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Photochemistry and Photobiology May 2021The 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... (Review)
Review
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.
Topics: COVID-19; Disinfection; Lighting; Ozone; SARS-CoV-2; Ultraviolet Rays; Virus Inactivation
PubMed: 33534912
DOI: 10.1111/php.13391 -
Viruses Aug 2022The pandemic due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has emerged as a serious global public health issue. Besides the high transmission rate... (Review)
Review
The pandemic due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has emerged as a serious global public health issue. Besides the high transmission rate from individual to individual, indirect transmission from inanimate objects or surfaces poses a more significant threat. Since the start of the outbreak, the importance of respiratory protection, social distancing, and chemical disinfection to prevent the spread of the virus has been the prime focus for infection control. Health regulatory organizations have produced guidelines for the formulation and application of chemical disinfectants to manufacturing industries and the public. On the other hand, extensive literature on the virucidal efficacy testing of microbicides for SARS-CoV-2 has been published over the past year and a half. This review summarizes the studies on the most common chemical disinfectants and their virucidal efficacy against SARS-CoV-2, including the type and concentration of the chemical disinfectant, the formulation, the presence of excipients, the exposure time, and other critical factors that determine the effectiveness of chemical disinfectants. In this review, we also critically appraise these disinfectants and conduct a discussion on the role they can play in the COVID-19 pandemic.
Topics: COVID-19; Disinfectants; Disinfection; Humans; Pandemics; SARS-CoV-2
PubMed: 36016342
DOI: 10.3390/v14081721 -
Photochemistry and Photobiology May 2021The COVID-19 pandemic has generated great interest in reviving an old intervention technology, particularly for air disinfection-ultraviolet germicidal irradiation... (Review)
Review
The COVID-19 pandemic has generated great interest in reviving an old intervention technology, particularly for air disinfection-ultraviolet germicidal irradiation (UVGI). Since UVGI was developed and refined more than 80-90 years ago, the ultraviolet source of choice has been almost exclusively the low-pressure mercury vapor discharge lamp. Today, with new lamp technologies, there has been significant interest in the application of ultraviolet light-emitting diodes and excimer lamps that emit in the UV-C (180-280 nm) spectral band. This paper reviews these competing technologies with the aim of giving a sound basis for decisions on how to choose and install UV systems for disinfection of air and surfaces given the COVID-19 pandemic.
Topics: Air Microbiology; COVID-19; Disinfection; Humans; Ozone; SARS-CoV-2; Ultraviolet Rays
PubMed: 33497482
DOI: 10.1111/php.13387 -
Chemosphere Dec 2022Sterilization and disinfection of pollutants and microorganisms have been extensively studied in order to address the problem of environmental contamination, which is a... (Review)
Review
Sterilization and disinfection of pollutants and microorganisms have been extensively studied in order to address the problem of environmental contamination, which is a crucial issue for public health and economics. Various form of hazardous materials/pollutants including microorganisms and harmful gases are released into the environment that enter into the human body either through inhalation, adsorption or ingestion. The human death rate rises due to various respiratory ailments, strokes, lung cancer, and heart disorders related with these pollutants. Hence, it is essential to control the environmental pollution by applying economical and effective sterilization and disinfections techniques to save life. In general, numerous forms of traditional physical and chemical sterilization and disinfection treatments, such as dry and moist heat, radiation, filtration, ethylene oxide, ozone, hydrogen peroxide, etc. are known along with advanced techniques. In this review we summarized both advanced and conventional techniques of sterilization and disinfection along with their uses and mode of action. This review gives the knowledge about the advantages, disadvantages of both the methods comparatively. Despite, the effective solution given by the advanced sterilization and disinfection technology, joint technologies of sterilization and disinfection has proven to be more effective innovation to protect the indoor and outdoor environments.
Topics: Disinfection; Environmental Pollutants; Ethylene Oxide; Hazardous Substances; Humans; Hydrogen Peroxide; Ozone; Sterilization
PubMed: 36165840
DOI: 10.1016/j.chemosphere.2022.136404 -
Journal of Hazardous Materials Jul 2023Ultraviolet (UV) irradiation is widely used for wastewater disinfection but suffers from low inactivation rates and can cause photoreactivation of microorganisms.... (Review)
Review
Ultraviolet (UV) irradiation is widely used for wastewater disinfection but suffers from low inactivation rates and can cause photoreactivation of microorganisms. Synergistic disinfection with UV and oxidants is promising for enhancing the inactivation performance. This review summarizes the inactivation effects on representative microorganisms by UV/hydrogen peroxide (HO), UV/ozone (O), UV/persulfate (PS), UV/chlorine, and UV/chlorine dioxide (ClO). UV synergistic processes perform better than UV or an oxidant alone. UV mainly attacks the DNA or RNA in microorganisms; the oxidants HO and O mainly attack the cell walls, cell membranes, and other external structures; and HOCl and ClO enter cells and oxidize proteins and enzymes. Free radicals can have strong oxidation effects on cell walls, cell membranes, proteins, enzymes, and even DNA. At similar UV doses, the inactivation rates of Escherichia coli with UV alone, UV/HO, UV/O, UV/PS (peroxydisulfate or peroxymonosulfate), and UV/chlorinated oxidant (chlorine, ClO, and NHCl) range from 2.03 to 3.84 log, 2.62-4.30 log, 4.02-6.08 log, 2.93-5.07 log, and 3.78-6.55 log, respectively. The E. coli inactivation rates are in the order of UV/O ≈ UV/Cl > UV/PS > UV/HO. This order is closely related to the redox potentials of the oxidants and quantum yields of the radicals. UV synergistic disinfection processes inhibit photoreactivation of E. coli in the order of UV/O > UV/PS > UV/HO. The activation mechanisms and formation pathways of free radicals with different UV-based synergistic processes are presented. In addition to generating HO·, O can reduce the turbidity and chroma of wastewater to increase UV penetration, which improves the disinfection performance of UV/O. This knowledge will be useful for further development of the UV-based synergistic disinfection processes.
Topics: Disinfection; Hydrogen Peroxide; Wastewater; Chlorine; Escherichia coli; Oxidants; Oxidation-Reduction; Chlorides; Ultraviolet Rays; Water Purification
PubMed: 37062094
DOI: 10.1016/j.jhazmat.2023.131393 -
The Journal of Hospital Infection Jan 2022Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease 2019, has caused millions of deaths worldwide. The virus is... (Review)
Review
BACKGROUND
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease 2019, has caused millions of deaths worldwide. The virus is transmitted by inhalation of infectious particles suspended in the air, direct deposition on mucous membranes and indirect contact via contaminated surfaces. Disinfection methods that can halt such transmission are important in this pandemic and in future viral infections.
AIM
To highlight the efficacy of several disinfection methods against SARS-CoV-2 based on up-to-date evidence found in the literature.
METHODS
Two databases were searched to identify studies that assessed disinfection methods used against SARS-CoV-2. In total, 1229 studies were identified and 60 of these were included in this review. Quality assessment was evaluated by the Office of Health Assessment and Translation's risk-of-bias tool.
FINDINGS
Twenty-eight studies investigated disinfection methods on environmental surfaces, 16 studies investigated disinfection methods on biological surfaces, four studies investigated disinfection methods for airborne coronavirus, and 16 studies investigated methods used to recondition personal protective equipment (PPE).
CONCLUSIONS
Several household and hospital disinfection agents and ultraviolet-C (UV-C) irradiation were effective for inactivation of SARS-CoV-2 on environmental surfaces. Formulations containing povidone-iodine can provide virucidal action on the skin and mucous membranes. In the case of hand hygiene, typical soap bars and alcohols can inactivate SARS-CoV-2. Air filtration systems incorporated with materials that possess catalytic properties, UV-C devices and heating systems can reduce airborne viral particles effectively. The decontamination of PPE can be conducted safely by heat and ozone treatment.
Topics: COVID-19; Disinfection; Humans; Pandemics; Povidone-Iodine; SARS-CoV-2
PubMed: 34673114
DOI: 10.1016/j.jhin.2021.07.014 -
Industrial & Engineering Chemistry... Mar 2023The control of infectious diseases can be improved via carefully designed decontamination equipment and systems. Research interest in ozone (a powerful antimicrobial... (Review)
Review
The control of infectious diseases can be improved via carefully designed decontamination equipment and systems. Research interest in ozone (a powerful antimicrobial agent) has significantly increased over the past decade. The COVID-19 pandemic has also instigated the development of new ozone-based technologies for the decontamination of personal protective equipment, surfaces, materials, and indoor environments. As this interest continues to grow, it is necessary to consider key factors affecting the applicability of lab-based findings to large-scale systems utilizing ozone. In this review, we present recent developments on the critical factors affecting the successful deployments of industrial ozone technologies. Some of these include the medium of application (air or water), material compatibility, efficient circulation and extraction, measurement and control, automation, scalability, and process economics. We also provide a comparative assessment of ozone relative to other decontamination methods/sterilization technologies and further substantiate the necessity for increased developments in gaseous and aqueous ozonation. Modeling methodologies, which can be applied for the design and implementation of ozone contacting systems, are also presented in this review. Key knowledge gaps and open research problems/opportunities are extensively covered including our recommendations for the development of novel solutions with industrial importance.
PubMed: 36943762
DOI: 10.1021/acs.iecr.2c03754 -
Journal of Hazardous Materials Aug 2022Chlorine dioxide (ClO) has emerged as a broad-spectrum, safe, and effective disinfectant due to its high oxidation efficiency and reduced formation of organochlorinated... (Review)
Review
Chlorine dioxide (ClO) has emerged as a broad-spectrum, safe, and effective disinfectant due to its high oxidation efficiency and reduced formation of organochlorinated by-products during application. This article provides an updated overview of ClO-based oxidation processes used in water treatment. A systematic review of scientific information and experimental data on ClO-based water purification procedures is presented. Concerning ClO-based oxidation derivative problems, the pros and cons of ClO-based combined processes are assessed and disinfection by-product (DBP) control approaches are proposed. The kinetic and mechanistic data on ClO reactivity towards micropollutants are discussed. ClO selectively reacts with electron-rich moieties (anilines, phenols, olefins, and amines) and eliminates certain inorganic ions and microorganisms with high efficiency. The formation of chlorite and chlorate during the oxidation process is a crucial concern when utilizing ClO. Future applications include the combination of ClO with ferrous ions, activated carbon, ozone, UV, visible light, or persulfate processes. The combined process can reduce by-product generation while still ensuring ClO sterilization and disinfection. Overall, this research could provide useful information and new insights into the application of ClO-based technologies.
Topics: Chlorine; Chlorine Compounds; Disinfectants; Disinfection; Oxides; Water Purification
PubMed: 35739725
DOI: 10.1016/j.jhazmat.2022.129195 -
International Journal of Pharmaceutics Mar 2023Hydrogels are extensively used in the biomedical field, as drug delivery systems, wound dressings, contact lenses or as scaffolds for tissue engineering. Due to their... (Review)
Review
Hydrogels are extensively used in the biomedical field, as drug delivery systems, wound dressings, contact lenses or as scaffolds for tissue engineering. Due to their polymeric nature and the presence of high amounts of water in their structure, hydrogels generally present high sensitivity to terminal sterilization. The establishment of an efficient sterilization protocol that does not compromise the functional properties of the hydrogels is one of the challenges faced by researchers when developing a hydrogel for a specific application. Yet, until very recently this aspect was largely ignored in the literature. The present paper reviews the state of literature concerning hydrogels sterilization, compiling the main findings. Conventional terminal sterilization methods (heat sterilization, radiation sterilization, and gas sterilization) as well as emerging sterilization techniques (ozone, supercritical carbon dioxide) are covered. Considerations about aseptic processing are also included. Additionally, and as a framework, hydrogels' polymeric materials, types of networks, and main biomedical applications are summarily described.
Topics: Hydrogels; Sterilization; Contact Lenses; Polymers; Water; Tissue Engineering
PubMed: 36736965
DOI: 10.1016/j.ijpharm.2023.122671 -
Brazilian Oral Research 2022The aim of this scoping review was to provide sufficient information about the effectiveness of ozone gas in virus inactivation of surfaces and objects under different... (Review)
Review
The aim of this scoping review was to provide sufficient information about the effectiveness of ozone gas in virus inactivation of surfaces and objects under different environmental conditions. The review was performed according to the list of PRISMA SrC recommendations and the JBI Manual for Evidence Synthesis for Scoping Reviews. The review was registered in Open Science Framework (OSF). EMBASE (Ovid), Lilacs, LIVIVO, MEDLINE (PubMed), SciELO, Scopus and Web of Science were primary sources, and "gray literature" was searched in OpenGray and OpenThesis. A study was included if it reported primary data on the effect of ozone gas application for vehicle-borne and airborne virus inactivation. No language or publication date restriction was applied. The search was conduct on July 1, 2020. A total of 16,120 studies were screened, and after exclusion of noneligible studies, fifteen studies fulfilled all selection criteria. Application of ozone gas varied in terms of concentration, ozone exposure period and the devices used to generate ozone gas. Twelve studies showed positive results for inactivation of different virus types, including bacteriophages, SARS-CoV-2 surrogates and other vehicle-borne viruses. Most of the studies were classified as unclear regarding sponsorship status. Although most of the population has not yet been vaccinated against COVID-19, disinfection of environments, surfaces, and objects is an essential prevention strategy to control the spread of this disease. The results of this Scoping Review demonstrate that ozone gas is promising for viral disinfection of surfaces.
Topics: COVID-19; Delivery of Health Care; Disinfection; Humans; Ozone; SARS-CoV-2
PubMed: 35081224
DOI: 10.1590/1807-3107bor-2022.vol36.0006