Covid-19 lockdown effect on aerosol optical depth in Delhi National Capital Region, India

Coronavirus cases in India have been steadily increasing since March 2020. COronaVIrus Disease 2019 (COVID-19) has been managed by a variety of preventative measures. A prominent measure by the Government of India to prevent the spread of Coronavirus Disease 2019 (COVID-19) began on March 25, 2020, with a complete suspension of all outdoor activities throughout the country. Such complete lockdown has resulted in a decrease in anthropogenic emissions, which is partly due to restrictions on human activities. Delhi National Capital Region (NCR), a landlocked area, suffers from high amounts of aerosols due to both natural and anthropogenic sources. The present research focuses on changes in Aerosol Optical Depth (AOD) prior to and during lockdown (initial and second lockdown phases) around satellite cities (Faridabad, Ghaziabad, Gautam Budh Nagar and Gurugram) of Delhi using high-resolution MODIS AOD product. With the implementation of lockdown measures in phase I and phase III of the current study region, AOD decreased dramatically, while phase II and phase IV lockdown phases had a higher concentration of aerosol. An unexpected increase in AOD occurred during the second lockdown compared with the initial lockdown and before the lockdown. Overall, the average percentage change from 2019 to 2020 during first lockdown is -4.44%, while the average percentage change from 2020 to 2021 is 27.63%. © 2022 The Author(s). Published by Forum geografic.

Annual Variation of PM2.5 Chemical Composition in Ho Chi Minh City, Vietnam Including the COVID-19 Outbreak Period

PM2.5 was continuously collected in Ho Chi Minh City (HCMC), Vietnam, during the period from September 2019 to August 2020, which included the period of socioeconomic suppression caused by restrictions imposed in the face of the coronavirus disease of 2019. The concentrations of PM2.5 mass, water-soluble ions (WSIs), organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were determined to evaluate the seasonal variations in PM2.5, the effect of socioeconomic suppression on PM2.5, and potential PM2.5 sources in HCMC. The PM2.5 mass concentration during the sampling period was 28.44 +/- 11.55 mu g m(-3) (average +/- standard deviation). OC, EC, and total WSIs accounted for 30.7 +/- 6.6%, 9.7 +/- 2.9%, and 24.9 +/- 6.6% of the PM2.5 mass, respectively. WSOC contributed 46.4 +/- 10.1% to OC mass. NO3-, SO42-, and NH4+ were the dominant species in WSIs (72.7 +/- 17.7% of the total WSIs' mass). The concentrations of PM2.5 mass and total WSIs during the rainy season were lower than those during the dry season, whereas the concentrations of carbonaceous species during the rainy season were higher. The concentrations of PM2.5 mass and chemical species during the socioeconomic suppression period significantly decreased by 45%-61% compared to the values before this period. The OC/EC ratio (3.28 +/- 0.61) and char-EC/soot-EC (4.88 +/- 2.72) suggested that biomass burning, coal combustion, vehicle emissions, cooking activities are major PM2.5 sources in HCMC. Furthermore, the results of a concentration-weighted trajectory analysis suggested that the geological sources of PM2.5 were in the local areas of HCMC and the northeast provinces of Vietnam (where coal-fired power plants are located).

Emergency Medical Services: COVID-19 crisis.

The COVID-19 epidemic required rapid and frequent adaptations from the prehospital emergency medical services (EMS). The exposure of EMS providers is significant, particularly during procedures at risk of aerosolization such as advanced airways management or cardiopulmonary resuscitation. EMS personal need to be equipped with appropriate personal protective equipment and trained in its use. Interhospital transfers from COVID-19 patients are complex and involve mainly intubated patients. The possible shortage of resources may motivate the implementation of dedicated prehospital triage and orientation recommendations, which should be consistent with the hospital processes.Copyright © 2020 Editions Medecine et Hygiene. All rights reserved.

Potential targets and traditional Chinese medicine treatment strategy of cough after SARS-CoV-2 infection.

The severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) Omicron variants BA.5.2 and BF.7 have become the main epidemic strains in China since the quarantine policy was lifted in 7th December 2022. Cough is one of the main symptoms induced by SARS-CoV-2 infection. SARS-CoV-2 infection-associated cough injuries the lung and upper respiratory tract, while the infected people cough out virus and liquid which forms virus-containing aerosols, a medium for quickly spreading. Furthermore, cough is one of primary sequelae of discharged patients in corona virus disease 2019 (COVID-19). By now, there are no efficacious drugs for treatment of upper respiratory tract infection associated cough induced by omicron. Traditional Chinese medicine (TCM) has a long history on treating cough. By reviewing the mechanisms of the occurrence of cough after SARS-CoV-2 infection, potential therapeutic targets and cough suppressant herbs with significant efficacy in clinical and basic research, we provide a reference for the treatment of cough after SARS-Cov-2 infection and a basis for the majority of infected patients to select appropriate herbs for cough relief under guidance of physicians.Copyright © 2023 Editorial Office of Chinese Traditional and Herbal Drugs. All rights reserved.

Impact of COVID-19 on spatio-temporal variation of aerosols and air pollutants concentration over India derived from MODIS, OMI and AIRS

The atmospheric aerosols and air pollutants affect the earth's atmosphere, human health and climate system. Human-induced aerosols and air pollutants are the major causes of the deterioration of air quality. The COVID-19 lockdown restricted the movement of people and vehicles, stopped industrial and agricultural activities and may have impacts on the aerosols in the atmosphere. Spatio-temporal map of MODIS Terra AOD_550 nm, OMI Aura UVAI, Ozone, NO2, SO2 and AIRS CO during the lockdown illustrates the significant reduction in their concentration. During the lockdown, the North India shows a record reduction of over 20% in Aerosol Optical Depth and Aerosol Index values. A substantial decrease in AOD and AI was also observed in Eastern and Western parts of India. The average AOD value were reduced from 1.36 (2016–2019) to 1.09 (2020) over India during the lockdown. The satellite-retrieved aerosol variables over India recorded lowest AOD values on 29th March, 2020 (0.2566) and 21st April 2020 (0.2591). Similarly, air pollutants CO, NO2 and SO2 also significantly reduced in India. Despite all variables showing a reduction in concentration, Ozone recorded an increase in value during lockdown primarily over North and North-eastern parts of India. Western India recorded a substantial reduction in SO2 (47%) followed by Central India (31%). As pan India is considered, CO was reduced by 1%, NO2 reduced by 15.29% and SO2 was reduced by 26.82% during the lockdown period. This abrupt reduction in aerosol and air pollutants concentration over India was mainly due to the lockdown of COVID-19. © 2023, The Author(s), under exclusive licence to Korea Spatial Information Society.

Winter-autumn air pollution control plan in North China modified the PM2.5 compositions and sources in Central China

The additional impact of emission-reduction measures in North China (NC) during autumn and winter on the air quality of downwind regions is an interesting but less addressed topic. The mass concentrations of routine air pollutants, the chemical compositions, and sources of fine particles (PM2.5) for January 2018, 2019, and 2020 at a megacity of Central China were identified, and meteorology-isolated by a machine-learning technique. Their variations were classified according to air mass direction. An unexpectedly sharp increase in emission-related PM2.5 by 22.7% (18.0 mug m-3) and 25.7% (19.4 mug m-3) for air masses from local and NC in 2019 was observed compared to those of 2018. Organic materials exhibited the highest increase in PM2.5 compositions by 6.90 mug m-3 and 6.23 mug m-3 for the air masses from local and NC. PM2.5 source contributions related to emission showed an upsurge from 1.39 mug m-3 (biomass burning) to 24.9 mug m-3 (secondary inorganic aerosol) in 2019 except for industrial processes, while all reduced in 2020. From 2018 to 2020, the emission-related contribution of coal combustion to PM2.5 increased from 10.0% to 19.0% for air masses from the local area. To support the priority natural gas quotas in northern China, additional coal in cities of southern China was consumed, raising related emissions from transportation activities and road dust in urban regions, as well as additional biofuel consumption in suburban or rural regions. All these activities could explain the increased primary PM2.5 and related precursor NO2. This study gave substantial evidence of air pollution control measures impacting the downwind regions and promote the necessity of air pollution joint control across the administration.Copyright © 2023 Elsevier Ltd

Emissions Background, Climate, and Season Determine the Impacts of Past and Future Pandemic Lockdowns on Atmospheric Composition and Climate

COVID-19 pandemic responses affected atmospheric composition and climate. These effects depend on the background emissions, climate, and season in which they occur. Although using multiple scenarios is common in explorations of long-term climate change, they are rarely used to explore atmospheric composition or climate changes in response to transient emission perturbations on the scale of COVID-19 lockdowns. We used the ModelE Earth system model to evaluate how atmospheric and climate impacts depend on the decade and season in which lockdowns occurred. Global COVID-19-related anomalies in aerosols and trace gases differed by up to an order of magnitude or more when comparing lockdowns in 1980, 2008, 2020, and 2051. Regional atmospheric composition anomalies tended to be largest when emissions were near a historical peak: 1980 in Europe and temperate North America, 2008 or 2020 in eastern Asia, and 2051 in south Asia. Regional aerosol direct effect anomalies were almost always less than 0.1 W m( -2) during the first pandemic year, but over 0.1 W m (-2) in Europe and exceeded 0.2 W m(-2) in Europe and temperate North America in 1980, generally changing in tandem with regional emissions. In contrast, direct effect anomalies in Asia were positive in 1980 and negative in 2008, suggesting they may be primarily determined by exogenous emission anomalies. Shifting COVID-19 onset in 2020 by 3, 6, or 9 months also altered atmospheric composition on the order of 2%-25% globally. In all scenarios, changes in surface temperature or precipitation appeared unrelated to local atmospheric compositional changes.

Large-Scale Urban Heating and Pollution Domes over the Indian Subcontinent

The unique geographical diversity and rapid urbanization across the Indian subcontinent give rise to large-scale spatiotemporal variations in urban heating and air emissions. The complex relationship between geophysical parameters and anthropogenic activity is vital in understanding the urban environment. This study analyses the characteristics of heating events using aerosol optical depth (AOD) level variability, across 43 urban agglomerations (UAs) with populations of a million or more, along with 13 industrial districts (IDs), and 14 biosphere reserves (BRs) in the Indian sub-continent. Pre-monsoon average surface heating was highest in the urban areas of the western (42 degrees C), central (41.9 degrees C), and southern parts (40 degrees C) of the Indian subcontinent. High concentration of AOD in the eastern part of the Indo-Gangetic Plain including the megacity: Kolkata (decadal average 0.708) was noted relative to other UAs over time. The statistically significant negative correlation (-0.51) between land surface temperature (LST) and AOD in urban areas during pre-monsoon time illustrates how aerosol loading impacts the surface radiation and has a net effect of reducing surface temperatures. Notable interannual variability was noted with, the pre-monsoon LST dropping in 2020 across most of the selected urban regions (approx. 89% urban clusters) while it was high in 2019 (for approx. 92% urban clusters) in the pre-monsoon season. The results indicate complex variability and correlations between LST and urban aerosol at large scales across the Indian subcontinent. These large-scale observations suggest a need for more in-depth analysis at city scales to understand the interplay and combined variability between physical and anthropogenic atmospheric parameters in mesoscale and microscale climates.

Dysphagia rehabilitation in post-COVID patients: Review of the literature

COVID-19 causes acute respiratory failure syndrome (SIRA), leading patients to require intubation in the intensive care unit (ICU). A common complication of this ventilatory support is dysphagia, which has a prevalence of up to 30%.This work aims to describe rehabilitation methods in patients with coronavirus infection based on levels of evidence according to the GRADE System, so a systematic review of the literature was carried out. The selected articles were divided into the following subtopics: diagnosis of dysphagia and rehabilitation in COVID patients. The gold standard for the diagnosis of dysphagia is the videofluoroscopic swallowing study (VFS). Fiberoptic Evaluation of Swallowing Assessment (FEES) has high sensitivity and specificity, although they have the disjunction of an aerosol-generating procedure (AGP);however, in a pandemic situation, the study of choice in the literature is VF. Once the diagnosis is made, it is necessary to initiate rehabilitation as soon as possible, even from hospitalization in patients who have hemodynamic stability to prevent long-term effects and promote normal swallowing even before discharge. In patients with COVID-19 infection dysphagia, the risk-benefit of assessment tools and therapy used for diagnosis should be decided to help to maintain social distancing. It becomes imperative to carry out clinical studies with high levels of evidence that allow us to generate Clinical Practice Guides for the benefit of our patients.Copyright © 2021 Sociedad Medica del Hospital General de Mexico. Published by Permanyer.

Validation of an HPLC-CAD Method for Determination of Lipid Content in LNP-Encapsulated COVID-19 mRNA Vaccines.

Lipid nanoparticles (LNPs) are widely used as delivery systems for mRNA vaccines. The stability and bilayer fluidity of LNPs are determined by the properties and contents of the various lipids used in the formulation system, and the delivery efficiency of LNPs largely depends on the lipid composition. For the quality control of such vaccines, here we developed and validated an HPLC-CAD method to identify and determine the contents of four lipids in an LNP-encapsulated COVID-19 mRNA vaccine to support lipid analysis for the development of new drugs and vaccines.

COVID-19-specific adult basic life support guideline strategies for chiropractors and other healthcare providers to maximize the safety and efficacy of resuscitation: a commentary.

BACKGROUND: The emergence of an unprecedented novel severe acute respiratory syndrome coronavirus-2 (SARS-C0V-2), which causes the coronavirus disease 2019 (COVID-19) pandemic, has created new scenarios in basic life support (BLS) management. According to current evidence, SARS-CoV-2 can be transmitted airborne in aerosol particles during resuscitation. Research evidence found an alarming global increase in out-of-hospital cardiac arrests during the COVID-19 pandemic. Healthcare providers are legally obliged to respond to cardiac arrest as soon as possible. Chiropractors will likely encounter potential exercise-related and non-exercise-related cardiac emergencies at some point in their professional lives. They have a duty of care to respond to emergencies such as cardiac arrest. Chiropractors are increasingly involved in providing care, including emergency care, for athletes and spectators at sporting events. Also, exercise-related cardiac arrest in adult patients may occur during exercise testing or rehabilitation with exercise prescriptions in chiropractic and other healthcare settings. Little is known about the COVID-19 BLS guidelines for chiropractors. Knowledge of the current COVID-19-specific adult BLS guidelines is essential to developing an emergency response plan for the on-field and sideline management of exercise-related cardiac arrest and non-athletic, non-exercise-related cardiac arrest. MAIN TEXT: Seven peer-reviewed articles on the COVID-19-specific BLS guidelines, including two updates, were reviewed for this commentary. Responding to the COVID-19 pandemic, the national and international resuscitation organizations recommended interim COVID-19-specific BLS guidelines with precaution, resuscitation, and education strategies. BLS safety is paramount. A precautionary approach with the bare minimum of appropriate personal protective equipment for resuscitation is recommended. There was disagreement among the COVID-19 BLS guidelines on the level of personal protective equipment. All healthcare professionals should also undergo self-directed BLS e-learning and virtual skill e-training. The summarized COVID-19-specific adult BLS guideline strategies and protocols are tabled, respectively. CONCLUSIONS: This commentary provides a practical overview and highlights current evidence-based intervention strategies of the COVID-19-specific adult BLS guidelines that may help chiropractors and other healthcare providers reduce BLS-related exposures to SARS-CoV-2 and the risks of SARS-CoV-2 transmission and maximize the efficacy of resuscitation. This study is relevant to and impacts future COVID-19-related research in areas such as infection prevention and control.

A Negative-Pressure Face-Mounted System Reduces Aerosol Spread during Endonasal Endoscopic Surgery.

Purpose Due to the potential risk of COVID-19 transmission during endonasal surgery, we studied methods to reduce droplet and aerosol generation during these procedures. Methods Droplet spread was assessed using ultraviolet light and a camera that detected fluorescence in the operative field and surgeon's personal protective equipment. Density of aerosols sized <10 µm was measured using a photometric particle counter. We designed a face-mounted negative-pressure mask placed on the patients' face during endoscopic endonasal surgery. Sixteen patients were recruited between October 2020 and March 2021 and randomly assigned to the mask and no-mask groups. We compared droplet spread and aerosols generated in both groups, with copious irrigation and continuous suction during drilling forming the mainstay of surgical technique in all cases. Results Droplet contamination due to direct spillage of fluorescein from the syringe was noted in two patients. Aerosol density rose during sphenoid drilling in both groups, with no significant difference when continuous suction and irrigation were employed (1.27 times vs. 1.07 times the baseline, p = 0 .248 ). Aerosol density rose significantly when suction and irrigation were interrupted in the no-mask group (44.9 times vs. 1.2 times, p = 0 .028) , which was not seen when the mask was used. Conclusion Aerosol generation increases during drilling in endonasal procedures and is a concern during this pandemic. The use of a rigid suction close to the drill along with copious irrigation is effective in reducing aerosol spread. The use of a negative pressure mask provides additional safety when inadvertent blockage of suction and inadequate irrigation occur.

Can aerosols-generating dental, oral and maxillofacial, and orthopedic surgical procedures lead to disease transmission? An implication on the current COVID-19 pandemic.

Various dental, maxillofacial, and orthopedic surgical procedures (DMOSP) have been known to produce bioaerosols, that can lead to the transmission of various infectious diseases. Hence, a systematic review (SR) aimed at generating evidence of aerosols generating DMOSP that can result in the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), further investigating their infectivity and assessing the role of enhanced personal protective equipment (PPE) an essential to preventing the spreading of SARS-CoV-2 during aerosol-generating procedures (AGPs). This SR was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA) guidelines based on a well-designed Population, Intervention, Comparison, Outcomes and Study (PICOS) framework, and various databases were searched to retrieve the studies which assessed potential aerosolization during DMOSP. This SR included 80 studies (59 dental and 21 orthopedic) with 7 SR, 47 humans, 5 cadaveric, 16 experimental, and 5 animal studies that confirmed the generation of small-sized < 5 µm particles in DMOSP. One study confirmed that HIV could be transmitted by aerosolized blood generated by an electric saw and bur. There is sufficient evidence that DMOSP generates an ample amount of bioaerosols, but the infectivity of these bioaerosols to transmit diseases like SARS-CoV-2 generates very weak evidence but still, this should be considered. Confirmation through isolation and culture of viable virus in the clinical environment should be pursued. An evidence provided by the current review was gathered by extrapolation from available experimental and empirical evidence not based on SARS-CoV-2. The results of the present review, therefore, should be interpreted with great caution.

Research progress on distribution and exposure risk of microbial aerosols in animal houses.

Environmental aerosols in animal houses are closely related to the productive performance and health level of animals living in the houses. Preferable housing environments can improve animal welfare and production efficiency, so it is necessary to monitor and study these environments. In recent years, there have been many large-scale outbreaks of respiratory diseases related to biological aerosols, especially the novel coronavirus that has been sweeping the world. This has attracted much attention to the mode of aerosol transmission. With the rapid development of large-scale and intensive breeding, microbial aerosols have gradually become the main factor of environmental pollution in animal houses. They not only lead to a large-scale outbreak of infectious diseases, but they also have a certain impact on the health of animals and employees in the houses and increase the difficulty of prevention and control of animal-borne diseases. This paper reviews the distribution, harm, and control measures of microbial aerosols in animal house environments in order to improve people's understanding of them.

Comparison of aerosol box intubation with styletted endotracheal tube and intubation over bougie: A randomized controlled trial.

Background and Aims: Severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) is an infectious disease. The use of video laryngoscopes is recommended for intubation of patients with COVID-19. But in resource-poor countries, it is rare to have video laryngoscopes available. In this trial, we have compared the ease of oral intubation by direct laryngoscopy with styletted endotracheal tube and intubation over the bougie, with the use of the aerosol box. The secondary objectives were comparison of the incidence of airway loss, attempts taken to intubate, time for intubation and hemodynamic changes. Material and Methods: 80 non-coronavirus infected patients coming for an elective procedure under general anesthesia were recruited in this randomized control trial. Participants were assigned into groups S and B using a computer-generated random sequence of numbers by closed envelope technique. In both groups, aerosol box was used. In Group S, participants were intubated by direct laryngoscopy with a styletted endotracheal tube and in group B, after direct laryngoscopy, the endotracheal tube was railroaded over the bougie. Results: Ease of endotracheal intubation was good (67.5%% vs. 45%), satisfactory (32.5%% vs. 37.5%), and poor (0% vs. 17.5%) in group S and B respectively (P < 0.011). The attempts required for intubation were similar in both groups. The time for intubation was significantly less in group S than B (23 vs. 55 s). Conclusion: The use of a styletted endotracheal tube made intubation easier and faster than tracheal intubation with bougie when the aerosol box was used in patients without known or predicted difficult airway and significant medical comorbidities.

Aerosolized sulfated hyaluronan derivatives prolong the survival of K18 ACE2 mice infected with a lethal dose of SARS-CoV-2.

Despite several vaccines that are currently approved for human use to control the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is an urgent medical need for therapeutic and prophylactic options. SARS-CoV-2 binding and entry in human cells involves interactions of its spike (S) protein with several host cell surface factors, including heparan sulfate proteoglycans (HSPGs), transmembrane protease serine 2 (TMPRSS2), and angiotensin-converting enzyme 2 (ACE2). In this paper we investigated the potential of sulphated Hyaluronic Acid (sHA), a HSPG mimicking polymer, to inhibit the binding of SARS-CoV-2 S protein to human ACE2 receptor. After the assessment of different sulfation degree of sHA backbone, a series of sHA functionalized with different hydrophobic side chains were synthesized and screened. The compound showing the highest binding affinity to the viral S protein was further characterized by surface plasmon resonance (SPR) towards ACE2 and viral S protein binding domain. Selected compounds were formulated as solutions for nebulization and, after being characterized in terms of aerosolization performance and droplet size distribution, their efficacy was assessed in vivo using the K18 human (h)ACE2 transgenic mouse model of SARS-CoV-2 infection.

The effect of activity and face masks on exhaled particles in children.

Importance: Despite the high burden of respiratory infections among children, the production of exhaled particles during common activities and the efficacy of face masks in children have not been sufficiently studied. Objective: To determine the effect of type of activity and mask usage on exhaled particle production in children. Methods: Healthy children were asked to perform activities that ranged in intensity (breathing quietly, speaking, singing, coughing, and sneezing) while wearing no mask, a cloth mask, or a surgical mask. The concentration and size of exhaled particles were assessed during each activity. Results: Twenty-three children were enrolled in the study. Average exhaled particle concentration increased by intensity of activity, with the lowest particle concentration during tidal breathing (1.285 particles/cm3 [95% CI 0.943, 1.627]) and highest particle concentration during sneezing (5.183 particles/cm3 [95% CI 1.911, 8.455]). High-intensity activities were associated with an increase primarily in the respirable size (≤ 5 µm) particle fraction. Surgical and cloth masks were associated with lower average particle concentration compared to no mask (P = 0.026 for sneezing). Surgical masks outperformed cloth masks across all activities, especially within the respirable size fraction. In a multivariable linear regression model, we observed significant effect modification of activity by age and by mask type. Interpretation: Similar to adults, children produce exhaled particles that vary in size and concentration across a range of activities. Production of respirable size fraction particles (≤ 5 µm), the dominant mode of transmission of many respiratory viruses, increases significantly with coughing and sneezing and is most effectively reduced by wearing surgical face masks.

Spinal fusion is an aerosol generating procedure.

BACKGROUND: Transmission of severe acute respiratory syndrome coronavirus 2 can occur during aerosol generating procedures. Several steps in spinal fusion may aerosolize blood but little data exists to quantify the risk this may confer upon surgeons. Aerosolized particles containing infectious coronavirus are typically 0.5-8.0 µm. AIM: To measure the generation of aerosols during spinal fusion using a handheld optical particle sizer (OPS). METHODS: We quantified airborne particle counts during five posterior spinal instrumentation and fusions (9/22/2020-10/15/2020) using an OPS near the surgical field. Data were analyzed by 3 particle size groups: 0.3-0.5 µm/m3, 1.0-5.0 µm/m3, and 10.0 µm/m3. We used hierarchical logistic regression to model the odds of a spike in aerosolized particle counts based on the step in progress. A spike was defined as a > 3 standard deviation increase from average baseline levels. RESULTS: Upon univariate analysis, bovie (P < 0.0001), high speed pneumatic burring (P = 0.009), and ultrasonic bone scalpel (P = 0.002) were associated with increased 0.3-0.5 µm/m3 particle counts relative to baseline. Bovie (P < 0.0001) and burring (P < 0.0001) were also associated with increased 1-5 µm/m3 and 10 µm/m3 particle counts. Pedicle drilling was not associated with increased particle counts in any of the size ranges measured. Our logistic regression model demonstrated that bovie (OR = 10.2, P < 0.001), burring (OR = 10.9, P < 0.001), and bone scalpel (OR = 5.9, P < 0.001) had higher odds of a spike in 0.3-0.5 µm/m3 particle counts. Bovie (OR = 2.6, P < 0.001), burring (OR = 5.8, P < 0.001), and bone scalpel (OR = 4.3, P = 0.005) had higher odds of a spike in 1-5 µm/m3 particle counts. Bovie (OR = 0.3, P < 0.001) and drilling (OR = 0.2, P = 0.011) had significantly lower odds of a spike in 10 µm/m3 particle counts relative to baseline. CONCLUSION: Several steps in spinal fusion are associated with increased airborne particle counts in the aerosol size range. Further research is warranted to determine if such particles have the potential to contain infectious viruses. Previous research has shown that electrocautery smoke may be an inhalation hazard for surgeons but here we show that usage of the bone scalpel and high-speed burr also have the potential to aerosolize blood.

The role of the oral cavity in SARS-CoV-2- and other viral infections.

OBJECTIVE: This study aims to review the role of the oral cavity in SARS-CoV-2- and other viral upper respiratory tract infections. MATERIAL AND METHODS: Data reviewed in the text have been researched online and also reflect personal expertise. RESULTS: Numerous respiratory and other viruses replicate in the oral cavity and are transmitted via aerosols (< 5 µm) and droplets (> 5 µm). SARS-CoV-2 replication has been documented in the upper airways as well as in oral mucosa and salivary glands. These sites are also virus reservoirs that can infect other organs, e.g., the lungs and gastrointestinal tract, as well as other individuals. Laboratory diagnosis of viruses in the oral cavity and upper airways focuses on real-time PCR; antigen tests are less sensitive. For screening and monitoring infections, nasopharyngeal and oral swabs are tested; saliva is a good and more comfortable alternative. Physical means like social distancing or masks have been proven successful to reduce the risk of infection. Both wet-lab and clinical studies confirm that mouth rinses are effective against SARS-CoV-2 and other viruses. Antiviral mouth rinses can inactivate all viruses that replicate in the oral cavity. CONCLUSIONS: The oral cavity plays an important role in viral infections of the upper respiratory tract: it serves as a portal of entry, a site of replication, and a source of infection by droplets and aerosols. Physical means but also antiviral mouth rinses can help reduce the spread of viruses and contribute to infection control.

Inactivation characteristics of a 280 nm Deep-UV irradiation dose on aerosolized SARS-CoV-2.

A non-filter virus inactivation unit was developed that can control the irradiation dose of aerosolized viruses by controlling the lighting pattern of a 280 nm deep-UV (DUV)-LED and the air flowrate. In this study, the inactivation properties of aerosolized SARS-CoV-2 were quantitatively evaluated by controlling the irradiation dose to the virus inside the inactivation unit. The RNA concentration of SARS-CoV-2 remained constant when the total irradiation dose of DUV irradiation to the virus exceeded 16.5 mJ/cm2. This observation suggests that RNA damage may occur in regions below the detection threshold of RT-qPCR assay. However, when the total irradiation dose was less than 16.5 mJ/cm2, the RNA concentration monotonically increased with a decreasing LED irradiation dose. However, the nucleocapsid protein concentration of SARS-CoV-2 was not predominantly dependent on the LED irradiation dose. The plaque assay showed that 99.16% of the virus was inactivated at 8.1 mJ/cm2 of irradiation, and no virus was detected at 12.2 mJ/cm2 of irradiation, resulting in a 99.89% virus inactivation rate. Thus, an irradiation dose of 23% of the maximal irradiation capacity of the virus inactivation unit can activate more than 99% of SARS-CoV-2. These findings are expected to enhance versatility in various applications. The downsizing achieved in our study renders the technology apt for installation in narrow spaces, while the enhanced flowrates establish its viability for implementation in larger facilities.