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1.
Nutrients ; 14(12)2022 Jun 17.
Article in English | MEDLINE | ID: covidwho-1896907

ABSTRACT

Many diseases have large seasonal variations in which winter overall mortality rates are about 25% higher than in summer in mid-latitude countries, with cardiovascular diseases and respiratory infections and conditions accounting for most of the variation. Cancers, by contrast, do not usually have pronounced seasonal variations in incidence or mortality rates. This narrative review examines the epidemiological evidence for seasonal variations in blood pressure, cardiovascular disease rates and respiratory viral infections in relation to atmospheric temperature and humidity, and solar UV exposure through vitamin D production and increased blood concentrations of nitric oxide. However, additional mechanisms most likely exist by which solar radiation reduces the risk of seasonally varying diseases. Some studies have been reported with respect to temperature without considering solar UV doses, although studies regarding solar UV doses, such as for respiratory infections, often consider whether temperature can affect the findings. More research is indicated to evaluate the relative effects of temperature and sun exposure on the seasonality of mortality rates for several diseases. Since solar ultraviolet-B (UVB) doses decrease to vanishingly small values at higher latitudes in winter, the use of safe UVB lamps for indoor use in winter may warrant consideration.


Subject(s)
Respiratory Tract Infections , Sunlight , Humans , Seasons , Ultraviolet Rays/adverse effects , Vitamin D
2.
Nursing ; 52(6): 35-39, 2022 Jun 01.
Article in English | MEDLINE | ID: covidwho-1860916

ABSTRACT

ABSTRACT: In response to the COVID-19 pandemic, healthcare facilities have purchased more ultraviolet-C (UVC) disinfection devices than in previous years. This article discusses the safety and efficacy of UVC disinfection in healthcare settings.


Subject(s)
COVID-19 , Disinfection , COVID-19/epidemiology , COVID-19/prevention & control , Humans , Pandemics/prevention & control , SARS-CoV-2 , Ultraviolet Rays/adverse effects
3.
Oxid Med Cell Longev ; 2022: 9366494, 2022.
Article in English | MEDLINE | ID: covidwho-1807713

ABSTRACT

Trehalose, a natural disaccharide, is synthesized by many organisms when cells are exposed to stressful stimuli. On the basis of its ability to modulate autophagy, trehalose has been considered an innovative drug for ameliorating many diseases, but its molecular mechanism is not well described. Previous findings demonstrated that trehalose plays a photoprotective role against ultraviolet (UV) B-induced damage through autophagy induction in keratinocytes. In this study, coimmunoprecipitation, label-free quantitative proteomic and parallel reaction monitoring, and western blot analysis demonstrated that trehalose promotes the interaction between tissue inhibitor of metalloproteinase (TIMP) 3 and Beclin1. Western blot and immunofluorescence staining analysis suggested that trehalose increases ATG9A localization in lysosomes and decreases its localization in the endoplasmic reticulum. Furthermore, in the presence or absence of UVB radiation, we evaluated the influence of TIMP3 and ATG9A small interfering RNA (siRNA) on the effect of trehalose on autophagy, cell death, migration, or interleukin-8 expression in keratinocytes, including HaCaT, A431, and human epidermal keratinocytes. The results revealed that in HaCaT cells, TIMP3 and ATG9A siRNA resulted in attenuation of trehalose-induced autophagy and inhibited cell death. In A431 cells, TIMP3 and ATG9A siRNA led to attenuation of trehalose-induced autophagy and cell death and inhibited migration. In human epidermal keratinocytes, trehalose-induced autophagy and inhibition of the interleukin-8 expression were blocked by ATG9A but not TIMP3 siRNA. In addition, the results of quantitative real-time PCR and immunohistochemistry analysis demonstrated the abnormal expression of TIMP3 and ATG9A in actinic keratosis and cutaneous squamous cell carcinoma skin tissues. These findings suggest the protective effects of trehalose in normal keratinocytes and its inhibitory effects on cancerous keratinocytes, possibly mediated by activation of autophagy and regulation of TIMP3 and ATG9A, providing the mechanistic basis for the potential use of trehalose in the prevention or treatment of UVB-induced skin diseases.


Subject(s)
Carcinoma, Squamous Cell , Skin Neoplasms , Autophagy , Autophagy-Related Proteins/metabolism , Carcinoma, Squamous Cell/pathology , Humans , Interleukin-8/metabolism , Keratinocytes/metabolism , Membrane Proteins/metabolism , Proteomics , RNA, Small Interfering/metabolism , Skin Neoplasms/metabolism , Tissue Inhibitor of Metalloproteinase-3/genetics , Tissue Inhibitor of Metalloproteinase-3/metabolism , Tissue Inhibitor of Metalloproteinase-3/pharmacology , Trehalose/pharmacology , Ultraviolet Rays/adverse effects , Vesicular Transport Proteins/metabolism
4.
Front Public Health ; 9: 825468, 2021.
Article in English | MEDLINE | ID: covidwho-1686580

ABSTRACT

In the pandemic of COVID-19, it is crucial to consider the hygiene of the edible and nonedible things as it could be dangerous for our health to consume infected things. Furthermore, everything cannot be boiled before eating as it can destroy fruits and essential minerals and proteins. So, there is a dire need for a smart device that could sanitize edible items. The Germicidal Ultraviolet C (UVC) has proved the capabilities of destroying viruses and pathogens found on the surface of any objects. Although, a few minutes exposure to the UVC can destroy or inactivate the viruses and the pathogens, few doses of UVC light may damage the proteins of edible items and can affect the fruits and vegetables. To this end, we have proposed a novel design of a device that is employed with Artificial Intelligence along with UVC to auto detect the edible items and act accordingly. This causes limited UVC doses to be applied on different items as detected by proposed model according to their permissible limit. Additionally, the device is employed with a smart architecture which leads to consistent distribution of UVC light on the complete surface of the edible items. This results in saving the health as well as nutrition of edible items.


Subject(s)
COVID-19 , Disinfection , Artificial Intelligence , Humans , SARS-CoV-2 , Ultraviolet Rays/adverse effects
5.
Eur Rev Med Pharmacol Sci ; 25(22): 7135-7143, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1552080

ABSTRACT

OBJECTIVE: Understanding the evolutionary dynamics of the Coronavirus disease 2019 (COVID-19) pandemic in the coming months is a matter of great importance and urgency for governments worldwide, making fundamental decisions based on what is known about the transmission mechanisms of the virus and its survival in the environment. The present study aimed to evaluate the impact of demographic variables, solar radiation and relative humidity on the spread of the COVID-19 pandemic of the various regions in Italy. MATERIALS AND METHODS: The retrospective longitudinal study was conducted, and data used in this study was obtained from the Italian Health Ministry. Descriptive statistics included mean, frequency, and percentage, and results presented by graphs were calculated. RESULTS: The infection trend was investigated by comparing it with the demographic situation and the irradiation indices of solar ultraviolet light that are detected with the changing seasons. The present study reported that the geographic areas with higher population density and lower solar radiation during the autumn and winter months were most affected by SARS-CoV-2. CONCLUSIONS: The analysis carried out can provide a predictive model for the future phases of the COVID-19 pandemic in Italy, regardless of the adoption of lockdown measures and behavioral factors.


Subject(s)
COVID-19/transmission , Disease Outbreaks/prevention & control , Meteorological Concepts , Seasons , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/virology , Disease Outbreaks/statistics & numerical data , Humans , Italy/epidemiology , Longitudinal Studies , Population Density , Predictive Value of Tests , Quarantine/statistics & numerical data , Retrospective Studies , SARS-CoV-2/genetics , Ultraviolet Rays/adverse effects
6.
Sci Rep ; 11(1): 14295, 2021 07 12.
Article in English | MEDLINE | ID: covidwho-1387482

ABSTRACT

Methylene blue is an FDA (Food and Drug Administration) and EMA (European Medicines Agency) approved drug with an excellent safety profile. It displays broad-spectrum virucidal activity in the presence of UV light and has been shown to be effective in inactivating various viruses in blood products prior to transfusions. In addition, its use has been validated for methemoglobinemia and malaria treatment. In this study, we first evaluated the virucidal activity of methylene blue against influenza virus H1N1 upon different incubation times and in the presence or absence of light activation, and then against SARS-CoV-2. We further assessed the therapeutic activity of methylene blue by administering it to cells previously infected with SARS-CoV-2. Finally, we examined the effect of co-administration of the drug together with immune serum. Our findings reveal that methylene blue displays virucidal preventive or therapeutic activity against influenza virus H1N1 and SARS-CoV-2 at low micromolar concentrations and in the absence of UV-activation. We also confirm that MB antiviral activity is based on several mechanisms of action as the extent of genomic RNA degradation is higher in presence of light and after long exposure. Our work supports the interest of testing methylene blue in clinical studies to confirm a preventive and/or therapeutic efficacy against both influenza virus H1N1 and SARS-CoV-2 infections.


Subject(s)
COVID-19/drug therapy , Influenza, Human/drug therapy , Methylene Blue/pharmacology , Virus Inactivation/drug effects , Animals , COVID-19/genetics , COVID-19/virology , Chlorocebus aethiops , Humans , Influenza, Human/genetics , Influenza, Human/virology , SARS-CoV-2/drug effects , SARS-CoV-2/pathogenicity , Ultraviolet Rays/adverse effects , Vero Cells , Virus Inactivation/radiation effects , Virus Replication/drug effects , Virus Replication/radiation effects
7.
Photodermatol Photoimmunol Photomed ; 38(2): 95-98, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1381138

ABSTRACT

One early problem during the height of the COVID-19 global pandemic, caused by severe acute respiratory syndrome 2 (SARS-CoV-2), was the shortage of personal protective equipment donned by healthcare workers, particularly N95 respirators. Given the known virucidal, bactericidal, and fungicidal properties of ultraviolet irradiation, in particular ultraviolet C (UVC) radiation, our photomedicine and photobiology unit explored the role of ultraviolet germicidal irradiation (UVGI) using UVC in effectively decontaminating N95 respirators. The review highlights the important role of photobiology and photomedicine in this pandemic. Namely, the goals of this review were to highlight: UVGI as a method of respirator disinfection-specifically against SARS-CoV-2, adverse reactions to UVC and precautions to protect against exposure, other methods of decontamination of respirators, and the importance of respirator fit testing.


Subject(s)
COVID-19 , Pandemics , COVID-19/prevention & control , Decontamination , Equipment Reuse , Global Health , Humans , N95 Respirators , Pandemics/prevention & control , SARS-CoV-2 , Ultraviolet Rays/adverse effects
8.
J Cosmet Laser Ther ; 23(1-2): 1-7, 2021 Feb 17.
Article in English | MEDLINE | ID: covidwho-1323772

ABSTRACT

Social distancing is conducive to grow the impact of artificial light in the daily life of the worldwide population with reported consequences to the skin. Sunlight is also essential for human development, indeed, solar radiation is composed of different types of wavelengths, which generate different skin effects. It can be divided into ultraviolet (UV), infrared (IR), and visible. UV radiation (UVA and UVB) has cutaneous biological effects ranging from photoaging, immunosuppression to melanoma formation, through the production of reactive oxygen species (ROS), inflammation and elevation of the energy state of organic molecules, changing the DNA structure. IR radiation reaches deeper layers of the skin and is also related to the generation of ROS, photoaging and erythema while visible light is responsible for generating ROS, pigmentation, cytokine formation, and matrix metallopeptidases (MMPs). Furthermore, artificial light could be harmful to the skin, as it can generate ROS, hyperpigmentation, and stimulate photoaging. Currently, we briefly summarized the cutaneous biological effects of sunlight, as well as artificial light on skin and remarked the opportunity of the evolution of current photoprotective formulas through new strategies with broad spectrum protection.


Subject(s)
Skin , Sunscreening Agents , Humans , Infrared Rays , Sunlight , Ultraviolet Rays/adverse effects
9.
Int J Mol Sci ; 22(8)2021 Apr 14.
Article in English | MEDLINE | ID: covidwho-1299443

ABSTRACT

Photodegradation of the aqueous solutions of acetylsalicylic acid, in the absence (ASA) and the presence of excipients (ASE), is demonstrated by the photoluminescence (PL). A shift of the PL bands from 342 and 338 nm to 358 and 361-397 nm for ASA and ASE in solid state and as aqueous solutions was reported. By exposure of the solution of ASA 0.3 M to UV light, a decrease in the PL band intensity was highlighted. This behavior was revealed for ASA in the presence of phosphate buffer (PB) having the pH equal to 6.4, 7, and 8 or by the interaction with NaOH 0.3 M. A different behavior was reported in the case of ASE. In the presence of PB, an increase in the intensity of the PL band of ASE simultaneously with a change of the ratio between the intensities of the bands at 361-364 and 394-397 nm was highlighted. The differences between PL spectra of ASA and ASE have their origin in the presence of salicylic acid (SAL). The interaction of ASE with NaOH induces a shift of the PL band at 405-407 nm. Arguments for the reaction of ASA with NaOH are shown by Raman scattering and FTIR spectroscopy.


Subject(s)
Aspirin/chemistry , Photolysis/radiation effects , Solutions/radiation effects , Water/chemistry , Aspirin/radiation effects , Cadmium Compounds/chemistry , Luminescence , Quantum Dots/chemistry , Spectrum Analysis, Raman , Ultraviolet Rays/adverse effects
10.
Dermatol Ther ; 34(3): e14837, 2021 05.
Article in English | MEDLINE | ID: covidwho-1257898

ABSTRACT

It has become a general practice worldwide to wear a face mask serving as a barrier against the transmission of pathogens. This has prompted us to investigate whether masks could also protect our skin from UV radiation. We have studied eight masks, four surgical and four "homemade" using an in vitro method. The study demonstrated that they all offered protection against both UVB and UVA radiation. As with clothing, fabric masks offer the highest level of protection against UV radiation.


Subject(s)
COVID-19 , Humans , Masks , Skin , Ultraviolet Rays/adverse effects
11.
Redox Biol ; 45: 102042, 2021 09.
Article in English | MEDLINE | ID: covidwho-1275680

ABSTRACT

Hypochlorous acid (HOCl) is the active oxidizing principle underlying drinking water disinfection, also delivered by numerous skin disinfectants and released by standard swimming pool chemicals used on a global scale, a topic of particular relevance in the context of the ongoing COVID-19 pandemic. However, the cutaneous consequences of human exposure to HOCl remain largely unknown, posing a major public health concern. Here, for the first time, we have profiled the HOCl-induced stress response in reconstructed human epidermis and SKH-1 hairless mouse skin. In addition, we have investigated the molecular consequences of solar simulated ultraviolet (UV) radiation and HOCl combinations, a procedure mimicking co-exposure experienced for example by recreational swimmers exposed to both HOCl (pool disinfectant) and UV (solar radiation). First, gene expression elicited by acute topical HOCl exposure was profiled in organotypic human reconstructed epidermis. Next, co-exposure studies (combining topical HOCl and UV) performed in SKH-1 hairless mouse skin revealed that the HOCl-induced cutaneous stress response blocks redox and inflammatory gene expression elicited by subsequent acute UV exposure (Nos2, Ptgs2, Hmox1, Srxn1), a finding consistent with emerging clinical evidence in support of a therapeutic role of topical HOCl formulations for the suppression of inflammatory skin conditions (e.g. atopic dermatitis, psoriasis). Likewise, in AP-1 transgenic SKH-1 luciferase-reporter mice, topical HOCl suppressed UV-induced inflammatory signaling assessed by bioluminescent imaging and gene expression analysis. In the SKH-1 high-risk mouse model of UV-induced human keratinocytic skin cancer, topical HOCl blocked tumorigenic progression and inflammatory gene expression (Ptgs2, Il19, Tlr4), confirmed by immunohistochemical analysis including 3-chloro-tyrosine-epitopes. These data illuminate the molecular consequences of HOCl-exposure in cutaneous organotypic and murine models assessing inflammatory gene expression and modulation of UV-induced carcinogenesis. If translatable to human skin these observations provide novel insights on molecular consequences of chlorination stress relevant to environmental exposure and therapeutic intervention.


Subject(s)
COVID-19 , Skin Neoplasms , Animals , Carcinogenesis , Gene Expression , Humans , Hypochlorous Acid , Mice , Mice, Transgenic , Pandemics , SARS-CoV-2 , Skin , Ultraviolet Rays/adverse effects
12.
Medicine (Baltimore) ; 100(24): e26343, 2021 Jun 18.
Article in English | MEDLINE | ID: covidwho-1269622

ABSTRACT

ABSTRACT: An increased incidence of photokeratitis has occurred during the coronavirus disease 2019 (COVID-19) pandemic due to improper and unprotected use of ultraviolet lamps. Here, we summarize the clinical and epidemiological features of this increased incidence of photokeratitis and share advice in using health education to prevent it.We collected data from patients diagnosed with photokeratitis from October 7, 2019 to December 1, 2019, and from February 17, 2020 to April 12, 2020, and compared the frequency of onset, site of ultraviolet radiation (UVR) exposure, reason for exposure, exposure time, and recovery time. We also implemented and evaluated multiple measures of public health education to prevent increased disease.After the COVID-19 outbreak, the frequency of onset of photokeratitis increased significantly, especially among young women. The main reason for UVR exposure changed from welding to disinfection. The incidence sites varied, and the exposure time was longer. As a result, patients needed a longer time to recover. Positive health education was an useful and convenient measure to prevent the disease.While the COVID-19 pandemic is ongoing, more attention should be paid to public health and implement positive measures to prevent photokeratitis.


Subject(s)
COVID-19/prevention & control , Disinfection/methods , Keratitis/epidemiology , Keratitis/prevention & control , Ultraviolet Rays/adverse effects , Adult , China/epidemiology , Female , Health Education , Humans , Incidence , Keratitis/etiology , Male , Middle Aged , Pandemics , Patient Education as Topic , SARS-CoV-2 , Young Adult
13.
Dermatitis ; 32(3): 140-143, 2021.
Article in English | MEDLINE | ID: covidwho-1262259

ABSTRACT

Phytophotodermatitis is a cutaneous reaction that occurs after exposure to plant-derived furocoumarins and ultraviolet A light. Psoralen is the most common phototoxic furocoumarin and is present in varying levels within many different plant species. This article focuses on the diagnosis and management of psoralen-induced phytophotodermatitis along with other clinical applications.


Subject(s)
Dermatitis, Phototoxic/etiology , Ficusin/toxicity , Furocoumarins/toxicity , Photosensitivity Disorders/etiology , Ultraviolet Rays/adverse effects , Humans , Plants, Toxic
14.
JMIR Mhealth Uhealth ; 9(5): e25895, 2021 05 06.
Article in English | MEDLINE | ID: covidwho-1218467

ABSTRACT

BACKGROUND: Melanoma is attributable to predisposing phenotypical factors, such as skin that easily sunburns and unprotected exposure to carcinogenic UV radiation. Reducing the proportion of young adults who get sunburned may reduce the incidence of melanoma, a deadly form of skin cancer. Advances in technology have enabled the delivery of real-time UV light exposure and content-relevant health interventions. OBJECTIVE: This study aims to examine the feasibility of young adults performing the following tasks daily: wearing a UV dosimeter, receiving text messages and real-time UV-B doses on their smartphone, and responding to daily web-based surveys about sunburn and sun protection. METHODS: Young adults aged 18-39 years (n=42) were recruited in the United States in June 2020 via social media. Participants received the UV Guard sun protection system, which consisted of a UV dosimeter and a smartphone app. During 3 consecutive periods, intervention intensity increased as follows: real-time UV-B dose; UV-B dose and daily behavioral facilitation text messages; and UV-B dose, goal setting, and daily text messages to support self-efficacy and self-regulation. Data were self-reported through daily web-based surveys for 28 days, and UV-B doses were transmitted to cloud-based storage. RESULTS: Patients' median age was 22 years (IQR 20, 29), and all patients had sun-sensitive skin. Sunburns were experienced during the study by fewer subjects (n=18) than those in the preceding 28 days (n=30). In July and August, the face was the most commonly sunburned area among 13 body locations; 52% (22/42) of sunburns occurred before the study and 45% (19/42) occurred during the study. The mean daily UV-B dose decreased during the 3 periods; however, this was not statistically significant. Young adults were most often exercising outdoors from 2 to 6 PM, walking from 10 AM to 6 PM, and relaxing from noon to 2 PM. Sunburn was most often experienced during exercise (odds ratio [OR] 5.65, 95% CI 1.60-6.10) and relaxation (OR 3.69, 95% CI 1.03-4.67) relative to those that did not exercise or relax in each category. The self-reported exit survey indicated that participants felt that they spent less time outdoors this summer compared to the last summer because of the COVID-19 pandemic and work. In addition, 38% (16/42) of the participants changed their use of sun protection based on their app-reported UV exposure, and 48% (20/42) shifted the time they went outside to periods with less-intense UV exposure. A total of 79% (33/42) of the participants were willing to continue using the UV Guard system outside of a research setting. CONCLUSIONS: In this proof-of-concept research, young adults demonstrated that they used the UV Guard system; however, optimization was needed. Although some sun protection behaviors changed, sunburn was not prevented in all participants, especially during outdoor exercise. TRIAL REGISTRATION: ClinicalTrials.gov NCT03344796; http://clinicaltrials.gov/ct2/show/NCT03344796.


Subject(s)
COVID-19 , Sunburn , Adolescent , Adult , Health Behavior , Humans , Pandemics , Prospective Studies , SARS-CoV-2 , Sunburn/drug therapy , Sunburn/epidemiology , Sunburn/prevention & control , Sunscreening Agents/therapeutic use , Ultraviolet Rays/adverse effects , United States , Young Adult
15.
Ital J Dermatol Venerol ; 156(3): 366-373, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1207967

ABSTRACT

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has become pandemic on March 11th, 2020. COVID-19 has a range of symptoms that includes fever, fatigue, dry cough, aches, and labored breathing to acute respiratory distress and possibly death. Health systems and hospitals have been completely rearranged since March 2020 in order to limit the high rate of virus spreading. Hence, a great debate on deferrable visits and treatments including phototherapy for skin diseases is developing. In particular, as regards phototherapy very few data are currently available regarding the chance to continue it, even if it may be a useful resource for treating numerous dermatological patients. However, phototherapy has an immunosuppressive action possibly facilitating virus infection. In the context of COVID-19 infection risk it is important to pointed out whether sunlight, phototherapy and in particular ultraviolet radiation (UV-R) constitute or not a risk for patients. In this review we aimed to focus on the relationship between UV-R, sunlight, phototherapy, and viral infections particularly focusing on COVID-19.


Subject(s)
COVID-19/epidemiology , Pandemics , SARS-CoV-2/radiation effects , Sunlight , Ultraviolet Rays , Vitamin D/physiology , Adaptive Immunity/radiation effects , Animals , Antimicrobial Cationic Peptides/biosynthesis , Antimicrobial Cationic Peptides/physiology , Cytokines/metabolism , Disease Models, Animal , Disease Susceptibility , Humans , Immunity, Innate/radiation effects , Interleukin-6/blood , Pathogen-Associated Molecular Pattern Molecules , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Skin Diseases/radiotherapy , Sunlight/adverse effects , Toll-Like Receptors/physiology , Ultraviolet Rays/adverse effects , Ultraviolet Therapy/adverse effects , Viruses/radiation effects , Vitamin D/biosynthesis , Vitamin D/therapeutic use
16.
Br J Dermatol ; 185(2): 363-370, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1175029

ABSTRACT

BACKGROUND: Understanding factors impacting deaths from COVID-19 is of the highest priority. Seasonal variation in environmental meteorological conditions affects the incidence of many infectious diseases and may also affect COVID-19. Ultraviolet (UV) A (UVA) radiation induces release of cutaneous photolabile nitric oxide (NO) impacting the cardiovascular system and metabolic syndrome, both COVID-19 risk factors. NO also inhibits the replication of SARS-CoV2. OBJECTIVES: To investigate the relationship between ambient UVA radiation and COVID-19 deaths. METHODS: COVID-19 deaths at the county level, across the USA, were modelled in a zero-inflated negative-binomial model with a random effect for states adjusting for confounding by demographic, socioeconomic and long-term environmental variables. Only those areas where UVB was too low to induce significant cutaneous vitamin D3 synthesis were modelled. We used satellite-derived estimates of UVA, UVB and temperature and relative humidity. Replication models were undertaken using comparable data for England and Italy. RESULTS: The mortality rate ratio (MRR) in the USA falls by 29% [95% confidence interval (CI) 40% to 15%) per 100 kJ m-2 increase in mean daily UVA. We replicated this in independent studies in Italy and England and estimate a pooled decline in MRR of 32% (95% CI 48% to 12%) per 100 kJ m-2 across the three studies. CONCLUSIONS: Our analysis suggests that higher ambient UVA exposure is associated with lower COVID-19-specific mortality. Further research on the mechanism may indicate novel treatments. Optimized UVA exposure may have population health benefits.


Subject(s)
COVID-19 , Humans , Italy , RNA, Viral , SARS-CoV-2 , Ultraviolet Rays/adverse effects , United States/epidemiology
17.
Photochem Photobiol ; 97(3): 471-476, 2021 05.
Article in English | MEDLINE | ID: covidwho-1096925

ABSTRACT

The COVID-19 pandemic has generated a great deal of interest in ultraviolet germicidal irradiation (UVGI) as an important means to disinfect air and surfaces. The traditional lamp employed for UVGI has been the low-pressure mercury-discharge lamp that emits primarily at 254 nm in the ultraviolet photobiological band UV-C (100-280 nm). The recent development of even shorter-wavelength UV-C lamps, such as the Krypton-Chloride, 222-nm lamp, has led to greater concerns about the UV-C generation of ozone. It is well known that wavelengths below 240 nm more readily generate ozone. However, there is a great misunderstanding with regard to the actual generation and dissipation of ozone molecules by UV-C lamps. A review of this subject is much warranted. An overview of the ozone generation of various UV-C light sources is presented to give users a better understanding of risk and how to assure control of ozone when employing UV-C lamps.


Subject(s)
COVID-19/prevention & control , Disinfection/instrumentation , Lighting/adverse effects , Ozone , SARS-CoV-2/radiation effects , Ultraviolet Rays/adverse effects , COVID-19/virology , Virus Inactivation/radiation effects
18.
Photochem Photobiol ; 97(3): 485-492, 2021 05.
Article in English | MEDLINE | ID: covidwho-1088155

ABSTRACT

The COVID-19 pandemic has greatly heightened interest in ultraviolet germicidal irradiation (UVGI) as an important intervention strategy to disinfect air in medical treatment facilities and public indoor spaces. However, a major drawback of UVGI is the challenge posed by assuring safe installation of potentially hazardous short-wavelength (UV-C) ultraviolet lamps. Questions have arisen regarding what appear to be unusually conservative exposure limit values in the UV-C spectral band between 180 and 280 nm. We review the bases for the current limits and proposes some adjustments that would provide separate limits for the eye and the skin at wavelengths less than 300 nm and to increase both skin and eye limits in the UV-C below 250 nm.


Subject(s)
Radiation Exposure/adverse effects , Radiation Exposure/standards , Ultraviolet Rays/adverse effects , COVID-19/prevention & control , Disinfection , Humans , SARS-CoV-2/radiation effects , Virus Inactivation
19.
Photochem Photobiol ; 97(3): 527-531, 2021 05.
Article in English | MEDLINE | ID: covidwho-1066753

ABSTRACT

Far-UVC devices are being commercially sold as "safe for humans" for the inactivation of SARS-CoV-2, without supporting human safety data. We felt there was a need for rapid proof-of-concept human self-exposure, to inform future controlled research and promote informed discussion. A Fitzpatrick Skin Type II individual exposed their inner forearms to large radiant exposures from a filtered Krypton-Chloride (KrCl) far-UVC system (SafeZoneUVC, Ushio Inc., Tokyo, Japan) with peak emission at 222 nm. No visible skin changes were observed at 1500 mJ cm-2 ; whereas, skin yellowing that appeared immediately and resolved within 24 h occurred with a 6000 mJ cm-2 exposure. No erythema was observed at any time point with exposures up to 18 000 mJ cm-2 . These results combined with Monte Carlo Radiative Transfer computer modeling suggest that filtering longer ultraviolet wavelengths is critical for the human skin safety of far-UVC devices. This work also contributes to growing arguments for the exploration of exposure limit expansion, which would subsequently enable faster inactivation of viruses.


Subject(s)
Radiation Exposure/adverse effects , Skin/radiation effects , Ultraviolet Rays/adverse effects , Adult , COVID-19/prevention & control , Dose-Response Relationship, Radiation , Humans , Male , SARS-CoV-2/radiation effects
20.
Photochem Photobiol ; 97(3): 477-484, 2021 05.
Article in English | MEDLINE | ID: covidwho-1035316

ABSTRACT

Germicidal ultraviolet radiation (GUV) provides a means of dramatically reducing airborne spread of microorganisms in residential and workspace environments. Regarding design and use of GUV, both efficacy and safety data have accumulated over several decades, with a substantial increase of attention during the current COVID-19 pandemic. Considerations for skin and eye safety previously resulted in guidance on exposures in institutional and workplace settings. This report details the evolution of limits for skin exposures, with particular attention to the risk of skin neoplasia.


Subject(s)
COVID-19/prevention & control , Carcinogenesis , SARS-CoV-2/radiation effects , Ultraviolet Rays/adverse effects , Disinfection/methods , Humans , Virus Inactivation
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