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Görlitz M, Justen L, Rochette PJ, Buonanno M, Welch D, Kleiman NJ, Eadie E, Kaidzu S, Bradshaw WJ, Javorsky E, Cridland N, Galor A, Guttmann M, Meinke MC, Schleusener J, Jensen P, Söderberg P, Yamano N, Nishigori C, O'Mahoney P, Manstein D, Croft R, Cole C, de Gruijl FR, Forbes PD, Trokel S, Marshall J, Brenner DJ, Sliney D, Esvelt K. Assessing the safety of new germicidal far-UVC technologies. Photochem Photobiol 2024; 100:501-520. [PMID: 37929787 DOI: 10.1111/php.13866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 11/07/2023]
Abstract
The COVID-19 pandemic underscored the crucial importance of enhanced indoor air quality control measures to mitigate the spread of respiratory pathogens. Far-UVC is a type of germicidal ultraviolet technology, with wavelengths between 200 and 235 nm, that has emerged as a highly promising approach for indoor air disinfection. Due to its enhanced safety compared to conventional 254 nm upper-room germicidal systems, far-UVC allows for whole-room direct exposure of occupied spaces, potentially offering greater efficacy, since the total room air is constantly treated. While current evidence supports using far-UVC systems within existing guidelines, understanding the upper safety limit is critical to maximizing its effectiveness, particularly for the acute phase of a pandemic or epidemic when greater protection may be needed. This review article summarizes the substantial present knowledge on far-UVC safety regarding skin and eye exposure and highlights research priorities to discern the maximum exposure levels that avoid adverse effects. We advocate for comprehensive safety studies that explore potential mechanisms of harm, generate action spectra for crucial biological effects and conduct high-dose, long-term exposure trials. Such rigorous scientific investigation will be key to determining safe and effective levels for far-UVC deployment in indoor environments, contributing significantly to future pandemic preparedness and response.
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Affiliation(s)
- Maximilian Görlitz
- Massachusetts Institute of Technology, Media Lab, Cambridge, Massachusetts, USA
- SecureBio, Inc., Cambridge, Massachusetts, USA
| | - Lennart Justen
- Massachusetts Institute of Technology, Media Lab, Cambridge, Massachusetts, USA
- SecureBio, Inc., Cambridge, Massachusetts, USA
| | - Patrick J Rochette
- Centre de recherche du CHU de Québec-Université Laval, Axe Médecine Régénératrice Quebec, Quebec City, Quebec, Canada
| | - Manuela Buonanno
- Center for Radiological Research, Columbia University Medical Center, New York City, New York, USA
| | - David Welch
- Center for Radiological Research, Columbia University Medical Center, New York City, New York, USA
| | - Norman J Kleiman
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York City, New York, USA
| | - Ewan Eadie
- Photobiology Unit, Ninewells Hospital, Dundee, UK
| | - Sachiko Kaidzu
- Department of Ophthalmology, Shimane University Faculty of Medicine, Izumo, Japan
| | - William J Bradshaw
- Massachusetts Institute of Technology, Media Lab, Cambridge, Massachusetts, USA
- SecureBio, Inc., Cambridge, Massachusetts, USA
| | - Emilia Javorsky
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
- Future of Life Institute, Cambridge, Massachusetts, USA
| | - Nigel Cridland
- Radiation, Chemicals and Environment Directorate, UK Health Security Agency, Didcot, UK
| | - Anat Galor
- Miami Veterans Affairs Medical Center, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, USA
| | | | - Martina C Meinke
- Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Johannes Schleusener
- Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Paul Jensen
- Final Approach Inc., Port Orange, Florida, USA
| | - Per Söderberg
- Ophthalmology, Department of Surgical Sciences, Uppsala Universitet, Uppsala, Sweden
| | - Nozomi Yamano
- Division of Dermatology, Department of Internal Related, Kobe University, Kobe, Japan
| | - Chikako Nishigori
- Division of Dermatology, Department of Internal Related, Kobe University, Kobe, Japan
- Japanese Red Cross Hyogo Blood Center, Kobe, Japan
| | - Paul O'Mahoney
- Optical Radiation Effects, UK Health Security Agency, Chilton, UK
| | - Dieter Manstein
- Department of Dermatology, Cutaneous Biology Research Center, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Rodney Croft
- International Commission on Non-Ionizing Radiation Protection (ICNIRP), Chair, Wollongong, New South Wales, Australia
- University of Wollongong, Wollongong, New South Wales, Australia
| | - Curtis Cole
- Sun & Skin Consulting LLC, New Holland, Pennsylvania, USA
| | - Frank R de Gruijl
- Department of Dermatology, Universiteit Leiden, Leiden, South Holland, The Netherlands
| | | | - Stephen Trokel
- Department of Ophthalmology, Columbia University Vagelos College of Physicians and Surgeons, New York City, New York, USA
| | - John Marshall
- Institute of Ophthalmology, University College London, London, UK
| | - David J Brenner
- Center for Radiological Research, Columbia University Medical Center, New York City, New York, USA
| | - David Sliney
- IES Photobiology Committee, Chair, Fallston, Maryland, USA
- Consulting Medical Physicist, Fallston, Maryland, USA
| | - Kevin Esvelt
- Massachusetts Institute of Technology, Media Lab, Cambridge, Massachusetts, USA
- SecureBio, Inc., Cambridge, Massachusetts, USA
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Corzo-Leon DE, Abbood HM, Colamarino RA, Steiner MF, Munro C, Gould IM, Hijazi K. Methods for SARS-CoV-2 hospital disinfection, in vitro observations. Infect Prev Pract 2024; 6:100339. [PMID: 38317676 PMCID: PMC10840105 DOI: 10.1016/j.infpip.2024.100339] [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: 11/21/2023] [Accepted: 01/09/2024] [Indexed: 02/07/2024] Open
Abstract
Introduction Escalation of chemical disinfection during the COVID-19 pandemic has raised occupational hazard concerns. Alternative and potentially safer methods such as ultraviolet-C (UVC) irradiation and ozone have been proposed, notwithstanding the lack of standardized criteria for their use in the healthcare environment. Aim Compare the virucidal activity of 70% ethanol, sodium dichloroisocyanurate (NaDCC), chlorhexidine, ozonated water, UVC-222 nm, UVC-254 nm against three SARS-CoV-2 variants of concern cultured in vitro. Methods Inactivation of three SARS-CoV-2 variants (alpha, beta, gamma) by the following chemical methods was tested: ethanol 70%, NaDCC (100 ppm, 500 ppm, 1000 ppm), chlorhexidine (2%, 1% and 0.5%), ozonated water 7 ppm. For irradiation, a je2Care 222nm UVC Lamp was compared to a Sylvania G15 UV254 nm lamp. Results Viral inactivation by >3 log was achieved with ethanol, NaDCC and chlorhexidine. The minor virucidal effect of ozonated water was <1 log. Virus treatment with UVC-254 nm reduced viral activity by 1-5 logs with higher inactivation after exposure for 3 minutes compared to 6 seconds. For all three variants, under equivalent conditions, exposure to UVC-222 nm did not achieve time-dependent inactivation as was observed with treatment with UVC-254 nm. Conclusion The virucidal activity on replication-competent SARS-CoV-2 by conventional chemical methods, including chlorhexidine at concentrations as low as 0.5%, was not matched by UVC irradiation, and to an even lesser extent by ozonated water treatment.
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Affiliation(s)
- Dora E. Corzo-Leon
- School of Medicine Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, Scotland, UK
- MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Hadeel Mohammed Abbood
- School of Medicine Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, Scotland, UK
- College of Dentistry, Tikrit University, Tikrit, Iraq
| | - Rosa A. Colamarino
- School of Medicine Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, Scotland, UK
| | - Markus F.C. Steiner
- School of Medicine Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, Scotland, UK
- GO Health Services – NHS Grampian Occupational Health, Aberdeen, Scotland, UK
| | - Carol Munro
- School of Medicine Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, Scotland, UK
| | - Ian M. Gould
- Department of Medical Microbiology, Aberdeen Royal Infirmary, Aberdeen, Scotland, UK
| | - Karolin Hijazi
- School of Medicine Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, Scotland, UK
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3
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Rufyikiri AS, Martinez R, Addo PW, Wu BS, Yousefi M, Malo D, Orsat V, Vidal SM, Fritz JH, MacPherson S, Lefsrud M. Germicidal efficacy of continuous and pulsed ultraviolet-C radiation on pathogen models and SARS-CoV-2. Photochem Photobiol Sci 2024; 23:339-354. [PMID: 38308169 DOI: 10.1007/s43630-023-00521-2] [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: 07/14/2023] [Accepted: 12/12/2023] [Indexed: 02/04/2024]
Abstract
Ultraviolet radiation's germicidal efficacy depends on several parameters, including wavelength, radiant exposure, microbial physiology, biological matrices, and surfaces. In this work, several ultraviolet radiation sources (a low-pressure mercury lamp, a KrCl excimer, and four UV LEDs) emitting continuous or pulsed irradiation were compared. The greatest log reductions in E. coli cells and B. subtilis endospores were 4.1 ± 0.2 (18 mJ cm-2) and 4.5 ± 0.1 (42 mJ cm-2) with continuous 222 nm, respectively. The highest MS2 log reduction observed was 2.7 ± 0.1 (277 nm at 3809 mJ cm-2). Log reductions of SARS-CoV-2 with continuous 222 nm and 277 nm were ≥ 3.4 ± 0.7, with 13.3 mJ cm-2 and 60 mJ cm-2, respectively. There was no statistical difference between continuous and pulsed irradiation (0.83-16.7% [222 nm and 277 nm] or 0.83-20% [280 nm] duty rates) on E. coli inactivation. Pulsed 260 nm radiation (0.5% duty rate) at 260 nm yielded significantly greater log reduction for both bacteria than continuous 260 nm radiation. There was no statistical difference in SARS-CoV-2 inactivation between continuous and pulsed 222 nm UV-C radiation and pulsed 277 nm radiation demonstrated greater germicidal efficacy than continuous 277 nm radiation. Greater radiant exposure for all radiation sources was required to inactivate MS2 bacteriophage. Findings demonstrate that pulsed irradiation could be more useful than continuous UV radiation in human-occupied spaces, but threshold limit values should be respected. Pathogen-specific sensitivities, experimental setup, and quantification methods for determining germicidal efficacy remain important factors when optimizing ultraviolet radiation for surface decontamination or other applications.
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Affiliation(s)
- Anne Sophie Rufyikiri
- Department of Bioresource Engineering, Macdonald Campus, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Rebecca Martinez
- Department of Bioresource Engineering, Macdonald Campus, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Philip W Addo
- Department of Bioresource Engineering, Macdonald Campus, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Bo-Sen Wu
- Department of Bioresource Engineering, Macdonald Campus, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Mitra Yousefi
- Dahdaleh Institute of Genomic Medicine and McGill University Research Centre on Complex Traits, Life Sciences Complex, McGill University, 3649 Promenade Sir William Osler, Montreal, QC, H3G 0B1, Canada
| | - Danielle Malo
- Dahdaleh Institute of Genomic Medicine and McGill University Research Centre on Complex Traits, Life Sciences Complex, McGill University, 3649 Promenade Sir William Osler, Montreal, QC, H3G 0B1, Canada
- Department of Medicine, McGill University, 3649 Promenade Sir William Osler, Montreal, QC, H3G 0B1, Canada
- Department of Human Genetics, McGill University, 3649 Promenade Sir William Osler, Montreal, QC, H3G 0B1, Canada
| | - Valérie Orsat
- Department of Bioresource Engineering, Macdonald Campus, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Silvia M Vidal
- Dahdaleh Institute of Genomic Medicine and McGill University Research Centre on Complex Traits, Life Sciences Complex, McGill University, 3649 Promenade Sir William Osler, Montreal, QC, H3G 0B1, Canada
- Department of Human Genetics, McGill University, 3649 Promenade Sir William Osler, Montreal, QC, H3G 0B1, Canada
- Department of Microbiology and Immunology, McGill University, 3775 Rue University, Montreal, QC, H3A 2B4, Canada
| | - Jörg H Fritz
- Dahdaleh Institute of Genomic Medicine and McGill University Research Centre on Complex Traits, Life Sciences Complex, McGill University, 3649 Promenade Sir William Osler, Montreal, QC, H3G 0B1, Canada
- Department of Microbiology and Immunology, McGill University, 3775 Rue University, Montreal, QC, H3A 2B4, Canada
| | - Sarah MacPherson
- Department of Bioresource Engineering, Macdonald Campus, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada
| | - Mark Lefsrud
- Department of Bioresource Engineering, Macdonald Campus, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada.
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Huang R, Ma C, Huangfu X, Ma J. Preparing for the Next Pandemic: Predicting UV Inactivation of Coronaviruses with Machine Learning. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:13767-13777. [PMID: 37660353 DOI: 10.1021/acs.est.3c03707] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
The epidemic of coronaviruses has posed significant public health concerns in the last two decades. An effective disinfection scheme is critical to preventing ambient virus infections and controlling the spread of further outbreaks. Ultraviolet (UV) irradiation has been a widely used approach to inactivating pathogenic viruses. However, no viable framework or model can accurately predict the UV inactivation of coronaviruses in aqueous solutions or on environmental surfaces, where viruses are commonly found and spread in public places. By conducting a systematic literature review to collect data covering a wide range of UV wavelengths and various subtypes of coronaviruses, including severe acute respiratory syndrome 2 (SARS-CoV-2), we developed machine learning models for predicting the UV inactivation effects of coronaviruses in aqueous solutions and on environmental surfaces, for which the optimal test performance was obtained with R2 = 0.927, RMSE = 0.565 and R2 = 0.888, RMSE = 0.439, respectively. Besides, the required UV doses at different wavelengths to inactivate the SARS-CoV-2 to 1 Log TCID50/mL titer from different initial titers were predicted for inactivation in protein-free water, saliva on the environmental surface, or the N95 respirator. Our models are instructive for eliminating the ongoing pandemic and controlling the spread of an emerging and unknown coronavirus outbreak.
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Affiliation(s)
- Ruixing Huang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
- Key Laboratory of Eco-environments in the Three Gorges Reservoir Region, Ministry of Education, College of Environmental and Ecology, Chongqing University, Chongqing 400044, China
| | - Chengxue Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
- Key Laboratory of Eco-environments in the Three Gorges Reservoir Region, Ministry of Education, College of Environmental and Ecology, Chongqing University, Chongqing 400044, China
| | - Xiaoliu Huangfu
- Key Laboratory of Eco-environments in the Three Gorges Reservoir Region, Ministry of Education, College of Environmental and Ecology, Chongqing University, Chongqing 400044, China
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
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5
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Ittycheri A, Lipsky ZW, Hookway TA, German GK. Ultraviolet light induces mechanical and structural changes in full thickness human skin. J Mech Behav Biomed Mater 2023; 143:105880. [PMID: 37172426 DOI: 10.1016/j.jmbbm.2023.105880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/07/2023] [Accepted: 04/30/2023] [Indexed: 05/15/2023]
Abstract
While the detrimental health effects of prolonged ultraviolet (UV) irradiation on skin health have been widely accepted, the biomechanical process by which photoaging occurs and the relative effects of irradiation with different UV ranges on skin biomechanics have remained relatively unexplored. In this study, the effects of UV-induced photoageing are explored by quantifying the changes in the mechanical properties of full-thickness human skin irradiated with UVA and UVB light for incident dosages up to 1600 J/cm2. Mechanical testing of skin samples excised parallel and perpendicular to the predominant collagen fiber orientation show a rise in the fractional relative difference of elastic modulus, fracture stress, and toughness with increased UV irradiation. These changes become significant with UVA incident dosages of 1200 J/cm2 for samples excised both parallel and perpendicular to the dominant collagen fiber orientation. However, while mechanical changes occur in samples aligned with the collagen orientation at UVB dosages of 1200 J/cm2, statistical differences in samples perpendicular to the collagen orientation emerge only for UVB dosages of 1600 J/cm2. No notable or consistent trend is observed for the fracture strain. Analyses of toughness changes with maximum absorbed dosage reveals that no one UV range is more impactful in inducing mechanical property changes, but rather these changes scale with maximum absorbed energy. Evaluation of the structural characteristics of collagen further reveals an increase in collagen fiber bundle density with UV irradiation, but not collagen tortuosity, potentially linking mechanical changes to altered microstructure.
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Affiliation(s)
- Abraham Ittycheri
- Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Zachary W Lipsky
- Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Tracy A Hookway
- Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Guy K German
- Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA.
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6
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Fujimoto N, Nagaoka K, Tatsuno I, Oishi H, Tomita M, Hasegawa T, Tanaka Y, Matsumoto T. Wavelength dependence of ultraviolet light inactivation for SARS-CoV-2 omicron variants. Sci Rep 2023; 13:9706. [PMID: 37322228 PMCID: PMC10272214 DOI: 10.1038/s41598-023-36610-6] [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: 11/01/2022] [Accepted: 06/07/2023] [Indexed: 06/17/2023] Open
Abstract
Ultraviolet (UV) irradiation offers an effective and convenient method for the disinfection of pathogenic microorganisms. However, UV irradiation causes protein and/or DNA damage; therefore, further insight into the performance of different UV wavelengths and their applications is needed to reduce risks to the human body. In this paper, we determined the efficacy of UV inactivation of the SARS-CoV-2 omicron BA.2 and BA.5 variants in a liquid suspension at various UV wavelengths by the 50% tissue culture infection dose (TCID50) method and quantitative polymerase chain reaction (qPCR) assay. The inactivation efficacy of 220 nm light, which is considered safe for the human body, was approximately the same as that of health hazardous 260 nm light for both BA.2 and BA.5. Based on the inactivation rate constants determined by the TCID50 and qPCR methods versus the UV wavelength, the action spectra were determined, and BA.2 and BA.5 showed almost the same spectra. This result suggests that both variants have the same UV inactivation characteristics.
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Affiliation(s)
- Nahoko Fujimoto
- Department of Gastroenterology and Hepatology, Faculty of Life Sciences, Kumamoto University, Kumamoto, 860-8556, Japan
| | - Katsuya Nagaoka
- Department of Gastroenterology and Hepatology, Faculty of Life Sciences, Kumamoto University, Kumamoto, 860-8556, Japan
| | - Ichiro Tatsuno
- Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan
| | - Hisashi Oishi
- Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan
| | - Makoto Tomita
- Department of Physics, Faculty of Science, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Tadao Hasegawa
- Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan
| | - Yasuhito Tanaka
- Department of Gastroenterology and Hepatology, Faculty of Life Sciences, Kumamoto University, Kumamoto, 860-8556, Japan
| | - Takahiro Matsumoto
- Department of Gastroenterology and Hepatology, Faculty of Life Sciences, Kumamoto University, Kumamoto, 860-8556, Japan.
- Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan.
- Graduate School of Design and Architecture, Nagoya City University, Nagoya, 464-0083, Japan.
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7
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UVC-Based Air Disinfection Systems for Rapid Inactivation of SARS-CoV-2 Present in the Air. Pathogens 2023; 12:pathogens12030419. [PMID: 36986341 PMCID: PMC10053150 DOI: 10.3390/pathogens12030419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 12/24/2022] [Accepted: 12/28/2022] [Indexed: 03/09/2023] Open
Abstract
The World Health Organization (WHO) declared in May 2021 that SARS-CoV-2 is transmitted not only by close contact with infectious respiratory fluids from infected people or contaminated materials but also indirectly through air. Airborne transmission has serious implications for the control measures we can deploy, given the emergence of more transmissible variants. This emphasizes the need to deploy a mechanism to reduce the viral load in the air, especially in closed and crowded places such as hospitals, public transport buses, etc. In this study, we explored ultraviolet C (UVC) radiation for its ability to inactivate the SARS-CoV-2 particles present in aerosols and designed an air disinfection system to eliminate infectious viruses. We studied the virus inactivation kinetics to identify the UVC dosage required to achieve maximum virus inactivation. Based on the experimental data, UVC-based devices were designed for the sanitization of air through HVAC systems in closed spaces. Further, a risk assessment model to estimate the risk reduction was applied which showed that the use of UVC radiation could result in the reduction of the risk of infection in occupied spaces by up to 90%.
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8
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Singh D, Soorneedi AR, Vaze N, Domitrovic R, Sharp F, Lindsey D, Rohr A, Moore MD, Koutrakis P, Nardell E, Demokritou P. Assessment of SARS-CoV-2 surrogate inactivation on surfaces and in air using UV and blue light-based intervention technologies. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2023; 73:200-211. [PMID: 36594726 DOI: 10.1080/10962247.2022.2157907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/11/2022] [Accepted: 11/21/2022] [Indexed: 06/17/2023]
Abstract
The COVID-19 pandemic has created an urgent need to utilize existing and develop new intervention technologies for SARS-CoV-2 inactivation on surfaces and in the air. Ultraviolet (UV) technology has been shown to be an effective antimicrobial intervention. Here a study was conducted to determine the efficacy of commercially available UV and blue light-based devices for inactivating HCoV-229E, a surrogate of SARS-CoV-2. The results indicate that two UV devices designed for surface disinfection, with doses of 8.07 µJ/cm2 for the 254 nm device and 20.61 µJ/cm2 for the 275 nm device, were efficient in inactivating 4.94 logs of surface inoculated HCoV-229E. Additionally, a 222 nm UV device with intended ceiling-based operation was effective in inactivating 1.7 logs of the virus inoculated on surface, with a dose of 6 mJ/cm2. A ceiling-based device designed to emit blue light at 405 nm was found to produce 89% reduction in HCoV-229E inoculated on a surface for a dose of 78 J/cm2. Finally, the UV based 222 nm device was found to produce a 90% reduction in the concentration of airborne HCoV-229E, at a 55 µJ/cm2 dose. These results are indicative of the great potential of using UV based technology for the control of SARS-CoV-2.Implications: An important avenue of arresting COVID-19 and future pandemics caused by infectious pathogens is through environmental disinfection. To this effect, the study presented here evaluates commercially available UV and blue light based antimicrobial devices for their ability to kill the human coronavirus HCoV-229E, a surrogate of SARS-CoV-2, on surfaces and in air. The results indicate that two handheld UV devices produced complete inactivation of surface viral inoculum and a UVC ceiling based device produced 1 log reduction in HCoV-229E in air. These results imply the efficacy of UV technology as an antimicrobial tool, especially for rapid disinfection of indoor air.
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Affiliation(s)
- Dilpreet Singh
- Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Anand R Soorneedi
- Department of Food Science, University of Massachusetts Amherst, Amherst, MA, USA
| | - Nachiket Vaze
- Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
- Nanoscience and Advanced Materials Research Center, Rutgers Biomedical Health Sciences, School of Public Health, Rutgers University, Piscataway, NJ, USA
| | - Ron Domitrovic
- The Electric Power Research Institute, Palo Alto, CA, USA
| | - Frank Sharp
- The Electric Power Research Institute, Palo Alto, CA, USA
| | | | - Annette Rohr
- The Electric Power Research Institute, Palo Alto, CA, USA
| | - Matthew D Moore
- Department of Food Science, University of Massachusetts Amherst, Amherst, MA, USA
| | - Petros Koutrakis
- Department of Environmental Health, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Ed Nardell
- Brigham and Women's Hospital, Division of Global Health Equity, Boston, MA, USA
| | - Philip Demokritou
- Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
- Nanoscience and Advanced Materials Research Center, Rutgers Biomedical Health Sciences, School of Public Health, Rutgers University, Piscataway, NJ, USA
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9
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Shin S, Dowden B, Doh IJ, Rajwa B, Bae E, Robinson JP. Surface Environment and Energy Density Effects on the Detection and Disinfection of Microorganisms Using a Portable Instrument. SENSORS (BASEL, SWITZERLAND) 2023; 23:2135. [PMID: 36850732 PMCID: PMC9968048 DOI: 10.3390/s23042135] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/08/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Real-time detection and disinfection of foodborne pathogens are important for preventing foodborne outbreaks and for maintaining a safe environment for consumers. There are numerous methods for the disinfection of hazardous organisms, including heat treatment, chemical reaction, filtration, and irradiation. This report evaluated a portable instrument to validate its simultaneous detection and disinfection capability in typical laboratory situations. In this challenging study, three gram-negative and two gram-positive microorganisms were used. For the detection of contamination, inoculations of various concentrations were dispensed on three different surface types to estimate the performance for minimum-detectable cell concentration. Inoculations higher than 103~104 CFU/mm2 and 0.15 mm of detectable contaminant size were estimated to generate a sufficient level of fluorescence signal. The evaluation of disinfection efficacy was conducted on three distinct types of surfaces, with the energy density of UVC light (275-nm) ranging from 4.5 to 22.5 mJ/cm2 and the exposure time varying from 1 to 5 s. The study determined the optimal energy dose for each of the microorganisms species. In addition, surface characteristics may also be an important factor that results in different inactivation efficacy. These results demonstrate that the proposed portable device could serve as an in-field detection and disinfection unit in various environments, and provide a more efficient and user-friendly way of performing disinfection on large surface areas.
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Affiliation(s)
- Sungho Shin
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Brianna Dowden
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Iyll-Joon Doh
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Bartek Rajwa
- Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907, USA
| | - Euiwon Bae
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - J. Paul Robinson
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
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