Ozone use in surface disinfection: an integrative review

Objective: To analyze the scientific evidence regarding the effectiveness of using ozone to disinfect surfaces based on an integrative literature review.Methods: A search was carried out in the SciELO, MEDLINE, LILACS, PubMed, Science Direct databases. Eleven articles published January 2010 to August 2021 were analyzed. All employed the experimental laboratory research model and achieved different levels of disinfection by O3, however, with varied surfaces and products tested, in addition to different methodological procedures.Results: The majority had an inhibition rate by O3 equal to or greater than 90%, thus proving the effectiveness of this agent as a surface disinfectant, even with variations in parameter values such as concentration and exposure time, in all selected articles, even those that did not prove the effectiveness of O3.Conclusion: This review shows the inhibitory power that O3 has on different pathogens, even if there are variables in the factors used for this purpose, highlighting it in front of other disinfectants. Thus, it corroborates the composition of surface disinfection protocols and decision-making among managers and committees about sanitizing technologies.

The effects of enhanced formaldehyde clearance in a gross anatomy laboratory by floor plan redesign and dissection table adjustment.

Formaldehyde has carcinogenic properties. It is associated with nasopharyngeal cancer and causes irritation of the eyes, nose, throat, and respiratory system. Formaldehyde exposure is a significant health concern for those participating in the gross anatomy laboratory, but no learning method can substitute cadaver dissection. We performed a formaldehyde level study in 2018, which found that most of the breathing zone (S-level) and environment (R-level) formaldehyde levels during laboratory sessions at the Faculty of Medicine Siriraj Hospital exceeded international ceiling standards. In the academic year 2019, we adapted the engineering rationale of the NIOSH hierarchy of controls to facilitate formaldehyde clearance by opening the dissection table covers and increasing the area per dissection table, then measured formaldehyde ceiling levels by formaldehyde detector tube with a gas-piston hand pump during (1) body wall, (2) upper limb, (3) head-neck, (4) thorax, (5) spinal cord removal, (6) lower limb, (7) abdomen, and (8) organs of special senses dissection sessions and comparing the results with the 2018 study. The perineum region data were excluded from analyses due to the laboratory closure in 2019 from the COVID-19 outbreak. There were statistically significant differences between the 2018 and 2019 S-levels (p < 0.001) and R-levels (p < 0.001). The mean S-level decreased by 64.18% from 1.34 ± 0.71 to 0.48 ± 0.26 ppm, and the mean R-level decreased by 70.18% from 0.57 ± 0.27 to 0.17 ± 0.09 ppm. The highest formaldehyde level in 2019 was the S-level in the body wall region (1.04 ± 0.3 ppm), followed by the S-level in the abdomen region (0.56 ± 0.08 ppm) and the spinal cord removal region (0.51 ± 0.29 ppm). All 2019 formaldehyde levels passed the OSHA 15-min STEL standard (2 ppm). The R-level in the special sense region (0.06 ± 0.02 ppm) passed the NIOSH 15-min ceiling limit (0.1 ppm). Three levels for 2019 were very close: the R-level in the head-neck region (0.11 ± 0.08 ppm), the abdomen region (0.11 ± 0.08), the body wall region (0.14 ± 0.12 ppm), and the S-level in the special sense region (0.12 ± 0.04 ppm). In summary, extensive analysis and removal of factors impeding formaldehyde clearance can improve the general ventilation system and achieve the OSHA 15-min STEL standard.

Analysis of Volatile Organic Compounds in Exhaled Breath of COVID-19 Patients

Background: More than 2 years since COVID-19's first cases were reported in 2019. Diagnosis of COVID-19 is a key to controlling the pandemic. Sample for COVID-19 testing is collected by naso-oro-pharyngeal swab. This procedure is often uncomfortable and requires a trained examiner. Exhaled breath contains thousands of volatile organic compounds (VOC) which are likely to change during infection. Aims and objectives: This study aims to analyze the difference of VOC in the exhaled breath between COVID-19 and healthy subjects. Method(s): A cross-sectional study was carried out recruiting 90 confirmed cases of COVID-19 and 42 healthy subjects. A sample of exhaled breath was collected by using a 500 ml airbag in both groups. Contained VOC was analyzed using an arrayed sensor breath analyzer to quantify the concentration of CO2, C7H8, C6H14, CH2O, NH4, TVOC, NO2, PM1.0, CO, NH3and Acetone. Statistical analysis was conducted using Mann whitney test. Result(s): The median of CO2, C6H14, NH4, TVOC, NO2, and Acetone are significantly higher in COVID-19 patients compared to healthy subjects (respectively 1175.1 vs 607.3, 0.47 vs 0.0, 1.05 vs 0.0, 146.6 vs 0.05, 1.55 vs 0.04, and 0.23 vs 0.0) while C7H8, CH2O, PM1.0, CO, and NH3are significantly lower (respectively 0.0 vs 0.92, 0.01 vs 0.55, 0.0 vs 4.13, 0.0 vs 0.24, and 0.67 vs 1.99;all with p-value of <0.05.). Furthermore, we found NH4, Acetone, NH3, and CO are positively correlate with severity of COVID-19. Conclusion(s): COVID-19 patients emit distinctive VOC profiles in comparison with healthy subjects.

Integral Assessment of Atmospheric Air Quality in the Largest Cities of Russia Based on TROPOMI (Sentinel-5P) Data for 2019–2020

This paper considers the level of atmospheric air pollution of the 20 largest cities in Russia in 2019–2020. The data used for the study is initially collected by a TROPOMI instrument (on the Sentinel-5P satellite), including measurements of carbon monoxide, formaldehyde, nitrogen dioxide, sulfur dioxide, and aerosol (aerosol index). The measurements were obtained using the cloud-based platform, Google Earth Engine, which presents L3 level data available for direct analysis. The Tropomi Air Quality Index (TAQI) integrates available TROPOMI measurements into a single indicator. The calculation results showed that most of the cities under consideration (15 out of 20) have a low or higher than usual level of pollution. Formaldehyde (35.7%) and nitrogen dioxide (26.4%) play the main role in the composition of pollution particles. A significant share is occupied by sulfur dioxide (16.4%). The contribution of carbon monoxide and aerosol averages 10.8 and 10.6%, respectively. Air pollution in cities is caused by both natural (wildfires, dust storms) and anthropogenic (seasonal migrations of the population, restrictions due to the COVID-19 pandemic) factors. Estimating atmospheric pollution levels in urban areas using an integral index based on remote data (such as TAQI) can be considered as a valuable information addition to existing ground-based measuring systems within the multisensory paradigm.

A Framework for Bang Saen Safe Food Avenue Management System

The coronavirus (COVID-19) epidemic has had a significant impact on people's lives and businesses. After the epidemic situation, Saensuk Sub-district, Chonburi is one area that has a need to change its tourism management. Saen Suk Municipality launched a campaign to promote Bang Saen as a "Safe Food Avenue". The pilot project began with production of an application to support a special test for formalin (FA) in sea foods which shows the result to food shops and tourists online. The FA test kit was produced and approved with accurate test results verified by a team of specialists from Burapha university. The application was developed using a responsive website technique. Specialists used the system to upload images of FA test results. Then a machine learning in image processing technique was used to analyze the test results. The Server sends the result through a RESTFUL API in JSON format to the application so that users can see the results online. The experiment using Circular Hough Transform (CHT) algorithm to detect circular shape in two-dimensional space by voting in Hough parameter with 400 data records for training. Based on the FA test result dataset, training accuracy are 100%. The SafeFoodAvenue mobile application using responsive technology FA test result's dataset accuracy is 100%. © 2022 IEEE.

HOCl as a Promising Candidate for Effective Containment of Covid 19 From Biological and Non-Biological Surfaces

Covid 19 is a pandemic disease spread almost in the whole world. To date, no medical advancement to curb the virus. Coronavirus is an enveloped virus transmitted from the biological and non-biological surface by direct or indirect contact. Limited literature revealed that the enveloped virus can be killed by disinfectants. There are many biocidal agents used for decontamination of the virus, yet they have many issues like toxicity, killing time, activation requirement, etc. Some are specific to the inanimate surface but not used by a human being. This current situation showed an urgent need for a biocidal agent which can act on biological as well as non-biological surfaces without any potential toxicity. Moreover, it should be easy to handle, inexpensive, and safe for the environment. Hypochlorous acid is a weak acid that acts as a powerful disinfectant and shows biocidal efficacy against a wide range of microorganisms. Hypochlorous acid is simple to use, inexpensive, eco-friendly, non-toxic, and stable. The properties of HOCl can be regulated at the site of preparation and therefore, its compliance is high. Hypochlorous acid seems to be a promising agent in disinfection and sterilization in healthcare facilities. Due to its diverse biocidal actions, it may be used as a potent disinfectant against novel coronavirus.Copyright © 2022 Bentham Science Publishers.

Volatile Organic Compounds in Patients' Breath during Conversation

Purpose: The protracted coronavirus disease (COVID-19) pandemic has caused an unprecedented global health, social, economic, and psychological crisis. COVID-19 is transmitted via droplets, which include volatile organic compounds (VOCs) emitted by COVID-19 carriers. As a result, medical healthcare workers interacting with COVID-19 patients are at a high risk of infection. In this study, we measured the concentration of total VOCs (TVOCs) in the droplets of patients during conversations. Method(s): Thirty patients aged 20-88 years were enrolled in this study. The amounts of VOCs, formaldehyde (HCHO), and carbon dioxide (CO2) as surrogate parameters for the patient's droplets were measured at a distance of 1 m from the patients under the following conditions: 1) no conversation with a mask on, 2) conversation with a mask on, 3) conversation without a mask on, and 4) no conversation without a mask on. Result(s): The average concentrations of TVOCs (mg/m3 ), HCHO (mg/m3 ), and CO2 (ppm) were all the lowest before the masked conversation (1.79 +/- 1.72, 0.25 +/- 0.25, 1193 +/- 516), increased during the masked conversation (1.99 +/- 1.87, 0.29 +/- 0.24, 1288 +/- 555), were the highest during the unmasked conversation (3.10 +/- 1.86, 0.45 +/- 0.28, 1705 +/- 729), and decreased to baseline after the unmasked conversation (1.89 +/- 1.88, 0.26 +/- 0.27, 1191 +/- 518, respectively). Variations in TVOC and HCHO concentrations were positively correlated with patient age (TVOC: r = 0.42, p = 0.019 and HCHO: r = 0.47, p = 0.008). Conclusion(s): Wearing a mask reduced the VOC concentrations measured during conversations more than when a mask was not worn. Therefore, wearing a mask can reduce the emission of airborne droplet-derived VOCs and thereby reduce the risk of transmission of unknown patient-derived infections. Clinical Trial Registration no: The Clinical Trial Registration no: (UMIN000039595).Copyright © 2023 Ito et al.

Identification of volatile organic compound emissions from anthropogenic and biogenic sources based on satellite observation of formaldehyde and glyoxal.

Anthropogenic volatile organic compounds (VOCs) are serious pollutants in the atmosphere because of their toxicity and as precursors of secondary organic aerosols and ozone pollution. Although in-situ measurements provide accurate information on VOCs, their spatial coverage is limited and insufficient. In this study, we provide a global perspective for identifying anthropogenic VOC emission sources through the ratio of glyoxal to formaldehyde (RGF) based on satellite observations. We assessed typical cities and polluted areas in the mid latitudes and found that some Asian cities had higher anthropogenic VOC emissions than cities in Europe and America. For heavily polluted areas, such as the Yangtze River Delta (YRD), the areas dominated by anthropogenic VOCs accounted for 23 % of the total study areas. During the COVID-19 pandemic, a significant decline in RGF values was observed in the YRD and western United States, corresponding to a reduction in anthropogenic VOC emissions. Furthermore, developing countries appeared to have higher anthropogenic VOC emissions than developed countries. These observations could contribute to optimising industrial structures and setting stricter pollution standards to reduce anthropogenic VOCs in developing countries.

Impacts of Omicron associated restrictions on vertical distributions of air pollution at a suburb site in Shanghai

To prevent the Omicron transmission, Shanghai government implemented varying degrees of restraint measures. This study provided a new insight into the responses of air pollution altitude dependence to restraint measures by conducting vertical observations at a suburb site in Shanghai. Based on the difference-in-differences (DiD) models that compare the results in 2021 (normal scenario) and 2022 (Omicron-based restriction), we evaluated the casual effects of restrictions on (i) nitrogen dioxide (NO 2), (ii) aerosol (presented by aerosol extinction coefficient (AEC)), formaldehyde (HCHO) and glyoxal (CHOCHO) and (iii) ozone (O 3), which are generally treaded as primary, multi-sources and secondary pollutants, respectively. The estimated results from 0.0 to 2.0 km show that the drop/rise induced by restrictions is greater below 1.0 km than that above 1.0 km. Averaged on vertical distributions, AEC, NO 2 , HCHO and CHOCHO during restrictions felled by 15.1% (0.12 km−1), 40.3% (1.65 ppbv), 10.0% (0.26 ppbv) and 28.6% (21.79 pptv), respectively, while O 3 increased by 21.3% (18.12 μg/m3). It indicates that restrictions induce significant drops in primary pollutants and enhancements in secondary pollutants. For multi-sources pollutants, the decline from primary sources can be partly offset by enhanced secondary productions, and the ratio of increased secondary sources to decreased primary sources can be elevated with height. The discrepancies of responses to restrictions are reflected in vertical distribution and types of air pollution, emphasizing the significance of vertical observations for diversified pollution. These finding can also be meaningful in the strategy development for prevention and control of air pollution. [Display omitted] • This study provided a new insight into the responses of air pollution altitude dependence to restraint measures by employing vertical observations. • The difference-in differences model was applied to evaluate the casual effects of restrictions on different types of pollution. • The decline of multi-sources pollutants from primary sources can be partly offset by enhanced secondary productions. [ FROM AUTHOR]

Structural and Immunoreactivity Properties of the SARS-CoV-2 Spike Protein upon the Development of an Inactivated Vaccine.

Inactivated vaccines are promising tools for tackling the COVID-19 pandemic. We applied several protocols for SARS-CoV-2 inactivation (by ß-propiolactone, formaldehyde, and UV radiation) and examined the morphology of viral spikes, protein composition of the preparations, and their immunoreactivity in ELISA using two panels of sera collected from convalescents and people vaccinated by Sputnik V. Transmission electron microscopy (TEM) allowed us to distinguish wider flail-like spikes (supposedly the S-protein's pre-fusion conformation) from narrower needle-like ones (the post-fusion state). While the flails were present in all preparations studied, the needles were highly abundant in the ß-propiolactone-inactivated samples only. Structural proteins S, N, and M of SARS-CoV-2 were detected via mass spectrometry. Formaldehyde and UV-inactivated samples demonstrated the highest affinity/immunoreactivity against the convalescent sera, while ß-propiolactone (1:2000, 36 h) and UV-inactivated ones were more active against the sera of people vaccinated with Sputnik V. A higher concentration of ß-propiolactone (1:1000, 2 h) led to a loss of antigenic affinity for both serum panels. Thus, although we did not analyze native SARS-CoV-2 for biosafety reasons, our comparative approach helped to exclude some destructive inactivation conditions and select suitable variants for future animal research. We believe that TEM is a valuable tool for inactivated COVID-19 vaccine quality control during the downstream manufacturing process.

Compliance courses for North American importers

This article presents compliance courses made by the International Wood Products Association (IWPA) for the Lacey Act and other laws affecting the wood-products industry. The training encourages importers to work closely with suppliers to ensure they have access to the information needed to understand the rules and conduct robust due diligence. The course was crafted in the hope that it would help develop an industry-wide class of wood trade compliance professionals. The initial compliance and due-diligence course in 2016 was extremely well-received, it led to a series of more advanced courses, comprising, "Advanced Wood Trade Compliance", "Audits for the Wood Trade Professional", "Wood Products Supply Chain Mapping Basics", and "Formaldehyde Emissions Regulations for the Wood Trade Professional". IWPA has conducted briefings and training for suppliers worldwide, partnering with organizations, such as the International Tropical Timber Technical Association, the Global Timber Forum, the Malaysia Timber Council, and several Chinese industry associations. The global COVID-19 pandemic has led IWPA to re-examine how stakeholders access its wood-trade compliance training courses. In the due-diligence space, travel restrictions are requiring that wood-product importers re-evaluate their due-diligence procedures to ensure they continue to meet the requirements of the Lacey Act and other relevant laws and regulations. IWPA will continue to update its courses to reflect the new reality. In particular, and for the first time, it will offer courses virtually and via IWPA's e-learning platform in the second half of 2020.

Comparing the Immunogenicity and Protective Effects of Three MERS-CoV Inactivation Methods in Mice.

The Middle East respiratory syndrome (MERS) is a fatal acute viral respiratory disease caused by MERS-coronavirus (MERS-CoV) infection. To date, no vaccine has been approved for MERS-CoV despite continuing outbreaks. Inactivated vaccines are a viable option when developed using the appropriate inactivation methods and adjuvants. In this study, we evaluated the immunogenicity and protective effects of MERS-CoV vaccine candidates inactivated by three different chemical agents. MERS-CoV was effectively inactivated by formaldehyde, hydrogen peroxide, and binary ethylene imine and induced humoral and cellular immunity in mice. Although inflammatory cell infiltration was observed in the lungs four days after the challenge, the immunized hDPP4-transgenic mouse group showed 100% protection against a challenge with MERS-CoV (100 LD50). In particular, the immune response was highly stimulated by MERS-CoV inactivated with formaldehyde, and all mice survived a challenge with the minimum dose. In the adjuvant comparison test, the group immunized with inactivated MERS-CoV and AddaVax had a higher immune response than the group immunized with aluminum potassium sulfate (alum). In conclusion, our study indicates that the three methods of MERS-CoV inactivation are highly immunogenic and protective in mice and show strong potential as vaccine candidates when used with an appropriate adjuvant.

Immunoglobulin M (IgM) Inhibits Replication of SARS-CoV-2 In Vero E6 Cells In Vitro and Delays Disease in K18-hACE2 Mice Infected with SARSCoV-2 In Vivo

Purpose: To determine if IgM has a direct effect in preventing SARS-CoV-2 replication in Vero E6 cells, and delaying or preventing disease in infected K18- hACE2 mice. Method(s): 1) Vero E6 cells, grown to confluence in 12 well plates, were used to test the effect of IgM in reducing the number of plaque-forming units (PFU).There were 4 groups: a) 25PFU WA-1 SARS-CoV-2 was combined with 20, 5 or 0.8mug IgM in growth medium, and incubated for 1hr in a final volume of 500ul. 100mul was added to Vero E6 cells in replicate wells and incubated for 1hr;b) 100mul of 20, 5 or 0.8mug IgM was added to Vero E6 cells and incubated. Media was aspirated and the cells were then inoculated with 25PFU WA-1 and incubated for 1hr;c) Virus control - as above, but with no IgM;d) No virus or IgM. FBS growth medium containing Avicel was overlain in the wells and incubated for 48 hours. Virus replication was stopped by incubating with 10% buffered formalin. Following removal of formalin, plates were stained with Giemsa violet, dried, and photographed. 2) A COVID -19 Spike- ACE2 binding assay kit was used to determine if IgM (2ug, 4.5ug, 20ug, 45ug IgM) inhibits the interaction between the Spike-receptor binding domain (S-RBD) and Angiotensin I ConvertingEnzyme 2 (ACE2) receptor. 3) K18-hACE2 mice were divided into 3 groups based on treatment regimen;Group 1: with IgM, No virus;2: with Saline, with virus;3: with IgM, with virus. 35ug IgM was injected intraperitoneal in a single dose, 2 days prior to infection. Mice were innoculated intranasally with 1250 pfu of HK SARS-CoV-2. Result(s): 1) Exposure of 25PFU SARS-CoV-2 to IgM (at all concentrations) prior to incubation with Vero E6 cells, inhibited its replication in Vero E6 cells. When Vero E6 cells were incubated with IgM prior to infection, no plaques were seen in wells with 20ug and 5ug IgM but were observed in wells with 0.8ug IgM. Plaques were also observed in the Virus alone group, but none were seen in the 'No IgM-No virus' group. 2) 45ug IgM/100uls inhibited the binding of S-RBD to ACE2 by ~94-100%, 20ug IgM/100uls inhibited it by ~80%, and 2 or 4.5ug/100ul by ~70-75%. Control without IgM did not inhibit the S-RBD-ACE-2 binding. 3) Pretreatment with a single low dose IgM injection delayed weight loss and mortality. Conclusion(s): IgM inhibits the replication of SARS-CoV-2 in Vero cells in vitro. It also inhibits the interaction between S-RBD that is present on the viral surface and the ACE2 receptor, by binding to S-RBD. A single low dose of IgM given prechallenge delayed disease in infected mice. The discovery that IgM interferes with the formation of the S-RBD-ACE2 complex, and that a single low dose can delay disease, indicates its translational potential as a vaccine/therapeutic to prevent or treat COVID-19.

Antiseptic drugs and disinfectants with experience of the second year of COVID-19 pandemic-related side effects

This review covers publications during the period January 2021 to December 2021 on adverse reactions to antiseptic drugs and disinfectants. Specific agents discussed are alcohols (ethanol, isopropanol), aldehydes (formaldehyde), ethylene oxide, guanidines (chlorhexidine, polyhexamethylene guanidine, and polyhexamethylene biguanidine), benzalkonium compounds, triclosan, povidone-iodine, and sodium hypochlorite. No new data were identified for glutaraldehyde, cetrimide, tosylchloramide, triclocarban, and phenolic compounds. The use of antiseptic drugs and disinfectants has increased considerably since 2020 in various medical and occupational settings, in commerce and gastronomy, as well as in the home, due to their antiviral properties against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the still ongoing Coronavirus Disease 2019 (COVID-19) pandemic. Irritant effects on the respiratory system, the skin and eyes were the most common adverse reaction, while the widespread and occasionally excessive use led to increased reports of poisonings as well as of oral misuse of disinfectants, sometimes associated with serious outcomes such as death from methanol intoxication. Eye exposures in children caused by inadvertent exposures due to unsupervised dispensers in public spaces were pointed out as being specifically problematic. Side effects in the eye may also occur in the general population by improper and unprotected use of UV lamps. The need to improve the safe use of disinfectant devices was pointed out in general.

Antimicrobial Activity of a Titanium Dioxide Additivated Thermoset

The transmission of pathogens via surfaces poses a major health problem, particularly in hospital environments. Antimicrobial surfaces can interrupt the path of spread, while photocatalytically active titanium dioxide (TiO2) nanoparticles have emerged as an additive for creating antimicrobial materials. Irradiation of such particles with ultraviolet (UV) light leads to the formation of reactive oxygen species that can inactivate bacteria. The aim of this research was to incorporate TiO2 nanoparticles into a cellulose-reinforced melamine-formaldehyde resin (MF) to obtain a photocatalytic antimicrobial thermoset, to be used, for example, for device enclosures or tableware. To this end, composites of MF with 5, 10, 15, and 20 wt% TiO2 were produced by ultrasonication and hot pressing. The incorporation of TiO2 resulted in a small decrease in tensile strength and little to no decrease in Shore D hardness, but a statistically significant decrease in the water contact angle. After 48 h of UV irradiation, a statistically significant decrease in tensile strength for samples with 0 and 10 wt% TiO2 was measured but with no statistically significant differences in Shore D hardness, although a statistically significant increase in surface hydrophilicity was measured. Accelerated methylene blue (MB) degradation was measured during a further 2.5 h of UV irradiation and MB concentrations of 12% or less could be achieved. Samples containing 0, 10, and 20 wt% TiO2 were investigated for long-term UV stability and antimicrobial activity. Fourier-transform infrared spectroscopy revealed no changes in the chemical structure of the polymer, due to the incorporation of TiO2, but changes were detected after 500 h of irradiation, indicating material degradation. Specimens pre-irradiated with UV for 48 h showed a total reduction in Escherichia coli when exposed to UV irradiation.

Assessing the indoor air quality and their predictor variable in 21 home offices during the Covid-19 pandemic in Norway.

In this study, concentrations of pollutants: formaldehyde, carbon dioxide (CO2), and total volatile organic compounds (TVOC) and parameters: indoor room temperature and relative humidity (RH) were measured in 21 home offices for at least one week in winter in Trondheim, Norway. Eleven of these were measured again for the same duration in summer. Potentially explanatory variables of these parameters were collected, including building and renovation year, house type, building location, trickle vent status, occupancy, wood stove, floor material, pets, RH, and air temperature. The association between indoor air pollutants and their potential predictor variables was analyzed using generalized estimation equations to determine the significant parameters to control pollutants. Significantly seasonal differences in concentrations were observed for CO2 and formaldehyde, while no significant seasonal difference was observed for TVOC. For TVOC and formaldehyde, trickle vent, RH, and air temperature were among the most important predictor variables. Although higher concentrations of CO2 were measured in cases where the trickle vent was closed, the most important predictor variables for CO2 were season, RH, and indoor air temperature. The formaldehyde concentrations were higher outside working hours but mostly below health thresholds recommendations; for CO2, 11 of the measured cases had indoor concentrations exceeding 1000 ppm in 10% of the measured time. For TVOC, the concentrations were above the recommended values by WHO in 73% of the cases. RH was generally low in winter. The temperature was generally kept over the recommended level of 22-24 °C during working hours.

Comparison of Physical and Biochemical Characterizations of SARS-CoV-2 Inactivated by Different Treatments.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused huge social and economic distress. Given its rapid spread and the lack of specific treatment options, SARS-CoV-2 needs to be inactivated according to strict biosafety measures during laboratory diagnostics and vaccine development. The inactivation method for SARS-CoV-2 affects research related to the natural virus and its immune activity as an antigen in vaccines. In this study, we used size exclusion chromatography, western blotting, ELISA, an electron microscope, dynamic light scattering, circular dichroism, and surface plasmon resonance to evaluate the effects of four different chemical inactivation methods on the physical and biochemical characterization of SARS-CoV-2. Formaldehyde and ß-propiolactone (BPL) treatment can completely inactivate the virus and have no significant effects on the morphology of the virus. None of the four tested inactivation methods affected the secondary structure of the virus, including the α-helix, antiparallel ß-sheet, parallel ß-sheet, ß-turn, and random coil. However, formaldehyde and long-term BPL treatment (48 h) resulted in decreased viral S protein content and increased viral particle aggregation, respectively. The BPL treatment for 24 h can completely inactivate SARS-CoV-2 with the maximum retention of the morphology, physical properties, and the biochemical properties of the potential antigens of the virus. In summary, we have established a characterization system for the comprehensive evaluation of virus inactivation technology, which has important guiding significance for the development of vaccines against SARS-CoV-2 variants and research on natural SARS-CoV-2.

Threats to operating room personnel's occupational safety and health: a qualitative study

Background & Objective: Every operating room has been associated with a variety of occupational hazards, but not many studies have been conducted to assess and address these hazards. We used a qualitative approach to explore operating room personnel's experiences of workplace hazards and how these hazards threaten their occupational safety and health (OSH). Methodology: This qualitative study was conducted in five teaching hospitals in the south-west of Iran from February 2019 to March 2021. The sample was 24 operating room personnel who were selected under convenient sampling technique. Data were collected using semi-structured, individual interviews, document review and non-participant observation. The collected data were analyzed according to the qualitative content analysis method using MAXQDA v. 2020. Results: After prolonged analysis of the data, the researchers extracted 644 codes, 13 subcategories, 4 categories, and 1 main theme. The main theme of the study was working in a context of occupational hazards. Conclusions: Operating rooms are full of potential dangers, which, when combined with the personnel's negligence and management inefficiencies, increase the risk of occupational health and safety. Therefore, making working conditions safe by providing adequate personal protective equipment (PPE), in-service training, and identifying and managing the causes of personnel negligence are recommended. Moreover, strategies should be introduced to manage stress and conflicts among the healthcare personnel, thus controlling psychological hazards.

New trends in application of the fumigation method in medical and non-medical fields.

INTRODUCTION: In the twentieth century, fumigation became a very popular method of disinfection, although in the same century many agents used as fumigants were withdrawn for ecological reasons. Fogging (fumigation) is a relatively new disinfection technology using dry fog, which behaves more like a gas and easily fills the sanitized space, reaching all surfaces in the room. The undoubted advantage of fumigation is the possibility of disinfecting difficult to clean areas. Fumigation has become particularly important in the twenty-first century due to procedures related to combating and preventing the spread of the coronavirus that causes COVID-19. OBJECTIVE: The aim of this review article is to summarize the current state of knowledge in the field of fumigation on the basis of past results of original research, taking into account new trends and possibilities of its application. BRIEF DESCRIPTION OF THE STATE OF KNOWLEDGE: Due to the fact that fumigation is safe for apparatus, equipment, and electronics, while simultaneously enabling the highest possible bactericidal and virucidal levels, this method is widely used in various areas, both medical and non-medical. Fogging technology is used in the medical, pharmaceutical, and food industries, as well as in transportation, for air fumigation or surface disinfection in closed spaces, such as hospital and laboratory rooms, incubators, refrigerators, ships, trucks, railway containers, and aircraft, to name only a few. The most common fumigants are hydrogen peroxide and peracetic acid, and their mechanism of action is related to their oxidizing properties. SUMMARY: Hydrogen peroxide and peracetic acid are highly effective and non-toxic fumigants that can be safely used for fogging laboratory and medical equipment, pharmaceutical facilities, hospital rooms, and animal breeding rooms.

A Simple and Low-cost Photocatalytic Air Purification Test Method

The application of photocatalytic oxidation (PCO) in air purifiers (AP) to remove viruses, bacteria, and toxic gases in the air is intensively being studied, especially after the Covid-19 pandemic broke out. The testing method of PCO materials for AP purposes has been standardized through ISO 22197-4 (2013). However, the standard required a set of complex, high precision, and costly equipment. The present study demonstrates a simpler and low-cost test setup without compromising any accuracy in the overall result. The proposed test consists of a test chamber and mixing chamber, and sets of equipment installed in it. A 3D printer fabricated a PCO reactor, and TiO2 was coated on the surface. Formaldehyde (HCHO) is used as a sample pollutant to be observed, injected into the test chamber. Before the measurement of the concentration of HCHO, the intensity of UV A LED was measured. Then, the amount of formaldehyde concentration was monitored online by indoor air quality measurement equipment. The result shows that the intensity of UV light was enough to generate a photocatalytic oxidation reaction. After 20 minutes of reaction, the HCHO concentration inside the chamber was decreased around 21.76%.