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Yan C, Hu YN, Gui ZC, Lai TN, Ali W, Wan NH, He SS, Liu S, Li X, Jin TX, Nasir ZA, Alcega SG, Coulon F. Quantitative SARS-CoV-2 exposure assessment for workers in wastewater treatment plants using Monte-Carlo simulation. WATER RESEARCH 2024; 248:120845. [PMID: 37976948 DOI: 10.1016/j.watres.2023.120845] [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: 05/03/2023] [Revised: 10/17/2023] [Accepted: 11/05/2023] [Indexed: 11/19/2023]
Abstract
Several studies on COVID-19 pandemic have shown that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originating from human stool are detected in raw sewage for several days, leading to potential health risks for workers due to the production of bioaerosols and droplets during wastewater treatment process. In this study, data of SARS-CoV-2 concentrations in wastewater were gathered from literatures, and a quantitative microbial risk assessment with Monte Carlo simulation was used to estimate the daily probability of infection risk through exposure to viable infectious viral airborne particles of the workers during four seasons and under six environmental conditions. Inhalation of bioaerosols and direct ingestion of wastewater droplets were selected as exposure pathways. Spearman rank correlation coefficients were used for sensitivity analysis to identify the variables with the greatest influence on the infection risk probability. It was found that the daily probability of infection risk decreased with temperature (T) and relative humidity (RH) increase. The probability of direct droplet ingestion exposure pathway was higher than that of the bioaerosol inhalation pathway. The sensitivity analysis indicated that the most sensitive variable for both exposure pathways was the concentration of SARS-CoV-2 in stool. So, appropriate aeration systems, covering facilities, and effective ventilation are suggested to implement in wastewater treatment plants (WWTPs) to reduce emission concentration. Further to this, the exposure time (t) had a larger variance contribution than T and RH for the bioaerosol inhalation pathway. Implementing measures such as adding more work shifts, mandating personal protective equipment for all workers, and implementing coverage for treatment processes can significantly reduce the risk of infection among workers at WWTPs. These measures are particularly effective during environmental conditions with low temperatures and humidity levels.
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Affiliation(s)
- Cheng Yan
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China; Hubei Key Laboratory of Environmental Water Science in the Yangtze River Basin, China University of Geosciences, Wuhan 430074, PR China.
| | - Yi-Ning Hu
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China
| | - Zi-Cheng Gui
- CCDI (Suzhou) exploration and design consultant Co., Ltd., Suzhou 215123, PR China
| | - Tian-Nuo Lai
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China
| | - Wajid Ali
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China
| | - Nian-Hong Wan
- Central & Southern China Municipal Engineering Design and Research Institute Co, Ltd., Wuhan 430010, PR China
| | - Shan-Shan He
- Central & Southern China Municipal Engineering Design and Research Institute Co, Ltd., Wuhan 430010, PR China
| | - Sai Liu
- CITIC Treated Water into River Engineering Investment Co., Ltd., Wuhan 430200, PR China
| | - Xiang Li
- Three Gorges Base Development Co., Ltd., Yichang 443002, PR China
| | - Ting-Xu Jin
- Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou 215123, PR China; School of Public Health, the Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang 550025, PR China
| | - Zaheer Ahmad Nasir
- School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK
| | - Sonia Garcia Alcega
- School of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK6 7AA, UK
| | - Frederic Coulon
- School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK
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2
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Liu J, Ge J, Kang X, Tian H. Bioaerosol-related studies in wastewater treatment plant with anaerobic-anoxic-oxic processes: Characterization, source analysis, control measures. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 339:117760. [PMID: 37031601 DOI: 10.1016/j.jenvman.2023.117760] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 02/21/2023] [Accepted: 03/16/2023] [Indexed: 05/03/2023]
Abstract
Sewage in wastewater treatment plants (WWTPs) can produce fugitive bioaerosols that pose a health risk to employees and residents. This study aimed to fugitive bioaerosols from two WWTPs with anaerobic-anoxic-oxic (AAO) processes, and bioaerosols control measures were proposed based on the results of these studies. It was found that the bioaerosols were mainly composed of microorganisms from dominant genera such as Romboutsia, Rubellimicrobium, Sphingomonas, Acidea, Cryptotrichosporon and water-soluble ions dominated by SO42-. Moreover, total suspended particulate (TSP), relative humidity (RH), wind speed (WS), Ca2+, NH4+, Na+, Cl-, NO3-, and K+ had positive effects on most dominant genera, while temperature (T) and SO42- had negative effects on most dominant genera. The source analysis showed that the bioaerosols in the indoor treatment facility's fine screen room and sludge dewatering plant mainly originated from sewage or sludge, and those in the aeration tank of the outdoor treatment facility mainly originated from the background air of WWTPs . By combining the characteristics of bioaerosols and the results of source analysis, targeted control measures were proposed from three aspects: source reduction of bioaerosol fugitives, control of bioaerosol propagation, and collection and treatment systems. This study provides the theoretical basis and ideas for controlling bioaerosols in WWTPs with AAO processes.
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Affiliation(s)
- Jianwei Liu
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China.
| | - Jingyun Ge
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China.
| | - Xinyue Kang
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China.
| | - Hongyu Tian
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; School of Environment and Energy Engineering, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.
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3
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Li Y, Yang L, Song H, Ba Y, Li L, Hong Q, Wang Y. The changing pattern of bioaerosol characteristics, source and risk under diversity brush aerator speed. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 236:113478. [PMID: 35390686 DOI: 10.1016/j.ecoenv.2022.113478] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/27/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
Bioaerosols containing pathogens released from wastewater treatment plants (WWTP) may pose potential health risks to workers on-site and residents downwind. In this study, sampling points were set up in the wastewater treatment facility to investigate the generation pattern of bioaerosols in the aeration tank section. High-throughput sequencing was utilized to assay the intestinal bacteria population, while the health risks associated with airborne bacteria were estimated based on average daily dose rates. The contribution of wastewater to bioaerosols was evaluated using the traceability analysis. As the rotational speed increased from 200 rpm to 800 rpm, the concentration of culturable bacteria increased from 397 CFU/m3 to 1611 CFU/m3, the proportion of bacteria attached to particles with an aerodynamic diameter larger than 4.7 µm increased from 30.41% to 48.44%, and the Shannon index of air samples increased from 1.032485 to 1.282065. Microbial composition, sources, and health risks of bioaerosols also changed as the rotational speed increased. The results showed that the predominant bacteria in the air at 200 rpm were Bacillus (78.78%), Paenibacillus (11.77%) and Lysinibacillus (1.40%). When the rotating speed reached 800 rpm, the dominant bacteria became Bacillus (55.50%), Acinetobacter (31.01%), and Paenarthrobacter (13.17%). The contribution of the wastewater to bioaerosols increased from 46.49% to 65.10%, in which surface water was the main source of bioaerosols (34.64% on average). Although the contribution of bottom water was lower than that of surface water, its contribution increased more, from 15.36% to 29.31%. The health risk of bioaerosols was 1.28 × 10-2 on average, which increased with the increase of rotational speed. At the same exposure concentration, children (2.31 × 10-2) have a higher exposure risk than adults (7.67 × 10-3). This study is aimed at exploring the variation law of bioaerosols discharged from WWTP with oxidation ditch process and providing preliminary data for reducing its risk.
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Affiliation(s)
- Yan Li
- Zhengzhou University, Zhengzhou, Henan 450001, PR China
| | - Liying Yang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, PR China
| | - Huiling Song
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, PR China
| | - Yue Ba
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, PR China
| | - Lin Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Qing Hong
- The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450001, PR China
| | - Yanjie Wang
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, PR China; State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
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4
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Kataki S, Patowary R, Chatterjee S, Vairale MG, Sharma S, Dwivedi SK, Kamboj DV. Bioaerosolization and pathogen transmission in wastewater treatment plants: Microbial composition, emission rate, factors affecting and control measures. CHEMOSPHERE 2022; 287:132180. [PMID: 34560498 DOI: 10.1016/j.chemosphere.2021.132180] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 07/19/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
Environmental consequences during wastewater management are vital and getting increased attention to interrupt any possible disease transmission pathways. Evidence of bioaerosolization of pathogen from wastewater to atmosphere during wastewater treatment have been highlighted previously. Understanding aerosol-based transmission in wastewater treatment plant (WWTP) is important because of the hazard it presents to the workers involved or to the population around and appears to be very significant during pandemic occurrences. This work aims to evaluate the possibility of pathogenic content of wastewater getting aerosolized during treatment by synthesizing the evidence on the potential aerosol generating treatment phases of WWTP, bioaerosol microbial composition, emission load and the factors affecting the bioaerosol formation. We also present some potential control strategies to take up in WWTP which may be useful to avoid such occurrences. Implementation of Aeration based strategies (use of diffused, submerged aeration, reduction in aeration rate), Improved ventilation based strategies (effective ventilation with adequate supply of clean air, minimizing air recirculation, supplementation with infection control measures such as filtration, irradiation), Improved protection based strategy (periodic monitoring of disinfection efficiency, pathogenic load of wastewater, improved operation policy) and other strategies (provision of buffer zone, wind shielding, water spraying on aerosol, screened surface of treatment units) could be very much relevant and significant in case of disease outbreak through aerosol formation in wastewater environment. Recent progress in sensor-based data collection, analysis, cloud-based storage, and early warning techniques in WWTP may help to reduce the risk of infectious transmission, especially during a pandemic situation.
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Affiliation(s)
- Sampriti Kataki
- Biodegradation Technology Division, Defence Research Laboratory, DRDO, Tezpur, Assam, India
| | - Rupam Patowary
- Foundation for Environmental and Economic Development Services, Manipur, India
| | - Soumya Chatterjee
- Biodegradation Technology Division, Defence Research Laboratory, DRDO, Tezpur, Assam, India.
| | - Mohan G Vairale
- Biodegradation Technology Division, Defence Research Laboratory, DRDO, Tezpur, Assam, India
| | - Sonika Sharma
- Biodegradation Technology Division, Defence Research Laboratory, DRDO, Tezpur, Assam, India
| | - Sanjai K Dwivedi
- Biodegradation Technology Division, Defence Research Laboratory, DRDO, Tezpur, Assam, India
| | - Dev Vrat Kamboj
- Biodegradation Technology Division, Defence Research Laboratory, DRDO, Tezpur, Assam, India
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5
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Singh NK, Sanghvi G, Yadav M, Padhiyar H, Thanki A. A state-of-the-art review on WWTP associated bioaerosols: Microbial diversity, potential emission stages, dispersion factors, and control strategies. JOURNAL OF HAZARDOUS MATERIALS 2021; 410:124686. [PMID: 33309139 DOI: 10.1016/j.jhazmat.2020.124686] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/21/2020] [Accepted: 11/24/2020] [Indexed: 05/13/2023]
Abstract
Wastewater treatment plants (WWTPs) associated bioaerosols have emerged as one of the critical sustainability indicators, ensuring health and well-being of societies and cities. In this context, this review summarizes the various wastewater treatment technologies which have been studied with a focus of bioaerosols emissions, potential emission stages, available sampling strategies, survival and dispersion factors, dominant microbial species in bioaerosols, and possible control approaches. Literature review revealed that most of the studies were devoted to sampling, enumerating and identifying cultivable microbial species of bioaerosols, as well as measuring their concentrations. However, the role of treatment technologies and their operational factors are investigated in limited studies only. Moreover, few studies have been reported to investigate the presence and concentrations of air borne virus and fungi in WWTP, as compared to bacterial species. The common environmental factors, affecting the survival and dispersion of bioaerosols, are observed as relative humidity, temperature, wind speed, and solar illumination. Further, research studies on recent episodes of COVID-19 (SARS-CoV-2 virus) pandemic also revealed that continuous and effective surveillance on WWTPs associated bioaerosols may led to early sign for future pandemics. The evaluation of reported data is bit complicated, due to the variation in sampling approaches, ambient conditions, and site activities of each study. Therefore, such studies need a standardized methodology and improved guidance to help informed future policies, contextual research, and support a robust health-based risk assessment process. Based on this review, an integrated sampling and analysis framework is suggested for future WWTPs to ensure their sustainability at social and/or health associated aspects.
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Affiliation(s)
- Nitin Kumar Singh
- Department of Environmental Science and Engineering, Marwadi Education Foundations Group of Institutions, Rajkot, India.
| | - Gaurav Sanghvi
- Department of Microbiology, Marwadi University, Rajkot, India.
| | - Manish Yadav
- Central Mine Planning Design Institute, Bhubaneshwar, India.
| | - Hirendrasinh Padhiyar
- Department of Environmental Science and Engineering, Marwadi Education Foundations Group of Institutions, Rajkot, India.
| | - Arti Thanki
- Department of Microbiology, Marwadi University, Rajkot, India.
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6
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Polanco-Guzmán I, Rodríguez-Troncoso M, Hammad AWA, Haddad AN, Tam VWY, Vasco DA. An improved ventilation system for settling stage of a wastewater treatment plant: a computational simulation analysis. INTERNATIONAL JOURNAL OF CONSTRUCTION MANAGEMENT 2020. [DOI: 10.1080/15623599.2020.1857003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Iván Polanco-Guzmán
- Departamento de Ingeniería Mecánica, Universidad de Santiago de Chile, Santiago de Chile, Chile
| | | | - Ahmed W. A. Hammad
- Faculty of Built Environment, University of New South Wales, Sydney, Australia
| | - Assed N. Haddad
- Departamento de Construção Civil, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Vivian W. Y. Tam
- School of Built Environment, Western Sydney University, Penrith, NSW, Australia
| | - Diego A. Vasco
- Departamento de Ingeniería Mecánica, Universidad de Santiago de Chile, Santiago de Chile, Chile
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7
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Han Y, Yang T, Han C, Li L, Liu J. Study of the generation and diffusion of bioaerosol under two aeration conditions. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 267:115571. [PMID: 33254721 DOI: 10.1016/j.envpol.2020.115571] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/20/2020] [Accepted: 08/28/2020] [Indexed: 06/12/2023]
Abstract
Given that studies on actual sewage treatment plants are often affected by environmental conditions, it is challenging to clearly understand the associated bioaerosol generation and diffusion characteristics during the aeration process. Therefore, to enhance understanding in this regard, in this study, bioaerosol generator was used to simulate bioaerosol generation and diffusion under two aeration modes, i.e., bubble bottom aeration and brush surface aeration. The total concentration range of culturable bacteria in the bioaerosol produced by bubble bottom aeration and that produced by brush surface aeration were 300-3000 CFU/m3. Under bubble bottom aeration, the generated bioaerosol was symmetrically distributed around the source point, whereas under brush surface aeration, it was primarily distributed in the forward direction of the rotating brush surface. These bioaerosols from bubble bottom aeration predominantly consisted of particles with sizes below 3.3 μm, particularly those with sizes in the range 1.1-2.1 μm. On the contrary, the bioaerosols produced via brush surface aeration predominantly consisted of particles with sizes above 3.3 μm. The distribution characteristics of population structure in the two aeration modes were consistent with the distribution characteristics of concentration in the corresponding models. Additionally, the results showed that when the aeration process is unaffected by environmental conditions (particle matters, wind direct, wind speed, etc.), the bioaerosol components originate primarily from the parent sewage or sludge, and do not diffuse far from the source point. Therefore, source reduction (capping or sealing) can be recommended as the primary control strategy for bioaerosols in sewage treatment plants. The adoption of such measures will significantly limit the diffusion of bioaerosols, thereby reducing the potential risks associated with human exposure.
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Affiliation(s)
- Yunping Han
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 101408, PR China.
| | - Tang Yang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 101408, PR China; School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, PR China.
| | - Chao Han
- Tianjin Chengjian University, Tianjin, 300384, PR China.
| | - Lin Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 101408, PR China.
| | - Junxin Liu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 101408, PR China.
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8
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Liu J, Yue P, Huang L, Zhao M, Kang X, Liu X. Styrene removal with an acidic biofilter with four packing materials: Performance and fungal bioaerosol emissions. ENVIRONMENTAL RESEARCH 2020; 191:110154. [PMID: 32877704 DOI: 10.1016/j.envres.2020.110154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 08/16/2020] [Accepted: 08/22/2020] [Indexed: 05/17/2023]
Abstract
The packing material used in acidic biofilters (ABFs) has a significant impact on styrene removal. The bioaerosol emission was rarely considered when evaluating the packing materials in the ABFs. Four ABFs packed with ceramsite, compost, lava and polyurethane (PU) were developed and compared for their styrene removal and fungal bioaerosol emissions characteristics over 529 days. The removal efficiencies of styrene in the ABFs were higher under the condition of longer empty bed residence time (EBRT) and lower inlet concentration. The maximum styrene elimination capacities of the ABFs with ceramsite, compost, lava and PU were 74.57, 87.81, 67.13 and 101.88 g/m3 h, respectively. A lower pressure drop and the highest fungi count were observed in the ABF packed with PU. The emissions concentrations of fungal bioaerosols at the humidity of 63.5% were lower than those at a humidity of 42.7% and it increased with the air velocity. Additionally, the concentrations of fungal bioaerosols emitted from the ABFs packed with PU were 2168 ± 145-3661 ± 257 CFU/m3, which was 33%-90% lower than those of the other three ABFs. The particle size distributions of the fungal bioaerosols emitted from the ABFs packed with PU and compost were mainly centered around large particles. Considering the removal of styrene and the fungal bioaerosols emissions, PU was the optimal packing material for ABF.
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Affiliation(s)
- Jianwei Liu
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China.
| | - Peng Yue
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China
| | - Lihua Huang
- School of Resources and Environment, Linyi University, Linyi, 276005, China
| | - Mengfei Zhao
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China
| | - Xinyue Kang
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China
| | - Xueli Liu
- Beijing Engineering Research Center of Sustainable Urban Sewage System Construction and Risk Control, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China; Key Laboratory of Urban Stormwater System and Water Environment, Ministry of Education, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China
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9
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Xu P, Zhang C, Mou X, Wang XC. Bioaerosol in a typical municipal wastewater treatment plant: concentration, size distribution, and health risk assessment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2020; 82:1547-1559. [PMID: 33107849 DOI: 10.2166/wst.2020.416] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
An investigation on bioaerosol in a wastewater treatment plant (WWTP) located in Xi'an, China, was conducted to understand the characteristics of bioaerosol released from wastewater and sludge treatment facilities because the bioaerosols may pose a threat to human health. Using the Andersen impactor sampler collection and colony-counting method, bioaerosol concentrations and size distributions were detected. The risk quotient method was used to evaluate the health risks associated with inhalation of bioaerosol for WWTP staff, based on the average daily dose rates of exposure. The health risk in relation to Legionella pneumophila was quantitatively calculated using quantitative microbial risk assessment (QMRA), based on the assumption of the percentage. The maximum concentration of airborne bacteria (3,767 ± 280 colony forming units (CFU)/m3) and fungi (8,775 ± 406 CFU/m3) occurred from the aerated grit chamber and sludge thickening house, respectively, which all exceeded 500 CFU/m3 as the acceptable guideline proposed by the American Conference of Governmental Industrial Hygienists. The particle size of airborne bacteria was mainly distributed in the first three stages (>3.3 µm), while that of airborne fungi was from the second to the fourth stage (2.1-7.0 µm). The hazard index exposure to bioaerosol for adult males and females by inhalation were higher than 1. The proportion of L. pneumophila should be strictly controlled below 10-8, based on the QMRA approach.
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Affiliation(s)
- Pengcheng Xu
- International Science and Technology Cooperation Center for Urban Alternative Water Resources Development; Key Lab of Northwest Water Resource, Environment and Ecology, Ministry of Education; Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi Province; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China E-mail:
| | - Chongmiao Zhang
- International Science and Technology Cooperation Center for Urban Alternative Water Resources Development; Key Lab of Northwest Water Resource, Environment and Ecology, Ministry of Education; Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi Province; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China E-mail:
| | - Xiao Mou
- Shaanxi Institute for Food and Drug Control, Xi'an 710065, China
| | - Xiaochang C Wang
- International Science and Technology Cooperation Center for Urban Alternative Water Resources Development; Key Lab of Northwest Water Resource, Environment and Ecology, Ministry of Education; Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi Province; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China E-mail:
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10
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Noh JH, Choi H, Kim HY, Choi S, Maeng SK. Reducing bacterial aerosol emissions from membrane bioreactors: The impact of SRT and the addition of PAC and calcium. WATER RESEARCH 2019; 156:58-70. [PMID: 30904711 DOI: 10.1016/j.watres.2019.03.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 03/03/2019] [Accepted: 03/13/2019] [Indexed: 05/20/2023]
Abstract
Bacterial aerosols resulting from membrane bioreactor (MBR) processes, which require excessive aeration in a confined space, are important to investigate because of their possible adverse effects on human health. This study investigated the influence of solid retention time (SRT) on bacterial aerosols from MBRs. Moreover, powdered activated carbon (PAC) and calcium were used to attenuate bacterial aerosol emissions from MBRs. The particulate matter (PM) emitted from the MBRs was reduced by 30.5 and 25.2% at SRTs of 20 and 80 d, respectively, compared to the level emitted at an SRT of 10 d. Total cell counts were similarly reduced at SRTs of 20 and 80 d. Longer SRTs also led to greater reductions in the particle size distribution of the sludge within 10 μm. Several factors in the MBR influenced the behavior of the bacterial aerosol emissions from the MBRs. This study showed that changes in viscosity and particle size induced by the SRT influenced the bacterial aerosol emissions in MBRs. Therefore, SRT was identified as an important design parameter affecting bacterial aerosol emissions in MBR processes. The amounts of particulate matter and bacterial aerosols were reduced in MBRs using PAC and calcium, both of which exerted an immediate effect on the bacterial aerosol emissions in MBRs by increasing the aerosol-particle size.
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Affiliation(s)
- Jin Hyung Noh
- Department of Civil and Environmental Engineering, Sejong University, 209 Neungdongro, Gwangjin-gu, Seoul, 05006, Republic of Korea
| | - Hanna Choi
- Taeyoung E&C 111, Yeouigongwon-ro, Yeongdeungpo-gu, Seoul, 07241, Republic of Korea
| | - Han Yong Kim
- Taeyoung E&C 111, Yeouigongwon-ro, Yeongdeungpo-gu, Seoul, 07241, Republic of Korea
| | - Soohoon Choi
- Department of Civil and Environmental Engineering, Sejong University, 209 Neungdongro, Gwangjin-gu, Seoul, 05006, Republic of Korea
| | - Sung Kyu Maeng
- Department of Civil and Environmental Engineering, Sejong University, 209 Neungdongro, Gwangjin-gu, Seoul, 05006, Republic of Korea.
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11
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Yang K, Li L, Wang Y, Xue S, Han Y, Liu J. Airborne bacteria in a wastewater treatment plant: Emission characterization, source analysis and health risk assessment. WATER RESEARCH 2019; 149:596-606. [PMID: 30522052 DOI: 10.1016/j.watres.2018.11.027] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/24/2018] [Accepted: 11/11/2018] [Indexed: 05/21/2023]
Abstract
Wastewater treatment plants (WWTPs) are major sources of airborne bacteria, which could pose health risks to WWTP workers and surrounding residents. In this study, air samples were collected from various treatment facilities of a typical WWTP. Community compositions of airborne bacteria were identified by high-throughput sequencing technique. SourceTracker was used to determine the percentages of airborne bacteria from wastewater, sludge, ambient air, and other environment. Health risks associated with airborne bacteria were estimated based on the average daily dose rates (ADD) of exposure by inhalation and skin contact. Concentrations of airborne bacteria varied in a wide range of 23-4878 CFU/m3. The main emission sources of airborne bacteria were treatment facilities with aeration, mechanical agitation, and located indoors. For treatment facilities located indoors, higher percentages of airborne bacteria were associated with wastewater and sludge, while more airborne bacteria were originated from the ambient air for outdoor installations. Opportunistic pathogens such as Micrococcus, Bacteroides, Chryseobacterium, Pseudomonas, and Acinetobacter, were detected in airborne bacteria. Inhalation was the main pathway for on-site workers exposure to airborne bacteria. Due to the presence of opportunistic pathogens, strict control measures should be employed in WWTPs to reduce the infection risks.
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Affiliation(s)
- Kaixiong Yang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
| | - Lin Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
| | - Yanjie Wang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
| | - Song Xue
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
| | - Yunping Han
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
| | - Junxin Liu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
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Quantitative Microbial Risk Assessment for Workers Exposed to Bioaerosol in Wastewater Treatment Plants Aimed at the Choice and Setup of Safety Measures. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15071490. [PMID: 30011925 PMCID: PMC6069154 DOI: 10.3390/ijerph15071490] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/21/2018] [Accepted: 07/12/2018] [Indexed: 12/24/2022]
Abstract
Biological risk assessment in occupational settings currently is based on either qualitative or semiquantitative analysis. In this study, a quantitative microbial risk assessment (QMRA) has been applied to estimate the human adenovirus (HAdV) health risk due to bioaerosol exposure in a wastewater treatment plant (WWTP). A stochastic QMRA model was developed considering HAdV as the index pathogen, using its concentrations in different areas and published dose–response relationship for inhalation. A sensitivity analysis was employed to examine the impact of input parameters on health risk. The QMRA estimated a higher average risk in sewage influent and biological oxidation tanks (15.64% and 12.73% for an exposure of 3 min). Sensitivity analysis indicated HAdV concentration as a predominant factor in the estimated risk. QMRA results were used to calculate the exposure limits considering four different risk levels (one illness case per 100, 1.000, 10.000, and 100.000 workers): for 3 min exposures, we obtained 565, 170, 54, and 6 GC/m3 of HAdV. We also calculated the maximum time of exposure for each level for different areas. Our findings can be useful to better define the effectiveness of control measures, which would thus reduce the virus concentration or the exposure time.
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Wu S, Jiang Y, Lou B, Feng J, Zhou Y, Guo L, Forsythe SJ, Man C. Microbial community structure and distribution in the air of a powdered infant formula factory based on cultivation and high-throughput sequence methods. J Dairy Sci 2018; 101:6915-6926. [PMID: 29729917 DOI: 10.3168/jds.2017-13968] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 03/24/2018] [Indexed: 11/19/2022]
Abstract
The air in a powdered infant formula (PIF) factory is a potential transfer medium for microorganisms. In this study, air samples from 6 main processing areas, almost covering the whole PIF processing line and 1 outdoor location, were collected from a PIF manufacturing plant during the winter and summer periods. A cultivation-based and an Illumina (San Diego, CA) high-throughput 16S rRNA sequencing method was used to investigate the community structures and distributions of bacteria in the air. High microbial diversity (25 genera, 56 species), with a dominant community including Staphylococcus, Bacillus, Acinetobacter, and Kocuria, was found by the cultivation-based method. Moreover, 104 genera were obtained from all samples by high-throughput sequencing methods. Lactococcus (32.3%), Bacillus (29.6%), and Staphylococcus (14.0%) were the preponderant genera. The indices from high-throughput sequencing results indicated that the bacterial community of the air samples was highly diverse. Significant differences in the diversity and distribution at 6 sampling locations were revealed using the 2 methods. In particular, the packaging process contained the highest proportion (39.4%) of isolated strains. The highest diversity in bacterial community structure was found in the outdoor location. More bacterial isolates and higher community diversity were observed in the summer samples compared with the winter samples. In addition, some pathogens, such as Acinetobacter baumannii, Bacillus cereus, and Staphylococcus cohnii, were mainly found in the large bag filling process, can filling, and packaging process areas. The present study provides greater insight into the microbial community and identifies potential sources of air contamination in PIF production environments and can serve as a guide to reduce the risk of microbial contamination in the production of PIF.
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Affiliation(s)
- Shuang Wu
- Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin, China, 150030
| | - Yujun Jiang
- Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin, China, 150030
| | - Binbin Lou
- Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin, China, 150030
| | - Jing Feng
- Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin, China, 150030
| | - Yanhong Zhou
- Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin, China, 150030
| | - Ling Guo
- Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin, China, 150030
| | | | - Chaoxin Man
- Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin, China, 150030.
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14
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Concentrations and Size Distributions of Fungal Bioaerosols in a Municipal Landfill. DATA MINING AND BIG DATA 2018. [DOI: 10.1007/978-3-319-93803-5_23] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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15
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Duquenne P. On the Identification of Culturable Microorganisms for the Assessment of Biodiversity in Bioaerosols. Ann Work Expo Health 2017; 62:139-146. [DOI: 10.1093/annweh/wxx096] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 11/10/2017] [Indexed: 11/14/2022] Open
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16
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Haig CW, Mackay WG, Walker JT, Williams C. Bioaerosol sampling: sampling mechanisms, bioefficiency and field studies. J Hosp Infect 2016; 93:242-55. [PMID: 27112048 PMCID: PMC7124364 DOI: 10.1016/j.jhin.2016.03.017] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 03/15/2016] [Indexed: 11/21/2022]
Abstract
Investigations into the suspected airborne transmission of pathogens in healthcare environments have posed a challenge to researchers for more than a century. With each pathogen demonstrating a unique response to environmental conditions and the mechanical stresses it experiences, the choice of sampling device is not obvious. Our aim was to review bioaerosol sampling, sampling equipment, and methodology. A comprehensive literature search was performed, using electronic databases to retrieve English language papers on bioaerosol sampling. The review describes the mechanisms of popular bioaerosol sampling devices such as impingers, cyclones, impactors, and filters, explaining both their strengths and weaknesses, and the consequences for microbial bioefficiency. Numerous successful studies are described that point to best practice in bioaerosol sampling, from the use of small personal samplers to monitor workers' pathogen exposure through to large static samplers collecting airborne microbes in various healthcare settings. Of primary importance is the requirement that studies should commence by determining the bioefficiency of the chosen sampler and the pathogen under investigation within laboratory conditions. From such foundations, sampling for bioaerosol material in the complexity of the field holds greater certainty of successful capture of low-concentration airborne pathogens. From the laboratory to use in the field, this review enables the investigator to make informed decisions about the choice of bioaerosol sampler and its application.
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Affiliation(s)
- C W Haig
- Institute of Healthcare Associated Infection, University of the West of Scotland, Paisley, UK.
| | - W G Mackay
- Institute of Healthcare Associated Infection, University of the West of Scotland, Paisley, UK
| | - J T Walker
- Public Health England, National Infection Service, Biosafety Unit, Porton Down, UK
| | - C Williams
- Institute of Healthcare Associated Infection, University of the West of Scotland, Paisley, UK
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Yu Y, Yin S, Kuan Y, Xu Y, Gao X. Characteristics of airborne micro-organisms in a neurological intensive care unit: Results from China. J Int Med Res 2015; 43:332-40. [PMID: 25762516 DOI: 10.1177/0300060514562055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 11/06/2014] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE To describe the characteristics of airborne micro-organisms in the environment in a Chinese neurological intensive care unit (NICU). METHODS This prospective study monitored the air environment in two wards (large and small) of an NICU in a tertiary hospital in China for 12 months, using an LWC-1 centrifugal air sampler. Airborne micro-organisms were identified using standard microbiology techniques. RESULTS The mean ± SD number of airborne bacteria was significantly higher in the large ward than in the small ward (200 ± 51 colony-forming units [CFU]/m(3) versus 110 ± 40 CFU/m(3), respectively). In the large ward only, the mean number of airborne bacteria in the autumn was significantly higher than in any of the other three seasons. A total of 279 airborne micro-organisms were identified (large ward: 195; small ward: 84). There was no significant difference in the type and distribution of airborne micro-organisms between the large and small wards. The majority of airborne micro-organisms were Gram-positive cocci in both wards. CONCLUSION These findings suggest that the number of airborne micro-organisms was related to the number of patients on the NICU ward.
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Affiliation(s)
- Yao Yu
- Department of Neurology, Peking University People's Hospital, Beijing, China
| | - Sufeng Yin
- Department of Statistics and Epidemiology, Public Health and Preventive Medicine College, Hebei United University, Tangshan, Hebei Province, China Hebei Province Coal Mine Health and Safety Laboratory, Tangshan, Hebei Province, China
| | - Yi Kuan
- Department of Neurology, Kailuan General Hospital, Hebei United University, Tangshan, Hebei Province China
| | - Yingjun Xu
- Department of Statistics and Epidemiology, Public Health and Preventive Medicine College, Hebei United University, Tangshan, Hebei Province, China Hebei Province Coal Mine Health and Safety Laboratory, Tangshan, Hebei Province, China
| | - Xuguang Gao
- Department of Neurology, Peking University People's Hospital, Beijing, China
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