1 Durham School of Architecture Engineering and Construction, University of Nebraska-Lincoln, 1110 S 67th Street, Omaha, NE 68182, USA
2 Department of Biostatistics, College of Public Health, University of Nebraska Medical Center, 984375 Nebraska Medical Center, Omaha, NE 68198, USA

Recently, the requirement to continuously collect bioaerosol samples using shorter response times has called for the use of real-time detection. The decreased cost of this technology makes it available for a wider application than military use, and makes it accessible to pharmaceutical and academic research. In this case study, real-time bioaerosol monitors (RBMs) were applied in elementary school classrooms—a densely occupied environment—along with upper-room ultraviolet germicidal irradiation (UVGI) devices. The classrooms were separated into a UVGI group and a non-UVGI control group. Fluorescent bioaerosol counts (FBCs) were monitored on 20 visiting days over a four-month period. The classroom with upper-room UVGI showed significantly lower concentrations of fine size (<3 μm) and total FBCs than the control classroom during 13 of the 20 visiting days. The results of the study indicate that the upper-room UVGI could be effective in reducing FBCs in the school environment, and RBMs may be applicable in reflecting the transient conditions of the classrooms due to the dynamic activity levels of the students and teachers.

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(GMS Hygiene and Infection Control, 14 May 2020)


Background: To slow the increasing global spread of the SARS-CoV-2 virus, appropriate disinfection techniques are required. Ultraviolet radiation (UV) has a well-known antiviral effect, but measurements on the radiation dose necessary to inactivate SARS-CoV-2 have not been published so far. Methods: Coronavirus inactivation experiments with ultraviolet light performed in the past were evaluated to determine the UV radiation dose required for a 90% virus reduction. This analysis is based on the fact that all coronaviruses have a similar structure and similar RNA strand length. Results: The available data reveals large variations, which are apparently not caused by the coronaviruses but by the experimental conditions selected. If these are excluded as far as possible, it appears that coronaviruses are very UV sensitive. The upper limit determined for the log-reduction dose (90% reduction) is approximately 10.6 mJ/cm2 (median), while the true value is probably only 3.7 mJ/cm2 (median). Conclusion: Since coronaviruses do not differ structurally to any great exent, the SARS-CoV-2 virus - as well as possible future mutations - will very likely be highly UV sensitive, so that common UV disinfection procedures will inactivate the new SARS-CoV-2 virus without any further modification.

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Lice Science 
Donavyn Coffey - Live Science Contributor July 12, 2020

Ultraviolet light has been used to stop pathogens in their tracks for decades. But does it work against SARS-CoV-2, the virus behind the pandemic?

The short answer is yes. But it takes the right kind of UV in the right dosage, a complex operation that is best administered by trained professionals. In other words, many at-home UV-light devices claiming to kill SARS-CoV-2 likely aren't a safe bet.

UV radiation can be classified into three types based on wavelength: UVA, UVB and UVC. Nearly all the UV radiation that reaches Earth is UVA, because most of UVB and all of UVC light is absorbed by the ozone layer, according to the Centers for Disease Control and Prevention. And it's UVC, which has the shortest wavelength and the highest energy, that can act as a disinfectant. 

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Journal of Photochemistry & Photobiology, B: Biology 


 Department of Clinical Analysis, Faculty of Pharmaceutical Sciences, University of São Paulo, SP, Brazil b BioLambda, Scientific and Commercial LTD, São Paulo, SP, Brazil c GAMA Therapeutics LLC, Massachusetts Biomedical Initiatives, Worcester, USA d Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil. e Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA f Vaccine and Immunotherapy Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA g Laser Research Centre, Faculty of Health Science, University of Johannesburg, Doornfontein, South Africa h Center for Lasers and Applications, Nuclear, and Energy Research Institute, National Commission for Nuclear Energy, São Paulo, SP, Brazil i Department of Chemistry Rice University, Houston, TX, USA j IdISBA - Fundación de Investigación Sanitaria de las Islas Baleares, Palma, Spain k Department of Internal Medicine, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, SP, Brazil l School of Veterinary Medicine, Metropolitan University of Santos, Santos, Brazil. m Micromoria LLC, Marlborough, USA n School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool, UK 

The global dissemination of the novel coronavirus disease (COVID-19) has accelerated the need for the implementation of effective antimicrobial strategies to target the causative agent SARS-CoV-2. Light-based technologies have a demonstrable broad range of activity over standard chemotherapeutic antimicrobials and conventional disinfectants, negligible emergence of resistance, and the capability to modulate the host immune response. This perspective article identifies the benefits, challenges, and pitfalls of repurposing light-based strategies to combat the emergence of COVID-19 pandemic.

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a Center for Biologics Evaluation and Research, US Food and Drug Administration, 8800 Rockville Pike, HFM448, Bethesda, MD 20892, USA
b Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA

Severe acute respiratory syndrome (SARS) is a life-threatening disease caused by a novel coronavirus termed SARS-CoV. Due to the severity of this disease, the World Health Organization (WHO) recommends that manipulation of active viral cultures of SARS-CoV be performed in containment laboratories at biosafety level 3 (BSL3). The virus was inactivated by ultraviolet light (UV) at 254 nm, heat treatment of 65 °C or greater, alkaline (pH > 12) or acidic (pH < 3) conditions, formalin and glutaraldehyde treatments. We describe the kinetics of these efficient viral inactivation methods, which will allow research with SARS-CoV containing materials, that are rendered non-infectious, to be conducted at reduced safety levels.


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Virus, appropriate disinfection techniques are required. Ultraviolet radiation (UV) has a well-known antiviral effect, but measurements on the‭ ‭radiation dose necessary to inactivate SARS-CoV-2 have not been published so far.‭ ‭Coronavirus inactivation experiments with ultraviolet light‬ performed in the past were evaluated to determine the UV radiation‭ dose required for a 90% virus reduction. This analysis is based on the fact that all coronaviruses have a similar structure and similar RNA strand length. The available data reveals large variations, which are apparently not caused by the coronaviruses but by the experimental conditions selected. If these are excluded as far as possible, it appears that coronaviruses are very UV sensitive. The upper limit determined for the Log-reduction dose (90% reduction) is approximately 10.6 mJ/cm2 (median), while the true value is probably only 3.7 mJ/cm2(median). Conclusion: Since coronaviruses do not differ structurally to any great The SARS-CoV-2 virus – as well as possible future mutations – will very likely be highly UV sensitive, so that common UV disinfection procedures will inactivate the new SARS-CoV-2 virus without any further modification


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