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Link MF, Robertson RL, Shore A, Hamadani BH, Cecelski CE, Poppendieck DG. Ozone generation and chemistry from 222 nm germicidal ultraviolet light in a fragrant restroom. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024; 26:1090-1106. [PMID: 38787731 PMCID: PMC11421862 DOI: 10.1039/d4em00144c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
Devices using 222 nm germicidal ultraviolet light (GUV222) have been marketed to reduce virus transmission indoors with low risk of occupant harm from direct UV exposure. GUV222 generates ozone, an indoor air pollutant and oxidant, under constrained laboratory conditions, but the chemistry byproducts of GUV222-generated ozone in real indoor spaces is uncharacterized. We deployed GUV222 in a public restroom, with an air change rate of 1 h-1 one weekend and 2 h-1 the next, to measure ozone formation and byproducts generated from ozone chemistry indoors. Ozone from GUV222 increased background concentrations by 5 ppb on average for both weekends and reacted rapidly (e.g., at rates of 3.7 h-1 for the first weekend and 2.0 h-1 for the second) with gas-phase precursors emitted by urinal screens and on surfaces. These ozone reactions generated volatile organic compound and aerosol byproducts (e.g., up to 2.6 μg m-3 of aerosol mass). We find that GUV222 is enhancing indoor chemistry by at least a factor of two for this restroom. The extent of this enhanced chemistry will likely be different for different indoor spaces and is dependent upon ventilation rates, species and concentrations of precursor VOCs, and surface reactivity. Informed by our measurements of ozone reactivity and background aerosol concentrations, we present a framework for predicting aerosol byproduct formation from GUV222 that can be extended to other indoor spaces. Further research is needed to understand how typical uses of GUV222 could impact air quality in chemically diverse indoor spaces and generate indoor air chemistry byproducts that can affect human health.
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Affiliation(s)
- Michael F Link
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
| | - Rileigh L Robertson
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
| | - Andrew Shore
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
| | - Behrang H Hamadani
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
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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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Belland K, Garcia D, DeJohn C, Allen GR, Mills WD, Glaudel SP. Safety and Effectiveness Assessment of Ultraviolet-C Disinfection in Aircraft Cabins. Aerosp Med Hum Perform 2024; 95:147-157. [PMID: 38356125 DOI: 10.3357/amhp.6350.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
INTRODUCTION: Aircraft cabins, susceptible to disease transmission, require effective strategies to minimize the spread of airborne diseases. This paper reviews the James Reason Swiss Cheese Theory in mitigating these risks, as implemented by the International Civil Aviation Organization during the COVID-19 pandemic. It also evaluates the use of airborne ultraviolet-C (UV-C) light as an additional protective measure.METHODS: Our approach involved a thorough literature review by experts and a detailed risk-vs.-benefit analysis. The review covered existing research to understand the scientific foundation, while the analysis used established techniques to assess the impact of influenza and COVID-19 in terms of infections, deaths, and economic costs.RESULTS: Integrating UV-C light in aircraft cabins, when applied with appropriate scientific understanding and engineering safeguards, has the potential to reduce in-flight disease transmission. This additional mitigation strategy can work synergistically with existing measures.DISCUSSION: The research and risk-vs.-benefit analysis present strong evidence for the safety and effectiveness of continuous UV-C disinfection in aircraft cabins. It suggests that UV-C light, maintained below exposure limits, can be a valuable addition to existing measures against disease transmission during flights.Belland K, Garcia D, DeJohn C, Allen GR, Mills WD, Glaudel SP. Safety and effectiveness assessment of ultraviolet-C disinfection in aircraft cabins. Aerosp Med Hum Perform. 2024; 95(3):147-157.
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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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de Souza M, Sammarro Silva KJ, Garbuio M, Inada NM, Bagnato VS, Lima AR. Photon spectra effects tested on the vegetal model Allium cepa. JOURNAL OF BIOPHOTONICS 2023; 16:e202300168. [PMID: 37679880 DOI: 10.1002/jbio.202300168] [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: 05/11/2023] [Revised: 07/26/2023] [Accepted: 09/05/2023] [Indexed: 09/09/2023]
Abstract
The use of artificial light sources in plants is considered a type of photobiomodulation (PBM), a trend in agriculture and food industries, aiming at decontamination, pest control, and increased production yield. However, literature lacks a broader assessment to address the effects of photon light spectra on plant characteristics. Here, we aimed to describe the effects of visible light, infrared, and ultraviolet light upon Allium cepa, a known bioindicator, under various light doses. Samples irradiated under visible and infrared light did not show cytotoxicity, genotoxicity, or mutagenicity in any of the evaluated doses. Light induction at 460 and 635 nm significantly stimulated root development of the test organism. In contrast, 254 nm irradiation proved to be cytotoxic, genotoxic, and mutagenic. This work reveals and quantifies the spectral response of A. cepa seeds, suggesting that it can be proposed as a model for future research on mechanisms of PBM in plants.
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Affiliation(s)
- Mariana de Souza
- São Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
- Central Paulista University, São Paulo, São Carlos, SP, Brazil
| | | | - Matheus Garbuio
- São Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
- PPG Biotec, Federal University of São Carlos, São Carlos, SP, Brazil
| | - Natalia Mayumi Inada
- São Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
| | - Vanderlei Salvador Bagnato
- São Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA
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Donskey CJ. Continuous surface and air decontamination technologies: Current concepts and controversies. Am J Infect Control 2023; 51:A144-A150. [PMID: 37890945 DOI: 10.1016/j.ajic.2023.03.017] [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: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 10/29/2023]
Abstract
Effective and safe continuous surface and air decontamination technologies could be a useful adjunct to routine cleaning and disinfection in health care settings. Continuously active quaternary ammonium disinfectants that provide residual antimicrobial activity on undisturbed surfaces for up to 24.ßhours have been shown to reduce the recovery of clinically important pathogens in some but not all real-world studies. Although quaternary ammonium-based supplemental coatings have been reported to provide prolonged residual efficacy in patient care settings, there is concern that some of these products may be removed by routine cleaning and disinfection. To address this concern, the Environmental Protection Agency has recently issued updated guidance requiring demonstration of efficacy after multiple abrasion and chemical exposures for registration of supplemental residual antimicrobial coatings. Far-ultraviolet-C and direct irradiation below exposure limits are promising technologies for continuous air and surface decontamination in occupied spaces, but additional studies are needed to evaluate their long-term safety and efficacy. Given the increasing use of electronic air cleaning technologies in community and health care settings, there is a need for studies to assess real-world efficacy and safety.
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Affiliation(s)
- Curtis J Donskey
- Geriatric Research, Education and Clinical Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH; Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH.
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Harris DM, Sulewski JG. Photoinactivation and Photoablation of Porphyromonas gingivalis. Pathogens 2023; 12:1160. [PMID: 37764967 PMCID: PMC10535405 DOI: 10.3390/pathogens12091160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/31/2023] [Accepted: 09/02/2023] [Indexed: 09/29/2023] Open
Abstract
Several types of phototherapy target human pathogens and Porphyromonas gingivitis (Pg) in particular. The various approaches can be organized into five different treatment modes sorted by different power densities, interaction times, effective wavelengths and mechanisms of action. Mode 1: antimicrobial ultraviolet (aUV); mode 2: antimicrobial blue light (aBL); mode 3: antimicrobial selective photothermolysis (aSP); mode 4: antimicrobial vaporization; mode 5: antimicrobial photodynamic therapy (aPDT). This report reviews the literature to identify for each mode (a) the putative molecular mechanism of action; (b) the effective wavelength range and penetration depth; (c) selectivity; (d) in vitro outcomes; and (e) clinical trial/study outcomes as these elements apply to Porphyromonas gingivalis (Pg). The characteristics of each mode influence how each is translated into the clinic.
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Affiliation(s)
- David M. Harris
- Bio-Medical Consultants, Inc., Canandaigua, NY 14424, USA
- Department of Periodontics, Rutgers School of Dental Medicine, Newark, NJ 07103, USA
| | - John G. Sulewski
- Institute for Advanced Dental Technologies, Huntington Woods, MI 48070, USA
- Millennium Dental Technologies, Inc., Cerritos, CA 90703, USA
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Sharma AA, Rakshita M, Pradhan PP, Prasad KAKD, Mishra S, Jayanthi K, Haranath D. Noninvasive treatment of psoriasis and skin rejuvenation using an akermanite-type narrowband emitting phosphor. LUMINESCENCE 2023; 38:1668-1677. [PMID: 37434298 DOI: 10.1002/bio.4554] [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: 02/03/2023] [Revised: 05/28/2023] [Accepted: 07/03/2023] [Indexed: 07/13/2023]
Abstract
Psoriasis is a noncontagious, long-lasting skin infection that affects many people around the world. Numerous therapeutic artificial treatments are available for the treatment of psoriasis, such as photodynamic therapy using broadband ultraviolet (UV) lamps, which have harmful effects on human skin. Similarly, the natural healing systems such as sunlight have a higher risk of sunburn and can cause dangerous forms of skin cancer. Significant light emission of a specific wavelength (in the UV range), and phosphor-based devices demonstrate the effectiveness of treating psoriasis without damaging the skin. Gd3+ -doped calcium magnesium silicate [Ca2 MgSi2 O7 :Gd3+ ,(CMS:Gd3+ )] phosphor is one of the ideal phosphors that emit specific narrow UV wavelengths for curing psoriasis and is in great demand in the field of dermatology. Photoluminescence analysis at room temperature (~25°C) shows that the synthesized CMS:Gd3+ phosphor emits narrowband UV-B light with a peak intensity at 314 nm. Comparative studies of the standard action spectrum of psoriasis with the emission spectrum of the CMS:Gd3+ phosphor show that the synthesized phosphor was the most suitable material for treating a variety of diseases, including psoriasis, vitiligo, type-1 diabetes, dental disease, sleep and mood disorders, and other skin diseases.
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Affiliation(s)
- Aachal A Sharma
- Luminescence Materials and Devices (LMD) Group, Department of Physics, National Institute of Technology Warangal, Telangana, India
| | - M Rakshita
- Luminescence Materials and Devices (LMD) Group, Department of Physics, National Institute of Technology Warangal, Telangana, India
| | - Payal P Pradhan
- Luminescence Materials and Devices (LMD) Group, Department of Physics, National Institute of Technology Warangal, Telangana, India
| | - K A K Durga Prasad
- Luminescence Materials and Devices (LMD) Group, Department of Physics, National Institute of Technology Warangal, Telangana, India
| | - Siju Mishra
- Luminescence Materials and Devices (LMD) Group, Department of Physics, National Institute of Technology Warangal, Telangana, India
| | - K Jayanthi
- Department of Physical and Chemical Sciences, Sri Satya Sai University of Human Excellence, Kalaburagi, Karnataka, India
| | - D Haranath
- Luminescence Materials and Devices (LMD) Group, Department of Physics, National Institute of Technology Warangal, Telangana, India
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Karthik S, Joseph J, Jayakumar J, Manoj R, Shetty M, Bota M, Verma R, Mitra P, Sivaprakasam M. Wide field block face imaging using deep ultraviolet induced autofluorescence of the human brain. J Neurosci Methods 2023; 397:109921. [PMID: 37459898 DOI: 10.1016/j.jneumeth.2023.109921] [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: 03/24/2023] [Revised: 06/26/2023] [Accepted: 07/13/2023] [Indexed: 08/22/2023]
Abstract
BACKGROUND Imaging large volume human brains at cellular resolution involve histological methods that cause structural changes. A reference point prior to sectioning is needed to quantify these changes and is achieved by serial block face imaging (BFI) methods that have been applied to small volume tissue (∼1 cm3). NEW METHOD We have developed a BFI uniquely designed for large volume tissues (∼1300 cm3) with a very large field of view (20 × 20 cm) at a resolution of 70 µm/pixel under deep ultraviolet (UV-C) illumination which highlights key features. RESULTS The UV-C imaging ensures high contrast imaging of the brain tissue and highlights salient features of the brain. The system is designed to provide uniform and stable illumination across the entire surface area of the tissue and to work at low temperatures, which are required during cryosectioning. Most importantly, it has been designed to maintain its optical focus over the large depth of tissue and over long periods of time, without readjustments. The BFI was installed within a cryomacrotome, and was used to image a large cryoblock of an adult human cerebellum and brainstem (∼6 cm depth resulting in 2995 serial images) with precise optical focus and no loss during continuous serial acquisition. COMPARISON WITH EXISTING METHOD(S) The deep UV-C induced BFI highlights several large fibre tracts within the brain including the cerebellar peduncles, and the corticospinal tract providing important advantage over white light BFI. CONCLUSIONS The 3D reconstructed serial BFI images can assist in the registration and alignment of the microscopic high-resolution histological tissue sections.
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Affiliation(s)
- Srinivasa Karthik
- Healthcare Technology Innovation Centre, No. 1, 5th Floor, 'C' Block, Phase-II, IIT Madras Research Park, Kanagam Road, Taramani, Chennai 600113, India; Department of Electrical Engineering, Indian Institute of Technology Madras, IIT P.O., Chennai 600036, India.
| | - Jayaraj Joseph
- Department of Electrical Engineering, Indian Institute of Technology Madras, IIT P.O., Chennai 600036, India
| | - Jaikishan Jayakumar
- Sudha Gopalakrishnan Brain Centre (SGBC), Indian Institute of Technology Madras, NAC Building 1, Stilt Floor, IIT P.O., Chennai 600036, India; Center for Computational Brain Research, Indian Institute of Technology Madras, IIT P.O., Chennai 600036, India
| | - Rahul Manoj
- Healthcare Technology Innovation Centre, No. 1, 5th Floor, 'C' Block, Phase-II, IIT Madras Research Park, Kanagam Road, Taramani, Chennai 600113, India; Department of Electrical Engineering, Indian Institute of Technology Madras, IIT P.O., Chennai 600036, India
| | - Mahesh Shetty
- Sudha Gopalakrishnan Brain Centre (SGBC), Indian Institute of Technology Madras, NAC Building 1, Stilt Floor, IIT P.O., Chennai 600036, India
| | - Mihail Bota
- Sudha Gopalakrishnan Brain Centre (SGBC), Indian Institute of Technology Madras, NAC Building 1, Stilt Floor, IIT P.O., Chennai 600036, India
| | - Richa Verma
- Sudha Gopalakrishnan Brain Centre (SGBC), Indian Institute of Technology Madras, NAC Building 1, Stilt Floor, IIT P.O., Chennai 600036, India
| | - Partha Mitra
- Center for Computational Brain Research, Indian Institute of Technology Madras, IIT P.O., Chennai 600036, India; Cold Spring Harbor Laboratory, 1, Bungtown Road, Cold Spring Harbor, New York 11724, United States
| | - Mohanasankar Sivaprakasam
- Healthcare Technology Innovation Centre, No. 1, 5th Floor, 'C' Block, Phase-II, IIT Madras Research Park, Kanagam Road, Taramani, Chennai 600113, India; Department of Electrical Engineering, Indian Institute of Technology Madras, IIT P.O., Chennai 600036, India; Sudha Gopalakrishnan Brain Centre (SGBC), Indian Institute of Technology Madras, NAC Building 1, Stilt Floor, IIT P.O., Chennai 600036, India
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Insero G, Fusi F, Romano G. The safe use of lasers in biomedicine: Principles of laser-matter interaction. J Public Health Res 2023; 12:22799036231187077. [PMID: 37539442 PMCID: PMC10395181 DOI: 10.1177/22799036231187077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 06/23/2023] [Indexed: 08/05/2023] Open
Abstract
Optical radiation sources, and in particular lasers, find an ever-increasing number of applications in the medical field. It is essential that personnel who are in the presence of an optical radiation source, whether operator, patient or researcher, know precisely the risks inherent in the exposure of the human body to radiation. In order to reduce the risk of biological damage, beyond the provisions of the law on safety regulations, the precise information and accurate preparation of personnel are the main guarantee for the correct use of these sources. In all the application fields, the possibility of a biological damage cannot be completely eliminated, assuming the connotation of occupational risks. In order to understand the risks and operate their effective mitigation, the basic knowledge of the fundamental concepts at the basis of laser-matter interaction will be presented and discussed, with a focus on the physical parameters needed to efficiently estimate and mitigate the related occupational risks, in both a laboratory and clinical context.
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Affiliation(s)
- Giacomo Insero
- Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, Florence, Italy
| | - Franco Fusi
- Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, Florence, Italy
- Probiomedica srl, Florence, Italy
| | - Giovanni Romano
- Department of Experimental and Clinical Biomedical Sciences ‘Mario Serio’, University of Florence, Florence, Italy
- Probiomedica srl, Florence, Italy
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11
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Truong CS, Muthukutty P, Jang HK, Kim YH, Lee DH, Yoo SY. Filter-Free, Harmless, and Single-Wavelength Far UV-C Germicidal Light for Reducing Airborne Pathogenic Viral Infection. Viruses 2023; 15:1463. [PMID: 37515151 PMCID: PMC10385069 DOI: 10.3390/v15071463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/22/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023] Open
Abstract
Germicidal lamps that primarily emit 254 nm ultraviolet (UV) radiation have been effectively utilized for surface sterilization, but they cannot be used on human skin and eyes due to their harmful and genotoxic activity. Recent reports have shown that far UV-C light (207-222 nm) can efficiently kill pathogens with potentially no harm to exposed human tissues. However, these methods still require additional filtering and/or further protective equipment. In this study, we demonstrate a filter-free, harmless, and single-wavelength far UV-C 207 nm germicidal light source that can be used to inactivate different respiratory viruses. It can be exploited as a safe and effective disinfection tool for various airborne viruses. We successfully developed a single-wavelength far UV-C source that produces an exact wavelength of 207 nm. We examined its safety on human skin and corneal cell lines, as well as its effects on inactivating different airborne viruses, such as coronavirus, adenovirus, and vaccinia virus. We expect that our far UV-C lamps can be safely and conveniently used to reduce COVID-19 infections and protect both our living spaces and hospitals from the threat of contamination by possible new or mutant viruses.
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Affiliation(s)
- Cao-Sang Truong
- BIO-IT Foundry Technology Institute, Pusan National University, Busan 46241, Republic of Korea
| | - Palaniyandi Muthukutty
- BIO-IT Foundry Technology Institute, Pusan National University, Busan 46241, Republic of Korea
| | - Ho Kyung Jang
- SUNJE HI TEK Co., Ltd., Busan 46047, Republic of Korea
| | - Young-Ho Kim
- Department of Molecular Biology and Immunology, College of Medicine, Kosin University, Busan 49267, Republic of Korea
| | - Dong Hoon Lee
- SUNJE HI TEK Co., Ltd., Busan 46047, Republic of Korea
| | - So Young Yoo
- BIO-IT Foundry Technology Institute, Pusan National University, Busan 46241, Republic of Korea
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12
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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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13
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Keil JN, Kätker H, Wegh RT, Peeters MPJ, Jüstel T. Novel bandpass filter for far UV-C emitting radiation sources. OPTICAL MATERIALS 2023; 140:113866. [PMID: 37193363 PMCID: PMC10165311 DOI: 10.1016/j.optmat.2023.113866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/30/2023] [Indexed: 05/18/2023]
Abstract
Disinfection with far UV-C radiation (<230 nm) is an effective method to inactivate harmful microorganisms like the SARS-CoV2 virus. Due to the stronger absorption than regular UV-C radiation (254 nm) and hence limited penetration into human tissues, it has the promise of enabling disinfection in occupied spaces. The best far-UV sources so far are discharge lamps based on the KrCl* excimer discharge peaking at 222 nm, however they produce longer wavelength radiation as a by-product. In current KrCl* excimer lamps usually a dichroic filter is used to suppress these undesired longer wavelengths. A phosphor-based filter is an alternative which is cheaper and easier to apply. This paper describes the results of our exploration of this opportunity. Various compounds were synthesized and characterized to find a replacement for the dichroic filter. It was found that Bi3+-doped ortho-borates with the pseudo-vaterite crystal structure exhibit the best absorption spectrum i.e. high transmission around 222 nm and strong absorption in the 235-280 nm range. Y0.24Lu0.75Bi0.01BO3 showed the best absorption spectrum in the UV-C. To suppress the unwanted Bi3+ emission (UV-B), the excitation energy can be transferred to a co-dopant. Ho3+ turned out to be the best co-dopant, and Ho0.24Lu0.75Bi0.01BO3 appeared to be the best overall candidate for the phosphor filter material. A suitable formulation for a coating suspension containing this material was found, and quite homogeneous coatings were achieved. The efficiency of these filter layers was investigated and the results in terms of exposure limit increase i.e. gain factor vs. no filter were compared with the dichroic filter. We achieved a gain factor for the Ho3+ containing sample of up to 2.33, i.e. not as good as that of the dichroic filter (∼4.6), but a very relevant improvement, making Ho0.24Lu0.75Bi0.01BO3 an interesting material for a cost-effective filter for KrCl* far UV-C lamps.
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Affiliation(s)
- Jan-Niklas Keil
- Department of Chemical Engineering, FH Münster University of Applied Sciences, Stegerwaldstrasse 39, D-48565, Steinfurt, Germany
| | - Heike Kätker
- Department of Chemical Engineering, FH Münster University of Applied Sciences, Stegerwaldstrasse 39, D-48565, Steinfurt, Germany
| | - René T Wegh
- Signify Research, High Tech Campus 7, NL-5656, AE Eindhoven, Netherlands
| | - Mart P J Peeters
- Signify Research, High Tech Campus 7, NL-5656, AE Eindhoven, Netherlands
| | - Thomas Jüstel
- Department of Chemical Engineering, FH Münster University of Applied Sciences, Stegerwaldstrasse 39, D-48565, Steinfurt, Germany
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14
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Hessling M, Sicks B, Lau B. Far-UVC Radiation for Disinfecting Hands or Gloves? Pathogens 2023; 12:213. [PMID: 36839485 PMCID: PMC9963788 DOI: 10.3390/pathogens12020213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/10/2023] [Accepted: 01/23/2023] [Indexed: 02/03/2023] Open
Abstract
(1) Background: Far-UVC radiation in the spectral range 200-230 nm has, according to previous findings, a strong antimicrobial effect on pathogens, but exhibits hardly any harmful effect on human skin. Therefore, the present study will discuss whether such radiation could also be suitable for hand disinfection in the healthcare sector. (2) Methods: Hands and gloves were microbially contaminated and exposed to radiation from a 222 nm krypton-chloride-excimer lamp. The applied doses were 23 mJ/cm2 and 100 mJ/cm2, respectively. Irradiated and non-irradiated hands and gloves were pressed onto agar plates and colonies were counted and compared after 24 h of incubation. For comparison, we also treated hands and gloves with a commercial liquid alcohol-based disinfectant. (3) Results: On the hand, the 23 mJ/cm2 resulted in the reduction of the observed colonies on the agar plates by one log level. For the gloves irradiated with 100 mJ/cm2, a colony reduction of 1.3 log levels was recorded. In the comparative experiments with the commercial disinfectant, a colony reduction of 1.9 and approximately one log level was observed on hand and gloves, respectively. (4) Conclusion: In both cases, far-UVC radiation provided a considerable reduction in microorganisms. However, compared to published far-UVC irradiation results in suspensions, the disinfection success on hands and gloves was rather low. With regard to the irradiation limits currently existing in the European Union, multiple daily hand disinfection with far-UVC radiation is actually legally not possible at present, but the thresholds are currently under discussion and could change in the future. Far-UVC disinfection of hands in gloves seems theoretically possible if attention is paid to potential perforations in the gloves.
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Affiliation(s)
- Martin Hessling
- Institute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Albert-Einstein-Allee 55, D-89081 Ulm, Germany
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15
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Zhang H, Lai ACK. Evaluation of Single-Pass Disinfection Performance of Far-UVC Light on Airborne Microorganisms in Duct Flows. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:17849-17857. [PMID: 36469399 DOI: 10.1021/acs.est.2c04861] [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] [Indexed: 06/17/2023]
Abstract
Far-UVC irradiation (222 nm) is considered an emerging and sustainable solution for future infection and pandemic challenges. We examined the disinfection performance of a krypton-chloride lamp, with a quasi-monochromatic UVC peak at 222 nm, for inactivating airborne microorganisms in a full-scale ventilation duct system. Single-pass disinfection efficacy of far-UVC was determined and compared with that of a conventional mercury-type UVC (254 nm) lamp. Four bacteria, Escherichia coli (E. coli), Pseudomonas alcaligenes (P. alcaligenes), Serratia marcescens (S. marcescens), and Staphylococcus epidermidis (S. epidermidis), as well as bacteriophage P22, were tested under UV exposure with different velocities of duct flows. The data revealed that as the air velocity increased from 0.7 to 4 m/s, the far-UVC disinfection efficacies would decrease by 42, 47, 35, 39, and 33% for these five microorganisms, respectively. The inactivation rate constants to far-UVC light were 4.9, 7.5, 3.3, 6.3, and 3.0 cm2/mJ for aerosolized E. coli, P. alcaligenes, S. marcescens, S. epidermidis, and bacteriophage P22, respectively. Far-UVC irradiation showed a comparable disinfection ability on airborne microorganisms compared with the 254 nm UV irradiation. This first study of far-UVC in real duct applications provides a better understanding of the disinfection performance of this solution in bioaerosol inactivation. It offers a valuable database in the sizing and design of excimer lamps for novel portable air purifiers or in-duct disinfection units.
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Affiliation(s)
- Huihui Zhang
- Department of Architecture and Civil Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong00000, China
| | - Alvin C K Lai
- Department of Architecture and Civil Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong00000, China
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16
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O'Mahoney P, Wood K, Ibbotson SH, Eadie E. Potential harm to the skin from unfiltered krypton chloride 'far-ultraviolet-C' lamps, even below an occupational exposure limit. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2022; 42:043501. [PMID: 36317283 DOI: 10.1088/1361-6498/ac9e60] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
Ultraviolet-C (UVC) radiation can effectively inactivate pathogens on surfaces and in the air. Due to the potential for harm to skin and eyes, human exposure to UVC should be limited within the guideline exposure limits produced by the International Commission on Non-Ionising Radiation Protection (ICNIRP) or the American Conference of Governmental Industrial Hygienists (ACGIHs). Both organisations state an effective spectrally weighted limit of 3 mJ cm-2, although the spectral weighting factors of the two organisations diverged following a revision of the ACGIH guidelines in 2022. Using existing published human exposure data, the effective spectrally weighted radiant exposure was calculated for both unfiltered and filtered (to reduce UV emissions above 230 nm) krypton chloride (KrCl*) excimer lamps. The effective radiant exposure of the filtered KrCl* lamp was greater than 3 mJ cm-2when applying ICNIRP or either of the revised ACGIH spectral weightings. This indicates that both guidelines are appropriately conservative for this specific lamp. However, the effective radiant exposure of the unfiltered KrCl* lamp was as low as 1 mJ cm-2with the revised ACGIH weighting function that can be applied to the skin if the eyes are protected. Erythema has therefore been directly observed in a clinical study at an exposure within the revised ACGIH guideline limits. Extrapolating this information means that a mild sunburn could be induced in Fitzpatrick skin types I and II if that particular ACGIH weighting function were applied and an individual received an effective exposure of 3 mJ cm-2. Whilst it is improbable that such an effect would be seen in current deployment of KrCl* lamp technology, it does highlight the need for further research into skin sensitivity and irradiance-time reciprocity for UVC wavelengths.
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Affiliation(s)
- Paul O'Mahoney
- School of Medicine, University of Dundee, Dundee, United Kingdom
- Photobiology Unit, NHS Tayside, Ninewells Hospital and Medical School, Dundee, United Kingdom
| | - Kenneth Wood
- School of Physics and Astronomy, University of St Andrews, St Andrews, United Kingdom
| | - Sally H Ibbotson
- School of Medicine, University of Dundee, Dundee, United Kingdom
- Photobiology Unit, NHS Tayside, Ninewells Hospital and Medical School, Dundee, United Kingdom
| | - Ewan Eadie
- Photobiology Unit, NHS Tayside, Ninewells Hospital and Medical School, Dundee, United Kingdom
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17
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Zhu S, Lin T, Wang L, Nardell EA, Vincent RL, Srebric J. Ceiling impact on air disinfection performance of Upper-Room Germicidal Ultraviolet (UR-GUV). BUILDING AND ENVIRONMENT 2022; 224:109530. [PMID: 36065253 PMCID: PMC9429126 DOI: 10.1016/j.buildenv.2022.109530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/12/2022] [Accepted: 08/21/2022] [Indexed: 06/15/2023]
Abstract
This study used Computational Fluid Dynamics (CFD) to investigate air disinfection for SARS-CoV-2 by the Upper-Room Germicidal Ultraviolet (UR-GUV), with focus on ceiling impact. The study includes three indoor settings, i.e., low (airport bus), medium (classroom) and high (rehearsal room) ceilings, which were ventilated with 100% clean air (CA case), 80% air-recirculation with a low filtration (LF case), and 80% air-recirculation with a high filtration (HF case). According to the results, using UR-GUV can offset the increased infection risk caused by air recirculation, with viral concentrations in near field (NF) and far field (FF) in the LF case similar to those in the CA case. In the CA case, fraction remaining (FR) was 0.48-0.73 with 25% occupancy rate (OR) and 0.49-0.91 with 45% OR in the bus, 0.41 in NF and 0.11 in FF in the classroom, and 0.18 in NF and 0.09 in FF in the rehearsal room. Obviously, UR-GUV performance in NF can be improved in a room with a high ceiling where FR has a power relationship with UV zone height. As using UR-GUV can only extend the exposure time to get infection risk of 1% (T 1% ) to 8 min in NF in the classroom, and 47 min in NF in the rehearsal room, it is necessary to abide by social distancing in the two rooms. In addition, T 1% in FF was calculated to be 18.3 min with 25% OR and 21.4% with 45% OR in the airport bus, showing the necessity to further wear a mask.
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Affiliation(s)
- Shengwei Zhu
- Department of Mechanical Engineering, University of Maryland, College Park, MD, USA
| | - Tong Lin
- Department of Mechanical Engineering, University of Maryland, College Park, MD, USA
| | - Lingzhe Wang
- Department of Mechanical Engineering, University of Maryland, College Park, MD, USA
| | - Edward A Nardell
- Departments of Environmental Health and Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | - Jelena Srebric
- Department of Mechanical Engineering, University of Maryland, College Park, MD, USA
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18
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Sugihara K, Kaidzu S, Sasaki M, Ichioka S, Takayanagi Y, Shimizu H, Sano I, Hara K, Tanito M. One-Year Ocular Safety Observation of Workers and Estimations of Microorganism Inactivation Efficacy in the Room Irradiated with 222-Nm far Ultraviolet-C Lamps. Photochem Photobiol 2022; 99:967-974. [PMID: 36081379 DOI: 10.1111/php.13710] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 09/05/2022] [Indexed: 11/30/2022]
Abstract
Two krypton-chloride germicidal excimer lamp units (Care222 TRT-104C11-UI-U3, USHIO Inc.) were installed in the examination room of an ophthalmology department. The irradiation dose was set not to exceed the former (i.e., before 2022) threshold limit value (TLV) (22 mJ/cm2 /8 hours) recommended by the ACGIH. Section 1: The eyes and lids of the 6 ophthalmologists (5 wore glasses for myopic correction) who worked in the room for a mean stay of 6.7 hours/week were prospectively observed for 12 months. Slitlamp examinations revealed neither acute adverse events such as corneal erosion, conjunctival hyperemia, lid skin erythema nor chronic adverse events such as pterygium, cataract, or lid tumor. The visual acuity, refractive error, corneal endothelial cell density remained unchanged during the study. Section 2: The irradiation of samples placed on the table or floor using the same fixtures in the room (5-7.5 mJ/cm2 ) was associated with >99% inhibition of φX174 phage and >90% inhibition of S. aureus. In conclusion, no acute or chronic health effects in human participants was observed in a clinical setting of full-room ultraviolet germicidal irradiation by 222-nm lamp units and high efficacy in deactivation of microorganisms was determined in the same setting.
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Affiliation(s)
- Kazunobu Sugihara
- Department of Ophthalmology, Shimane University Faculty of Medicine, Izumo, Japan
| | - Sachiko Kaidzu
- Department of Ophthalmology, Shimane University Faculty of Medicine, Izumo, Japan
| | | | - Sho Ichioka
- Department of Ophthalmology, Shimane University Faculty of Medicine, Izumo, Japan
| | - Yuji Takayanagi
- Department of Ophthalmology, Shimane University Faculty of Medicine, Izumo, Japan
| | - Hiroshi Shimizu
- Department of Ophthalmology, Shimane University Faculty of Medicine, Izumo, Japan
| | - Ichiya Sano
- Department of Ophthalmology, Shimane University Faculty of Medicine, Izumo, Japan
| | - Katsunori Hara
- Department of Ophthalmology, Shimane University Faculty of Medicine, Izumo, Japan
| | - Masaki Tanito
- Department of Ophthalmology, Shimane University Faculty of Medicine, Izumo, Japan
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19
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McPhaul KM. Indoor Air Disinfection: Answering Questions About Germicidal Ultraviolet Lights. Workplace Health Saf 2022. [DOI: 10.1177/21650799221119149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Kathleen M. McPhaul
- Maryland Institute for Applied Environmental Health, School of Public Health, University of Maryland, College Park
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20
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Zhang Y, Hui FKP, Duffield C, Saeed AM. A review of facilities management interventions to mitigate respiratory infections in existing buildings. BUILDING AND ENVIRONMENT 2022; 221:109347. [PMID: 35782231 PMCID: PMC9238148 DOI: 10.1016/j.buildenv.2022.109347] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 05/01/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
The Covid-19 pandemic reveals that the hazard of the respiratory virus was a secondary consideration in the design, development, construction, and management of public and commercial buildings. Retrofitting such buildings poses a significant challenge for building owners and facilities managers. This article reviews current research and practices in building operations interventions for indoor respiratory infection control from the perspective of facilities managers to assess the effectiveness of available solutions. This review systematically selects and synthesises eighty-six articles identified through the PRISMA process plus supplementary articles identified as part of the review process, that deal with facilities' operations and maintenance (O&M) interventions. The paper reviewed the context, interventions, mechanisms, and outcomes discussed in these articles, concluding that interventions for respiratory virus transmission in existing buildings fall into three categories under the Facilities Management (FM) discipline: Hard services (HVAC and drainage system controls) to prevent aerosol transmissions, Soft Services (cleaning and disinfection) to prevent fomite transmissions, and space management (space planning and occupancy controls) to eliminate droplet transmissions. Additionally, the research emphasised the need for FM intervention studies that examine occupant behaviours with integrated intervention results and guide FM intervention decision-making. This review expands the knowledge of FM for infection control and highlights future research opportunities.
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Affiliation(s)
- Yan Zhang
- Department of Infrastructure Engineering, University of Melbourne, Level 6, Building 290, 700 Swanston Street, Carlton, Victoria, Australia
| | - Felix Kin Peng Hui
- Department of Infrastructure Engineering, University of Melbourne, Australia
| | - Colin Duffield
- Department of Infrastructure Engineering, University of Melbourne, Australia
| | - Ali Mohammed Saeed
- Department of Jobs, Regions and Precincts, Level 13, 1 Spring Street, Melbourne, Victoria, Australia
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21
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Kodithuwakku P, Jayasundara D, Munaweera I, Jayasinghe R, Thoradeniya T, Weerasekera M, Ajayan PM, Kottegoda N. A Review on Recent Developments in Structural Modification of TiO2 For Food Packaging Applications. PROG SOLID STATE CH 2022. [DOI: 10.1016/j.progsolidstchem.2022.100369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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22
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Enrichment of glucosinolate and carotenoid contents of mustard sprouts by using green elicitors during germination. J Food Compost Anal 2022. [DOI: 10.1016/j.jfca.2022.104546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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23
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Romano G, Insero G, Marrugat SN, Fusi F. Innovative light sources for phototherapy. Biomol Concepts 2022; 13:256-271. [DOI: 10.1515/bmc-2022-0020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 05/03/2022] [Indexed: 11/15/2022] Open
Abstract
Abstract
The use of light for therapeutic purposes dates back to ancient Egypt, where the sun itself was an innovative source, probably used for the first time to heal skin diseases. Since then, technical innovation and advancement in medical sciences have produced newer and more sophisticated solutions for light-emitting sources and their applications in medicine. Starting from a brief historical introduction, the concept of innovation in light sources is discussed and analysed, first from a technical point of view and then in the light of their fitness to improve existing therapeutic protocols or propose new ones. If it is true that a “pure” technical advancement is a good reason for innovation, only a sub-system of those advancements is innovative for phototherapy. To illustrate this concept, the most representative examples of innovative light sources are presented and discussed, both from a technical point of view and from the perspective of their diffusion and applications in the clinical field.
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Affiliation(s)
- Giovanni Romano
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence , Viale G. Pieraccini 6 , 50139 Florence , Italy
| | - Giacomo Insero
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence , Viale G. Pieraccini 6 , 50139 Florence , Italy
- National Research Council, National Institute of Optics (CNR-INO) , Via Carrara 1 , 50019 Sesto Fiorentino , FI , Italy
| | - Santi Nonell Marrugat
- Institut Quimic de Sarria, Universidad Ramon Llull , Via Augusta 390 , 08017 Barcelona , Spain
| | - Franco Fusi
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence , Viale G. Pieraccini 6 , 50139 Florence , Italy
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24
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Toto E, Laurenzi S, Santonicola MG. Recent Trends in Graphene/Polymer Nanocomposites for Sensing Devices: Synthesis and Applications in Environmental and Human Health Monitoring. Polymers (Basel) 2022; 14:1030. [PMID: 35267853 PMCID: PMC8914833 DOI: 10.3390/polym14051030] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 02/28/2022] [Accepted: 03/03/2022] [Indexed: 02/04/2023] Open
Abstract
Graphene-based nanocomposites are largely explored for the development of sensing devices due to the excellent electrical and mechanical properties of graphene. These properties, in addition to its large specific surface area, make graphene attractive for a wide range of chemical functionalization and immobilization of (bio)molecules. Several techniques based on both top-down and bottom-up approaches are available for the fabrication of graphene fillers in pristine and functionalized forms. These fillers can be further modified to enhance their integration with polymeric matrices and substrates and to tailor the sensing efficiency of the overall nanocomposite material. In this review article, we summarize recent trends in the design and fabrication of graphene/polymer nanocomposites (GPNs) with sensing properties that can be successfully applied in environmental and human health monitoring. Functional GPNs with sensing ability towards gas molecules, humidity, and ultraviolet radiation can be generated using graphene nanosheets decorated with metallic or metal oxide nanoparticles. These nanocomposites were shown to be effective in the detection of ammonia, benzene/toluene gases, and water vapor in the environment. In addition, biological analytes with broad implications for human health, such as nucleic bases or viral genes, can also be detected using sensitive, graphene-based polymer nanocomposites. Here, the role of the biomolecules that are immobilized on the graphene nanomaterial as target for sensing is reviewed.
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Affiliation(s)
- Elisa Toto
- Department of Chemical Engineering Materials Environment, Sapienza University of Rome, Via del Castro Laurenziano 7, 00161 Rome, Italy;
| | - Susanna Laurenzi
- Department of Astronautical Electrical and Energy Engineering, Sapienza University of Rome, Via Salaria 851-881, 00138 Rome, Italy;
| | - Maria Gabriella Santonicola
- Department of Chemical Engineering Materials Environment, Sapienza University of Rome, Via del Castro Laurenziano 7, 00161 Rome, Italy;
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Shamim JA, Hsu WL, Daiguji H. Review of component designs for post-COVID-19 HVAC systems: Possibilities and challenges. Heliyon 2022; 8:e09001. [PMID: 35224237 PMCID: PMC8863315 DOI: 10.1016/j.heliyon.2022.e09001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 09/16/2021] [Accepted: 02/18/2022] [Indexed: 11/01/2022] Open
Abstract
The globally occurring recurrent waves of the COVID-19 pandemic, primarily caused by the transmission of aerosolized droplets from an infected person to a healthy person in the indoor environment, has led to the urgency of designing new modes of indoor ventilation. To prevent cross-contaminations due to airborne viruses, bacteria, and other pollutants in indoor environments, heating ventilation and air-conditioning (HVAC) systems need to be redesigned with anti-pandemic components. The three vital anti-pandemic components for the post-COVID-19 HVAC systems, as identified by the authors, are: a biological contaminant inactivation unit, a volatile organic compound decomposition unit, and an advanced air filtration unit. The purpose of the current article is to provide an overview of the latest research outcomes toward designing these anti-pandemic components and pointing out the future promises and challenges. In addition, the role of personalized ventilation in minimizing the risk of indoor cross-contamination by employing various air terminal devices is discussed. The authors believe that this article will encourage HVAC designers to develop effective anti-pandemic components to minimize the indoor airborne transmission.
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Affiliation(s)
- Jubair A Shamim
- Department of Mechanical Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Wei-Lun Hsu
- Department of Mechanical Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Hirofumi Daiguji
- Department of Mechanical Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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Mariita RM, Davis JH, Randive RV. Illuminating Human Norovirus: A Perspective on Disinfection of Water and Surfaces Using UVC, Norovirus Model Organisms, and Radiation Safety Considerations. Pathogens 2022; 11:226. [PMID: 35215169 PMCID: PMC8879714 DOI: 10.3390/pathogens11020226] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/22/2022] [Accepted: 02/03/2022] [Indexed: 02/04/2023] Open
Abstract
Human noroviruses (HuNoVs) are a major cause of gastroenteritis and are associated with high morbidity because of their ability to survive in the environment and small inoculum size required for infection. Norovirus is transmitted through water, food, high touch-surfaces, and human-to-human contact. Ultraviolet Subtype C (UVC) light-emitting diodes (LEDs) can disrupt the norovirus transmission chain for water, food, and surfaces. Here, we illuminate considerations to be adhered to when picking norovirus surrogates for disinfection studies and shine light on effective use of UVC for norovirus infection control in water and air and validation for such systems and explore the blind spot of radiation safety considerations when using UVC disinfection strategies. This perspective also discusses the promise of UVC for norovirus mitigation to save and ease life.
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Affiliation(s)
- Richard M. Mariita
- Crystal IS Inc., an Asahi Kasei Company, 70 Cohoes Avenue, Green Island, NY 12183, USA; (J.H.D.); (R.V.R.)
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Corrêa TQ, Blanco KC, Vollet-Filho JD, Morais VS, Trevelin WR, Pratavieira S, Bagnato VS. Efficiency of an air circulation decontamination device for micro-organisms using ultraviolet radiation. J Hosp Infect 2021; 115:32-43. [PMID: 34126104 DOI: 10.1016/j.jhin.2021.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/31/2021] [Accepted: 06/03/2021] [Indexed: 12/23/2022]
Abstract
BACKGROUND The concern with environmental security to avoid contamination of individuals was intensified with the crisis established by SARS-CoV-2. The COVID-19 pandemic has shown the necessity to create systems and devices capable of clearing the air in an environment of micro-organisms more efficiently. The development of systems that allow the removal of micro-droplets mainly originating from breathing or talking from the air was the motivation of this study. AIM This article describes a portable and easy-to-operate system that helps to eliminate the droplets or aerosols present in the environment by circulating air through an ultraviolet-C (UV-C) reactor. METHODS An air circulation device was developed, and a proof-of-principle study was performed using the device against bacteria in simulated and natural environments. The microbiological analysis was carried out by the simple sedimentation technique. In order to compare the experimental results and the expected results for other micro-organisms, the reduction rate values for bacteria and viruses were calculated and compared with the experimental results based on technical parameters (clean air delivery rate (CADR) and air changes per hour (ACH)). FINDINGS Results showed that the micro-organisms were eliminated with high efficiency by the air circulation decontamination device, with reductions of 99.9% in the proof-of-principle study, and 84-97% in the hospital environments study, contributing to reducing contamination of individuals in environments considered to present risk. CONCLUSION This study resulted in a low-cost and relatively simple device, which was shown to be effective and safe, and could be replicated, especially in low-income countries, respecting the standards for air disinfection using UV-C technologies.
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Affiliation(s)
- T Q Corrêa
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil.
| | - K C Blanco
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil
| | - J D Vollet-Filho
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil
| | - V S Morais
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil
| | | | - S Pratavieira
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil
| | - V S Bagnato
- São Carlos Institute of Physics, University of São Paulo, São Carlos, São Paulo, Brazil; Texas A&M University, College Station, TX, USA
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