Disinfection of Airborne Organisms by Ultraviolet‐C Radiation and Sunlight

Kesavan, Jana; Sagripanti, José-Luis

doi:10.1002/9781118682555.ch17

Cited by 10 publications

(7 citation statements)

References 46 publications

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“…It is well known that 200-290 nm ultraviolet photons (hereinafter UV-C radiation) are absorbed by both the nucleic acid (RNA and DNA) and proteins and are endowed with germicidal properties that are also effective on viruses because they induce irreversible modifications that inhibit the virus replication [1][2][3][4][5][6][7][8][9] (see Methods). Fortunately, Solar UV-C photons of this wavelength are filtered out by the Ozone layer of the upper Atmosphere, at around 35 km [10].…”

Section: Introductionmentioning

confidence: 99%

“…Herein, and in a companion paper that presents our laboratory measurements [40], we show that the action spectrum of Covid-19 in response to photons with λ=366-405 nm (UV-A) is surprisingly efficient. As a consequence, UV-B/A integrated direct light from the Sun on the Earth have a strong disinfection power on the Severe Acute Respiratory Syndrome CoV-2 (SARS-CoV-2), inactivating 63% of the virus in 1.5x10 3 TCID 50 /mL concentrations (higher than typical aerosol concentrations) in about 1-2 minute at noon during north/south summers or at the Equator. We also present a number of concurring circumstantial evidence suggesting that the evolution and strength of the recent SARS-Cov-2 pandemics [41,42], has been (and is being) modulated by the intensity of UV-B and UV-A Solar radiation hitting different regions of Earth during the diffusion of the outbreak between January 2020 and April 2021.…”

Section: Introductionmentioning

confidence: 99%

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Solar UV–B/A Radiation is Highly Effective in Inactivating SARS-CoV-2

Nicastro

Sironi

Antonello

et al. 2020

Preprint

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It is well known that 200-290 nm ultraviolet photons (hereinafter UV-C radiation) photo-chemically interacts with DNA and RNA and are endowed with germicidal properties that are also effective on viruses. Fortunately, Solar UV-C photons of this wavelength are filtered out by the Ozone layer of the upper Atmosphere, at around 35 km. Softer UV photons from the Sun with wavelengths in the range 290-320 nm (UV-B) and 320-400 nm (UV-A), however, do reach the Earth s surface. The effect of these photons on Single- and Double-Stranded RNA/DNA viruses and the possible role they play on the seasonality of epidemics, are nevertheless little studied and highly debated in alternative or complementarity to other environmental causes. Notably though, the effects of both direct and indirect radiation from the Sun needs to be considered in order to completely explain the effects of UV radiations in life processes (with e.g. the UV virucidal effect enhanced in combination to the concomitant process of water droplets depletion because of Solar heat). Herein we present a number of concurring circumstantial evidence suggesting that the evolution and strength of the recent Severe Acute Respiratory Syndrome (SARS-Cov-2) pandemics, might be have been modulated by the intensity of UV-B and UV-A Solar radiation hitting different regions of Earth during the diffusion of the outbreak between January and May 2020. Out findings, if confirmed by more in depth data analysis and modeling of the epidemics, which includes Solar modulation, could help in designing the social behaviors to be adopted depending on season and environmental conditions.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Solar UV–B/A Radiation is Highly Effective in Inactivating SARS-CoV-2

Nicastro

Sironi

Antonello

et al. 2020

Preprint

View full text Add to dashboard Cite

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“…If numerous bacteria clump together, those in the centre of the cluster will be shielded from light exposure, and thus, appear to be resistant. Kesevan and Sagripanti (2012) stated that if one bacterium was shielded by two others, then only 37% of the irradiated light would reach that third bacterium 20 . Although the authors' findings relate to UV-irradiated bacteria, it is highly likely that a similar phenomenon would occur for visible light exposure.…”

Section: Discussionmentioning

confidence: 99%

Efficacy of antimicrobial 405 nm blue-light for inactivation of airborne bacteria

Dougall

Anderson

Timoshkin

et al. 2018

Light-Based Diagnosis and Treatment of Infectious Diseases

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“…This is because NAs contain monosaccharides and nucleobases, which have a maximum absorption peak at 200 and 265 nm, respectively. Conversely, near UV-A light was found to be less effective in triggering NAs damage, as it is not directly absorbed by such biopolymers [ 42 , 43 , 44 ]. Nonetheless, UV-A radiations were found to induce photo-oxidation through the generation of free radicals and ROS, that, in turn, may ultimately damage NAs, proteins, and lipids [ 39 , 42 , 45 ].…”

Section: Uv-induced Disinfectionmentioning

confidence: 99%

“…In this regard, the pyrimidine dimers T-T and T-C were found more photoreactive than C-C and C-T analogues [ 53 , 54 , 55 ], and single-stranded NAs (ssDNA and ssRNA) were more sensitive to UV exposure than the double-stranded counterparts. Moreover, regardless of the number of strands, DNA is less prone than RNA to UV-induced damage [ 43 , 56 ]. Nevertheless, the effects of UV light on RNA have been much less investigated.…”

Section: Uv-induced Disinfectionmentioning

confidence: 99%

Effect of UV Irradiation and TiO2-Photocatalysis on Airborne Bacteria and Viruses: An Overview

et al. 2021

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Current COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has put a spotlight on the spread of infectious diseases brought on by pathogenic airborne bacteria and viruses. In parallel with a relentless search for therapeutics and vaccines, considerable effort is being expended to develop ever more powerful technologies to restricting the spread of airborne microorganisms in indoor spaces through the minimization of health- and environment-related risks. In this context, UV-based and photocatalytic oxidation (PCO)-based technologies (i.e., the combined action of ultraviolet (UV) light and photocatalytic materials such as titanium dioxide (TiO2)) represent the most widely utilized approaches at present because they are cost-effective and ecofriendly. The virucidal and bactericidal effect relies on the synergy between the inherent ability of UV light to directly inactivate viral particles and bacteria through nucleic acid and protein damages, and the production of oxidative radicals generated through the irradiation of the TiO2 surface. In this literature survey, we draw attention to the most effective UV radiations and TiO2-based PCO technologies available and their underlying mechanisms of action on both bacteria and viral particles. Since the fine tuning of different parameters, namely the UV wavelength, the photocatalyst composition, and the UV dose (viz, the product of UV light intensity and the irradiation time), is required for the inactivation of microorganisms, we wrap up this review coming up with the most effective combination of them. Now more than ever, UV- and TiO2-based disinfection technologies may represent a valuable tool to mitigate the spread of airborne pathogens.

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Disinfection of Airborne Organisms by Ultraviolet‐C Radiation and Sunlight

Cited by 10 publications

References 46 publications

Solar UV–B/A Radiation is Highly Effective in Inactivating SARS-CoV-2

Solar UV–B/A Radiation is Highly Effective in Inactivating SARS-CoV-2

Efficacy of antimicrobial 405 nm blue-light for inactivation of airborne bacteria

Effect of UV Irradiation and TiO2-Photocatalysis on Airborne Bacteria and Viruses: An Overview

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