Microscopy of Woven and Nonwoven Face Covering Materials: Implications for Particle Filtration

A suite of natural, synthetic, and mixed synthetic-natural woven fabrics, along with nonwoven filtration layers from a surgical mask and an N95 respirator, was examined using visible light microscopy, scanning electron microscopy, and micro-X-ray computed tomography (µXCT) to determine the fiber diameter distribution, fabric thickness, and the volume of solid space of the fabrics. Nonwoven materials exhibit a positively skewed distribution of fiber diameters with a mean value of ≈3 μm, whereas woven fabrics exhibit a normal distribution of diameters with mean values roughly five times larger (>15 μm). The mean thickness of the N95 filtration material is 1093 μm and is greater than that of the woven fabrics that span from 420 to 650 μm. A new procedure for measuring the thickness of flannel fabrics is proposed that accounts for raised fibers. µXCT allowed for a quantitative nondestructive approach to measure fabric porosity as well as the surface area/volume. Cotton flannel showed the largest mean isotropy of any fabric, though fiber order within the weave is poorly represented in the surface electron images. Surface fabric isotropy and surface area/volume ratios are proposed as useful microstructural quantities to consider for future particle filtration modeling efforts of woven materials.

N95 respirators alter facial skin physiological functions and lipidome composition in health care personnel

BACKGROUND

During the coronavirus disease 2019 pandemic, wearing medical respirators and masks was essential to prevent transmission.

OBJECTIVE

To quantify the effects of N95 mask usage by measuring facial skin biophysical characteristics and changes in the lipidome.

METHODS

Sixty healthy volunteers wore N95 respirators for 3 or 6 h. Facial images were acquired and physiological parameters were measured in specific facial areas, before and after mask-wearing. Lipidome analysis was also performed.

RESULTS

After N95 respirator usage, facial erythema was observed in both the 3 and 6 h groups. Both sebum secretion and trans-epidermal water loss increased significantly in mask-covered cheeks and chins after 6 h of mask wearing compared with before mask wearing (p < 0.05). Principal component analysis revealed significant differences in lipid composition after mask wearing compared with before. The ceramide subclass NS exhibited a positive correlation with stratum corneum hydration, whereas the AP subclass was negatively correlated with trans-epidermal water loss in the 6 h group.

CONCLUSION

Prolonged wear of N95 respirators may impair facial skin function and alter lipidome composition.

Best practices for communication while wearing facemasks: A scoping review

INTRODUCTION

Facemasks are an important piece of personal protective equipment (PPE) to mitigate the spread of respiratory illnesses, but they can impede communication between patients and healthcare providers. The purpose of this scoping review is to identify effective communication practices while wearing facemasks.

DESIGN

Scoping review using a systematic search of articles from the PubMed, CINAHL, and Embase databases.

METHODS

The PEO (population, exposure, outcome) methodology was selected for this systematic scoping review. The population of interest (P) includes humans of all ages (children, adults, and older adults); the exposure of interest (E) is PPE that covers the mouth (i.e., facemasks); and the outcome of interest (O) is successful or unsuccessful communication practices. The Johns Hopkins Evidence-Based Practice for Nurses and Healthcare Professionals appraisal guidelines were used to determine the level and quality of the research.

RESULTS

Thirty-nine articles met the inclusion criteria. Seventeen of these were high- or good-quality research studies, and the remaining 22 were non-research articles included with separate analysis as part of the scoping review. The 17 articles encompassed 2656 participants. The highest quality evidence indicated that standard surgical masks have the least impact on speech perception compared to other non-transparent mask types, and that recognizing emotions is less accurate with facemasks, necessitating compensatory actions (i.e., reducing extraneous noise, using a microphone to amplify voice, and employing clear speech). Evidence was contradictory regarding the use of transparent masks. Evidence was of limited quality for other non-verbal and verbal communication strategies.

CONCLUSION

Awareness of communication challenges is crucial when wearing facemasks. More high-quality studies are needed to evaluate communication techniques when speakers are wearing facemasks. Basic strategies such as selecting an appropriate mask type, reducing extraneous noise, using microphones, verbalizing emotions, and employing clear speech appear to be beneficial.

CLINICAL RELEVANCE

The findings of this scoping review highlight the importance of considering communication challenges while wearing facemasks in the healthcare settings. The review suggests that selecting an appropriate mask type, reducing extraneous noise, verbalizing emotions, and employing clear speech are some strategies that may be effective in mitigating the impact of facemasks on communication between patients and healthcare providers.

Study on the relationship between the fitness of three types of N95 respirators and facial dimensions

N95 respirators are the core equipment used by healthcare workers to prevent the spread of respiratory diseases. The protective effect of N95 against infection spread depends on the fit of the N95 to the wearer, which is related to the wearer's facial dimensions. The purpose of this cross-sectional study was to assess the relationship between the fit of three types of N95 and facial dimensions. A total of 305 healthcare workers from ten hospitals in Beijing were recruited for this study. Facial dimensions of workers were measured using Intel RealSense Depth Camera D435. Fit testing was conducted on three types of N95 using the TSI-8038 Porta Count Pro + Respirator Fit Tester. Possible associations between the fit test results and facial dimension data were examined. A Porta Count reading of 100 was used as the criterion for an acceptable fit. The fit of the folding respirators was positively correlated with nose length (r = 0.13, p = 0.02), nose height (r = 0.14, p = 0.02), and face width (r = 0.12, p = 0.03), whereas that of flat respirators was correlated with nose width (r = 0.16, p < 0.01), chin length (r = 0.18, p < 0.01), and pro-face width (r = 0.13, p = 0.02), and that of arched respirators was correlated with the nose length (r = 0.13, p = 0.03). The fit of N95 for wearers depends on their facial features. The results of this study can provide advice for medical workers to choose the appropriate N95. Medical staff should fully consider their facial dimensions when choosing an appropriate N95 to improve the protective efficacy of respirators and to reduce the risk of infection by respiratory diseases.

Impact of Concurrent Use of N95 and Surgical Masks on Peripheral Oxygen Saturation and Heart Rate Frequency-A Prospective Study during the COVID-19 Outbreak

Background and Objectives: The COVID-19 outbreak has necessitated the prolonged use of N95 facemasks in addition to traditional surgical facemasks by healthcare workers. The aim of this study was to investigate the effect of wearing N95 facemasks in addition to surgical facemasks on peripheral oxygen saturation (SpO2) and heart rate (HR) among dental professionals during routine care. Materials and Methods: This prospective study compared SpO2 and HR between dental providers wearing N95 + surgical facemasks vs. wearing a surgical facemask only. SpO2 and HR were recorded using a portable pulse oximeter before wearing the facemask (T0); at 30 min (T1); at 1 h (T2); and at the end of clinical activity (T3). Inter-group and intra-group differences were assessed with independent t tests and repeated measures ANOVA, respectively. Results: A total of 88 participants (57 wearing N95 + surgical facemasks, and 31 wearing a surgical facemask only) completed the study. The two groups did not statistically differ in SpO2 at different timepoints nor showed any intra-group differences. The participants wearing N95 + surgical facemasks exhibited a statistically higher HR at T0 (p = 0.007), T2 (p = 0.010), and T3 (p = 0.014) compared to those wearing a surgical facemask only. A statistically significant decrease was observed in HR between T0 and T3 in those wearing N95 + surgical facemasks (p = 0.012). No intra-group differences were seen in HR over time in those wearing a surgical facemask only. Conclusions: The continuous use of an N95 in addition to a surgical facemask did not show any significant effects in SpO2 during routine care; however, the concurrent use of an N95 and a surgical facemask seemed to be accompanied by a decrease in HR, although the values remained within the normal range.

The Impact of Wearing Different Face Masks on Vigorous Physical Exercise Performance and Perceived Exertion among COVID-19 Infected vs. Uninfected Female Students

Under certain circumstances, masks are an effective and immediate solution to reduce the spread of viral infection. However, the impact of masks on the ability to perform vigorous exercise remains an area of concern. Primarily, this impact has been explored in healthy subjects, yielding contradictory findings, and little is known of it among COVID-19-infected individuals. This study examined the effects of surgical masks, N-95 masks, and unmasked conditions on the performance and perceived exertion (RPE) of infected vs. non-infected young women during high-intensity, repeated sprint exercise (5mSRT). Following a familiarization session, eighty-three (42 COVID-19-previously infected (PIG) and 43 non-infected (NIG)), female participants (age 20.02 ± 1.05 years, BMI 21.07 ± 2.1 kg/m2) were randomly assigned to one of three mask conditions: unmasked, surgical mask, or N95 mask. All participants attended three test sessions (i.e., one session for each mask condition) at least one week apart. At the beginning of each test session, data related to participants' physical activity (PA) and sleep behaviours during the previous week were collected. In each test session, participants performed the 5mSRT, during which performance indicators (best distance (BD), total distance (TD), fatigue index (FI) and percentage decrement (PD)) were collected, along with RPE. ANOVA indicated no significant main effects of Groups and Masks, and no significant interaction for Groups × Masks for BD, FI, PD, RPE and most sleep and PA behaviours (p > 0.05). For TD, the Groups × Mask interaction was significant (p = 0.031 and ƞp2 = 0.042). Posthoc analysis revealed, in the unmasked condition, there was no difference in TD between PIG and NIG (p > 0.05). However, when wearing a surgical mask, PIG covered lower TD compared to NIG (p < 0.05). Additionally, different types of masks did not affect TD in NIG, while PIG performed the worst using the surgical mask (p < 0.05). These results suggest post-COVID-19 individuals can maintain physical fitness through regular exercise (i.e., sport science curricula) in unmasked conditions, but not when wearing a surgical mask. Furthermore, the impact of different types of face masks on physical performance seems to be minimal, particularly in uninfected populations; future research is warranted to further explore this impact in post-COVID conditions.

The Effectiveness of Face Masks in Preventing COVID-19 Transmission: A Systematic Review

INTRODUCTION

Since the beginning of the COVID-19 pandemic, face masks have been among the cornerstones of COVID-19 prevention. Therefore, evaluating their preventive effects against COVID-19 is crucial. This review aimed to systematically search for the systematic review articles that explored the role of various types of face masks in preventing COVID-19.

METHODS

We browsed the keywords of this study in the online databases of Scopus, Web of Science, PubMed, and Cochrane on 10th January 2023 and retrieved all the relevant systematic review articles. The records were downloaded into an Endnote file, and the duplicates were removed. A two-step screening process consisting of title/abstract and full-text screenings was conducted to select the most relevant articles. To ensure the validity and reliability of the results, this study adhered to the PRISMA protocol.

RESULTS

A total of 28 systematic reviews were included in this review. Most studies found that face masks are beneficial against viral respiratory infections, such as COVID-19. Different types of masks were evaluated in included studies. It appeared that mask efficacy depends on the material, layers, fitting on the face and user compliance. N 95 respirator had maximum efficacy, especially when used continuously.

CONCLUSION

Face masks have a beneficial effect against COVID-19. Home masks are less protective than surgical masks or N95 personal breathing masks. Besides, the use of masks may elicit a false sense of security in people, which may lead to poor hand hygiene and violation of social distancing. Therefore, the necessary training should be provided to the public to increase awareness and encourage the right practice of using the mask, emphasizing the preventive effects of washing hands, social distancing, and using a face mask against COVID-19.

The need for systematic quality controls in implementing N95 reprocessing and sterilization

BACKGROUND

Due to increased requirement for personal protective equipment during the coronavirus disease 2019 pandemic, many medical centres utilized sterilization systems approved under Food and Drug Administration Emergency Use Authorization for single-use N95 mask re-use. However, few studies have examined the real-world clinical challenges and the role of ongoing quality control measures in successful implementation.

AIMS

To demonstrate successful implementation of quality control measures in mask reprocessing, and the importance of continued quality assurance.

METHODS

A prospective quality improvement study was conducted at a tertiary care medical centre. In total, 982 3M 1860 masks and Kimberly-Clark Tecnol PFR95 masks worn by healthcare workers underwent sterilization using a vaporized hydrogen peroxide gas plasma-based reprocessing system. Post-processing qualitative fit testing (QFT) was performed on 265 masks. Mannequin testing at the National Institute for Occupational Safety and Health (NIOSH) laboratory was used to evaluate the impact of repeated sterilization on mask filtration efficacy and fit. A locally designed platform evaluated the filtration efficiency of clinically used and reprocessed masks.

FINDINGS

In total, 255 N95 masks underwent QFT. Of these, 240 masks underwent post-processing analysis: 205 were 3M 1860 masks and 35 were PFR95 masks. Twenty-five (12.2%) of the 3M masks and 10 (28.5%) of the PFR95 masks failed post-processing QFT. Characteristics of the failed masks included mask deformation (N=3, all 3M masks), soiled masks (N=3), weakened elastic bands (N=5, three PFR95 masks), and concern about mask shrinkage (N=3, two 3M masks). NIOSH testing demonstrated that while filter efficiency remained >98% after two cycles, mask strap elasticity decreased by 5.6% after reprocessing.

CONCLUSIONS

This study demonstrated successful quality control implementation for N95 mask disinfection, and highlights the importance of real-world clinical testing beyond laboratory conditions.

Effects of face masks on oxygen saturation at graded exercise intensities

CONTEXT

Mask wearing to mitigate the spread of COVID-19 and other viral infections may raise concerns on the effects of face masks on breathing and cardiopulmonary health. Non-evidence-based apprehensions may limit the use of masks in public.

OBJECTIVES

We will assess the parameters related to heart and lung physiology between healthy male and female adults exposed to wearing face masks (or not) under conditions of rest and graded exercise.

METHODS

We performed a cross-sectional study including 20 male and 20 female adults who met our inclusion criteria. Adults with underlying respiratory and cardiac conditions were excluded. Physiologic parameters were measured while the participants underwent three activity levels (10 min each) in a randomly assigned order: rest, walking, and stair climbing. Each activity level was conducted under three mask conditions: no mask, surgical mask, and N95 respirator. Heart rate (HR) and blood oxygen saturation (SpO₂) were recorded via pulse oximeter after each activity. Perceived exertion was recorded utilizing a Borg 15-point scale. A mixed-effects analysis of variance (ANOVA) was utilized to interpret the results.

RESULTS

A significant increase in perceived exertion was reported for N95 users (p<0.0001). There was also a significant increase in mean HR for N95 users in comparison to no-mask users (p=0.0031). The mean SpO₂ in females was higher than males under rest and walking conditions (p=0.0055). There was no change in SpO₂ between mask type overall, nor between mask type vs. exercise intensity, nor between mask type and sex.

CONCLUSIONS

Our findings provide evidence that surgical masks and N95 respirators do not influence SpO₂ at rest or during exercise.

Health effects of filtering facepiece respirators: Systematic review of pulmonary and cardiovascular effects

Filtering facepiece respirators (FFRs) were introduced to protect the wearer by removing small particles from inspired air. FFRs are now also used to reduce the spread of transmissible agents from the wearer and are worn outside traditional healthcare and other workplaces. The COVID-19 pandemic increased concerns about potential adverse effects on wearers. A PUBMED query retrieved articles through June 2022. Abstracts and selected full-text articles were systematically reviewed by the authors. This article focuses upon cardiopulmonary physiologic effects (e.g., ventilation, CO₂ elimination, oxygen uptake, and respiratory control) with emphasis upon current and potential research methods as well as summarizing results. 1985 records were identified, of which only 26% were published before 2020. FFR effects on CO₂ elimination appear more likely to be significant than effects on oxygenation or cardiovascular function. While FFRs appear well tolerated by healthy persons, more research is needed for those with pulmonary or cardiac disorders, and for children. Many traditional pulmonary exercise study methods require special care when applied to filtering facepiece respirators. Studying additional parameters may explain the paradox of many subjective discomfort reports despite very limited physiologic effects.

Perceived Workload Using Separate (Filtering Facepiece Respirator and Face Shield) and Powered Air-Purifying Respirator and Integrated Lightweight Protective Air-Purifying Respirator: Protocol for an International Multisite Human Factors Randomized Crossover Feasibility Study

BACKGROUND

The design of personal protective equipment (PPE) may affect well-being and clinical work. PPE as an integrated item may improve usability and increase adherence by healthcare professionals. Human factors design and safety may reduce occupational-acquired diseases. As an integrated PPE, a lightweight protective air-purifying respirator (L-PAPR) could be used during health procedures where healthcare professionals are exposed to airborne pathogens. The human factors affecting the implementation of alternative PPE such as L-PAPR have not been thoroughly studied. The population of interest is health care professionals, the intervention is the performance by PPE during tasks across the three PPE types 1.) N95 respirators and face shields, 2.)traditional powered air-purifying respirator(PAPR), and 3.) L-PAPR. The outcomes are user error, communications, safety, and end-user preferences.

OBJECTIVE

This study will assess whether the L-PAPR improves health care professionals' comfort in terms of perceived workload and physical and psychological burden during direct patient care when compared with the traditional PAPR or N95 and face shield. This study also aims to evaluate human factors during the comparison of the use of L-PAPR with a combination of N95 respirators plus face shields or the traditional PAPRs.

METHODS

This is an interventional randomized crossover quality improvement feasibility study consisting of a 3-site simulation phase with 10 participants per site and subsequent field testing in 2 sites with 30 participants at each site. The 3 types of respiratory PPE will be compared across medical tasks and while donning and doffing. We will evaluate the user's perceived workload, usability, usage errors, and heart rate. We will conduct semistructured interviews to identify barriers and enablers to implementation across each PPE type over a single continuous wear episode and observe interpersonal communications across conditions and PPE types.

RESULTS

We expect the research may highlight communication challenges and differences in usability and convenience across PPE types along with error frequency during PPE use across PPE types, tasks, and time.

CONCLUSIONS

The design of PPE may affect overall well-being and hinder or facilitate clinical work. Combining 2 pieces of PPE into a single integrated item may improve usability and reduce occupational-acquired diseases. The human factors affecting the implementation of an alternative PPE such as L-PAPR or PAPR have not been thoroughly studied.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/36549.

Utilization of a mask fitter or micropore tape to improve the fit of a surgical mask

PURPOSE

This study aimed to test the face seal of a surgical mask modified using a custom-made mask fitter or by sealing all borders with micropore tape, in comparison to the N95 mask as a gold standard.

METHODS

Fifteen participants were assigned to wear an N95 mask, a surgical mask sealed with a mask fitter, and a surgical mask sealed with micropore tape. A quantitative fit test was performed using a Portacount respirator fit tester in 4 different actions: bending over, talking, moving the head from side to side, and moving the head up and down.

RESULTS

The N95 showed the highest overall fit factor score (134.67 ± 66.62), passing Occupational Safety and Health Administration (OSHA) standards. The surgical mask alone had the lowest overall fit factor score of 4.73 ± 3.30. Modification of the surgical mask using a mask fitter or micropore tape significantly increased the overall fit factor to 35.33 ± 14.58 and 29.33 ± 9.73, respectively. This pattern was similar for all exercises.

CONCLUSION

The N95 was the only mask type that passed the OSHA standard for protection. Use of a mask fitter or micropore tape significantly increased the face seal of a surgical mask. This could offer useful levels of protection during a non-aerosol dental procedure.

Assessment of a novel, easy-to-implement, aerosolized H2O2 decontamination method for single-use filtering facepiece respirators in case of shortage

The COVID-19 pandemic has affected the world and caused a supply shortage of personal protection equipment, especially filtering facepiece respirators (FFP). This has increased the risk of many healthcare workers contracting SARS-CoV-2. Various strategies have been assessed to tackle these supply issues. In critical shortage scenarios, reusing single-use-designed respirators may be required. Thus, an easily applicable and reliable FFP2 (or alike) respirator decontamination method, allowing safe re-use of FFP2 respirators by healthcare personnel, has been developed and is presented in this study. A potent and gentle aerosolized hydrogen peroxide (12% wt) method was applied over 4 hr to decontaminate various brands of FFP2 respirators within a small common room, followed by adequate aeration and storage overnight. The microbial efficacy was tested on unused respirator pieces using spores of Geobacillus stearothermophilus. Further, decontamination effectiveness was tested on used respirators after one 12-hr shift by swabbing before and after the decontamination. The effects of up to ten decontamination cycles on the respirators' functionality were evaluated using material properties, the structural integrity of the respirators, and fit tests with subjects. The suggested H₂O₂ decontamination procedure was proven to be (a) sufficiently potent (no microbial recovery, total inactivation of biological indicators as well as spore inoculum on critical respirator surfaces), (b) gentle as no significant damage to the respirator structural integrity and acceptable fit factors were observed, and (c) safe as no H₂O₂ residue were detected after the defined aeration and storage. Thus, this easy-to-implement and scalable method could overcome another severe respirator shortage, providing enough flexibility to draft safe, effective, and logistically simple crisis plans. However, as highlighted in this study, due to the wealth of design and material used in different models and brands of respirators, the decontamination process should be validated for each FFP respirator model before its field implementation.

The Effect of Hypochlorous Acid on the Filtration Performance and Bacterial Decontamination of N95 Filtering Facemask Respirators

BACKGROUND

Stabilized Hypochlorous acid (HOCl) is increasingly used as a hospital disinfectant and antiseptic, yet its effect on N95 filtration facemask respirators (FFR) is unknown. These FFRs could also contribute to fomite-based transmission of nosocomial infections if worn for extended use between patient rooms.

METHODS

Filtration performance of N95 FFR fabric swatches was assessed after various levels of HOCl exposure. N95 swatches were then contaminated with 10⁸ E. coli or 10⁸ Staph aureus and treated with HOCl solution, 70% ethyl alcohol, or normal saline. Surviving bacterial numbers were assessed by plate counts.

RESULTS

The size-dependent filtration efficiency of HOCl-sprayed N95 FFR fabric ranged from 96 to 100%, showing no significant change. Flow resistance testing revealed almost no change compared to control. Submersion in HOCl, but not spraying, had an excellent bactericidal effect on contaminated swatches.

DISCUSSION

The role of the outer hydrophobic layer of N95 FFRs is discussed regarding the effects of HOCl on filtration and bacterial decontamination.

CONCLUSION

N95 material, sprayed with or briefly submerged in HOCl, maintained its filtration function. HOCl delivery by spray pump, however, would not accomplish decontamination of extended use FFRs between patient encounters. HOCl submersion of intact FFRs, contaminated with various hospital pathogens, is worth further study.

Feasibility of nasal bridge pressure injury prevention using a protective dressing and the Halyard Fluidshield® N95 mask in a COVID-positive environment

The purpose of this study was to prevent nasal bridge pressure injury among fit-tested employees, secondary to long-term wear of the N95 mask during working hours. A prospective, single-blinded, experimental cohort design. Participants were enrolled using the convenience sampling methods and randomisation was utilised for group assignment. Eligibility was determined by a COVID Anxiety Scale score and non-COVID clinical assignment. Participants with a history of previous skin injury or related condition were excluded. The experimental group was assigned Mepilex Lite® and the control group used Band- Aid®. Formal skin evaluations were done by Nurse Specialists who are certified in wound and ostomy care by the Wound, Ostomy, Continence, Nursing Certification Board (WOCNCB®). Fit test logs were provided to participants to measure subjective user feedback regarding mask fit and level of comfort. The results of this feasibility trial are promising in supporting the use of a thin polyurethane foam dressing as a safe and effective dressing to apply beneath the N95 mask. Additional research is needed to validate results due to limited data on efficacy and safety of the various barrier dressings as a potential intervention to prevent skin breakdown to the nasal bridge.

Effect of N95 Respirator on Oxygen and Carbon Dioxide Physiologic Response: A Systematic Review and Meta-Analysis

During the COVID-19 pandemic, N95 respirators were commonly used in many situations. Respiratory problems from prolonged use of respirators were discussed in many studies, which show varied results. From the inconclusive results, the current systematic review and meta-analysis discerned the effects of the N95 respirator by assessing the oxygen and carbon dioxide changes in both high- and low-to-moderate-intensity physical activities in a healthy population. Thirteen studies were identified for inclusion in the study. In high-intensity physical activities, our meta-analysis showed borderline lower oxygen saturation and higher carbon dioxide partial pressure, but oxygen saturation did not change in low-to-moderate physical activity. The use of N95 respirators could statistically affect the physiologic changes of carbon dioxide and oxygen in high-intensity physical activity among healthy participants, but this may not be clinically significant. Some users who have certain health conditions, such as respiratory problems, should be informed of the clinical symptoms related to hypercarbia and hypoxia for the early detection of adverse effects of N95 respirators.

Types and Prevalence of Adverse Skin Reactions Associated With Prolonged N95 and Simple Mask Usage during the COVID-19 Pandemic

Background

As the coronavirus 2019 (COVID‐19) pandemic persists on a global level, the chronic daily use of face masks within the healthcare system remains an important component of disease prevention and transmission. Increased use of personal protective equipment (PPE) may result in increased rates of occupational dermatoses and adverse skin reactions.

Objectives

The purpose of this study is to explore how chronic, prolonged use of N95 masks or simple surgical masks affects the prevalence of adverse skin reactions in Healthcare Workers (HCWs).

Methods

An optional, quantitative, web‐based survey was administered to patient‐facing HCWs across six network hospitals in a large metropolitan city. Data were analysed to assess the types and sites of adverse skin reactions, and to evaluate correlations between single mask use duration and adverse skin reactions.

Results

A total of 230 HCWs responded with 192 endorsing occupational dermatoses. Among the healthcare responders, (n = 192, 83.5%) experienced at least one adverse skin reaction. The most common occupational adverse skin reactions were acne (n = 133, 57.8%), dryness (n = 108, 47.0%) and redness (n = 105, 45.7%). Anatomical areas most commonly affected included the nasal bridge (n = 92, 40.0%), cheeks (n = 92, 40.0%) and chin (n = 91, 39.6%). Acne (P = 0.002), dryness/scaling (P = 0.002), increased pore size (0.003), itch (P = 0.003), nasal bridge scarring (P < 0.001), redness (P < 0.001), frictional erosions (P = 0.001) and ulcerations (P = 0.002) showed a positive correlation to duration of mask use.

Conclusions

Prolonged, daily usage of PPE is associated with numerous adverse skin reactions among HCWs with acne being the most commonly seen adverse reaction. Many adverse reactions are associated with prolonged use of single mask.

Face masks to fight against COVID-19 pandemics: A comprehensive review of materials, design, technology and product development

The outbreak of COVID-19 has created renewed attention on research and large scale manufacturing of face masks. In the last two decades, usage of face masks for respiratory protection has gained increased importance as a measure to control the maladies and fatalities due to exposure to particulate pollutants and toxic pathogens. Numerous variants of surgical and high-performance respirator masks are available in the market, and yet the fibrous materials science researchers, manufacturers and public health agencies are making concerted efforts towards improvising them with respect to self-sterilisability, facial fit, thermo-physiological comfort, reusability and biodegradability, while maintaining or rather enhancing the filtration efficiency. This review article presents a compendium of materials, design and performance standards of existing face masks, as well as elaborates on developments made for their performance enhancement. The criticality of inculcation of good hygiene habits and earnest compliance to correct mask donning and doffing practices has also been highlighted. This review is expected to make valuable contributions in the present COVID-19 scenario when donning a face mask has become mandatory.

Under-mask beard covers achieve an adequate seal with tight-fitting disposable respirators using quantitative fit testing

BACKGROUND

Tight-fitting respirators are a critical component of respiratory protection against airborne diseases for health workers. However, they are not recommended for health workers with facial hair. Some health workers are unable to shave for religious or medical reasons. Under-mask beard covers have been proposed as a solution to allow health workers with facial hair to wear tight-fitting respirators. However, studies to date have been limited by their predominant reliance on qualitative rather than quantitative fit testing techniques.

AIM

To assess the efficacy of under-mask beard covers in achieving an adequate seal with tight-fitting disposable P2/N95 respirators using quantitative fit testing.

METHODS

Bearded adult males underwent quantitative fit testing with an under-mask beard cover using either a TSI PortaCount Respirator Fit Tester 8038™ or AccuFit 9000 PRO™ fit testing device on up to five disposable P2/N95 respirators (3M 1860, 3M 1870+, BYD N95 Helathcare Particulate Respirator, BSN Medical ProShield N-95 Medium and Trident RTCFFP2). The primary outcome was the proportion of subjects that passed or failed quantitative fit testing with an under-mask beard cover.

FINDINGS

Thirty subjects were assessed, 24 (80%) passed quantitative fit testing with at least one tight-fitting P2/N95 disposable respirator. Among these subjects the median (IQR) best achieved fit factor was 200 (178-200). No subject had an adverse reaction to the under-mask beard cover.

CONCLUSION

The under-mask beard cover technique may be used to achieve a satisfactory seal with tight-fitting P2/N95 respirators in health workers with facial hair that cannot shave.

COVID-19 knowledge and adherence of dental practitioners to health authority safety guidelines during a pandemic

OBJECTIVES

This study aimed to assess the degree of dental practitioner adherence to recommendations made during the COVID-19 pandemic.

METHOD AND MATERIALS

An online questionnaire was distributed via social media among dental practitioners in Israel who worked during the COVID-19 outbreak.

RESULTS

In total, 144 dental practitioners completed the survey; it was found that dental practitioner adherence to all the official PPE use recommendations was 69.8%, whereas 36.8% of dental practitioners reported the use of N95 when needed. Knowledge of self-protection against COVID-19 was rated as "very good" by 37.5% of responders. However, only 25.7% felt "highly protected" by personal protective equipment. Interestingly, many dental practitioners (46.8%) reported adherence to extra protection in addition to the required PPE communicated by the Ministry of Health guidelines.

CONCLUSION

Stricter regimens should be applied for dealing with the current challenging pandemic, especially in clinical work with a higher risk for viral transmission. Specific strategies should be followed to ensure good practice to improve dental practitioners' and patients' safety.

Knowledge and Perceptions Regarding Coronavirus (COVID-19) among Pediatric Dentists during Lockdown Period

AIM

To assess the knowledge and perceptions of COVID-19 among pediatric dentists based on their dependent source of information.

METHODS

A descriptive-analytical cross-sectional survey using a self-administered questionnaire with 23 questions was sent via Google forms to pediatric dentists. All participants were divided into three groups [postgraduate residents (PGs), private practitioners (PP), and faculty (F)]. The comparison of knowledge and perception scores was made based on occupation, source of information, and descriptive statistics used for the analysis using SPSS 21.0 (IBM, Armonk, NY, USA).

RESULTS

A total of 291 pediatric dentists completed the survey, and the majority of them were females (65%). Overall, good mean scores were obtained for knowledge (9.2 ± 1.07) and perceptions (5.6 ± 1.5). The majority of the participants used health authorities (45%) to obtain updates on COVID-19, while social media (35.1%) and both (19.6%) accounted for the next two. A statistically significant difference (p < 0.05) was found among different pediatric dentists groups for relying on the source of information.

CONCLUSION

Overall good pediatric dentists showed sufficient knowledge regarding COVID-19. The pediatric dentists' age, occupation, and source of information influenced knowledge regarding COVID-19, whereas perceptions were influenced by age and gender of the participants. Health authorities successfully educated pediatric dentists than the social media.

N95 vs Half-face Respirator Wear in Surgical Trainees: Physiologic and Psychological Effects of Prolonged Use

Objectives

As specialists of the upper airway, otolaryngologists are at high risk for COVID-19 transmission. N95 and half-face respirator (HFR) masks are commonly worn, each with advantages in functionality and comfort. In this study, physiologic and psychological parameters of prolonged N95 vs HFR wear were compared.

Study Design

Prospective crossover cohort study.

Setting

Single academic tertiary care hospital.

Methods

A prospective crossover cohort study was performed. Healthy otolaryngology trainees and medical students (N = 23) participated and wore N95 and HFR masks continuously for 3 hours each on separate days. Various measures were analyzed: vitals, spirometry variables, scores on the State-Trait Anxiety Inventory and HIT-6 (Headache Impact Test-6), distress, and "difficulty being understood."

Results

The average age was 26.3 years (SD, 3.42). There were no significant differences in vital signs and spirometry variables between N95 and HFR wear. N95 wear was associated with decreases in oxygen saturation of approximately 1.09% more than with HFRs (95% CI, 0.105-2.077). State-Trait Anxiety Inventory scores increased more with HFR wear when compared with mean changes with N95 wear (95% CI, 1.350-8.741). There were no significant differences in HIT-6 scores or distress levels between masks. The proportions of participants reporting difficulty being understood was significantly higher with HFRs.

Conclusions

Oxygen saturation decreases with prolonged N95 wear, but anxiety and difficulty being understood are greater with HFR wear. Although HFRs have less resistance to gas exchange, N95 respirators may produce less anxiety and distress in clinical situations. Further studies are warranted to evaluate the clinical significance of these differences.

Level of Evidence

2.

Distributed manufacturing: A case study in additive manufacturing face masks for the COVID-19 pandemic

At the onset of the COVID-19 (Coronavirus Disease 2019) pandemic, USA faced supply chain issues causing a nationwide shortage of N95 respirators and PAPR devices. Researchers at Oak Ridge National Laboratory's (ORNL) Manufacturing Demonstration Facility (MDF) were sent to work from home to help slow the spread of the pandemic, and during that time they were tasked with using their manufacturing expertise to research alternative methods of producing face masks. To rapidly iterate on face mask designs without access to a research or manufacturing facility, 3D (3-Dimensional) printing and silicone casting were used. Molds and components for the masks are modeled with computer-aided design (CAD), printed with common home desktop 3D printers, and test poured with skin-safe silicone rubber. The resultant masks are form fitting and comfortable to wear. To ease the shortage of N95 filter media, the masks are designed to use existing filter materials such as home HVAC (heating, ventilation, and air conditioning) filters. The masks can be sanitized, and the filter replaced to allow the same mask to be reused. The result is not equivalent to an N95 mask, and not meant to be a replacement, but is meant to be a stopgap mask that is still able to provide the wearer filtered protection. Filtration testing has not been performed because it is not the intention of the authors to make medical claims. This research is meant to demonstrate the rapid design, iteration, and manufacturing processes of a stopgap mask.

Does wearing a facemask decrease arterial blood oxygenation and impair exercise tolerance?

INTRODUCTION

Concerns have been raised that COVID-19 face coverings compromise lung function and pulmonary gas exchange to the extent that they produce arterial hypoxemia and hypercapnia during high intensity exercise resulting in exercise intolerance in recreational exercisers. This study therefore aimed to investigate the effects of a surgical, flannel or vertical-fold N95 masks on cardiorespiratory responses to incremental exercise.

METHODS

This investigation studied 11 adult males and females at rest and while performing progressive cycle exercise to exhaustion. We tested the hypotheses that wearing a surgical (S), flannel (F) or horizontal-fold N95 mask compared to no mask (control) would not promote arterial deoxygenation or exercise intolerance nor alter primary cardiovascular variables during submaximal or maximal exercise.

RESULTS

Despite the masks significantly increasing end-expired peri-oral %CO₂ and reducing %O_2, each ∼0.8-2% during exercise (P < 0.05), our results supported the hypotheses. Specifically, none of these masks reduced sub-maximal or maximal exercise arterial O₂ saturation (P = 0.744), but ratings of dyspnea were significantly increased (P = 0.007). Moreover, maximal exercise capacity was not compromised nor were there any significant alterations of primary cardiovascular responses (mean arterial pressure, stroke volume, cardiac output) found during sub-maximal exercise.

CONCLUSION

Whereas these results are for young healthy recreational male and female exercisers and cannot be applied directly to elite athletes, older or patient populations, they do support that arterial hypoxemia and exercise intolerance are not the obligatory consequences of COVID-19-indicated mask-wearing at least for cycling exercise.

Moldable Mask: A Reusable, Hot Water Moldable, Additively Manufactured Mask to Be Used as an N95 Alternative

There has been high demand for personal protective equipment (PPE) during the COVID-19 pandemic, especially N95 respirators. Unfortunately, at the early stage of the pandemic, the supply could not meet the demand for N95 respirators, leading to a shortage and unsafe reuse of this form of PPE. We developed the Moldable Mask to ease the demand for N95 respirators by creating a 3D-printed mask that uses a piece of N95 material as a filter. A sheet of N95 material could be used or one N95 respirator to be turned into two masks. The main feature of the mask is the ability to easily mold it in hot water to create a custom fit for each user. It can also be easily assembled at home with affordable materials. The final mask design was qualitatively fit tested on 13 subjects, with all subjects showing an improvement in fit with the hot water molding technique and 10 (77%) subjects passing the fit test. This shows that the Moldable Mask is a viable option for a safe, affordable N95 alternative when N95 mask supply is strained.

Outpatient healthcare personnel knowledge and attitudes towards infection prevention measures for protection from respiratory infections

BACKGROUND

Healthcare personnel (HCP) knowledge and attitudes toward infection control measures are important determinants of practices that can protect them from transmission of infectious diseases.

METHODS

Healthcare personnel were recruited from Emergency Departments and outpatient clinics at seven sites. They completed knowledge surveys at the beginning and attitude surveys at the beginning and end of each season of participation. Attitudes toward infection prevention and control measures, especially medical masks and N95 respirators, were compared. The proportion of participants who correctly identified all components of an infection control bundle for seven clinical scenarios was calculated.

RESULTS

The proportion of participants in the medical mask group who reported at least one reason to avoid using medical masks fell from 88.5% on the pre-season survey to 39.6% on the post-season survey (odds ratio [OR] for preseason vs. postseason 0.11, 95% CI 0.10-0.14). Among those wearing N95 respirators, the proportion fell from 87.9% to 53.6% (OR 0.24, 95% CI 0.21-0.28). Participants correctly identified all components of the infection control bundle for 4.9% to 38.5% of scenarios.

CONCLUSIONS

Attitudes toward medical masks and N95 respirators improved significantly between the beginning and end of each season. The proportion of HCP who correctly identified the infection control precautions needed for clinical scenarios was low, but it improved over successive years of participation in the study.

High class filtering facepiece (FFP) are fundamental and effective in protection of emergency health care workers: an observational cohort study in a German community

Background

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a highly contagious airborne virus inducing pandemic coronavirus disease 2019 (COVID-19). This is most relevant for medical staff working under harmful conditions in emergencies often dealing with patients and an undefined SARS-CoV-2 status. We aimed to measure the effect of high-class filtering facepieces (FFP) in emergency medical service (EMS) staff by analyzing seroprevalence and history of positive polymerase chain reaction (PCR) for SARS-CoV-2.

Method

This observational cohort study included workers in EMS, who were compared with hospital staff (HS) and staff, which was not directly involved in patient care (NPC). All direct patient contacts of EMS workers were protected by FFP2/N95 (filtering face piece protection class 2/non-oil-based particulates filter efficiency 95%) masks, whereas HS was protected by FFP2/N95 exclusively when a patient had a proven or suspected SARS-CoV-2 infection. NPC was not protected by higher FFP. The seroprevalence of SARS-CoV-2 antibodies was analyzed by immunoassay by end of 12/2020 together with the history of a positive PCR. In addition, a self-assessment was performed regarding the quantity of SARS-CoV-2 positive contacts, about flu symptoms and personal belief of previous COVID-19 infections.

Results

The period in which contact to SARS-CoV-2 positive patients has been possible was 10 months (March to December 2020)—with 54,681 patient contacts documented for EMS—either emergencies (n = 33,241) or transportation services (n = 21,440). Seven hundred-thirty (n = 730) participants were included into the study (n = EMS: 325, HS: 322 and NPC: 83). The analysis of the survey showed that the exposure to patients with an unknown and consecutive positive SARS-CoV-2 result was significantly higher for EMS when compared to HS (EMS 55% vs. HS 30%, p = 0.01). The incidence of a SARS-CoV-2 infection in our cohort was 1.2% (EMS), 2.2% (HS) and 2.4% (NPC) within the three groups (ns) and lowest in EMS. Furthermore, the belief of previous COVID-19 was significant higher in EMS (19% vs. 10%),

Conclusion

The consistent use of FFP2/N95 in EMS is able to prevent work-related SARS-CoV-2 infections in emergency situations. The significance of physical airway protection in exposed medical staff is still relevant especially under the aspect of new viral variants and unclear effectiveness of new vaccines.

Graphical Abstract

[Limited Reuse and Extended Use of Filtering Facepiece Respirators]

Objetivo

Los equipos de protección individual (EPI), y dentro de ellos las mascarillas, son fundamentales en una pandemia como la del COVID-19, que ha requerido, en muchas ocasiones, de reutilización de material debido a su escasez. El objetivo de esta revisión es sintetizar la evidencia disponible sobre la reutilización y uso extendido de las mascarillas de media y alta filtración.

Método

Revisión exploratoria. Búsqueda a través de lenguaje natural en PubMed y Centros, Agencias y Organizaciones para el Control de Enfermedades. Se limitó a artículos publicados entre 2010-2020 en inglés y en español.

Resultados

Se localizaron 83 artículos, seleccionándose 14, más cinco recomendaciones. Los temas abordados se clasifican en siete apartados: Caducidad, uso extendido y reutilización de mascarillas, técnica de manipulación, sellado, efectos físicos psicológicos y cumplimentación, contaminación y descontaminación de mascarillas.

Conclusiones

La reutilización de las mascarillas no está recomendada por los organismos oficiales ni los fabricantes, sólo se acepta en casos extraordinarios, como las pandemias. Los estudios se caracterizan por contar con muestras pequeñas, usan diferentes modelos de mascarillas ajustando su recomendación al modelo.

Facial Mask-related Acne and Acneiform Eruption During the Coronavirus Disease 2019 Pandemic: A Case Series

Use of a facial mask is a necessity during the current pandemic. The associated occlusion with extended daily use can lead to physiological changes in the skin with resultant irritation, itching, and infections. This can lead to exacerbation of pre-existing dermatoses or induction of irritant dermatitis or bacterial folliculitis. We observed several patients with previously controlled acne vulgaris who developed a flare. Also, in those without a history of pre-existing acne, an acneiform eruption was noted. The majority of patients were women who had pre-existing acne and needed to wear a N95 respirator or a surgical mask for several hours a day, every day. A few suggested simple preventative measures provided herein might help this vulnerable population.

Vapourized hydrogen peroxide decontamination in a hospital setting inactivates SARS-CoV-2 and HCoV-229E without compromising filtration efficiency of unexpired N95 respirators

Background

The COVID-19 pandemic highlighted the need for evidence-based approaches to decontamination and reuse of N95 filtering facepiece respirators (FFRs). We sought to determine whether vapourized hydrogen peroxide (VHP) reduced SARS-CoV-2 bioburden on FFRs without compromising filtration efficiency. We also investigated coronavirus HCoV-229E as a surrogate for decontamination validation testing.

Methods

N95 FFRs were laced with SARS-CoV-2 or HCoV-229E and treated with VHP in a hospital reprocessing facility. After sterilization, viral burden was determined using viral outgrowth in a titration assay, and filtration efficiency of FFRs was tested against ATSM F2299 and NIOSH TEB-STP-APR-0059.

Results

Viable SARS-CoV-2 virus was not detected after VHP treatment. One replicate of the HCoV-229E laced FFRs yielded virus after processing. Unexpired N95 FFRs retained full filtration efficiency after VHP processing. Expired FFRs failed to meet design-specified filtration efficiency and therefore are unsuitable for reprocessing.

Discussion

In-hospital VHP is an effective decontaminant for SARS-CoV-2 on FFRs. Further, filtration efficiency of unexpired respirators is not affected by this decontamination process.

Conclusions

VHP is effective in inactivating SARS-CoV-2 on FFRs without compromising filtration efficiency. HCoV-229E is a suitable surrogate for SARS-CoV-2 for disinfection studies.

Adverse Effects of COVID-19 and Face Masks: A Systematic Review

BACKGROUND

Due to the public health risk associated with SARS-CoV-2 (COVID-19) infection, universal use of face masks has been recommended to protect against viral spread. Adverse facial reactions from the utilization of masks in the general public are poorly characterized in literature.

OBJECTIVE

We aimed to provide a systematic review of studies reporting adverse facial reactions associated with use of face masks during the COVID-19 pandemic.

METHODS

PubMed and Cochrane databases were searched using the following search terms: "masks" AND "skin reactions, facial dermatosis, rash, acne, atopic dermatitis, rosacea, OR seborrheic dermatitis."

METHODS

A total of 954 cases of dermatological adverse effects were reported. Over 17 different adverse facial reactions were found, including the top 10 in order: itch (370, 38.8%), indentation/ear pain (102, 10.7%), discomfort (90, 9.4%), erythema (72, 7.5%), dryness (62, 6.5%), rash (60, 6.3%), scarring (42, 4.4%), desquamation (22, 2.3%), pain (19, 2.0%), burning (19, 2.0%), and wheals (7, 0.7%). Face masks can increase acne (n=44), rosacea (n=14), and seborrheic dermatitis (n=9).

LIMITATIONS

Publication bias of articles, with limited studies available regarding this topic.

CONCLUSION

Wearing face masks to protect from COVID-19 can increase adverse facial dermatoses and exacerbate underlying dermatology conditions; however, several preventative measures may be taken.

Use of Industrial Filters by Health Care Workers During Shortages of N95 Respirators in Pandemic Times

The coronavirus disease 2019 (COVID-19) pandemic has led to a significant shortage of personal protective equipment in multiple health care facilities around the world, with the highest impact on N95 respirator masks. The N95 respirator is a mask that blocks at least 95% of very small (0.3 μm) particles and is considered a standard for enhanced respiratory precautions. The N95 mask shortage has created a need for other options for nasal and oral respiratory protection with similar filtration efficiency and "medical-grade" clearance, which can be used in health care settings. However, the literature around various filter types, their filtration capabilities, and the organizations certifying their use is dense, confusing, and not easily accessible to the public. Here, we synthesize relevant literature to analyze and disseminate information on (1) alternative viable filter options to N95s, (2) the National Institute for Occupational Safety and Health certification process, (3) the relationship of National Institute for Occupational Safety and Health certification to Food and Drug Administration certification of filtration devices and surgical masks, and (4) how this relationship may affect future filtration usage in the medical community during a pandemic. Analysis of these standards is meant to inform regarding evidence of respirator efficacy but does not imply any official endorsement of these alternatives. With this article, we illuminate viable alternative respirator options during the COVID-19 pandemic to help alleviate the dependency on N95 face masks.

N95 respirator decontamination: a study in reusability

The coronavirus disease 2019 (COVID-19) pandemic had caused a severe depletion of the worldwide supply of N95 respirators. The development of methods to effectively decontaminate N95 respirators while maintaining their integrity is crucial for respirator regeneration and reuse. In this study, we systematically evaluated five respirator decontamination methods using vaporized hydrogen peroxide (VHP) or ultraviolet (254 nm wavelength, UVC) radiation. Through testing the bioburden, filtration, fluid resistance, and fit (shape) of the decontaminated respirators, we found that the decontamination methods using BioQuell VHP, custom VHP container, Steris VHP, and Sterrad VHP effectively inactivated Cardiovirus (3-log10 reduction) and bacteria (6-log10 reduction) without compromising the respirator integrity after 2-15 cycles. Hope UVC system was capable of inactivating Cardiovirus (3-log10 reduction) but exhibited relatively poorer bactericidal activity. These methods are capable of decontaminating 10-1000 respirators per batch with varied decontamination times (10-200 min). Our findings show that N95 respirators treated by the previously mentioned decontamination methods are safe and effective for reuse by industry, laboratories, and hospitals.

Physiologic Effects and Symptoms Associated with Extended-Use Medical Mask and N95 Respirators

OBJECTIVES

Compliance and tolerance of facemasks for extended periods are legitimate concerns. The goal of this study was to identify the physiologic and symptomatic effects of extended-use N95 filtering facepiece respirator (N95) compared with medical masks. We hypothesized that hospital personnel wearing medical masks alone would report fewer subjective complaints compared with personnel wearing an N95 with or without overlying medical mask.

METHODS

This was a nonrandomized cohort study of hospital-based healthcare personnel at a single tertiary center wearing a medical mask alone or N95 with or without overlying medical mask during routine clinical activity. Potential subjects were consented and asked to complete a structured survey, including a 10-point Likert scale for subjective symptoms: headache, lightheadedness, breathlessness, facial bruising, facial irritation, mental fatigue, physical fatigue, and yawning. Study investigators also obtained vital signs on the participants. Results between subjects wearing a medical mask and subjects wearing an N95 were compared. A sample of 144 subjects, 72 in each mask cohort, was needed to detect a 20% difference in a composite outcome of headache, shortness of breath, or lightheadedness between groups with an alpha of 0.05 and power of 0.8.

RESULTS

We enrolled 72 subjects in each group. There were no differences in baseline demographics. Overall 77% of the cohort reported subjective symptoms while donning a mask. There was no difference in the composite outcome, no difference recorded symptoms except facial bruising, and no difference in physiologic measures between groups.

CONCLUSIONS

Most medical mask and N95 users reported symptoms during mask use. However, there was no difference in the symptom proportion or severity in either user.

More than half of front-line healthcare workers unknowingly used an N95/P2 mask without adequate airborne protection: An audit in a tertiary institution

Front-line staff routinely exposed to aerosol-generating procedures are at a particularly high risk of transmission of severe acute respiratory syndrome coronavirus 2. We aimed to assess the adequacy of respiratory protection provided by available N95/P2 masks to staff routinely exposed to aerosol-generating procedures. We performed a prospective audit of fit-testing results. A convenience sample of staff from the Department of Anaesthesia and Pain Medicine, who opted to undergo qualitative and/or quantitative fit-testing of N95/P2 masks was included. Fit-testing was performed following standard guidelines including a fit-check. We recorded the type and size of mask, pass or failure and duration of fit-testing. Staff completed a short questionnaire on previous N95/P2 mask training regarding confidence and knowledge gained through fit-testing. The first fit-pass rate using routinely available N95/P2 masks at this institution was only 47%. Fit-pass rates increased by testing different types and sizes of masks. Confidence 'that the available mask will provide adequate fit' was higher after fit-testing compared with before fit-testing; (median, interquartile range) five-point Likert-scale (4.0 (4.0-5.0) versus 3.0 (2.0-4.0); P<0.001). This audit highlights that without fit-testing over 50% of healthcare workers were using an N95/P2 mask that provided insufficient airborne protection. This high unnoticed prevalence of unfit masks among healthcare workers can create a potentially hazardous false sense of security. However, fit-testing of different masks not only improved airborne protection provided to healthcare workers but also increased their confidence around mask protection.

Assessing the filtration efficiency and regulatory status of N95s and nontraditional filtering face-piece respirators available during the COVID-19 pandemic

Background

The COVID-19 pandemic has severely disrupted supply chains for many types of Personal Protective Equipment (PPE), particularly surgical N95 filtering facepiece respirators (FFRs; “masks”). As a consequence, an Emergency Use Authorization (EUA) from the FDA has allowed use of industrial N95 respirators and importation of N95-type masks manufactured to international standards; these include KN95 masks from China and FFP2 masks from the European Union.

Methods

We conducted a survey of masks in the inventory of major academic medical centers in Boston, MA to determine provenance and manufacturer or supplier. We then assembled a testing apparatus at a university laboratory and performed a modified test of filtration performance using KCl and ambient particulate matter on masks from hospital inventories; an accompanying website shows how to build and use the testing apparatus.

Results

Over 100 different makes and models of traditional and nontraditional filtering facepiece respirators (N95-type masks) were in the inventory of surveyed U.S. teaching hospitals as opposed to 2–5 models under normal circumstances. A substantial number of unfamiliar masks are from unknown manufacturers. Many are not correctly labelled and do not perform to accepted standards and a subset are obviously dangerous; many of these masks are likely to be counterfeit. Due to the absence of publicly available information on mask suppliers and inconsistent labeling of KN95 masks, it is difficult to distinguish between legitimate and counterfeit products.

Conclusions

Many FFRs available for procurement during the COVID-19 pandemic do not provide levels of fit and filtration similar to those of N95 masks and are not acceptable for use in healthcare settings. Based on these results, and in consultation with occupational health officers, we make six recommendations to assist end users in acquiring legitimate products. Institutions should always assess masks from non-traditional supply chains by checking their markings and manufacturer information against data provided by NIOSH and the latest FDA EUA Appendix A. In the absence of verifiable information on the legitimacy of mask source, institutions should consider measuring mask fit and filtration directly. We also make suggestions for regulatory agencies regarding labeling and public disclosure aimed at increasing pandemic resilience.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06008-8.

The Association between Using Personal Protective Equipment and Headache among Healthcare Workers in Saudi Arabia Hospitals during the COVID-19 Pandemic

It is mandatory that healthcare workers wear personal protective equipment (PPE) while caring for COVID-19 patients. Studies have shown that wearing PPE for a prolonged time may lead to symptoms of physical discomfort including headache. The aim of this study is to assess the prevalence and association between prolonged use of PPE and headaches. This was a cross-sectional study. A convenience sample of healthcare workers who worked with COVID-19 patients in clinical settings was recruited. The data were collected through an electronic survey shared as a link through social media. This study included 1060 participants, 753 (71%) female and 307 (29%) male. Participants were divided into two groups. Group A had 628 (60%) participants who did not have chronic headache before the COVID-19 pandemic, while Group B contained 432 (40%) participants who had a previous chronic headache. Headaches differed significantly between Groups A and B in frequency, type, location, and quality during the COVID-19 period. The analysis found a significant relationship between duration of PPE use and headache occurrence. The significant relationship between the duration of PPE usage and headache occurrence among healthcare workers should be considered when refining policies and procedures regarding prolonged PPE use.

Decontamination of respirators amid shortages due to SARS-CoV-2

The pandemic created by SARS-CoV-2 has caused a shortage in the supplies of N95 filtering facepiece respirators (FFRs), disposable respirators with at least 95% efficiency to remove non-oily airborne particles, due to increasing cases all over the world. The current article reviewed various possible decontamination methods for FFR reuse including ultraviolet germicidal irradiation (UVGI), hydrogen peroxide vapor (HPV), microwave-generated steam (MGS), hydrogen peroxide gas plasma (HPGP), and 70% or higher ethanol solution. HPV decontamination was effective against bacterial spores (6 log10 reduction of Geobacillus stearothermophilus spores) on FFRs and viruses (> 4 log10 reduction of various types of viruses) on inanimate surfaces, and no degradation of respirator materials and fit has been reported. 70% or higher ethanol decontamination showed high efficacy in inactivation of coronaviruses on inanimate surfaces (> 3.9 log10 reduction) but it was lower on FFRs which filtration efficiency was also decreased. UVGI method had good biocidal efficacy on FFRs (> 3 log10 reduction of H1N1 virus) combined with inexpensive, readily available equipment; however, it was more time-consuming to ensure sufficient reduction in SARS-CoV-2. MGS treatment also provided good viral decontamination on FFRs (> 4 log10 reduction of H1N1 virus) along with less time-intensive process and readily available equipment while inconsistent disinfection on the treated surfaces and deterioration of nose cushion of FFRs were observed. HPGP was a good virucidal system (> 6 log10 reduction of Vesicular stomatitis virus) but filtration efficiency after decontamination was inconsistent. Overall, HPV appeared to be one of the most promising methods based on the high biocidal efficacy on FFRs, preservation of respirator performance after multiple cycles, and no residual chemical toxicity. Nonetheless, equipment cost and time of the HPV process and a suitable operating room need to be considered.

Additively manufactured respirators: quantifying particle transmission and identifying system-level challenges for improving filtration efficiency

The COVID-19 pandemic has disrupted the supply chain for personal protective equipment (PPE) for medical professionals, including N95-type respiratory protective masks. To address this shortage, many have looked to the agility and accessibility of additive manufacturing (AM) systems to provide a democratized, decentralized solution to producing respirators with equivalent protection for last-resort measures. However, there are concerns about the viability and safety in deploying this localized download, print, and wear strategy due to a lack of commensurate quality assurance processes. Many open-source respirator designs for AM indicate that they do not provide N95-equivalent protection (filtering 95% of SARS-CoV-2 particles) because they have either not passed aerosol generation tests or not been tested. Few studies have quantified particle transmission through respirator designs outside of the filter medium. This is concerning because several polymer-based AM processes produce porous parts, and inherent process variation between printers and materials also threaten the integrity of tolerances and seals within the printed respirator assembly. No study has isolated these failure mechanisms specifically for respirators. The goal of this paper is to measure particle transmission through printed respirators of different designs, materials, and AM processes. The authors compare the performance of printed respirators to N95 respirators and cloth masks. Respirators in this study printed using desktop- and industrial-scale fused filament fabrication processes and industrial-scale powder bed fusion processes were not sufficiently reliable for widespread distribution and local production of N95-type respiratory protection. Even while assuming a perfect seal between the respirator and the user's face, although a few respirators provided >90% efficiency at the 100-300 nm particle range, almost all printed respirators provided <60% filtration efficiency. Post-processing procedures including cleaning, sealing surfaces, and reinforcing the filter cap seal generally improved performance, but the printed respirators showed similar performance to various cloth masks. The authors further explore the process-driven aspects leading to low filtration efficiency. Although the design/printer/material combination dictates the AM respirator performance, the identified failure modes originate from system-level constraints and are therefore generalizable across multiple AM processes. Quantifying the limitations of AM in producing N95-type respiratory protective masks advances understanding of AM systems toward the development of better part and machine designs to meet the needs of reliable, functional, end-use parts.

Headache Related to PPE Use during the COVID-19 Pandemic

PURPOSE OF REVIEW

Personal protection equipment (PPE)-associated headache is an unusual secondary headache disorder that predominantly occurs in healthcare workers as a consequence of the donning of protective respirators, face masks and/or eyewear. The appreciation of this entity is important given the significant ramifications upon the occupational health of healthcare workers and could additionally have an impact on persons living with pre-existing headache disorder(s).

RECENT FINDINGS

There has been a renewed interest and recognition of PPE-associated headaches amongst healthcare professionals, largely brought about by the ongoing COVID-19 pandemic which has besieged healthcare systems worldwide. De novo PPE-associated headaches may present with migrainous or tension-type features and can be viewed as a subtype of external compression headache. The prognosis of the disorder is generally favourable, given that most headaches are short-lived without long-term sequalae. Several aetiologies have been postulated to account for the development of these headaches. Notably, these headaches can affect the occupational health and work performance of healthcare workers. In this review, we discuss the epidemiology, clinical characteristics, probable etiopathogenesis, management and prognosis of PPE-associated headaches in the context of the COVID-19 pandemic. Future directions for research and PPE development are proposed.

Hair today, gone tomorrow: How personal protective equipment guidance changed doctor's facial hair during the COVID-19 pandemic

OBJECTIVES

To investigate how personal protective equipment (PPE) guidance altered the facial hair of hospital doctors and explore the wider impact and implications of these changes.

METHODS

A single site uncontrolled before-after survey study examining change in facial hairstyles, and wider implications on doctor's cultural, religious, and personal wellbeing. Outcome measures included change in facial hair between January and April 2020 and whether these changes adhered to guidance set by Public Health England. Participants were also asked about the wider impact of these changes which were thematically analyzed using an inductive approach.

RESULTS

Of those who completed the survey, 257 participants met the inclusion criteria. 68% (n = 67) of doctors who could grow facial hair changed their facial hairstyle during the COVID-19 pandemic and 96% (n = 64) reported that the change was in response to PPE guidance. The odds of having a facial hairstyle that complied with PPE guidance before the pandemic was 0.32, which rose to 2.77 after guidance was released, giving an odds ratio of 8.54 (95% CI 4.49-16.23, P < .001). When compared to those who sported a shaven face prepandemic, the odds ratio of a change in style for those with prepandemic full beards was 37.92 (95% CI 7.45-192.8, P < .001), for goatees was 7.22 (95% CI 1.076-48.47, P = .04), for moustaches was 4.33 (95% CI 0.207-90.85, P = .345), and for stubble was 9.06 (95% CI 2.133-38.49, P = .003). Qualitative analysis revealed multiple themes, including skin irritation, loss of identity, and a significant impact on participants required to maintain a beard due to religious or cultural reasons.

CONCLUSIONS

Facial hairstyles have changed significantly at our hospital during the COVID-19 pandemic. Facial hair can impact upon doctors' cultural, religious, and personal wellbeing and these factors need to be considered with policy and provision of PPE.

Room Temperature Wait and Reuse for Bioburden Reduction of SARS-CoV-2 on N95 Filtering Facepiece Respirators

Introduction: During a pandemic, when the supply of N95 filtering facepiece respirators (FFRs) is limited, health care workers may reuse N95 FFRs. Room temperature storage of N95 FFRs-waiting before reuse-could be a simple low-cost method to reduce severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) bioburden in such a situation. The U.S. Centers for Disease Control and Prevention specify this as a strategy for reducing self-contamination risk during a time of N95 FFR shortage. Objective: To review the literature on persistence of SARS-CoV-2 on surfaces to assess room temperature waiting times for bioburden reduction on N95 FFRs. Methods: The literature was searched for studies evaluating room temperature persistence of SARS-CoV-2. A 3-log decay time was extracted from published data for quantitative comparison between different studies. Studies using surgical masks and non-peer-reviewed studies that include N95 FFRs were used to draw conclusions. Key Findings: Experimental and analytical choices vary between studies and impact the estimated 3-log decay time. There is not a clear understanding of which material properties are significant. There are no peer-reviewed studies of virus persistence on an N95 FFR. Discussion and Conclusions: SARS-COV-2 inactivation occurs spontaneously at room temperature. The precise timing depends on factors including humidity, temperature, and surface material. In reviewed studies, a 7-day waiting period encompasses the 3-log reduction in infectious titer of SARS-COV-2 on specific N95 FFRs and surgical masks. Owing to variations between studies and among N95 FFR materials and room temperature conditions, it is impossible to extrapolate from these limited data to assign a precise 3-log decay time for all used N95 FFRs.

Quantitative Evaluation of Single-Use Particle Filtering Half Masks for SARS-CoV-2 Protection

Background: The SARS-CoV-2 pandemic put the entire healthcare sector under severe strain due to shortages of personal protection equipment. A large number of new filtering mask models were introduced on the market, claiming effectiveness that had undergone little or no objective and reliable verifications. Methods and Materials: Filter materials were tested against sodium chloride particles according to the EN149 §7.9.2 standard for particle penetration. Particle counters were used to measure the particle penetration of the filtering mask models, resolved over sizes in the range of 27-1000 nm. Results: We report on the results for 86 different filtering mask models. The majority of the tested models showed <3% penetration, whereas almost one third (i.e., 27 of 86) of the models performed poorly. Discussion: Interestingly, the poorest performing masks showed a tendency to have worse filtering effectiveness for larger particles than for smaller sized particles, following the opposite tendency of the best filtering masks. Conclusion: Almost one third of the filtering mask models tested failed the specified pass criteria as specified in the temporary EU COVID-19 standard. This fact, and the high health risks of COVID-19, highlights the need for independent testing.

The COVID-19 pandemic and N95 masks: reusability and decontamination methods

BACKGROUND

With the current SARS-CoV-2 pandemic, many healthcare facilities are lacking a steady supply of masks worldwide. This emergency situation warrants the taking of extraordinary measures to minimize the negative health impact from an insufficient supply of masks. The decontamination, and reuse of healthcare workers' N95/FFP2 masks is a promising solution which needs to overcome several pitfalls to become a reality.

AIM

The overall aim of this article is to provide the reader with a quick overview of the various methods for decontamination and the potential issues to be taken into account when deciding to reuse masks. Ultraviolet germicidal irradiation (UVGI), hydrogen peroxide, steam, ozone, ethylene oxide, dry heat and moist heat have all been methods studied in the context of the pandemic. The article first focuses on the logistical implementation of a decontamination system in its entirety, and then aims to summarize and analyze the different available methods for decontamination.

METHODS

In order to have a clear understanding of the research that has already been done, we conducted a systematic literature review for the questions: what are the tested methods for decontaminating N95/FFP2 masks, and what impact do those methods have on the microbiological contamination and physical integrity of the masks? We used the results of a systematic review on the methods of microbiological decontamination of masks to make sure we covered all of the recommended methods for mask reuse. To this systematic review we added articles and studies relevant to the subject, but that were outside the limits of the systematic review. These include a number of studies that performed important fit and function tests on the masks but took their microbiological outcomes from the existing literature and were thus excluded from the systematic review, but useful for this paper. We also used additional unpublished studies and internal communication from the University of Geneva Hospitals and partner institutions.

RESULTS

This paper analyzes the acceptable methods for respirator decontamination and reuse, and scores them according to a number of variables that we have defined as being crucial (including cost, risk, complexity, time, etc.) to help healthcare facilities decide which method of decontamination is right for them.

CONCLUSION

We provide a resource for healthcare institutions looking at making informed decisions about respirator decontamination. This informed decision making will help to improve infection prevention and control measures, and protect healthcare workers during this crucial time. The overall take home message is that institutions should not reuse respirators unless they have to. In the case of an emergency situation, there are some safe ways to decontaminate them.

Quantitative Fit Evaluation of N95 Filtering Facepiece Respirators and Coronavirus Inactivation Following Heat Treatment

Reuse of filtering facepiece respirators (FFRs, commonly referred to as N95s) normally meant for single use has become common in healthcare facilities due to shortages caused by the COVID-19 pandemic. Here, we report that murine hepatitis coronavirus initially seeded on FFR filter material is inactivated (6 order of magnitude reduction as measured by median tissue culture infective dose, TCID50) after dry heating at 75°C for 30 min. We also find that the quantitative fit of FFRs after heat treatment at this temperature, under dry conditions or at 90% relative humidity, is not affected by single or 10 heating cycles. Previous studies have reported that the filtration efficiency of FFRs is not negatively impacted by these heating conditions. These results suggest that thermal inactivation of coronaviruses is a potentially rapid and widely deployable method to reuse N95 FFRs in emergency situations where reusing FFRs is a necessity and broad-spectrum sterilization is unavailable. However, we also observe that a radiative heat source (e.g. an exposed heating element) results in rapid qualitative degradation of the FFR. Finally, we discuss differences in the results reported here and other recent studies investigating heat as a means to recycle FFRs. These differences suggest that while our repeated decontamination cycles do not affect FFR fit, overall wear time and the number of donning/doffing cycles are important factors that likely degrade FFR fit and must be investigated further.

The impact of face masks on performance and physiological outcomes during exercise: a systematic review and meta-analysis

Face masks are promoted for preventing spread of viruses; however, wearing a mask during exercise might increase CO₂ rebreathing, decrease arterial oxygenation, and decrease exercise performance. A systematic review and meta-analysis was conducted on the impact of wearing a mask during exercise. Data sources included SPORTDiscus, PubMed, and Medline. Eligibility criteria included all study designs comparing surgical, N95, or cloth masks to a no mask condition during any type of exercise where exercise performance and/or physiological parameters were evaluated. Healthy and clinical participants were included. Mean differences (MD) or standardized mean differences (SMD) with 95% confidence intervals were calculated and pooled effects assessed. Twenty-two studies involving 1573 participants (620 females, 953 males) were included. Surgical, or N95 masks did not impact exercise performance (SMD -0.05 [-0.16, 0.07] and -0.16 [-0.54, 0.22], respectively) but increased ratings of perceived exertion (SMD 0.33 [0.09, 0.58] and 0.61 [0.23, 0.99]) and dyspnea (SMD 0.6 [0.3, 0.9] for all masks). End-tidal CO₂ (MD 3.3 [1.0, 5.6] and 3.7 [3.0, 4.4] mm Hg), and heart rate (MD 2 [0,4] beats/min with N95 masks) slightly increased. Face masks can be worn during exercise with no influences on performance and minimal impacts on physiological variables. PROSPERO registration: CRD42020224988. Novelty: Face masks can be worn during exercise with no impacts on performance and minimal impacts on physiological variables.

Carbon dioxide increases with face masks but remains below short-term NIOSH limits

BACKGROUND AND PURPOSE

COVID-19 pandemic led to wide-spread use of face-masks, respirators and other personal protective equipment (PPE) by healthcare workers. Various symptoms attributed to the use of PPE are believed to be, at least in part, due to elevated carbon-dioxide (CO2) levels. We evaluated concentrations of CO2 under various PPE.

METHODS

In a prospective observational study on healthy volunteers, CO2 levels were measured during regular breathing while donning 1) no mask, 2) JustAir® powered air purifying respirator (PAPR), 3) KN95 respirator, and 4) valved-respirator. Serial CO2 measurements were taken with a nasal canula at a frequency of 1-Hz for 15-min for each PPE configuration to evaluate whether National Institute for Occupational Safety and Health (NIOSH) limits were breached.

RESULTS

The study included 11 healthy volunteers, median age 32 years (range 16-54) and 6 (55%) men. Percent mean (SD) changes in CO2 values for no mask, JustAir® PAPR, KN95 respirator and valve respirator were 0.26 (0.12), 0.59 (0.097), 2.6 (0.14) and 2.4 (0.59), respectively. Use of face masks (KN95 and valved-respirator) resulted in significant increases in CO2 concentrations, which exceeded the 8-h NIOSH exposure threshold limit value-weighted average (TLV-TWA). However, the increases in CO2 concentrations did not breach short-term (15-min) limits. Importantly, these levels were considerably lower than the long-term (8-h) NIOSH limits during donning JustAir® PAPR. There was a statistically significant difference between all pairs (p < 0.0001, except KN95 and valved-respirator (p = 0.25). However, whether increase in CO2 levels are clinically significant remains debatable.

CONCLUSION

Although, significant increase in CO2 concentrations are noted with routinely used face-masks, the levels still remain within the NIOSH limits for short-term use. Therefore, there should not be a concern in their regular day-to-day use for healthcare providers. The clinical implications of elevated CO2 levels with long-term use of face masks needs further studies. Use of PAPR prevents relative hypercapnoea. However, whether PAPR should be advocated for healthcare workers requiring PPE for extended hours needs to evaluated in further studies.

Modified full-face snorkel mask as COVID-19 personal protective equipment: Quantitative results

The COVID-19 crisis has resulted in a shortage of personal protective equipment (PPE). Adapting commercially available full-faced snorkel masks has been proposed as an alternative to narrow the gap in PPE. An advantage of the full-faced snorkel mask design is that it serves two critical purposes: eye and face protection, and high quality air filtration to protect against SARS-CoV-2. We performed quantitative testing on various full-faced snorkel masks with 3D printed adapters that accept commercially available particulate filters, and report on a design that passed Occupational Safety and Health Administration (OSHA) full-facepiece respirator standards.

COVID-19 global pandemic planning: Dry heat incubation and ambient temperature fail to consistently inactivate SARS-CoV-2 on N95 respirators

The ongoing pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has placed a substantial strain on the supply of personal protective equipment, particularly the availability of N95 respirators for frontline healthcare personnel. These shortages have led to the creation of protocols to disinfect and reuse potentially contaminated personal protective equipment. A simple and inexpensive decontamination procedure that does not rely on the use of consumable supplies is dry heat incubation. Although reprocessing with this method has been shown to maintain the integrity of N95 respirators after multiple decontamination procedures, information on the ability of dry heat incubation to inactivate SARS-CoV-2 is largely unreported. Here, we show that dry heat incubation does not consistently inactivate SARS-CoV-2-contaminated N95 respirators, and that variation in experimental conditions can dramatically affect viability of the virus. Furthermore, we show that SARS-CoV-2 can survive on N95 respirators that remain at room temperature for at least five days. Collectively, our findings demonstrate that dry heat incubation procedures and ambient temperature for five days are not viable methods for inactivating SARS-CoV-2 on N95 respirators for potential reuse. We recommend that decontamination procedures being considered for the reuse of N95 respirators be validated at each individual site and that validation of the process must be thoroughly conducted using a defined protocol.

Graphene oxide-based rechargeable respiratory masks

Respiratory masks having similar standards of 'N95', defined by the US National Institute for Occupational Safety and Health, will be highly sought after, post the current COVID-19 pandemic. Here, such a low-cost (∼$1/mask) mask design having electrostatic rechargeability and filtration efficiency of >95% with a quality factor of ∼20 kPa-1 is demonstrated. This filtration efficacy is for particles of size 300 nm. The tri-layer mask, named PPDFGO tri, contains nylon, modified polypropylene (PPY), and cotton nonwoven fabrics as three layers. The melt-spun PPY, available in a conventional N95 mask, modified with graphene oxide and polyvinylidene fluoride mixture containing paste using a simple solution casting method acts as active filtration layer. The efficacy of this tri-layer system toward triboelectric rechargeability using small mechanical agitations is demonstrated here. These triboelectric nanogenerator (TENG)-assisted membranes have high electrostatic charge retention capacity (∼1 nC/cm2 after 5 days in ambient condition) and high rechargeability even in very humid conditions (>80% RH). A simple but robust permeability measurement set up is also constructed to test these TENG-based membranes, where a flow rate of 30-35 L/min is maintained during the testing. Such a simple modification to the existing mask designs enabling their rechargeability via external mechanical disturbances, with enhanced usability for single use as well as for reuse with decontantamination, will be highly beneficial in the realm of indispensable personal protective equipment.