum smelter in the surface layer of the atmosphere were estimated using a semi-empirical method. The method is based on regression analysis of the horizontal profile of pollutants measured along the selected direction using moss bioindicators. The selection of epiphytic mosses Sanionia uncinata was carried out in 2013 in the zone of influence of a metallurgical industry enterprise in the city of Kandalaksha, Murmansk region. The concentrations of As, Si, Ni, Zn, Ti, Cd, Na, Pb, Co, K, Ba, Ca, Mg, Mn, Sr, Fe, Al, V, Cr, Cu were determined using atomic emission spectrometry. The conducted assessments showed that the average particle velocity toward the Earth's surface, when considering large spatial and temporal scales, is tens of times higher than gravitational settling velocities.
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Affiliation(s)
- N K Ryzhakova
- Research School of High-Energy Physics, National Research Tomsk Polytechnic University, Tomsk, Russia
| | - N S Rogova
- School of Nuclear Science & Engineering, National Research Tomsk Polytechnic University, Tomsk, Russia
| | - A L Borisenko
- Institute of Biology, National Research Tomsk State University, Tomsk, Russia
| | - K A Tailasheva
- School of Nuclear Science & Engineering, National Research Tomsk Polytechnic University, Tomsk, Russia
| | - E A Pokrovskaya
- Research School of High-Energy Physics, National Research Tomsk Polytechnic University, Tomsk, Russia
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3
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Sultan Z, Li J, Pantelic J, Schiavon S. Particle characterization in commercial buildings: A cross-sectional study in 40 offices in Singapore. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172126. [PMID: 38569949 DOI: 10.1016/j.scitotenv.2024.172126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/10/2024] [Accepted: 03/29/2024] [Indexed: 04/05/2024]
Abstract
There is a knowledge gap in understanding how existing office buildings are protecting occupants from exposure to particles from both indoor and outdoor sources. We report a cross-sectional study involving weekly measurements of size-resolved indoor and outdoor particle concentrations in forty commercial building offices in Singapore. The outdoor and indoor particles size distributions were single mode with daytime peak number concentrations at 36.5 nm and 48.7 nm. Outdoor concentrations were significantly greater than indoors for all particle diameters. Indoor particle concentrations were generally low due to: 1) relatively high indoor particle removal (IPR) rates; 2) low indoor source strengths; and 3) low indoor particle of outdoor proportion (IPOP). We found that the ventilation system type had a substantial effect on indoor particle levels, IPR and IPOP. Through linear mixed model analyses, we identified dependencies of IPR rates with the use of MERV13 filters in supply air and filter maintenance frequency, IPOP with the use of MERV13 filters in the fresh air and supply air ducts and low particle source strength with regular daily cleaning presumably due to dust reservoir removal. Lastly, the contribution of outdoor sources was mainly seen for ultrafine and fine particles but less pronounced for coarse particles. This study provided detailed understanding of particle exposure in building offices and their influencing factors, facilitating future research on health impact of particle exposures.
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Affiliation(s)
- Zuraimi Sultan
- Berkeley Education Alliance for Research in Singapore (BEARS) Limited, Singapore.
| | - Jiayu Li
- Berkeley Education Alliance for Research in Singapore (BEARS) Limited, Singapore; University of California Berkeley, Center for the Built Environment, USA
| | - Jovan Pantelic
- Katholieke Universiteit Leuven, Belgium; Well Living Lab, USA
| | - Stefano Schiavon
- Berkeley Education Alliance for Research in Singapore (BEARS) Limited, Singapore; University of California Berkeley, Center for the Built Environment, USA
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4
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Xie Y, Wang Y, He J, Yang X, Duan X, Zhao B. Human emissions of size-resolved fluorescent bioaerosols in control situations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171661. [PMID: 38490427 DOI: 10.1016/j.scitotenv.2024.171661] [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: 11/19/2023] [Revised: 03/09/2024] [Accepted: 03/09/2024] [Indexed: 03/17/2024]
Abstract
Human bioaerosols contribute significantly to indoor air quality. This study used a Wideband Integrated Bioaerosol Sensor (WIBS-4A) instrument for real-time measurement of particle size distribution and count to differentiate fluorescent bioaerosols from non-fluorescent aerosols. Through an experiment involving 12 subjects (six men and six women) wearing standard cotton clothing in a 2 m × 2 m × 2 m environmental chamber, we established a quantitative method to obtain the bioaerosol emission rate of a single subject, aiming to explore the effects of masks and sex on bioaerosol emissions from different individuals. The mean emission rates of fluorescent bioaerosols in the particle size ranges of 0.5-2.5 μm and 2.5-10 μm were 3.192±2.11×104 counts/(person·h) and 13.98±9.34×104 counts/(person·h), respectively. A comparison between those wearing and not wearing masks revealed no significant differences in the emissions of fluorescent bioaerosols. This suggests respiratory sources may not significantly impact the emissions of fluorescent bioaerosols from individuals under seated breathing conditions. Significant disparities in the fluorescent bioaerosol emission rates of different biological sexes were observed through independent sample analysis. Males exhibited 41 % and 15 % higher emission rates than females for particle size ranges of 0.5-2.5 μm and 2.5-10 μm, respectively, possibly because of different metabolic rates. A significant correlation between metabolic rates and fluorescent bioaerosols (sig = 0.044 < 0.05) was observed in all the subjects. These findings underscore the individual variations that affect bioaerosol emission rates. The data provided by this study will facilitate further analysis of the on-site measured data and source analysis.
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Affiliation(s)
- Yangyang Xie
- Department of Building Science, School of Architecture, Tsinghua University, Beijing, China; Department of Building Environment and Energy Engineering, School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing, China
| | - Yuxing Wang
- Department of Building Environment and Energy Engineering, School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing, China
| | - Junzhou He
- Department of Power Engineering, North China Electric Power University, Baoding, Hebei, China.
| | - Xudong Yang
- Department of Building Science, School of Architecture, Tsinghua University, Beijing, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Tsinghua University, Beijing, China
| | - Xiaoli Duan
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China
| | - Bin Zhao
- Department of Building Science, School of Architecture, Tsinghua University, Beijing, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Tsinghua University, Beijing, China.
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Myung H, Joung YS. Contribution of Particulates to Airborne Disease Transmission and Severity: A Review. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:6846-6867. [PMID: 38568611 DOI: 10.1021/acs.est.3c08835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/24/2024]
Abstract
The emergence of coronavirus disease 2019 (COVID-19) has catalyzed great interest in the spread of airborne pathogens. Airborne infectious diseases are classified into viral, bacterial, and fungal infections. Environmental factors can elevate their transmission and lethality. Air pollution has been reported as the leading environmental cause of disease and premature death worldwide. Notably, ambient particulates of various components and sizes are harmful pollutants. There are two prominent health effects of particles in the atmosphere: (1) particulate matter (PM) penetrates the respiratory tract and adversely affects health, such as heart and respiratory diseases; and (2) bioaerosols of particles act as a medium for the spread of pathogens in the air. Particulates contribute to the occurrence of infectious diseases by increasing vulnerability to infection through inhalation and spreading disease through interactions with airborne pathogens. Here, we focus on the synergistic effects of airborne particulates on infectious disease. We outline the concepts and characteristics of bioaerosols, from their generation to transformation and circulation on Earth. Considering that microorganisms coexist with other particulates as bioaerosols, we investigate studies examining respiratory infections associated with airborne PM. Furthermore, we discuss four factors (meteorological, biological, physical, and chemical) that may impact the influence of PM on the survival of contagious pathogens in the atmosphere. Our review highlights the significant role of particulates in supporting the transmission of infectious aerosols and emphasizes the need for further research in this area.
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Affiliation(s)
- Hyunji Myung
- Department of Mechanical Systems Engineering, Sookmyung Women's University, 100, Cheongpa-ro 47-gil, Yongsan-gu, Seoul 04310, Republic of Korea
| | - Young Soo Joung
- Department of Mechanical Systems Engineering, Sookmyung Women's University, 100, Cheongpa-ro 47-gil, Yongsan-gu, Seoul 04310, Republic of Korea
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Zhang T, Liu M, Zhou D, Ma Z, Chen L, Wu D, Diao H, Wang W, Li D, Zhen Q. Environmental factors and particle size shape the community structure of airborne total and pathogenic bacteria in a university campus. Front Public Health 2024; 12:1371656. [PMID: 38651126 PMCID: PMC11033423 DOI: 10.3389/fpubh.2024.1371656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 03/26/2024] [Indexed: 04/25/2024] Open
Abstract
Given the dense population on university campuses, indoor and outdoor airborne bacterial contamination may lead to the rapid spread of diseases in a university environment. However, there are few studies of the characteristics of airborne and pathogenic bacterial communities in different sites on a university campus. In this study, we collected particulate matter samples from indoor and outdoor locations at a university in Bengbu City, Anhui Province, China, and analyzed the community characteristics of airborne and pathogenic bacteria using a high-throughput sequencing technique. The results showed that the composition of the dominant airborne and pathogenic bacterial communities was consistent among sites at the phylum and genus levels, with differences in their relative abundance. There were significant differences in the structure of the airborne and pathogenic bacterial communities between indoor and outdoor sites (p < 0.05). An analysis of similarities (ANOSIM) indicated that the structure of airborne bacterial communities in indoor sites was influenced by the room occupancy rate, ventilation conditions, and the extent of indoor furnishing (p < 0.05), while the structure of pathogenic bacterial communities was influenced by the number of individuals and spatial dimensions (p < 0.05). The impact of particle size on the structure of airborne and pathogenic bacterial communities was relatively minor. A total of 194 suspected pathogenic bacterial species were identified, accounting for 0.0001-1.3923% of the total airborne bacteria, all of which were conditional pathogens. Among them, Saccharopolyspora rectivirgula, Acinetobacter johnsonii, and Moraxella osloensis exhibited relatively high relative abundance, accounting for 24.40, 16.22, and 8.66% of the total pathogenic bacteria, respectively. Moreover, 18 emerging or re-emerging pathogenic bacterial species with significant implications for human health were identified, although their relative abundance was relatively low (0.5098%). The relative abundance of pathogenic bacteria in indoor environments was significantly higher than outdoors, with the laboratory and dormitory having the highest levels. The findings of this study provide valuable guidance for the prevention and control of airborne bacterial contamination and the associated health risks in both a campus environment and other public spaces with high occupancy rates.
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Affiliation(s)
- Tianer Zhang
- School of Public Health, Bengbu Medical University, Bengbu, China
- Xinchang Center for Disease Control and Prevention, Shaoxing, China
| | - Mengmeng Liu
- School of Public Health, Bengbu Medical University, Bengbu, China
- Quality Management Department, Fuyang Tumor Hospital, Fuyang, China
| | - Dalin Zhou
- School of Public Health, Bengbu Medical University, Bengbu, China
| | - Zhijing Ma
- School of Public Health, Bengbu Medical University, Bengbu, China
| | - Liu Chen
- School of Public Health, Bengbu Medical University, Bengbu, China
| | - Danchen Wu
- School of Public Health, Bengbu Medical University, Bengbu, China
| | - Haitao Diao
- School of Public Health, Bengbu Medical University, Bengbu, China
| | - Wanru Wang
- School of Public Health, Bengbu Medical University, Bengbu, China
| | - Die Li
- School of Public Health, Bengbu Medical University, Bengbu, China
| | - Quan Zhen
- School of Public Health, Bengbu Medical University, Bengbu, China
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Yamaguchi H, Okubo T, Nozaki E, Osaki T. Differential impact of environmental factors on airborne live bacteria and inorganic particles in an underground walkway. PLoS One 2024; 19:e0300920. [PMID: 38512950 PMCID: PMC10956794 DOI: 10.1371/journal.pone.0300920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/05/2024] [Indexed: 03/23/2024] Open
Abstract
We previously reported that variations in the number and type of bacteria found in public spaces are influenced by environmental factors. However, based on field survey data alone, whether the dynamics of bacteria in the air change as a result of a single environmental factor or multiple factors working together remains unclear. To address this, mathematical modeling may be applied. We therefore conducted a reanalysis of the previously acquired data using principal component analysis (PCA) in conjunction with a generalized linear model (Glm2) and a statistical analysis of variance (ANOVA) test employing the χ2 distribution. The data used for the analysis were reused from a previous public environmental survey conducted at 8:00-20:00 on May 2, June 1, and July 5, 2016 (regular sampling) and at 5:50-7:50 and 20:15-24:15 on July 17, 2017 (baseline sampling) in the Sapporo underground walking space, a 520-meter-long underground walkway. The dataset consisted of 60 samples (22 samples for "bacterial flora"), including variables such as "temperature (T)," "humidity (H)," "atmospheric pressure (A)," "traffic pedestrians (TP)," "number of inorganic particles (Δ5: 1-5 μm)," "number of live airborne bacteria," and "bacterial flora." Our PCA with these environmental factors (T, H, A, and TP) revealed that the 60 samples could be categorized into four groups (G1 to G4), primarily based on variations in PC1 [Loadings: T(-0.62), H(-0.647), TP(0.399), A(0.196)] and PC2 [Loadings: A(-0.825), TP(0.501), H(0.209), T(-0.155)]. Notably, the number of inorganic particles significantly increased from G4 to G1, but the count of live bacteria was highest in G2, with no other clear pattern. Further analysis with Glm2 indicated that changes in inorganic particles could largely be explained by two variables (H/TP), while live bacteria levels were influenced by all explanatory variables (TP/A/H/T). ANOVA tests confirmed that inorganic particles and live bacteria were influenced by different factors. Moreover, there were minimal changes in bacterial flora observed among the groups (G1-G4). In conclusion, our findings suggest that the dynamics of live bacteria in the underground walkway differ from those of inorganic particles and are regulated in a complex manner by multiple environmental factors. This discovery may contribute to improving public health in urban settings.
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Affiliation(s)
- Hiroyuki Yamaguchi
- Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| | - Torahiko Okubo
- Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| | - Eriko Nozaki
- Department of Infectious Diseases, Kyorin University School of Medicine, Shinkawa, Mitaka, Tokyo, Japan
| | - Takako Osaki
- Department of Infectious Diseases, Kyorin University School of Medicine, Shinkawa, Mitaka, Tokyo, Japan
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Zhang T, Yan L, Wei M, Su R, Qi J, Sun S, Song Y, Li X, Zhang D. Bioaerosols in the coastal region of Qingdao: Community diversity, impact factors and synergistic effect. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170246. [PMID: 38246385 DOI: 10.1016/j.scitotenv.2024.170246] [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: 10/19/2023] [Revised: 12/26/2023] [Accepted: 01/15/2024] [Indexed: 01/23/2024]
Abstract
Atmospheric bioaerosols are influenced by multiple factors, including physical, chemical, and biotic interactions, and pose a significant threat to the public health and the environment. The nonnegligible truth however is that the primary driver of the changes in bioaerosol community diversity remains unknown. In this study, putative biological association (PBA) was obtained by constructing an ecological network. The relationship between meteorological conditions, atmospheric pollutants, water-soluble inorganic ions, PBA and bioaerosol community diversity was analyzed using random forest regression (RFR)-An ensemble learning algorithm based on a decision tree that performs regression tasks by constructing multiple decision trees and integrating the predicted results, and the contribution of different rich species to PBA was predicted. The species richness, evenness and diversity varied significantly in different seasons, with the highest in summer, followed by autumn and spring, and was lowest in winter. The RFR suggested that the explanation rate of alpha diversity increased significantly from 73.74 % to 85.21 % after accounting for the response of the PBA to diversity. The PBA, temperature, air pollution, and marine source air masses were the most crucial factors driving community diversity. PBA, particularly putative positive association (PPA), had the highest significance in diversity. We found that under changing external conditions, abundant taxa tend to cooperate to resist external pressure, thereby promoting PPA. In contrast, rare taxa were more responsive to the putative negative association because of their sensitivity to environmental changes. The results of this research provided scientific advance in the understanding of the dynamic and temporal changes in bioaerosols, as well as support for the prevention and control of microbial contamination of the atmosphere.
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Affiliation(s)
- Ting Zhang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, PR China
| | - Lingchong Yan
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, PR China
| | - Mingming Wei
- Laoshan District Meteorological Bureau, Qingdao 266107, PR China
| | - Rongguo Su
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, PR China
| | - Jianhua Qi
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, PR China
| | - Shaohua Sun
- Laoshan District Meteorological Bureau, Qingdao 266107, PR China
| | - Yongzhong Song
- Jufeng Peak Tourist Management Service Center of Laoshan Scenic Spot, Qingdao 266100, PR China
| | - Xianguo Li
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, PR China
| | - Dahai Zhang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, PR China.
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Zhang T, Zhang D, Lyu Z, Zhang J, Wu X, Yu Y. Effects of extreme precipitation on bacterial communities and bioaerosol composition: Dispersion in urban outdoor environments and health risks. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 344:123406. [PMID: 38244904 DOI: 10.1016/j.envpol.2024.123406] [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: 08/22/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/22/2024]
Abstract
Concerns about contaminants dispersed by seasonal precipitation have grown due to their potential hazards to outdoor environments and human health. However, studies on the crucial environmental factors influencing dispersion changes in bacterial communities are limited. This research adopted four-season in situ monitoring and sequencing techniques to examine the regional distribution profiles of bioaerosols, bacterial communities, and risks associated with extreme snowfall versus rainfall events in two monsoon cities. In the early-hours of winter snowfall, airborne cultivable bioaerosol concentrations were 4.1 times higher than the reference exposure limit (500 CFU/m3). The concentration of ambient particles (2.5 μm) exceeded 24,910 particles/L (97 μg/m3), positively correlating with the prevalence of cultivable bioaerosols. These bioaerosols contained cultivable bacterial species such as pathogenic Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, and Escherichia coli. Bioaerosol concentrations increased by 53.0% during 50-mm snow extremes. Taxonomic analysis revealed that Pseudomonas, Staphylococcus, and Veillonella were the most abundant bacterial taxa in the initial snowmelt samples during winter precipitation. However, their abundance decreased by 87.6% as snowing continued (24 h). Reduced water base cation concentration also led to a 1.15-fold increase in the Shannon index, indicating a similar yet heightened bacterial diversity. Seasonally, Pedobacter and Massilia showed higher relative abundance (25% and 18%, respectively), presenting increased bacterial transmission to the soil. Furthermore, Pseudomonas was identified in 60% of spring snowstorm samples, suggesting long-distance dispersal of pathogenic bacteria. When these atmospheric aerosol particles carrying biological entities (0.65-1.1 μm) penetrated human alveoli, the calculated hazard ratio was 0.55, which as observed in inhalation exposures. Consequently, this study underscores the risk of seasonal precipitation-enhanced ambient bacterial transmission.
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Affiliation(s)
- Ting Zhang
- College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Dingqiang Zhang
- College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Zhonghang Lyu
- College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Jitao Zhang
- College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Xian Wu
- College of Civil Engineering, Liaoning Technical University, Fuxin, 123000, China
| | - Yingxin Yu
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
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10
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Zhao J, Uhde E, Salthammer T, Antretter F, Shaw D, Carslaw N, Schieweck A. Long-term prediction of the effects of climate change on indoor climate and air quality. ENVIRONMENTAL RESEARCH 2024; 243:117804. [PMID: 38042519 DOI: 10.1016/j.envres.2023.117804] [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: 10/06/2023] [Revised: 11/15/2023] [Accepted: 11/26/2023] [Indexed: 12/04/2023]
Abstract
Limiting the negative impact of climate change on nature and humans is one of the most pressing issues of the 21st century. Meanwhile, people in modern society spend most of the day indoors. It is therefore surprising that comparatively little attention has been paid to indoor human exposure in relation to climate change. Heat action plans have now been designed in many regions to protect people from thermal stress in their private homes and in public buildings. However, in order to be able to plan effectively for the future, reliable information is required about the long-term effects of climate change on indoor air quality and climate. The Indoor Air Quality Climate Change (IAQCC) model is an expediant tool for estimating the influence of climate change on indoor air quality. The model follows a holistic approach in which building physics, emissions, chemical reactions, mold growth and exposure are combined with the fundamental parameters of temperature and humidity. The features of the model have already been presented in an earlier publication, and it is now used for the expected climatic conditions in Central Europe, taking into account various shared socioeconomic pathway (SSP) scenarios up to the year 2100. For the test house examined in this study, the concentrations of pollutants in the indoor air will continue to rise. At the same time, the risk of mold growth also increases (the mold index rose from 0 to 4 in the worst case for very sensitive material). The biggest problem, however, is protection against heat and humidity. Massive structural improvements are needed here, including insulation, ventilation, and direct sun protection. Otherwise, the occupants will be exposed to increasing thermal discomfort, which can also lead to severe heat stress indoors.
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Affiliation(s)
- Jiangyue Zhao
- Fraunhofer WKI, Department of Material Analysis and Indoor Chemistry, Riedenkamp 3, 38108, Braunschweig, Germany
| | - Erik Uhde
- Fraunhofer WKI, Department of Material Analysis and Indoor Chemistry, Riedenkamp 3, 38108, Braunschweig, Germany
| | - Tunga Salthammer
- Fraunhofer WKI, Department of Material Analysis and Indoor Chemistry, Riedenkamp 3, 38108, Braunschweig, Germany
| | - Florian Antretter
- C3RROlutions GmbH, Steinbrucker Str. 11, 83064, Raubling, Germany; Fraunhofer IBP, Fraunhoferstraße 10, 83626, Valley, Germany
| | - David Shaw
- University of York, Department of Environment and Geography, Heslington, York, YO10 5NG, UK
| | - Nicola Carslaw
- University of York, Department of Environment and Geography, Heslington, York, YO10 5NG, UK
| | - Alexandra Schieweck
- Fraunhofer WKI, Department of Material Analysis and Indoor Chemistry, Riedenkamp 3, 38108, Braunschweig, Germany.
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11
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Pyrri I, Stamatelopoulou A, Pardali D, Maggos T. The air and dust invisible mycobiome of urban domestic environments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166228. [PMID: 37591388 DOI: 10.1016/j.scitotenv.2023.166228] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/19/2023]
Abstract
Air and dust harbor a dynamic fungal biome that interacts with residential environment inhabitants usually with negative implications for human health. Fungal air and dust synthesis were investigated in houses across the Athens Metropolitan area. Active and passive culture dependent methods were employed to sample airborne and dustborne fungi for two sampling periods, one in winter and the other in summer. A core mycobiome was revealed both in air and dust constituted of the dominant Penicillium, Cladosporium, Aspergillus, Alternaria and yeasts and accompanied by several common and rare components. Penicillium and Aspergillus diversity included 22 cosmopolitan species, except the rarely found Penicillium citreonigrum, P. corylophilum, P. pagulum and Talaromyces albobiverticillius which are reported for the first time from Greece. Fungal concentrations were significantly higher during summer for both air and dust. Excessive levels of inhalable aerosol constituted mainly by certain Penicillium species were associated with indoor emission sources as these species are household molds related to food commodities rot. The ambient air fungal profile is a determinant factor of indoor fungal aerosol which subsequently shapes dustborne mycobiota. Indoor fungi can be useful bioindicators for indoor environment quality and at the same time provide insight to indoor fungal ecology.
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Affiliation(s)
- Ioanna Pyrri
- National and Kapodistrian University of Athens, Department of Biology, Section of Ecology and Systematics, Panepistimioupoli, 15784 Athens, Greece.
| | - Asimina Stamatelopoulou
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety, Atmospheric Chemistry and Innovative Technology Laboratory, NCSR Demokritos, Athens, Greece
| | - Dimitra Pardali
- National and Kapodistrian University of Athens, Department of Physics, Section of Applied Physics, Panepistimioupoli, 15784 Athens, Greece
| | - Thomas Maggos
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety, Atmospheric Chemistry and Innovative Technology Laboratory, NCSR Demokritos, Athens, Greece
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12
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Kek HY, Tan H, Othman MHD, Nyakuma BB, Goh PS, Wong SL, Deng X, Leng PC, Yatim AS, Wong KY. Perspectives on human movement considerations in indoor airflow assessment: a comprehensive data-driven systematic review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:121253-121268. [PMID: 37979109 DOI: 10.1007/s11356-023-30912-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 11/01/2023] [Indexed: 11/19/2023]
Abstract
Understanding particle dispersion characteristics in indoor environments is crucial for revising infection prevention guidelines through optimized engineering control. The secondary wake flow induced by human movements can disrupt the local airflow field, which enhances particle dispersion within indoor spaces. Over the years, researchers have explored the impact of human movement on indoor air quality (IAQ) and identified noteworthy findings. However, there is a lack of a comprehensive review that systematically synthesizes and summarizes the research in this field. This paper aims to fill that gap by providing an overview of the topic and shedding light on emerging areas. Through a systematic review of relevant articles from the Web of Science database, the study findings reveal an emerging trend and current research gaps on the topic titled Impact of Human Movement in Indoor Airflow (HMIA). As an overview, this paper explores the effect of human movement on human microenvironments and particle resuspension in indoor environments. It delves into the currently available methods for assessing the HMIA and proposes the integration of IoT sensors for potential indoor airflow monitoring. The present study also emphasizes incorporating human movement into ventilation studies to achieve more realistic predictions and yield more practical measures. This review advances knowledge and holds significant implications for scientific and public communities. It identifies future research directions and facilitates the development of effective ventilation strategies to enhance indoor environments and safeguard public health.
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Affiliation(s)
- Hong Yee Kek
- Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - Huiyi Tan
- Faculty of Chemical & Energy Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - Mohd Hafiz Dzarfan Othman
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - Bemgba Bevan Nyakuma
- Department of Chemical Sciences, Faculty of Science and Computing, Pen Resource University, P. M. B. 086, Gombe, Gombe State, Nigeria
| | - Pei Sean Goh
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - Syie Luing Wong
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands
| | - Xiaorui Deng
- Department of Building Environment and Energy Engineering, College of Civil Engineering, Hunan University, Changsha, 410082, Hunan, China
| | - Pau Chung Leng
- Faculty of Built Environment and Surveying, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - Ardiyansyah Saad Yatim
- Department of Mechanical Engineering, Universitas Indonesia, 16424, Depok, Jawa Barat, Indonesia
| | - Keng Yinn Wong
- Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia.
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13
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El Jaddaoui I, Ghazal H, Bennett JW. Mold in Paradise: A Review of Fungi Found in Libraries. J Fungi (Basel) 2023; 9:1061. [PMID: 37998867 PMCID: PMC10672585 DOI: 10.3390/jof9111061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/23/2023] [Accepted: 10/23/2023] [Indexed: 11/25/2023] Open
Abstract
Libraries contain a large amount of organic material, frequently stored with inadequate climate control; thus, mold growth represents a considerable threat to library buildings and their contents. In this essay, we review published papers that have isolated microscopic fungi from library books, shelving, walls, and other surfaces, as well as from air samples within library buildings. Our literature search found 54 published studies about mold in libraries, 53 of which identified fungi to genus and/or species. In 28 of the 53 studies, Aspergillus was the single most common genus isolated from libraries. Most of these studies used traditional culture and microscopic methods for identifying the fungi. Mold damage to books and archival holdings causes biodeterioration of valuable educational and cultural resources. Exposure to molds may also be correlated with negative health effects in both patrons and librarians, so there are legitimate concerns about the dangers of contact with high levels of fungal contamination. Microbiologists are frequently called upon to help librarians after flooding and other events that bring water into library settings. This review can help guide microbiologists to choose appropriate protocols for the isolation and identification of mold in libraries and be a resource for librarians who are not usually trained in building science to manage the threat molds can pose to library holdings.
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Affiliation(s)
- Islam El Jaddaoui
- Laboratory of Human Pathologies Biology, Department of Biology, Faculty of Sciences, University Mohammed V, Rabat 10000, Morocco
- Genomic Center of Human Pathologies, Faculty of Medicine and Pharmacy, University Mohammed V, Rabat 10000, Morocco
- Department of Plant Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA;
| | - Hassan Ghazal
- Laboratory of Genomics and Bioinformatics, School of Pharmacy, Mohammed VI University of Health Sciences, Casablanca 82403, Morocco;
- Royal Institute of Sports, Royal Institute for Managerial Training in Youth and Sport, Department of Sports Sciences, Laboratory of Sports Sciences and Performance Optimization, Salé 10102, Morocco
| | - Joan W. Bennett
- Department of Plant Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA;
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14
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Tanner K, Good KM, Goble D, Good N, Keisling A, Keller KP, L’Orange C, Morton E, Phillips R, Volckens J. Large Particle Emissions from Human Vocalization and Playing of Wind Instruments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:15392-15400. [PMID: 37796739 PMCID: PMC10586367 DOI: 10.1021/acs.est.3c03588] [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: 05/11/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 10/07/2023]
Abstract
Humans emit large salivary particles when talking, singing, and playing musical instruments, which have implications for respiratory disease transmission. Yet little work has been done to characterize the emission rates and size distributions of such particles. This work characterized large particle (dp > 35 μm in aerodynamic diameter) emissions from 70 volunteers of varying age and sex while vocalizing and playing wind instruments. Mitigation efficacies for face masks (while singing) and bell covers (while playing instruments) were also examined. Geometric mean particle count emission rates varied from 3.8 min-1 (geometric standard deviation [GSD] = 3.1) for brass instruments playing to 95.1 min-1 (GSD = 3.8) for talking. On average, talking produced the highest emission rates for large particles, in terms of both number and mass, followed by singing and then instrument playing. Neither age, sex, CO2 emissions, nor loudness (average dBA) were significant predictors of large particle emissions, contrary to previous findings for smaller particle sizes (i.e., for dp < 35 μm). Size distributions were similar between talking and singing (count median diameter = 53.0 μm, GSD = 1.69). Bell covers did not affect large particle emissions from most wind instruments, but face masks reduced large particle count emissions for singing by 92.5% (95% CI: 97.9%, 73.7%).
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Affiliation(s)
- Ky Tanner
- Department
of Mechanical Engineering, Colorado State
University, Fort Collins, Colorado 80523, United States
| | - Kristen M. Good
- Department
of Environmental and Radiological Health Sciences, Colorado State University, Fort
Collins, Colorado 80523, United States
- Colorado
Department of Public Health and Environment, Denver, Colorado 80246, United States
| | - Dan Goble
- School
of Music, Theatre, and Dance, Colorado State
University, Fort Collins, Colorado 80523, United States
| | - Nicholas Good
- Department
of Civil and Environmental Engineering, Colorado State University, Fort
Collins, Colorado 80523, United States
| | - Amy Keisling
- Department
of Mechanical Engineering, Colorado State
University, Fort Collins, Colorado 80523, United States
- School
of Music, Theatre, and Dance, Colorado State
University, Fort Collins, Colorado 80523, United States
| | - Kayleigh P. Keller
- Department
of Statistics, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Christian L’Orange
- Department
of Mechanical Engineering, Colorado State
University, Fort Collins, Colorado 80523, United States
| | - Emily Morton
- School
of Music, Theatre, and Dance, Colorado State
University, Fort Collins, Colorado 80523, United States
| | - Rebecca Phillips
- School
of Music, Theatre, and Dance, Colorado State
University, Fort Collins, Colorado 80523, United States
| | - John Volckens
- Department
of Mechanical Engineering, Colorado State
University, Fort Collins, Colorado 80523, United States
- Department
of Environmental and Radiological Health Sciences, Colorado State University, Fort
Collins, Colorado 80523, United States
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15
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Wood SGA, Craske J, Burridge HC. Relating quanta conservation and compartmental epidemiological models of airborne disease outbreaks in buildings. Sci Rep 2023; 13:17335. [PMID: 37833394 PMCID: PMC10575980 DOI: 10.1038/s41598-023-44527-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 10/09/2023] [Indexed: 10/15/2023] Open
Abstract
We investigate the underlying assumptions and limits of applicability of several documented models for outbreaks of airborne disease inside buildings by showing how they may each be regarded as special cases of a system of equations which combines quanta conservation and compartmental epidemiological modelling. We investigate the behaviour of this system analytically, gaining insight to its behaviour at large time. We then investigate the characteristic timescales of an indoor outbreak, showing how the dilution rate of the space, and the quanta generation rate, incubation rate and removal rate associated with the illness may be used to predict the evolution of an outbreak over time, and may also be used to predict the relative performances of other indoor airborne outbreak models. The model is compared to a more commonly used model, in which it is assumed the environmental concentration of infectious aerosols adheres to a quasi-steady-state, so that the the dimensionless quanta concentration is equal to the the infectious fraction. The model presented here is shown to approach this limit exponentially to within an interval defined by the incubation and removal rates. This may be used to predict the maximum extent to which a case will deviate from the quasi steady state condition.
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Affiliation(s)
- Samuel G A Wood
- Department of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UK.
| | - John Craske
- Department of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UK
| | - Henry C Burridge
- Department of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UK
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16
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Liu Z, Li H, Chu J, Huang Z, Xiao X, Wang Y, He J. The impact of high background particle concentration on the spatiotemporal distribution of Serratia marcescens bioaerosol. JOURNAL OF HAZARDOUS MATERIALS 2023; 458:131863. [PMID: 37354722 DOI: 10.1016/j.jhazmat.2023.131863] [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: 03/10/2023] [Revised: 06/07/2023] [Accepted: 06/13/2023] [Indexed: 06/26/2023]
Abstract
Airborne transmission is a well-established mode of dissemination for infectious diseases, particularly in closed environments. However, previous research has often overlooked the potential impact of background particle concentration on bioaerosol characteristics. We compared the spatial and temporal distributions of bioaerosols under two levels of background particle concentration: heavily polluted (150-250 μg/m3) and excellent (0-35 μg/m3) in a typical ward. Serratia marcescens bioaerosol was adopted as a bioaerosol tracer, and the bioaerosol concentrations were quantified using six-stage Andersen cascade impactors. The results showed a significant reduction (over at least 62.9%) in bioaerosol concentration under heavily polluted levels compared to excellent levels at all sampling points. The temporal analysis also revealed that the decay rate of bioaerosols was higher (at least 0.654 min-1) under heavily polluted levels compared to excellent levels. These findings suggest that background particles can facilitate bioaerosol removal, contradicting the assumption made in previous research that background particle has no effect on bioaerosol characteristics. Furthermore, we observed differences in the size distribution of bioaerosols between the two levels of background particle concentration. The average bioaerosols size under heavily polluted levels was found to be higher than that under excellent levels, and the average particle size under heavily polluted levels gradually increased with time. In conclusion, these results highlight the importance of considering background particle concentration in future research on bioaerosol characteristics.
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Affiliation(s)
- Zhijian Liu
- School of Energy and Power Engineering, North China Electric Power University, Baoding 071003, China
| | - Haochuan Li
- School of Energy and Power Engineering, North China Electric Power University, Baoding 071003, China
| | - Jiaqi Chu
- School of Energy and Power Engineering, North China Electric Power University, Baoding 071003, China
| | - Zhenzhe Huang
- School of Energy and Power Engineering, North China Electric Power University, Baoding 071003, China
| | - Xia Xiao
- School of Energy and Power Engineering, North China Electric Power University, Baoding 071003, China
| | - Yongxin Wang
- School of Energy and Power Engineering, North China Electric Power University, Baoding 071003, China
| | - Junzhou He
- School of Energy and Power Engineering, North China Electric Power University, Baoding 071003, China.
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17
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Smith BL, King MD. Sampling and Characterization of Bioaerosols in Poultry Houses. Microorganisms 2023; 11:2068. [PMID: 37630628 PMCID: PMC10459659 DOI: 10.3390/microorganisms11082068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
Two poultry Confined Animal Feeding Units (CAFUs), "House A" and "House B", were selected from the TAMU poultry facility for the study, and samples were collected over a five-day period. Bioaerosol sampling was conducted using a Wetted Wall Cyclone (WWC) bioaerosol collector at the two CAFU houses, in which House A housed approximately 720 broiler chickens and roosters, while House B remained unoccupied and served as a reference. Both houses consisted of 24 pens arranged on either side of a central walkway. Bacterial content analysis was conducted using microbial plating, real-time Polymerase Chain Reaction (PCR), and Fatty Acid Methyl Ester (FAME) analysis, while ambient temperature and relative humidity were also monitored. The concentrations of microorganisms in House A showed a highly dynamic range, ranging from 4000 to 60,000 colony forming units (CFU) per cubic meter of air. Second, the WWC samples contained approximately ten-fold more bacterial DNA than the filter samples, suggesting higher levels of viable cells captured by the WWC. Third, significant concentrations of pathogens, including Salmonella, Staphylococcus, and Campylobacter, were detected in the poultry facility. Lastly, the WWC system demonstrated effective functionality and continuous operation, even in the challenging sampling environment of the CAFU. The goal of this study was to characterize the resident population of microorganisms (pathogenic and non-pathogenic) present in the CAFUs and to evaluate the WWC's performance in such an environment characterized by elevated temperature, high dust content, and feathers. This knowledge could then be used to improve understanding microorganism dynamics in CAFUs including the spread of bacterial infections between animals and from animals to humans that work in these facilities, as well as of the WWC performance in this type of environment (elevated temperature, high content of dust and feathers). A more comprehensive understanding can aid in improving the management of bacterial infections in these settings.
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Affiliation(s)
| | - Maria D. King
- Aerosol Technology Laboratory, Biological & Agricultural Engineering Department, Texas A&M University, College Station, TX 77843, USA;
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18
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Zhang J, Jia Y, Lv X, Xiong T, Su J, Huang Y, Shen K. Synergistic graphene-MnOx/honeycomb activated carbon (G-MnOx/HAC) and plasma technology for eradication of pathogenic microorganisms. Front Chem 2023; 11:1207947. [PMID: 37601903 PMCID: PMC10433192 DOI: 10.3389/fchem.2023.1207947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 07/24/2023] [Indexed: 08/22/2023] Open
Abstract
This paper addresses the risk for environmental transmission of pathogenic microorganisms in confined spaces and the serious health hazards for personnel, and research on efficient eradication methods for the pathogenic microorganisms was carried out to provide technical support for ensuring the health of personnel in confined spaces. A series of graphene-MnO2 (G-MnO2) catalytic materials was prepared by hydrothermal and precipitation methods, and processing parameters such as the graphene doping method, the raw material ratio and the plasma action time were optimized. It was shown that G-MnOX-P/HAC prepared by a one-step precipitation method and with a graphene doping ratio of 10% had the best bactericidal effect in a dielectric barrier discharge (DBD) reactor after 4 min of reaction. The eradication rates for Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), coronavirus and Aspergillus niger were all greater than 99.9%. The characterization techniques TEM, SEM, XRD, XPS, BET and FT-IR showed that the G-MnOX-P samples prepared by the one-step precipitation method had larger specific surface areas with more oxygen vacancies and functional groups on the surfaces, which was conducive to decomposition of the ozone generated by the dissociated plasma and formation of reactive oxygen species (ROS) for the microbial eradication process. Finally, by comparing the ozone-decomposition activity with the plasma co-catalytic performance, it was verified that efficient decomposition of the ozone facilitated the eradication of microorganisms. Based on this, an analysis of the mechanism for efficient eradication was carried out.
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Affiliation(s)
- Jiqing Zhang
- College of Missile Engineering, Rocket Force University of Engineering, Xi’an, China
| | - Ying Jia
- College of Missile Engineering, Rocket Force University of Engineering, Xi’an, China
| | - Xiaomeng Lv
- College of Missile Engineering, Rocket Force University of Engineering, Xi’an, China
| | - Tiedan Xiong
- School of Marine Science and Technology, Harbin Institute of Technology, Weihai, China
| | - Jun Su
- College of Missile Engineering, Rocket Force University of Engineering, Xi’an, China
| | - Yuanzheng Huang
- College of Missile Engineering, Rocket Force University of Engineering, Xi’an, China
| | - Keke Shen
- College of Missile Engineering, Rocket Force University of Engineering, Xi’an, China
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19
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Jeong SB, Shin JH, Kim SW, Seo SC, Jung JH. Performance evaluation of an electrostatic precipitator with a copper plate using an aerosolized SARS-CoV-2 surrogate (bacteriophage phi 6). ENVIRONMENTAL TECHNOLOGY & INNOVATION 2023; 30:103124. [PMID: 36987524 PMCID: PMC10035800 DOI: 10.1016/j.eti.2023.103124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/29/2023] [Accepted: 03/21/2023] [Indexed: 06/19/2023]
Abstract
The global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has reminded us of the importance of developing technologies to reduce and control bioaerosols in built environments. For bioaerosol control, the interaction between researchers and biomaterials is essential, and considering the characteristics of target pathogens is strongly required. Herein, we used enveloped viral aerosols, bacteriophage phi 6, for evaluating the performance of an electrostatic precipitator (ESP) with a copper-collecting plate (Cu-plate). In particular, bacteriophage phi 6 is an accessible enveloped virus that can be operated in biosafety level (BSL)-1 as a promising surrogate for SARS-CoV-2 with structural and morphological similarities. ESP with Cu-plate showed >91% of particle removal efficiency for viral aerosols at 77 cm/s of airflow face velocity. Moreover, the Cu-plate presented a potent antiviral performance of 5.4-relative log reduction within <15 min of contact. We believe that the evaluation of ESP performance using an aerosolized enveloped virus and plaque assay is invaluable. Our results provide essential information for the development of bioaerosol control technologies that will lead the post-corona era.
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Affiliation(s)
- Sang Bin Jeong
- Department of Mechanical Engineering, Sejong University, Seoul 05006, Republic of Korea
| | - Jae Hak Shin
- Department of Mechanical Engineering, Sejong University, Seoul 05006, Republic of Korea
| | - Sam Woong Kim
- Agri-Food Bio Convergence Institute, Gyeongsang National University, Jinju 52725, Republic of Korea
| | - Sung Chul Seo
- Department of Nano, Chemical and Biological Engineering, Seokyeong University, Seoul 02713, Republic of Korea
| | - Jae Hee Jung
- Department of Mechanical Engineering, Sejong University, Seoul 05006, Republic of Korea
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20
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Zhang S, Liang Z, Wang X, Ye Z, Li G, An T. Bioaerosols in an industrial park and the adjacent houses: Dispersal between indoor/outdoor, the impact of air purifier, and health risk reduction. ENVIRONMENT INTERNATIONAL 2023; 172:107778. [PMID: 36724713 DOI: 10.1016/j.envint.2023.107778] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/20/2023] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Inhaling airborne pathogens may cause severe epidemics showing huge threats to indoor dwellings residents. The ventilation, environmental parameters, and human activities would affect the abundance and pathogenicity of bioaerosols in indoor. However, people know little about the indoor airborne microbes especially pathogens near the industrial park polluted with organics and heavy metals. Herein, the indoor bioaerosols' community composition, source and influencing factors near an electronic waste (e-waste) industrial park were investigated. Results showed that the average bioaerosol level in the morning was lower than evening. Bioaerosol concentration and activity in indoor (1936 CFU/m3 and 7.62 × 105 ng/m3 sodium fluorescein in average) were lower than the industrial park (4043 CFU/m3 and 7.77 × 105 ng/m3 sodium fluorescein), and higher microbial viability may be caused by other pollutants generated during e-waste dismantling process. Fluorescent biological aerosol particles occupied 17.6%-23.7% of total particles, indicating that most particles were non-biological. Bacterial communities were richer and more diverse than fungi. Furthermore, Bacillus and Cladosporium were the dominant indoor pathogens, and pathogenic fungi were more influenced by environmental factors than bacteria. SourceTracker analysis indicates that outdoor was the main source of indoor bioaerosols. The hazard quotient (<1) of airborne microbes through inhalation was negligible, but long-term exposure to pathogens could be harmful. Air purifiers could effectively remove the airborne fungi and spheroid bacteria than cylindrical bacteria, but open doors and windows would reduce the purification efficiency. This study is great important for risk assessments and control of indoor bioaerosols near industrial park.
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Affiliation(s)
- Simeng Zhang
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Zhishu Liang
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Xiaolong Wang
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Zikai Ye
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Guiying Li
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
| | - Taicheng An
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
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21
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Sauliene I, Valiulis A, Keriene I, Sukiene L, Dovydaityte D, Prokopciuk N, Valskys V, Valskiene R, Damialis A. Airborne pollen and fungi indoors: Evidence from primary schools in Lithuania. Heliyon 2023; 9:e12668. [PMID: 36685406 PMCID: PMC9850001 DOI: 10.1016/j.heliyon.2022.e12668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/14/2022] [Accepted: 12/20/2022] [Indexed: 01/05/2023] Open
Abstract
The number of children suffering from respiratory allergies and asthma has been increasing worldwide and, hence, it is crucial to understand the burden of inhalant biological particles present in school facilities, where children spend one third of their life. From the perspective of indoor air quality, while there are numerous studies on outdoor bioaerosol exposure, there are still uncertainties regarding the diversity and deposition of airborne pollen and fungi indoors. When it comes to schools, there is limited research as to the potential bioaerosol exposure. Here we studied the indoor environment of public schools aiming to reveal whether primary schools of different sizes and at localities of different levels of urbanization may exhibit a variability in the biodiversity and abundance of particles of biological origin, which could pose a risk to child health. To achieve this, 11 schools were selected, located in a variety of environments, from downtown, to city centre-periphery, and to the suburbs. Fungal and pollen samples were collected from various surfaces in school classrooms and corridors, using passive air sampling and swab sampling. We demonstrated that fungi and pollen are detected in school premises during and after the vegetation season. The highest diversity of bioaerosols was found on the top of cabinets and windowsills, with Penicillium, Cladosporium and Acremonium being the most abundant indoors. The levels of fungi were higher in schools with more students. The diversity and amount of pollen in the spring were significantly higher than in samples collected in autumn. Our findings complemented existing evidence that bioaerosol measurements in schools (including kindergartens or informal education facilities) are vital. Hence, we here suggest that, in addition to monitoring air quality and bacterial levels indoors, fungi and pollen measurements have to be integrated in the existing regular biomonitoring campaigns so as to prevent exposure, increase awareness and manage efficiently allergic symptomatology.
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Affiliation(s)
- Ingrida Sauliene
- Institute of Regional Development, Siauliai Academy, Vilnius University, Siauliai, Lithuania
| | - Arunas Valiulis
- Clinic of Children's Diseases, Institute of Clinical Medicine, Medical Faculty, Vilnius University, Vilnius, Lithuania,Department of Public Health, Institute of Health Sciences, Medical Faculty, Vilnius University, Vilnius, Lithuania
| | - Ilona Keriene
- Institute of Regional Development, Siauliai Academy, Vilnius University, Siauliai, Lithuania
| | - Laura Sukiene
- Institute of Regional Development, Siauliai Academy, Vilnius University, Siauliai, Lithuania
| | - Dovile Dovydaityte
- Institute of Regional Development, Siauliai Academy, Vilnius University, Siauliai, Lithuania
| | - Nina Prokopciuk
- Clinic of Children's Diseases, Institute of Clinical Medicine, Medical Faculty, Vilnius University, Vilnius, Lithuania
| | - Vaidotas Valskys
- Institute of Biosciences, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | | | - Athanasios Damialis
- Terrestrial Ecology and Climate Change, Department of Ecology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece,Corresponding author.
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22
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Argyropoulos CD, Skoulou V, Efthimiou G, Michopoulos AK. Airborne transmission of biological agents within the indoor built environment: a multidisciplinary review. AIR QUALITY, ATMOSPHERE, & HEALTH 2022; 16:477-533. [PMID: 36467894 PMCID: PMC9703444 DOI: 10.1007/s11869-022-01286-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
The nature and airborne dispersion of the underestimated biological agents, monitoring, analysis and transmission among the human occupants into building environment is a major challenge of today. Those agents play a crucial role in ensuring comfortable, healthy and risk-free conditions into indoor working and leaving spaces. It is known that ventilation systems influence strongly the transmission of indoor air pollutants, with scarce information although to have been reported for biological agents until 2019. The biological agents' source release and the trajectory of airborne transmission are both important in terms of optimising the design of the heating, ventilation and air conditioning systems of the future. In addition, modelling via computational fluid dynamics (CFD) will become a more valuable tool in foreseeing risks and tackle hazards when pollutants and biological agents released into closed spaces. Promising results on the prediction of their dispersion routes and concentration levels, as well as the selection of the appropriate ventilation strategy, provide crucial information on risk minimisation of the airborne transmission among humans. Under this context, the present multidisciplinary review considers four interrelated aspects of the dispersion of biological agents in closed spaces, (a) the nature and airborne transmission route of the examined agents, (b) the biological origin and health effects of the major microbial pathogens on the human respiratory system, (c) the role of heating, ventilation and air-conditioning systems in the airborne transmission and (d) the associated computer modelling approaches. This adopted methodology allows the discussion of the existing findings, on-going research, identification of the main research gaps and future directions from a multidisciplinary point of view which will be helpful for substantial innovations in the field.
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Affiliation(s)
| | - Vasiliki Skoulou
- B3 Challenge Group, Chemical Engineering, School of Engineering, University of Hull, Cottingham Road, Hull, HU6 7RX UK
| | - Georgios Efthimiou
- Centre for Biomedicine, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX UK
| | - Apostolos K. Michopoulos
- Energy & Environmental Design of Buildings Research Laboratory, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus
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23
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Li J, Zuraimi S, Schiavon S, Wan MP, Xiong J, Tham KW. Diurnal trends of indoor and outdoor fluorescent biological aerosol particles in a tropical urban area. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 848:157811. [PMID: 35931158 DOI: 10.1016/j.scitotenv.2022.157811] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 07/20/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
We evaluated diurnal trends of size-resolved indoor and outdoor fluorescent biological airborne particles (FBAPs) and their contributions to particulate matter (PM) within 0.5-20 μm. After a ten-week continuous sampling via two identical wideband integrated bioaerosol sensors, we found that both indoor and outdoor diurnal trends of PM were driven by its bioaerosol component. Outdoors, the median [interquartile range] FBAP mass concentration peaked at 8.2 [5.8-9.9] μg/m3 around sunrise and showed a downtrend from 6:00 to 18:00 during the daytime and an uptrend during the night. The nighttime FBAP level was 1.8 [1.4-2.2] times higher than that during the daytime, and FBAPs accounted for 45 % and 56 % of PM during daytime and nighttime, respectively. Indoors, the rise in concentrations of FBAPs smaller than 1 μm coincided with the starting operation of the heating, ventilation, and air conditioning (HVAC) system at 6:00, and the concentration peaked at 8:00 and dropped to the daily average by noontime. This indicated that the starting operation of the HVAC system dislodged the overnight settled and accumulated fine bioaerosols into the indoor environment. For particles larger than 1 μm, the variation of mass concentration was driven by occupancy. Based on regression modeling, the contributions of indoor PM, non-FBAP, and FBAP sources to indoor mass concentrations were estimated to be 93 %, 67 %, and 97 % during the occupied period.
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Affiliation(s)
- Jiayu Li
- Berkeley Education Alliance for Research in Singapore (BEARS), 1 Create Way, 138602, Singapore.
| | - Sultan Zuraimi
- Berkeley Education Alliance for Research in Singapore (BEARS), 1 Create Way, 138602, Singapore
| | - Stefano Schiavon
- Center for the Built Environment (CBE), UC Berkeley, 390 Wurster Hall, Berkeley, CA 94720, USA
| | - Man Pun Wan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Ave, 639798, Singapore
| | - Jinwen Xiong
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Ave, 639798, Singapore
| | - Kwok Wai Tham
- Department of Building, National University of Singapore, 4 Architecture Drive, 117566, Singapore
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24
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Shen Y, Haig SJ, Prussin AJ, LiPuma JJ, Marr LC, Raskin L. Shower water contributes viable nontuberculous mycobacteria to indoor air. PNAS NEXUS 2022; 1:pgac145. [PMID: 36712351 PMCID: PMC9802317 DOI: 10.1093/pnasnexus/pgac145] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 11/07/2022] [Indexed: 11/11/2022]
Abstract
Nontuberculous mycobacteria (NTM) are frequently present in municipal drinking water and building plumbing, and some are believed to cause respiratory tract infections through inhalation of NTM-containing aerosols generated during showering. However, the present understanding of NTM transfer from water to air is insufficient to develop NTM risk mitigation strategies. This study aimed to characterize the contribution of shower water to the abundance of viable NTM in indoor air. Shower water and indoor air samples were collected, and 16S rRNA and rpoB genes were sequenced. The sequencing results showed that running the shower impacted the bacterial community structure and NTM species composition in indoor air by transferring certain bacteria from water to air. A mass balance model combined with NTM quantification results revealed that on average 1/132 and 1/254 of NTM cells in water were transferred to air during 1 hour of showering using a rain and massage showerhead, respectively. A large fraction of the bacteria transferred from water to air were membrane-damaged, i.e. they had compromised membranes based on analysis by live/dead staining and flow cytometry. However, the damaged NTM in air were recoverable as shown by growth in a culture medium mimicking the respiratory secretions of people with cystic fibrosis, implying a potential infection risk by NTM introduced to indoor air during shower running. Among the recovered NTM, Mycobacterium mucogenicum was the dominant species as determined by rpoB gene sequencing. Overall, this study lays the groundwork for future pathogen risk management and public health protection in the built environment.
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Affiliation(s)
| | | | - Aaron J Prussin
- Department of Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, VA 24061, USA
| | - John J LiPuma
- Department of Pediatrics, University of Michigan Medical School, 1500 E. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Linsey C Marr
- Department of Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, VA 24061, USA
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25
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Addor YS, Baumgardner D, Hughes D, Newman N, Jandarov R, Reponen T. Assessing residential indoor and outdoor bioaerosol characteristics using the ultraviolet light-induced fluorescence-based wideband integrated bioaerosol sensor. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:1790-1804. [PMID: 36056699 DOI: 10.1039/d2em00177b] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We assessed and compared indoor and outdoor residential aerosol particles in a third-floor apartment from August through September 2020. The measurements were conducted using a direct-reading ultraviolet light-induced fluorescence (UV-LIF) wideband integrated bioaerosol spectrometer (WIBS). It measures individual particle light scattering and fluorescence from which particle properties can be derived. The number concentrations of total aerosol particles (TAP) and total fluorescent aerosol particles (TFAP) were significantly higher indoors. Daily and hourly TFAP mean concentrations followed the same trends as the TAP, both indoors and outdoors. The daily mean rank of the TFAP fraction (TFAP/TAP) was significantly higher indoors (23%) than outdoors (19%). Particles representing bacteria dominated indoors while particles representing fungi and pollen dominated outdoors. The mean volume-weighted median diameters for TFAP were 1.67 μm indoors and 2.09 μm outdoors. Higher TFAP fraction indoors was likely due to occupants' activities that generated or resuspended particles. This study contributes to understanding the characteristics of residential aerosol particles in situations when occupants spend most of their time indoors. Based on our findings, a large portion of all indoor aerosol particles could be biological (15-20%) and of respirable particle size (≥95%). Using a novel direct reading UV-LIF-based sensor can help quickly assess aerosol exposures relevant to human health.
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Affiliation(s)
- Yao S Addor
- University of Cincinnati, Department of the Environmental and Public Health Sciences, Cincinnati, OH, USA.
| | - Darrel Baumgardner
- Droplet Measurement Technologies LLC., 2400 Trade Centre Avenue, Longmont, CO 80503, USA
| | - Dagen Hughes
- Droplet Measurement Technologies LLC., 2400 Trade Centre Avenue, Longmont, CO 80503, USA
| | - Nicholas Newman
- University of Cincinnati, Department of the Environmental and Public Health Sciences, Cincinnati, OH, USA.
- University of Cincinnati, Department of Pediatrics, Cincinnati, OH, USA
- Cincinnati Children's Hospital Medical Center, Division of General and Community Pediatrics, Cincinnati, OH, USA
| | - Roman Jandarov
- University of Cincinnati, Department of the Environmental and Public Health Sciences, Cincinnati, OH, USA.
| | - Tiina Reponen
- University of Cincinnati, Department of the Environmental and Public Health Sciences, Cincinnati, OH, USA.
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26
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Minahan NT, Chen CH, Shen WC, Lu TP, Kallawicha K, Tsai KH, Guo YL. Fungal Spore Richness in School Classrooms is Related to Surrounding Forest in a Season-Dependent Manner. MICROBIAL ECOLOGY 2022; 84:351-362. [PMID: 34498118 DOI: 10.1007/s00248-021-01844-2] [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: 05/24/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Airborne fungal spores are important aeroallergens that are remarkably diverse in terms of taxonomic richness. Indoor fungal richness is dominated by outdoor fungi and is geographically patterned, but the influence of natural landscape is unclear. We aimed to elucidate the relationship between indoor fungal spore richness and natural landscape by examining the amount of surrounding forest cover. Passive sampling of airborne fungal spores was conducted in 24 schools in Taiwan during hot and cool seasons, and amplicon sequencing was used to study fungal spore (genus) richness targeting the internal transcribed spacer 2 (ITS2) region. In total, 693 fungal genera were identified, 12 of which were ubiquitous. Despite overall similarity of fungal spore richness between seasons, Basidiomycota and Ascomycota richness increased during the hot and cool seasons, respectively. Fungal spore richness in schools had a strong positive correlation with the amount of surrounding forest cover during the cool season, but not during the hot season. Fungal assemblages in schools were more similar during the hot season due to the increased ubiquity of Agaricomycetes genera. These observations indicate dispersal limitation at the kilometer scale during the cool season and increased long-distance dispersal during the hot season. Several allergenic fungi were commonly identified in schools, including some previously overlooked by conventional methods, which may be targeted as sensitizing agents in future investigations into atopic conditions. More generally, the relative importance of fungal spore richness in the development, chronicity, and severity of atopic conditions in children requires investigation.
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Affiliation(s)
- Nicholas T Minahan
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, No.17, Xu-Zhou Rd., Taipei, 100025, Taiwan
| | - Chi-Hsien Chen
- Department of Environmental and Occupational Medicine, National Taiwan University (NTU) College of Medicine and NTU Hospital, Taipei, Taiwan
| | - Wei-Chiang Shen
- Department of Plant Pathology and Microbiology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
| | - Tzu-Pin Lu
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Kraiwuth Kallawicha
- College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Kun-Hsien Tsai
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, No.17, Xu-Zhou Rd., Taipei, 100025, Taiwan.
- Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan.
| | - Yue Leon Guo
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, No.17, Xu-Zhou Rd., Taipei, 100025, Taiwan.
- Department of Environmental and Occupational Medicine, National Taiwan University (NTU) College of Medicine and NTU Hospital, Taipei, Taiwan.
- National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan.
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27
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Li Y, Wu C, Cao G, Guan D, Zhan C. Transmission characteristics of respiratory droplets aerosol in indoor environment: an experimental study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2022; 32:1768-1779. [PMID: 33825604 DOI: 10.1080/09603123.2021.1910629] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/25/2021] [Indexed: 06/12/2023]
Abstract
Transmission of droplets has been recognized as an important form of infection for the respiratory diseases. This study investigated the distribution of human respiratory droplets and assessed the effects of air change rate and generated velocity on droplet transmission using an active agent in an enclosed chamber (46 m3). Results revealed that the higher the air change rate was, the fewer viable droplets were detected in the range of <3.3 μm with ventilation; an increased air change rate can increase the attenuation of droplet aerosol. Without ventilation, the viable droplet size was observed to mainly distribute greater than 3.3 μm, which occupied up 87.5% of the total number. When the generated velocity was increased to 20 m/s, 29.38% of the viable droplets were detected at the position of 2.0 m. The findings are excepted to be useful for developing the technology of reducing droplet propagation and providing data verification for simulation research.
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Affiliation(s)
- Yanju Li
- School of Energy and Safety Engineering, Tianjin Chengjian University, Tianjin, China
| | - Chunbin Wu
- School of Energy and Safety Engineering, Tianjin Chengjian University, Tianjin, China
| | - Guoqing Cao
- Institute of Building Environment and Energy, China Academy of Building Research, Beijing, China
| | - Dexing Guan
- School of Energy and Safety Engineering, Tianjin Chengjian University, Tianjin, China
| | - Chaoguo Zhan
- School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin, China
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28
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Liu Y, Lu C, Li Y, Norbäck D, Deng Q. Outdoor Air Pollution and Indoor Window Condensation Associated with Childhood Symptoms of Allergic Rhinitis to Pollen. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19138071. [PMID: 35805726 PMCID: PMC9266097 DOI: 10.3390/ijerph19138071] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/24/2022] [Accepted: 06/25/2022] [Indexed: 12/10/2022]
Abstract
Pollen is the main factor causing asthma and allergic rhinitis (AR). However, the key indoor and outdoor factors associated with childhood symptoms of allergic rhinitis (SAR) to pollen are unclear. We investigate the association of exposure to outdoor air pollution and indoor environmental factors with childhood SAR to pollen and consider SAR to pollen in different seasons. A cross-sectional study of 2598 preschool children aged 3–6 was conducted in Changsha, China (2011–2012). The prevalence of SAR to pollen in children and information on indoor environmental factors were obtained by questionnaire. Children’s exposure to outdoor air pollutants (PM10, SO2, and NO2) was estimated from the monitored concentrations. The association of exposure to indoor environmental factors and outdoor air pollution with childhood SAR to pollen was estimated by multiple logistic regression models using odds ratio (OR) and a 95% confidence interval (CI), and the relationship between outdoor air pollutants and childhood SAR to pollen was investigated using restricted cubic splines. We found that early-life and current exposure to outdoor air pollution were significantly associated with childhood SAR to pollen in autumn, including exposure to SO2 one year before conception (OR = 1.60, 95% CI = 1.08–2.37) and during entire pregnancy (OR = 1.49, 95% CI = 1.01–2.20) periods, exposure to PM10 during the current period (OR = 1.78, 95% CI = 1.07–2.96), and exposure to NO2 during the early-life (one year before conception and entire pregnancy) and current periods with ORs (95% CI) of 1.72 (1.10–2.71), 1.82 (1.17–2.83), and 1.94 (1.11–3.40), respectively. Further, we found significant associations of both prenatal and postnatal exposure to window condensation with childhood SAR to pollen, with ORs (95% CI) = 1.37 (1.05–1.77) and 1.38 (1.02–1.88), respectively. We encourage SAR to pollen sufferers to stay indoors due to outdoor air pollution and higher pollen concentration outdoors, but indoor ventilation should be maintained.
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Affiliation(s)
- Yingjie Liu
- School of Energy Science and Engineering, Central South University, Changsha 410083, China;
| | - Chan Lu
- XiangYa School of Public Health, Central South University, Changsha 410078, China;
| | - Yuguo Li
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong 999077, China;
| | - Dan Norbäck
- Department of Medical Sciences, Uppsala University, 752 36 Uppsala, Sweden;
| | - Qihong Deng
- School of Public Health, Zhengzhou University, Zhengzhou 450001, China
- Correspondence:
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29
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Liu CY, Tseng CH, Wang KF. The Assessment of Indoor Formaldehyde and Bioaerosol Removal by Using Negative Discharge Electrostatic Air Cleaners. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19127209. [PMID: 35742458 PMCID: PMC9223538 DOI: 10.3390/ijerph19127209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 02/01/2023]
Abstract
This study investigated the single-pass performance of a negative corona electrostatic precipitators (ESP) in removing suspended particulates (PM2.5 and PM10), formaldehyde (HCHO), and bioaerosols (bacteria and fungi) and measured the ozone (O3) concentration generated by ESP. The experimental results revealed that if the operational conditions for the ESP were set to high voltage (−10.5 kV) and low air flow rate (2.4 m3/min), ESP had optimal air pollutant removal efficiency. In the laboratory system, its PM2.5 and PM10 removal rates both reached 99% at optimal conditions, and its HCHO removal rate was 55%. In field tests, its PM2.5, PM10, HCHO, bacteria, and fungi removal rates reached 89%, 90%, 46%, 69%, and 85% respectively. The ESP in the laboratory system (−10.5 kV and 2.4 m3/min) generated 7.374 ppm of O3 under optimal conditions. Under the same operational conditions, O3 generated by ESP in the food waste storage room and the meeting room were 1.347 ppm and 1.749 ppm, respectively. The removal of HCHO and bioaerosols was primarily attributed to their destruction in the corona, as well as ozone oxidation, and collection on the dust collection plate.
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Affiliation(s)
- Chao-Yun Liu
- Institute of Environmental Engineering and Management, National Taipei University of Technology, Taipei 106344, Taiwan;
| | - Chao-Heng Tseng
- Institute of Environmental Engineering and Management, National Taipei University of Technology, Taipei 106344, Taiwan;
- Correspondence: ; Tel.: +886-2-2771-2171 (ext. 4184)
| | - Kai-Feng Wang
- Union Professional Group of Architecture, Taipei 110057, Taiwan;
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30
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Abstract
This paper simulates the spread of COVID-19 at universities via airborne transmission in classroom settings. The transmission risk model used for these simulations accounts for student-specific class schedules, classroom sizes and occupancy, and ventilation rates, as well as vaccination rate and efficacy. We show the simulations reproduce trends observed in weekly infection rates at a large US university. We also evaluate the impact of campus operational policies. Model predictions show moving 90% of classes online can reduce new infections by as much as 18×, and universal mask usage can reduce new infections by up to 3.6×. For full-time in-person instruction, high vaccination rates are predicted to curb transmission even for more contagious variants of severe acute respiratory syndrome coronavirus 2. We study the airborne transmission risk associated with holding in-person classes on university campuses for the original strain and a more contagious variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We adopt a model for airborne transmission risk in an enclosed room that considers room properties, mask efficiency, and initial infection probability of the occupants. Additionally, we study the effect of vaccination on the spread of the virus. The presented model has been evaluated in simulations using fall 2019 (prepandemic) and fall 2020 (hybrid instruction) course registration data of a large US university, allowing for assessing the difference in transmission risk between in-person and hybrid programs and the impact of occupancy reduction, mask-wearing, and vaccination. The simulations indicate that without vaccination, moving 90% of the classes online leads to a 17 to 18× reduction in new cases, and universal mask usage results in an ∼2.7 to 3.6× reduction in new infections through classroom interactions. Furthermore, the results indicate that for the original variant and using vaccines with efficacy greater than 90%, at least 23% (64%) of students need to be vaccinated with (without) mask usage in order to operate the university at full occupancy while preventing an increase in cases due to classroom interactions. For the more contagious variant, even with universal mask usage, at least 93% of the students need to be vaccinated to ensure the same conditions. We show that the model is able to predict trends observed in weekly infection rates for fall 2021.
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31
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Felgueiras F, Mourão Z, Oliveira Fernandes ED, Gabriel MF. Airborne bacterial and fungal concentrations and fungal diversity in bedrooms of infant twins under 1 year of age living in Porto. ENVIRONMENTAL RESEARCH 2022; 206:112568. [PMID: 34932978 DOI: 10.1016/j.envres.2021.112568] [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: 04/30/2021] [Revised: 09/29/2021] [Accepted: 12/11/2021] [Indexed: 06/14/2023]
Abstract
Exposure to airborne microorganisms has been linked to the development of health detriments, particularly in children. Microbial pollution can constitute a relevant health concern indoors, where levels of airborne microorganisms may be specially increased. This work aimed to characterize the airborne bacterial levels, and fungal concentration and diversity to which twins are exposed in their bedrooms (n = 30) during the first year of life. Bacterial and fungal levels varied widely across the studied bedrooms, with 10% of the rooms presenting values exceeding the national limit for both indoor bacterial and fungal counts. Cladosporium was the predominant genera, but Penicillium, Aspergillus, Alternaria, Trichoderma and Chrysonilia were also identified in the samples collected. In addition, two toxicogenic species, A. flavus and T. viride, were identified at counts that exceeded the established limit (12 CFU/m3) in 3 and 7% of the bedrooms surveyed, respectively. Based on indoor-to-outdoor concentration ratios, outdoor air seemed to be the main contributor to the total load of fungi found indoors, while airborne bacteria appeared to be mainly linked to indoor sources. Higher indoor nitrogen dioxide levels were negatively correlated with indoor fungi concentrations, whereas particulate matter and volatile organic compounds concentrations were associated with an increase in fungal prevalence. In addition, rooms with small carpets or located near outdoor agriculture sources presented significantly greater total fungal concentrations. Multiple linear regression models showed that outdoor levels were the single significant predictor identified, explaining 38.6 and 53.6% of the Cladosporium sp. and total fungi counts, respectively. The results also suggest the existence of additional factors contributing to airborne biologicals load in infants' bedrooms that deserve further investigation. Findings stress the need for investigating the existence of declared interactive effects between chemical and biological air pollutants to accurately understand the health risk that the assessed levels can represent to infants.
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Affiliation(s)
- Fátima Felgueiras
- INEGI, Institute of Science and Innovation in Mechanical and Industrial Engineering, Campus da FEUP, Rua Dr. Roberto Frias 400, 4200-465, Porto, Portugal
| | - Zenaida Mourão
- INEGI, Institute of Science and Innovation in Mechanical and Industrial Engineering, Campus da FEUP, Rua Dr. Roberto Frias 400, 4200-465, Porto, Portugal
| | | | - Marta Fonseca Gabriel
- INEGI, Institute of Science and Innovation in Mechanical and Industrial Engineering, Campus da FEUP, Rua Dr. Roberto Frias 400, 4200-465, Porto, Portugal.
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32
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Nathu VD, Virkutyte J, Rao MB, Nieto-Caballero M, Hernandez M, Reponen T. Direct-Read Fluorescence-Based Measurements of Bioaerosol Exposure in Home Healthcare. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19063613. [PMID: 35329300 PMCID: PMC8951687 DOI: 10.3390/ijerph19063613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 02/06/2023]
Abstract
Home healthcare workers (HHCWs) are subjected to variable working environments which increase their risk of being exposed to numerous occupational hazards. One of the potential occupational hazards within the industry includes exposure to bioaerosols. This study aimed to characterize concentrations of three types of bioaerosols utilizing a novel fluorescence-based direct-reading instrument during seven activities that HHCWs typically encounter in patients’ homes. Bioaerosols were measured in an indoor residence throughout all seasons in Cincinnati, OH, USA. A fluorescence-based direct-reading instrument (InstaScope, DetectionTek, Boulder, CO, USA) was utilized for all data collection. Total particle counts and concentrations for each particle type, including fluorescent and non-fluorescent particles, were utilized to form the response variable, a normalized concentration calculated as a ratio of concentration during activity to the background concentration. Walking experiments produced a median concentration ratio of 52.45 and 2.77 for pollen and fungi, respectively. Fungi and bacteria produced the highest and lowest median concentration ratios of 17.81 and 1.90 for showering, respectively. Lastly, our current study showed that sleeping activity did not increase bioaerosol concentrations. We further conclude that utilizing direct-reading methods may save time and effort in bioaerosol-exposure assessment.
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Affiliation(s)
- Vishal D. Nathu
- Department of Environmental & Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, OH 45267-0056, USA; (V.D.N.); (J.V.); (M.B.R.)
| | - Jurate Virkutyte
- Department of Environmental & Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, OH 45267-0056, USA; (V.D.N.); (J.V.); (M.B.R.)
| | - Marepalli B. Rao
- Department of Environmental & Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, OH 45267-0056, USA; (V.D.N.); (J.V.); (M.B.R.)
| | - Marina Nieto-Caballero
- Department of Environmental Engineering, College of Engineering & Applied Science, University of Colorado Boulder, Boulder, CO 80309-0428, USA; (M.N.-C.); (M.H.)
| | - Mark Hernandez
- Department of Environmental Engineering, College of Engineering & Applied Science, University of Colorado Boulder, Boulder, CO 80309-0428, USA; (M.N.-C.); (M.H.)
| | - Tiina Reponen
- Department of Environmental & Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, OH 45267-0056, USA; (V.D.N.); (J.V.); (M.B.R.)
- Correspondence:
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33
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Peng Z, Rojas ALP, Kropff E, Bahnfleth W, Buonanno G, Dancer SJ, Kurnitski J, Li Y, Loomans MGLC, Marr LC, Morawska L, Nazaroff W, Noakes C, Querol X, Sekhar C, Tellier R, Greenhalgh T, Bourouiba L, Boerstra A, Tang JW, Miller SL, Jimenez JL. Practical Indicators for Risk of Airborne Transmission in Shared Indoor Environments and Their Application to COVID-19 Outbreaks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022. [PMID: 34985868 DOI: 10.1101/2021.04.21.21255898] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Some infectious diseases, including COVID-19, can undergo airborne transmission. This may happen at close proximity, but as time indoors increases, infections can occur in shared room air despite distancing. We propose two indicators of infection risk for this situation, that is, relative risk parameter (Hr) and risk parameter (H). They combine the key factors that control airborne disease transmission indoors: virus-containing aerosol generation rate, breathing flow rate, masking and its quality, ventilation and aerosol-removal rates, number of occupants, and duration of exposure. COVID-19 outbreaks show a clear trend that is consistent with airborne infection and enable recommendations to minimize transmission risk. Transmission in typical prepandemic indoor spaces is highly sensitive to mitigation efforts. Previous outbreaks of measles, influenza, and tuberculosis were also assessed. Measles outbreaks occur at much lower risk parameter values than COVID-19, while tuberculosis outbreaks are observed at higher risk parameter values. Because both diseases are accepted as airborne, the fact that COVID-19 is less contagious than measles does not rule out airborne transmission. It is important that future outbreak reports include information on masking, ventilation and aerosol-removal rates, number of occupants, and duration of exposure, to investigate airborne transmission.
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Affiliation(s)
- Z Peng
- Dept. of Chemistry and CIRES, University of Colorado, Boulder, Colorado 80309, United States
| | - A L Pineda Rojas
- CIMA, UMI-IFAECI/CNRS, FCEyN, Universidad de Buenos Aires─UBA/CONICET, Buenos Aires C1428EGA, Argentina
| | - E Kropff
- Leloir Institute─IIBBA/CONICET, CBA, Buenos Aires C1405BWE, Argentina
| | - W Bahnfleth
- Dept. of Architectural Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - G Buonanno
- Dept. of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino 03043, Italy
| | - S J Dancer
- Dept. of Microbiology, NHS Lanarkshire, Glasgow, Scotland G75 8RG, U.K
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, Scotland EH11 4BN, U.K
| | - J Kurnitski
- REHVA Technology and Research Committee, Tallinn University of Technology, Tallinn 19086, Estonia
| | - Y Li
- Dept. of Mechanical Engineering, The University of Hong Kong, Hong Kong 999077, China
| | - M G L C Loomans
- Dept. of the Built Environment, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
| | - L C Marr
- Dept. of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - L Morawska
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland 4001, Australia
| | - W Nazaroff
- Dept. of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - C Noakes
- School of Civil Engineering, University of Leeds, Leeds LS2 9JT, U.K
| | - X Querol
- Institute of Environmental Assessment and Water Research, IDAEA, Spanish Research Council, CSIC, Barcelona 08034, Spain
| | - C Sekhar
- Dept. of the Built Environment, National University of Singapore , 117566 Singapore
| | - R Tellier
- Dept. of Medicine, McGill University and McGill University Health Centre, Montreal, Québec H4A 3J1, Canada
| | - T Greenhalgh
- Nuffield Dept. of Primary Care Health Sciences, University of Oxford, Oxford OX2 6GG, U.K
| | - L Bourouiba
- The Fluid Dynamics of Disease Transmission Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - A Boerstra
- REHVA (Federation of European Heating, Ventilation and Air Conditioning Associations), BBA Binnenmilieu, The Hague 2501 CJ, The Netherlands
| | - J W Tang
- Dept. of Respiratory Sciences, University of Leicester, Leicester LE1 7RH, U.K
| | - S L Miller
- Dept. of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - J L Jimenez
- Dept. of Chemistry and CIRES, University of Colorado, Boulder, Colorado 80309, United States
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34
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Peng Z, Rojas ALP, Kropff E, Bahnfleth W, Buonanno G, Dancer SJ, Kurnitski J, Li Y, Loomans MGLC, Marr LC, Morawska L, Nazaroff W, Noakes C, Querol X, Sekhar C, Tellier R, Greenhalgh T, Bourouiba L, Boerstra A, Tang JW, Miller SL, Jimenez JL. Practical Indicators for Risk of Airborne Transmission in Shared Indoor Environments and Their Application to COVID-19 Outbreaks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1125-1137. [PMID: 34985868 DOI: 10.1021/acs.est.1c06531] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Some infectious diseases, including COVID-19, can undergo airborne transmission. This may happen at close proximity, but as time indoors increases, infections can occur in shared room air despite distancing. We propose two indicators of infection risk for this situation, that is, relative risk parameter (Hr) and risk parameter (H). They combine the key factors that control airborne disease transmission indoors: virus-containing aerosol generation rate, breathing flow rate, masking and its quality, ventilation and aerosol-removal rates, number of occupants, and duration of exposure. COVID-19 outbreaks show a clear trend that is consistent with airborne infection and enable recommendations to minimize transmission risk. Transmission in typical prepandemic indoor spaces is highly sensitive to mitigation efforts. Previous outbreaks of measles, influenza, and tuberculosis were also assessed. Measles outbreaks occur at much lower risk parameter values than COVID-19, while tuberculosis outbreaks are observed at higher risk parameter values. Because both diseases are accepted as airborne, the fact that COVID-19 is less contagious than measles does not rule out airborne transmission. It is important that future outbreak reports include information on masking, ventilation and aerosol-removal rates, number of occupants, and duration of exposure, to investigate airborne transmission.
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Affiliation(s)
- Z Peng
- Dept. of Chemistry and CIRES, University of Colorado, Boulder, Colorado 80309, United States
| | - A L Pineda Rojas
- CIMA, UMI-IFAECI/CNRS, FCEyN, Universidad de Buenos Aires─UBA/CONICET, Buenos Aires C1428EGA, Argentina
| | - E Kropff
- Leloir Institute─IIBBA/CONICET, CBA, Buenos Aires C1405BWE, Argentina
| | - W Bahnfleth
- Dept. of Architectural Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - G Buonanno
- Dept. of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino 03043, Italy
| | - S J Dancer
- Dept. of Microbiology, NHS Lanarkshire, Glasgow, Scotland G75 8RG, U.K
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, Scotland EH11 4BN, U.K
| | - J Kurnitski
- REHVA Technology and Research Committee, Tallinn University of Technology, Tallinn 19086, Estonia
| | - Y Li
- Dept. of Mechanical Engineering, The University of Hong Kong, Hong Kong 999077, China
| | - M G L C Loomans
- Dept. of the Built Environment, Eindhoven University of Technology, Eindhoven 5612 AZ, The Netherlands
| | - L C Marr
- Dept. of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - L Morawska
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland 4001, Australia
| | - W Nazaroff
- Dept. of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - C Noakes
- School of Civil Engineering, University of Leeds, Leeds LS2 9JT, U.K
| | - X Querol
- Institute of Environmental Assessment and Water Research, IDAEA, Spanish Research Council, CSIC, Barcelona 08034, Spain
| | - C Sekhar
- Dept. of the Built Environment, National University of Singapore , 117566 Singapore
| | - R Tellier
- Dept. of Medicine, McGill University and McGill University Health Centre, Montreal, Québec H4A 3J1, Canada
| | - T Greenhalgh
- Nuffield Dept. of Primary Care Health Sciences, University of Oxford, Oxford OX2 6GG, U.K
| | - L Bourouiba
- The Fluid Dynamics of Disease Transmission Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - A Boerstra
- REHVA (Federation of European Heating, Ventilation and Air Conditioning Associations), BBA Binnenmilieu, The Hague 2501 CJ, The Netherlands
| | - J W Tang
- Dept. of Respiratory Sciences, University of Leicester, Leicester LE1 7RH, U.K
| | - S L Miller
- Dept. of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - J L Jimenez
- Dept. of Chemistry and CIRES, University of Colorado, Boulder, Colorado 80309, United States
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35
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Yang Z, Chen LA, Yang C, Gu Y, Cao R, Zhong K. Portable ultrasonic humidifier exacerbates indoor bioaerosol risks by raising bacterial concentrations and fueling pathogenic genera. INDOOR AIR 2022; 32:e12964. [PMID: 34837421 DOI: 10.1111/ina.12964] [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: 08/07/2021] [Revised: 10/11/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
Portable ultrasonic humidifiers are frequently used in heating rooms to ease air dryness. However, it has also posed serious health concerns such as "humidifier fever" because the bioaerosol concentration and community in the humidified space may alter quickly before the occupants could even notice. We compared the microbial proliferation rates in the humidifiers' reservoirs filled with three commonly used water types and investigated the impacts of the ultrasonic humidifiers on the temporal concentration, size distribution, and community variations of indoor bacterial and fungal aerosols during two-week humidification. The concentration of indoor bacterial aerosols increased exponentially, concentrating in the respiratory size ranges (≤1.1 µm), and was proportional to the humidification level, which soon exceeded 1000 CFU/m3 in one week (at RH = 70%), while the fungal concentration always remained low (≤177 CFU/m3 ). The indoor bioaerosol community, significantly associated with the humidifier water, was substantially distorted after humidification and dominated by the pathogenic Pseudomonas spp. (40.50%), Brevundimonas spp. (3.02%), Acinetobacter spp. (0.98%) and Legionella spp. (0.69%). Our results show that ultrasonic humidification contaminates indoor air by raising bacterial concentrations and fueling the pathogenic genera. To minimize the exposure risks, occupants should avoid long-term and excessive humidification (RH ≥ 70%) and clean the ultrasonic humidifier weekly.
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Affiliation(s)
- Zili Yang
- College of Environmental Science & Engineering, Donghua University, Shanghai, China
| | - Lu-An Chen
- College of Environmental Science & Engineering, Donghua University, Shanghai, China
| | - Chuanjun Yang
- College of Environmental Science & Engineering, Donghua University, Shanghai, China
| | - Yuqian Gu
- College of Environmental Science & Engineering, Donghua University, Shanghai, China
| | - Rong Cao
- Department of Radiology, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Ke Zhong
- College of Environmental Science & Engineering, Donghua University, Shanghai, China
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36
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Compendium of analytical methods for sampling, characterization and quantification of bioaerosols. ADV ECOL RES 2022. [DOI: 10.1016/bs.aecr.2022.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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37
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Nazaroff WW. Indoor aerosol science aspects of SARS-CoV-2 transmission. INDOOR AIR 2022; 32:e12970. [PMID: 34873752 DOI: 10.1111/ina.12970] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 11/17/2021] [Accepted: 11/26/2021] [Indexed: 05/04/2023]
Abstract
Knowledge about person-to-person transmission of SARS-CoV-2 is reviewed, emphasizing three components: emission of virus-containing particles and drops from infectious persons; transport and fate of such emissions indoors; and inhalation of viral particles by susceptible persons. Emissions are usefully clustered into three groups: small particles (diameter 0.1-5 µm), large particles (5-100 µm), and ballistic drops (>100 µm). Speaking generates particles and drops across the size spectrum. Small particles are removed from indoor air at room scale by ventilation, filtration, and deposition; large particles mainly deposit onto indoor surfaces. Proximate exposure enhancements are associated with large particles with contributions from ballistic drops. Masking and social distancing are effective in mitigating transmission from proximate exposures. At room scale, masking, ventilation, and filtration can contribute to limit exposures. Important information gaps prevent a quantitative reconciliation of the high overall global spread of COVID-19 with known transmission pathways. Available information supports several findings with moderate-to-high confidence: transmission occurs predominantly indoors; inhalation of airborne particles (up to 50 µm in diameter) contributes substantially to viral spread; transmission occurs in near proximity and at room scale; speaking is a major source of airborne SARS-CoV-2 virus; and emissions can occur without strong illness symptoms.
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Affiliation(s)
- William W Nazaroff
- Department of Civil and Environmental Engineering, University of California, Berkeley, California, USA
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38
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Nieto-Caballero M, Gomez OM, Shaughnessy R, Hernandez M. Aerosol fluorescence, airborne hexosaminidase, and quantitative genomics distinguish reductions in airborne fungal loads following major school renovations. INDOOR AIR 2022; 32:e12975. [PMID: 34897813 DOI: 10.1111/ina.12975] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 11/26/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
Fluorescent aerosol cytometry (FAC) was compared to concurrent recovery of airborne β-N-acetylhexosaminidase (NAHA) and quantitative polymerase chain reaction (qPCR) for the respective ability of these methods to detect significant changes in airborne fungal loads in response to building renovations. Composite, site-randomized indoor aerosol samples for airborne fungi measurements were acquired from more than 70 occupied classrooms in 26 different public schools in the Colorado Rocky Mountain Front Range region of the United States. As judged by ANOVA and Pearson's correlation test, statistically significant associations were observed between real-time FAC and airborne NAHA levels, which detected significant reductions in airborne fungal loads immediately following building rehabilitations. With lower confidence, a statistically significant association was also resolved between fluorescing aerosols, NAHA levels, and the recovery of fungal 18S rRNA gene copies by qPCR from simultaneous, collocated aerosol samples. Quantitative differences encountered between the recovery of common genomic markers for airborne fungi and that of optical and biochemical methods are attributed to the variance in 18S rRNA target gene copies that different fungal species can host.
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Affiliation(s)
- Marina Nieto-Caballero
- Civil, Environmental and Architectural Engineering Department, Environmental Engineering Program, University of Colorado, Boulder, Colorado, USA
| | - Odessa M Gomez
- Civil, Environmental and Architectural Engineering Department, Environmental Engineering Program, University of Colorado, Boulder, Colorado, USA
| | - Richard Shaughnessy
- Chemical Engineering Department, Indoor Air Program, University of Tulsa, Tulsa, Oklahoma, USA
| | - Mark Hernandez
- Civil, Environmental and Architectural Engineering Department, Environmental Engineering Program, University of Colorado, Boulder, Colorado, USA
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39
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Nazaroff WW, Weschler CJ. Indoor ozone: Concentrations and influencing factors. INDOOR AIR 2022; 32:e12942. [PMID: 34609012 DOI: 10.1111/ina.12942] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/21/2021] [Accepted: 09/24/2021] [Indexed: 05/03/2023]
Abstract
Because people spend most of their time indoors, much of their exposure to ozone occurs in buildings, which are partially protective against outdoor ozone. Measurements in approximately 2000 indoor environments (residences, schools, and offices) show a central tendency for average indoor ozone concentration of 4-6 ppb and an indoor to outdoor concentration ratio of about 25%. Considerable variability in this ratio exists among buildings, as influenced by seven building-associated factors: ozone removal in mechanical ventilation systems, ozone penetration through the building envelope, air-change rates, ozone loss rate on fixed indoor surfaces, ozone loss rate on human occupants, ozone loss by homogeneous reaction with nitrogen oxides, and ozone loss by reaction with gas-phase organics. Among these, the most important are air-change rates, ozone loss rate on fixed indoor surfaces, and, in densely occupied spaces, ozone loss rate on human occupants. Although most indoor ozone originates outdoors and enters with ventilation air, indoor emission sources can materially increase indoor ozone concentrations. Mitigation technologies to reduce indoor ozone concentrations are available or are being investigated. The most mature of these technologies, activated carbon filtration of mechanical ventilation supply air, shows a high modeled health-benefit to cost ratio when applied in densely occupied spaces.
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Affiliation(s)
- William W Nazaroff
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, USA
| | - Charles J Weschler
- Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ, USA
- International Centre for Indoor Environment and Energy, Technical University of Denmark, Lyngby, Denmark
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40
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Fu L, Yang M, Niu J, Ren W, You R. Transient tracer gas measurements: Development and evaluation of a fast-response SF 6 measuring system based on quartz-enhanced photoacoustic spectroscopy. INDOOR AIR 2022; 32:e12952. [PMID: 34747064 DOI: 10.1111/ina.12952] [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: 06/04/2021] [Revised: 10/08/2021] [Accepted: 10/27/2021] [Indexed: 06/13/2023]
Abstract
This study aims to develop a fast-response sulfur hexafluoride (SF6 ) measuring system, and evaluate its performance in tracer gas measurements for studying transient airborne contaminant transport. The new system is based on a quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor using a quantum cascade laser. Transient SF6 tracer gas measurements were carried out in an environmental chamber with an instantaneous source using both the QEPAS system and a traditional commercial instrument. Real-time SF6 concentrations, peak SF6 concentrations and average SF6 concentrations for one room time constant under two air change rates obtained by the two instruments were compared. The results show that the QEPAS system, which features a 0.4 s data acquisition interval, can provide detailed real-time SF6 concentrations even when the concentration is changing rapidly. The QEPAS system successfully captured the peak SF6 concentrations for all the studies cases, while commercial instrument failed in most studied cases. In most of the cases, the two instruments obtained similar average SF6 concentrations for one room time constant. However, when the concentration was in rapid change, the two systems would report significantly different results. The QEPAS system can be potentially applied in transient tracer gas measurements under complex scenarios.
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Affiliation(s)
- Liye Fu
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Min Yang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, China
| | - Jianlei Niu
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Wei Ren
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, New Territories, Hong Kong SAR, China
| | - Ruoyu You
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
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41
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Room HVAC Influences on the Removal of Airborne Particulate Matter: Implications for School Reopening during the COVID-19 Pandemic. ENERGIES 2021. [DOI: 10.3390/en14227463] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
(1) Background: Many schools and higher education settings have confronted the issue of reopening their facilities after the COVID-19 pandemic. In response, several airflow strategies spanning from adding portable air purifiers to major mechanical overhauls have been suggested to equip classrooms with what is necessary to provide a safe and reliable environment. Yet, there are many unknowns about specific contributions of the building system and its design and performance on indoor air quality (IAQ) improvements. (2) Methods: this study examined the combined effect of ventilation type, airflow rates, and filtration on IAQ in five different classrooms. Experiments were conducted by releasing inert surrogate particles into the classrooms and measuring the concentrations in various locations of the room. (3) Results: we showed that while the distribution of particles in the space is a complex function of space geometry and air distribution configurations, the average decay rate of contaminants is proportional to the number of air changes per hour in the room. (4) Conclusions: rooms with a central HVAC system responded quicker to an internal source of contamination than rooms with only fan coil units. Furthermore, increasing the ventilation rate without improved filtration is an inefficient use of energy.
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42
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Ari A, Blain K, Soubra S, Hanania NA. Treating COPD Patients with Inhaled Medications in the Era of COVID-19 and Beyond: Options and Rationales for Patients at Home. Int J Chron Obstruct Pulmon Dis 2021; 16:2687-2695. [PMID: 34611397 PMCID: PMC8487292 DOI: 10.2147/copd.s332021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/13/2021] [Indexed: 01/29/2023] Open
Abstract
COVID-19 has affected millions of patients, caregivers, and clinicians around the world. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads via droplets and close contact from person to person, and there has been an increased concern regarding aerosol drug delivery due to the potential aerosolizing of viral particles. To date, little focus has been given to aerosol drug delivery to patients with COVID-19 treated at home to minimize their hospital utilization. Since most hospitals were stressed with multiple admissions and experienced restricted healthcare resources in the era of COVID-19 pandemic, treating patients with COPD at home became essential to minimize their hospital utilization. However, guidance on how to deliver aerosolized medications safely and effectively to this patient population treated at home is still lacking. In this paper, we provide some strategies and rationales for device and interface selection, delivery technique, and infection control for patients with COPD who are being treated at home in the era of COVID-19 and beyond.
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Affiliation(s)
- Arzu Ari
- Department of Respiratory Care, Texas State University, Round Rock, TX, USA
| | - Karen Blain
- Department of Respiratory Therapy, University of North Carolina Wilmington, Wilmington, NC, USA
| | - Said Soubra
- Department of Respiratory Care, Texas State University, Round Rock, TX, USA
| | - Nicola A Hanania
- Airways Clinical Research Center, Baylor College of Medicine, Houston, TX, USA
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43
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Nguyen M, Holmes EC, Angenent LT. The short-term effect of residential home energy retrofits on indoor air quality and microbial exposure: A case-control study. PLoS One 2021; 16:e0230700. [PMID: 34543270 PMCID: PMC8452058 DOI: 10.1371/journal.pone.0230700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 08/13/2021] [Indexed: 11/19/2022] Open
Abstract
Weatherization of residential homes is a widespread procedure to retrofit older homes to improve the energy efficiency by reducing building leakage. Several studies have evaluated the effect of weatherization on indoor pollutants, such as formaldehyde, radon, and indoor particulates, but few studies have evaluated the effect of weatherization on indoor microbial exposure. Here, we monitored indoor pollutants and bacterial communities during reductions in building leakage for weatherized single-family residential homes in New York State and compared the data to non-weatherized homes. Nine weatherized and eleven non-weatherized single-family homes in Tompkins County, New York were sampled twice: before and after the weatherization procedures for case homes, and at least 3 months apart for control homes that were not weatherized. We found that weatherization efforts led to a significant increase in radon levels, a shift in indoor microbial community, and a warmer and less humid indoor environment. In addition, we found that changes in indoor airborne bacterial load after weatherization were more sensitive to shifts in season, whereas indoor radon levels were more sensitive to ventilation rates.
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Affiliation(s)
- Mytien Nguyen
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, United States of America
| | - Eric C. Holmes
- Department of GeoSciences, University of Tübingen, Tübingen, Germany
| | - Largus T. Angenent
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, United States of America
- Department of GeoSciences, University of Tübingen, Tübingen, Germany
- Max Planck Institute for Developmental Biology, Tübingen, Germany
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44
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Nozza E, Valentini S, Melzi G, Vecchi R, Corsini E. Advances on the immunotoxicity of outdoor particulate matter: A focus on physical and chemical properties and respiratory defence mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 780:146391. [PMID: 33774291 DOI: 10.1016/j.scitotenv.2021.146391] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/16/2021] [Accepted: 03/07/2021] [Indexed: 06/12/2023]
Abstract
Particulate matter (PM) is acknowledged to have multiple detrimental effects on human health. In this review, we report literature results on the possible link between outdoor PM and health outcomes with a focus on pulmonary infections and the mechanisms responsible for observed negative effects. PM physical and chemical properties, such as size and chemical composition, as well as major emission sources are described for a more comprehensive view about the role played by atmospheric PM in the observed adverse health effects; to this aim, major processes leading to the deposition of PM in the respiratory tract and how this can pave the way to the onset of pathologies are also presented. From the literature works here reviewed, two ways in which PM can threaten human health promoting respiratory infectious diseases are mostly taken into account. The first pathway is related to an enhanced susceptibility and here we will also report on molecular mechanisms in the lung immune system responsible for the augmented susceptibility to pathogens, such as the damage of mechanical defensive barriers, the alteration of the innate immune response, and the generation of oxidative stress. The second one deals with the relationship between infectious agents and PM; here we recall that viruses and bacteria (BioPM) are themselves part of atmospheric PM and are collected during sampling together with particles of different origin; so, data should be analysed with caution in order to avoid any false cause-effect relation. To face these issues a multidisciplinary approach is mandatory as also evident from the ongoing research about the mechanisms hypothesized for the SARS-CoV-2 airborne spreading, which is still controversial and claims for further investigation. Therefore, we preferred not to include papers dealing with SARS-CoV-2.
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Affiliation(s)
- E Nozza
- Department of Environmental Science and Policy, Università degli Studi di Milano, via Balzaretti 9, 20133 Milan, Italy; Department of Physics, Università degli Studi di Milano, via Celoria 16, 20133 Milan, Italy
| | - S Valentini
- Department of Physics, Università degli Studi di Milano, via Celoria 16, 20133 Milan, Italy
| | - G Melzi
- Department of Pharmacological and Biomolecular Sciences (DiSFeB), Università degli Studi di Milano, via Balzaretti 9, 20133 Milan, Italy
| | - R Vecchi
- Department of Physics, Università degli Studi di Milano, via Celoria 16, 20133 Milan, Italy.
| | - E Corsini
- Department of Environmental Science and Policy, Università degli Studi di Milano, via Balzaretti 9, 20133 Milan, Italy
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45
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Lee CH, Seok H, Jang W, Kim JT, Park G, Kim HU, Rho J, Kim T, Chung TD. Bioaerosol monitoring by integrating DC impedance microfluidic cytometer with wet-cyclone air sampler. Biosens Bioelectron 2021; 192:113499. [PMID: 34311208 PMCID: PMC8275843 DOI: 10.1016/j.bios.2021.113499] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/27/2021] [Accepted: 07/08/2021] [Indexed: 12/17/2022]
Abstract
The recent outbreak of COVID-19 has highlighted the seriousness of airborne diseases and the need for a proper pathogen detection system. Compared to the ample amount of research on biological detection, work on integrated devices for air monitoring is rare. In this work, we integrated a wet-cyclone air sampler and a DC impedance microfluidic cytometer to build a cyclone-cytometer integrated air monitor (CCAM). The wet-cyclone air sampler sucks the air and concentrates the bioaerosols into 10 mL of aqueous solvent. After 5 min of air sampling, the bioaerosol-containing solution was conveyed to the microfluidic cytometer for detection. The device was tested with aerosolized microbeads, dust, and Escherichia coli (E. coli). CCAM is shown to differentiate particles from 0.96 to 2.95 μm with high accuracy. The wet cyclone air-sampler showed a 28.04% sampling efficiency, and the DC impedance cytometer showed 87.68% detection efficiency, giving a total of 24.59% overall CCAM efficiency. After validation of the device performance, CCAM was used to detect bacterial aerosols and their viability without any separate pretreatment step. Differentiation of dust, live E. coli, and dead E. coli was successfully performed by the addition of BacLight bacterial viability reagent in the sampling solvent. The usage could be further extended to detection of specific species with proper antibody fluorescent label. A promising strategy for aerosol detection is proposed through the constructive integration of a DC impedance microfluidic cytometer and a wet-cyclone air sampler.
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Affiliation(s)
- Chang Heon Lee
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Hyunho Seok
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Woohyuk Jang
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Ji Tae Kim
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Geunsang Park
- School of Mechanical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Hyeong-U Kim
- Plasma Engineering Laboratory, Korea Institute of Machinery and Materials, Daejeon, 32103, Republic of Korea
| | - Jihun Rho
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Taesung Kim
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea; School of Mechanical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Taek Dong Chung
- Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea.
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Chatoutsidou SE, Saridaki A, Raisi L, Katsivela E, Tsiamis G, Zografakis M, Lazaridis M. Airborne particles and microorganisms in a dental clinic: Variability of indoor concentrations, impact of dental procedures, and personal exposure during everyday practice. INDOOR AIR 2021; 31:1164-1177. [PMID: 34080742 DOI: 10.1111/ina.12820] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/26/2021] [Accepted: 02/27/2021] [Indexed: 06/12/2023]
Abstract
This study presents for the first time comprehensive measurements of the particle number size distribution (10 nm to 10 μm) together with next-generation sequencing analysis of airborne bacteria inside a dental clinic. A substantial enrichment of the indoor environment with new particles in all size classes was identified by both activities to background and indoor/outdoor (I/O) ratios. Grinding and drilling were the principal dental activities to produce new particles in the air, closely followed by polishing. Illumina MiSeq sequencing of 16S rRNA of bioaerosol collected indoors revealed the presence of 86 bacterial genera, 26 of them previously characterized as potential human pathogens. Bacterial species richness and concentration determined both by qPCR, and culture-dependent analysis were significantly higher in the treatment room. Bacterial load of the treatment room impacted in the nearby waiting room where no dental procedures took place. I/O ratio of bacterial concentration in the treatment room followed the fluctuation of I/O ratio of airborne particles in the biology-relevant size classes of 1-2.5, 2.5-5, and 5-10 μm. Exposure analysis revealed increased inhaled number of particles and microorganisms during dental procedures. These findings provide a detailed insight on airborne particles of both biotic and abiotic origin in a dental clinic.
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Affiliation(s)
| | - Aggeliki Saridaki
- School of Environmental Engineering, Technical University of Crete, Chania, Greece
| | - Louiza Raisi
- School of Environmental Engineering, Technical University of Crete, Chania, Greece
- Department of Electronic Engineering, Hellenic Mediterranean University, Chania, Greece
| | - Eleftheria Katsivela
- Department of Electronic Engineering, Hellenic Mediterranean University, Chania, Greece
| | - George Tsiamis
- Department of Environmental Engineering, University of Patras, Agrinio, Greece
| | | | - Mihalis Lazaridis
- School of Environmental Engineering, Technical University of Crete, Chania, Greece
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47
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Bonadonna L, Briancesco R, Coccia AM, Meloni P, Rosa GL, Moscato U. Microbial Air Quality in Healthcare Facilities. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:6226. [PMID: 34207509 PMCID: PMC8296088 DOI: 10.3390/ijerph18126226] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/26/2021] [Accepted: 06/04/2021] [Indexed: 12/26/2022]
Abstract
There is increasing evidence that indoor air quality and contaminated surfaces provide an important potential source for transmission of pathogens in hospitals. Airborne hospital microorganisms are apparently harmless to healthy people. Nevertheless, healthcare settings are characterized by different environmental critical conditions and high infective risk, mainly due to the compromised immunologic conditions of the patients that make them more vulnerable to infections. Thus, spread, survival and persistence of microbial communities are important factors in hospital environments affecting health of inpatients as well as of medical and nursing staff. In this paper, airborne and aerosolized microorganisms and their presence in hospital environments are taken into consideration, and the factors that collectively contribute to defining the infection risk in these facilities are illustrated.
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Affiliation(s)
- Lucia Bonadonna
- Department of Environment and Health, Italian National Institute of Health, 00161 Rome, Italy; (R.B.); (A.M.C.); (P.M.); (G.L.R.)
| | - Rossella Briancesco
- Department of Environment and Health, Italian National Institute of Health, 00161 Rome, Italy; (R.B.); (A.M.C.); (P.M.); (G.L.R.)
| | - Anna Maria Coccia
- Department of Environment and Health, Italian National Institute of Health, 00161 Rome, Italy; (R.B.); (A.M.C.); (P.M.); (G.L.R.)
| | - Pierluigi Meloni
- Department of Environment and Health, Italian National Institute of Health, 00161 Rome, Italy; (R.B.); (A.M.C.); (P.M.); (G.L.R.)
| | - Giuseppina La Rosa
- Department of Environment and Health, Italian National Institute of Health, 00161 Rome, Italy; (R.B.); (A.M.C.); (P.M.); (G.L.R.)
| | - Umberto Moscato
- Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy;
- Section of Occupational Medicine, Institute of Public Health, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
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48
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Haas CN. Action Levels for SARS-CoV-2 in Air: Preliminary Approach. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2021; 41:705-709. [PMID: 33818802 PMCID: PMC8251121 DOI: 10.1111/risa.13728] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Quantitative microbial risk assessment has been used to develop criteria for exposure to many microorganisms. In this article, the dose-response curve for Coronavirus 229E is used to develop preliminary risk-based exposure criteria for SARS-CoV-2 via the respiratory portals of entry.
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Affiliation(s)
- Charles N. Haas
- Department of Civil, Architectural and Environmental EngineeringDrexel UniversityPhiladelphiaPAUSA
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49
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Theisinger SM, de Smidt O, Lues JFR. Categorisation of culturable bioaerosols in a fruit juice manufacturing facility. PLoS One 2021; 16:e0242969. [PMID: 33882058 PMCID: PMC8059861 DOI: 10.1371/journal.pone.0242969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 11/12/2020] [Indexed: 11/18/2022] Open
Abstract
Bioaerosols are defined as aerosols that comprise particles of biological origin or activity that may affect living organisms through infectivity, allergenicity, toxicity, or through pharmacological or other processes. Interest in bioaerosol exposure has increased over the last few decades. Exposure to bioaerosols may cause three major problems in the food industry, namely: (i) contamination of food (spoilage); (ii) allergic reactions in individual consumers; or (iii) infection by means of pathogenic microorganisms present in the aerosol. The aim of this study was to characterise the culturable fraction of bioaerosols in the production environment of a fruit juice manufacturing facility and categorise isolates as harmful, innocuous or potentially beneficial to the industry, personnel and environment. Active sampling was used to collect representative samples of five areas in the facility during peak and off-peak seasons. Areas included the entrance, preparation and mixing area, between production lines, bottle dispersion and filling stations. Microbes were isolated and identified using 16S, 26S or ITS amplicon sequencing. High microbial counts and species diversity were detected in the facility. 239 bacteria, 41 yeasts and 43 moulds were isolated from the air in the production environment. Isolates were categorised into three main groups, namely 27 innocuous, 26 useful and 39 harmful bioaerosols. Harmful bioaerosols belonging to the genera Staphylococcus, Pseudomonas, Penicillium and Candida were present. Although innocuous and useful bioaerosols do not negatively influence human health their presence act as an indicator that an ideal environment exists for possible harmful bioaerosols to emerge.
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Affiliation(s)
- Shirleen M. Theisinger
- Centre for Applied Food Sustainability and Biotechnology (CAFSaB), Faculty of Health and Environmental Sciences, Central University of Technology, Free State, Bloemfontein, South Africa
| | - Olga de Smidt
- Centre for Applied Food Sustainability and Biotechnology (CAFSaB), Faculty of Health and Environmental Sciences, Central University of Technology, Free State, Bloemfontein, South Africa
| | - Jan F. R. Lues
- Centre for Applied Food Sustainability and Biotechnology (CAFSaB), Faculty of Health and Environmental Sciences, Central University of Technology, Free State, Bloemfontein, South Africa
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50
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Epple P, Steppert M, Florschütz M, Dahlem P. Partition walls as effective protection from bio-aerosols in classrooms - an experimental investigation. GMS HYGIENE AND INFECTION CONTROL 2021; 16:Doc09. [PMID: 33796437 PMCID: PMC7982998 DOI: 10.3205/dgkh000380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Introduction: During a pandemic, protective measures to prevent bio-aerosol based infections, such as Corona Virus Infection Disease 19 (COVID 19), are very important. Everyday face masks can only partially block aerosols, and their effectiveness also depend on how well the person is wearing it. They are recommended for classroom situations during high pandemic activity. However, 'unprotected' communication with and among children is fundamental from the pedagogical and psychological point of view for normal psychosocial development and teaching. Partition walls around the persons can theoretically provide substantial standardized mechanical protection against the spread of droplets and aerosols, either as additional protection to face masks or as an alternative. Methods: In the present research, the protection effectiveness of partition walls was investigated. With mannequin heads, fog generators, line lasers and a classroom-like setup with protective walls, flow visualization and aerosol concentration measurements were performed. Additionally, an active fan-suction system was tested to remove the channelled aerosols on top of the partition walls before they reach other persons in the room. Results: It was found that partition walls protect neighbours from bio-aerosol contact regardless of whether they wear masks or not. The combination with standardized room ventilation enforces this effect. Moreover, the experiments performed here clearly showed that partition walls may protect neighbours from bio-aerosols better than suboptimally fitting everyday face masks only. Conclusion: Partition walls are the most effective protection against infectious bio-aerosols in classroom settings and should be combined with standardized ventilation as the preferred method for classrooms during the current COVID 19 pandemic.
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Affiliation(s)
- Philipp Epple
- Coburg University of Applied Sciences, Department of Mechanical Engineering, Coburg, Germany
| | - Michael Steppert
- Coburg University of Applied Sciences, Department of Mechanical Engineering, Coburg, Germany
| | - Michael Florschütz
- Coburg University of Applied Sciences, Department of Mechanical Engineering, Coburg, Germany
| | - Peter Dahlem
- REGIOMED Medical Center, Coburg, Germany and Faculty of Medicine, University of Split, Croatia
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