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Tehrani AM, Berijani N, Hajiketabi S, Samadi M. Tracking bioaerosol exposure among municipal solid waste workers using hematological and inflammatory biomarkers. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 352:124124. [PMID: 38723706 DOI: 10.1016/j.envpol.2024.124124] [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: 02/16/2024] [Revised: 04/20/2024] [Accepted: 05/07/2024] [Indexed: 06/06/2024]
Abstract
High levels of bioaerosols may exist in the air of municipal solid waste (MSW) management facilities, constituting a significant occupational hazard for workers. In this study, we investigated the potential association between exposure to bioaerosols and inflammatory biomarkers among municipal solid waste workers (MSWWs) at both the landfill site and the municipal solid waste transfer station (MSWTS), in comparison to a control group without exposure. Air sampling was conducted at six points around the landfill, two points at the MSWTS, and one point in a public park (as a control area) during the spring and summer of 2019. The results of our study revealed that airborne pathogens were highly prevalent at the sampling points, especially in the active zone and leachate collection pond. Aspergillus species were the predominant fungal species detected in this study, with the highest occurrence observed for Aspergillus flavus (83.3%), Aspergillus niger, and Aspergillus fumigatus (75.0%). Furthermore, Staphylococcus species accounted for over 75% of the total bacterial bioaerosols detected across all study areas. The blood test results of workers revealed a significant increase in platelets (PLT), immunoglobulin G (IgG), white blood cells (WBC), neutrophils, basophils, and high-sensitivity C-reactive protein (hs-CRP) compared to the control group. Conversely, platelet distribution width (PDW), mean platelet volume (MPV), and platelet-large cell ratio (P-LCR) in the exposed subjects exhibited a decreasing trend compared to the control group. These findings suggest a potential association between exposure to bioaerosols, particularly in the vicinity of open dumpsites, and elevated levels of hematologic and inflammatory markers in circulation. Furthermore, the influence of smoking status and confounding factors appears to be significant in both the control and exposure groups.
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Affiliation(s)
- Ashraf Mazaheri Tehrani
- Social Determinants of Health Research Center, Kashan University of Medical Sciences, Kashan, Iran; Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran
| | | | - Sajjad Hajiketabi
- Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran; Student Research Committee, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran
| | - Mohammadtaghi Samadi
- Research Center for Health Sciences, Department of Environmental Health Engineering, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.
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Oswin HP, Blake E, Haddrell AE, Finn A, Sriskandan S, Reid JP, Halliday A, Goenka A. An assessment of the airborne longevity of group A Streptococcus. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001421. [PMID: 38180461 PMCID: PMC10866022 DOI: 10.1099/mic.0.001421] [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: 09/06/2023] [Accepted: 12/08/2023] [Indexed: 01/06/2024]
Abstract
Group A streptococcus (GAS) infections result in more than 500 000 deaths annually. Despite mounting evidence for airborne transmission of GAS, little is known about its stability in aerosol. Measurements of GAS airborne stability were carried out using the Controlled Electrodynamic Levitation and Extraction of Bioaerosols onto a Substrate (CELEBS) instrument. CELEBS measurements with two different isolates of GAS suggest that it is aerostable, with approximately 70 % of bacteria remaining viable after 20 min of levitation at 50 % relative humidity (RH), with lower survival as RH was reduced. GAS airborne viability loss was driven primarily by desiccation and efflorescence (i.e. salt crystallization), with high pH also potentially playing a role, given reduced survival in bicarbonate containing droplet compositions. At low enough RH for efflorescence to occur, a greater proportion of organic components in the droplet appeared to protect the bacteria from efflorescence. These first insights into the aerosol stability of GAS indicate that airborne transmission of these respiratory tract bacteria may occur, and that both the composition of the droplet containing the bacteria, and the RH of the air affect the duration of bacterial survival in this environment. Future studies will explore a broader range of droplet and air compositions and include a larger selection of GAS strains.
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Affiliation(s)
- Henry P. Oswin
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, UK
| | - Evie Blake
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Allen E. Haddrell
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, UK
| | - Adam Finn
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
- Paediatric Immunology and Infectious Diseases, Bristol Royal Hospital for Children, Bristol, UK
| | - Shiranee Sriskandan
- NIHR Health Protection Research Unit in Healthcare-associated Infection and Antimicrobial Resistance, Imperial College London, London, UK
- Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | - Jonathan P. Reid
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, UK
| | - Alice Halliday
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Anu Goenka
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
- Paediatric Immunology and Infectious Diseases, Bristol Royal Hospital for Children, Bristol, UK
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Oswin HP, Haddrell AE, Hughes C, Otero-Fernandez M, Thomas RJ, Reid JP. Oxidative Stress Contributes to Bacterial Airborne Loss of Viability. Microbiol Spectr 2023; 11:e0334722. [PMID: 36912675 PMCID: PMC10101003 DOI: 10.1128/spectrum.03347-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 01/18/2023] [Indexed: 03/14/2023] Open
Abstract
While the airborne decay of bacterial viability has been observed for decades, an understanding of the mechanisms driving the decay has remained elusive. The airborne transport of bacteria is often a key step in their life cycle and as such, characterizing the mechanisms driving the airborne decay of bacteria is an essential step toward a more complete understanding of microbial ecology. Using the Controlled Electrodynamic Levitation and Extraction of Bioaerosols onto a Substrate (CELEBS), it was possible to systematically evaluate the impact of different physicochemical and environmental parameters on the survival of Escherichia coli in airborne droplets of Luria Bertani broth. Rather than osmotic stress driving the viability loss, as was initially considered, oxidative stress was found to play a key role. As the droplets evaporate and equilibrate with the surrounding environment, the surface-to-volume ratio increases, which in turn increased the formation of reactive oxygen species in the droplet. These reactive oxygen species appear to play a key role in driving the airborne loss of viability of E. coli. IMPORTANCE The airborne transport of bacteria has a wide range of impacts, from disease transmission to cloud formation. By understanding the factors that influence the airborne stability of bacteria, we can better understand these processes. However, while we have known for several decades that airborne bacteria undergo a gradual loss of viability, we have not previously identified the mechanisms driving this process. In this work, we discovered that oxygen surrounding an airborne droplet facilitates the formation of reactive oxygen species within the droplet, which then gradually damage and kill bacteria within the droplet. This discovery indicates that adaptations to help bacteria deal with oxidative stress may also aid their airborne survival and be essential adaptations for bacterial airborne pathogens. Understanding the adaptations bacteria need to survive in airborne droplets could eventually lead to the development of novel antimicrobials designed to inhibit their airborne survival, helping to prevent the transmission of disease.
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Affiliation(s)
- Henry P. Oswin
- School of Chemistry, Cantock’s Close, University of Bristol, Bristol, United Kingdom
| | - Allen E. Haddrell
- School of Chemistry, Cantock’s Close, University of Bristol, Bristol, United Kingdom
| | - Cordelia Hughes
- School of Chemistry, Cantock’s Close, University of Bristol, Bristol, United Kingdom
| | - Mara Otero-Fernandez
- School of Chemistry, Cantock’s Close, University of Bristol, Bristol, United Kingdom
| | - Richard J. Thomas
- Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury, United Kingdom
| | - Jonathan P. Reid
- School of Chemistry, Cantock’s Close, University of Bristol, Bristol, United Kingdom
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Abstract
The advent and application of high-throughput molecular techniques for analyzing microbial communities in the indoor environment have led to illuminating findings and are beginning to change the way we think about human health in relation to the built environment. Here I review recent studies on the microbiology of the built environment, organize their findings into 12 major thematic categories, and comment on how these studies have or have not advanced knowledge in each area beyond what we already knew from over 100 years of applying culture-based methods to building samples. The advent and application of high-throughput molecular techniques for analyzing microbial communities in the indoor environment have led to illuminating findings and are beginning to change the way we think about human health in relation to the built environment. Here I review recent studies on the microbiology of the built environment, organize their findings into 12 major thematic categories, and comment on how these studies have or have not advanced knowledge in each area beyond what we already knew from over 100 years of applying culture-based methods to building samples. I propose that while we have added tremendous complexity to the rich existing knowledge base, the practical implications of this added complexity remain somewhat elusive. It remains to be seen how this new knowledge base will change how we design, build, and operate buildings. Much more research is needed to better understand the complexity with which indoor microbiomes may affect human health in both positive and negative ways.
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Stephens B. What Have We Learned about the Microbiomes of Indoor Environments? mSystems 2016. [PMID: 27822547 DOI: 10.1128/msystems.00083-16.editor] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
The advent and application of high-throughput molecular techniques for analyzing microbial communities in the indoor environment have led to illuminating findings and are beginning to change the way we think about human health in relation to the built environment. Here I review recent studies on the microbiology of the built environment, organize their findings into 12 major thematic categories, and comment on how these studies have or have not advanced knowledge in each area beyond what we already knew from over 100 years of applying culture-based methods to building samples. I propose that while we have added tremendous complexity to the rich existing knowledge base, the practical implications of this added complexity remain somewhat elusive. It remains to be seen how this new knowledge base will change how we design, build, and operate buildings. Much more research is needed to better understand the complexity with which indoor microbiomes may affect human health in both positive and negative ways.
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Affiliation(s)
- Brent Stephens
- Department of Civil, Architectural and Environmental Engineering, Illinois Institute of Technology, Chicago, Illinois, USA
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Ramos T, Dedesko S, Siegel JA, Gilbert JA, Stephens B. Spatial and temporal variations in indoor environmental conditions, human occupancy, and operational characteristics in a new hospital building. PLoS One 2015; 10:e0118207. [PMID: 25729898 PMCID: PMC4346405 DOI: 10.1371/journal.pone.0118207] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 01/08/2015] [Indexed: 11/20/2022] Open
Abstract
The dynamics of indoor environmental conditions, human occupancy, and operational characteristics of buildings influence human comfort and indoor environmental quality, including the survival and progression of microbial communities. A suite of continuous, long-term environmental and operational parameters were measured in ten patient rooms and two nurse stations in a new hospital building in Chicago, IL to characterize the indoor environment in which microbial samples were taken for the Hospital Microbiome Project. Measurements included environmental conditions (indoor dry-bulb temperature, relative humidity, humidity ratio, and illuminance) in the patient rooms and nurse stations; differential pressure between the patient rooms and hallways; surrogate measures for human occupancy and activity in the patient rooms using both indoor air CO2 concentrations and infrared doorway beam-break counters; and outdoor air fractions in the heating, ventilating, and air-conditioning systems serving the sampled spaces. Measurements were made at 5-minute intervals over consecutive days for nearly one year, providing a total of ∼8×106 data points. Indoor temperature, illuminance, and human occupancy/activity were all weakly correlated between rooms, while relative humidity, humidity ratio, and outdoor air fractions showed strong temporal (seasonal) patterns and strong spatial correlations between rooms. Differential pressure measurements confirmed that all patient rooms were operated at neutral pressure. The patient rooms averaged about 100 combined entrances and exits per day, which suggests they were relatively lightly occupied compared to higher traffic environments (e.g., retail buildings) and more similar to lower traffic office environments. There were also clear differences in several environmental parameters before and after the hospital was occupied with patients and staff. Characterizing and understanding factors that influence these building dynamics is vital for hospital environments, where they can impact patient health and the survival and spread of healthcare associated infections.
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Affiliation(s)
- Tiffanie Ramos
- Department of Civil, Architectural and Environmental Engineering, Illinois Institute of Technology, Chicago, Illinois, United States of America
| | - Sandra Dedesko
- Department of Civil Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Jeffrey A. Siegel
- Department of Civil Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Jack A. Gilbert
- Argonne National Laboratory, Institute for Genomic and Systems Biology, Argonne, Illinois, United States of America
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
| | - Brent Stephens
- Department of Civil, Architectural and Environmental Engineering, Illinois Institute of Technology, Chicago, Illinois, United States of America
- * E-mail:
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Fernstrom A, Goldblatt M. Aerobiology and its role in the transmission of infectious diseases. J Pathog 2013; 2013:493960. [PMID: 23365758 PMCID: PMC3556854 DOI: 10.1155/2013/493960] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 11/02/2012] [Indexed: 12/28/2022] Open
Abstract
Aerobiology plays a fundamental role in the transmission of infectious diseases. As infectious disease and infection control practitioners continue employing contemporary techniques (e.g., computational fluid dynamics to study particle flow, polymerase chain reaction methodologies to quantify particle concentrations in various settings, and epidemiology to track the spread of disease), the central variables affecting the airborne transmission of pathogens are becoming better known. This paper reviews many of these aerobiological variables (e.g., particle size, particle type, the duration that particles can remain airborne, the distance that particles can travel, and meteorological and environmental factors), as well as the common origins of these infectious particles. We then review several real-world settings with known difficulties controlling the airborne transmission of infectious particles (e.g., office buildings, healthcare facilities, and commercial airplanes), while detailing the respective measures each of these industries is undertaking in its effort to ameliorate the transmission of airborne infectious diseases.
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Affiliation(s)
- Aaron Fernstrom
- Mid-Atlantic Venture Investment Company, LLC, Washington, DC 20009, USA
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Aliabadi AA, Rogak SN, Bartlett KH, Green SI. Preventing airborne disease transmission: review of methods for ventilation design in health care facilities. Adv Prev Med 2011; 2011:124064. [PMID: 22162813 PMCID: PMC3226423 DOI: 10.4061/2011/124064] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 09/09/2011] [Indexed: 12/03/2022] Open
Abstract
Health care facility ventilation design greatly affects disease transmission by aerosols. The desire to control infection in hospitals and at the same time to reduce their carbon footprint motivates the use of unconventional solutions for building design and associated control measures. This paper considers indoor sources and types of infectious aerosols, and pathogen viability and infectivity behaviors in response to environmental conditions. Aerosol dispersion, heat and mass transfer, deposition in the respiratory tract, and infection mechanisms are discussed, with an emphasis on experimental and modeling approaches. Key building design parameters are described that include types of ventilation systems (mixing, displacement, natural and hybrid), air exchange rate, temperature and relative humidity, air flow distribution structure, occupancy, engineered disinfection of air (filtration and UV radiation), and architectural programming (source and activity management) for health care facilities. The paper describes major findings and suggests future research needs in methods for ventilation design of health care facilities to prevent airborne infection risk.
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Affiliation(s)
- Amir A. Aliabadi
- Department of Mechanical Engineering, University of British Columbia, 122-6250 Applied Science Lane, Vancouver, BC, Canada V6T 1Z4
| | - Steven N. Rogak
- Department of Mechanical Engineering, University of British Columbia, 103-6250 Applied Science Lane, Vancouver, BC, Canada V6T 1Z4
| | - Karen H. Bartlett
- School of Population and Public Health, University of British Columbia, 364-2206 East Mall, Vancouver, BC, Canada V6T 1Z4
| | - Sheldon I. Green
- Department of Mechanical Engineering, University of British Columbia, 2058-6250 Applied Science Lane, Vancouver, BC, Canada V6T 1Z4
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Tang JW. The effect of environmental parameters on the survival of airborne infectious agents. J R Soc Interface 2009; 6 Suppl 6:S737-46. [PMID: 19773291 DOI: 10.1098/rsif.2009.0227.focus] [Citation(s) in RCA: 291] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The successful transmission of infection via the airborne route relies on several factors, including the survival of the airborne pathogen in the environment as it travels between susceptible hosts. This review summarizes the various environmental factors (particularly temperature and relative humidity) that may affect the airborne survival of viruses, bacteria and fungi, with the aim of highlighting specific aspects of environmental control that may eventually enhance the aerosol or airborne infection control of infectious disease transmission within hospitals.
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Affiliation(s)
- Julian W Tang
- Department of Laboratory Medicine, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074, Republic of Singapore.
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Novel Light-Activated Antimicrobial Coatings Are Effective Against Surface-Deposited Staphylococcus aureus. Curr Microbiol 2008; 57:269-73. [DOI: 10.1007/s00284-008-9188-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Accepted: 04/09/2008] [Indexed: 11/30/2022]
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Handley B, Roe J. An alternative microthread for the study of airborne survival of bacteria outdoors. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1365-2672.1994.tb04394.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Handley BA, Webster AJ. Some factors affecting the airborne survival of bacteria outdoors. THE JOURNAL OF APPLIED BACTERIOLOGY 1995; 79:368-78. [PMID: 7592129 DOI: 10.1111/j.1365-2672.1995.tb03150.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Airborne survival of two pseudomonads and a reference strain of Escherichia coli (strain MRE 162) was studied outdoors using a modified microthread technique. When cells of E. coli were suspended as clusters, survival was much greater than single cells, particularly outdoors. Culture age had a highly significant effect on survival of Pseudomonas maltophila with survival of 24 h cultures being more than 100-fold higher than 48 h cultures. Survival of Pseudomonas fluorescens was variable and depended also upon the method of culture. Survival of E. coli and Ps. maltophila was studied at three locations differing in air quality and was found to be significantly reduced outdoors, particularly when held in direct daylight. Outdoor survival was not significantly different at the three locations but was reduced at increasing temperatures. There was no apparent effect of wind direction or air quality. Results are discussed with reference to the release of genetically-modified micro-organisms.
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Affiliation(s)
- B A Handley
- Division of Animal Health and Husbandry, University of Bristol, Langford, UK
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