The tiny effects of respiratory masks on physiological, subjective, and behavioral measures under mental load in a randomized controlled trial

Design of biodegradable cellulose filtration material with high efficiency and breathability

Using respiratory protective equipment is one of the relevant preventive measures for infectious diseases, including COVID-19, and for various occupational respiratory hazards. Because experienced discomfort may result in a decrease in the utilization of respirators, it is important to enhance the material properties to resolve suboptimal usage. We combined several technologies to produce a filtration material that met requirements set by a cross-disciplinary interview study on the usability of protective equipment. Improved breathability, environmental sustainability, and comfort of the material were achieved by electrospinning poly(ethylene oxide) (PEO) nanofibers on a thin foam-formed fabric from regenerated cellulose fibers. The high filtration efficiency of sub-micron-sized diethylhexyl sebacate (DEHS) aerosol particles resulted from the small mean segment length of 0.35 μm of the nanofiber network. For a particle diameter of 0.6 μm, the filtration efficiency of a single PEO layer varied in the range of 80-97 % depending on the coat weight. The corresponding pressure drop had the level of 20-90 Pa for the airflow velocity of 5.3 cm/s. Using a multilayer structure, a very high filtration efficiency of 99.5 % was obtained with only a slightly higher pressure drop. This opens a route toward designing sustainable personal protective media with improved user experience.

Health effects of filtering facepiece respirators: Research and clinical implications of comfort, thermal, skin, psychologic, and workplace effects

Filtering facepiece respirators (FFR's) such as N95s have become widely used in appropriate settings for personal respiratory protection and are increasingly used beyond workplace settings. Concerns about possible adverse effects have appeared in many publications, particularly since the COVID-19 pandemic led to much more widespread use. This paper synthesizes known effects based upon review of publications in PubMed since 1995, addressing effects other than pulmonary and cardiovascular (reviewed elsewhere). Findings: (1) Subjective discomfort is very frequently reported; this includes general discomfort or organ-system-specific complaints such as respiratory, headache, dermatologic, and heat. Research methods are widely divergent, and we propose a taxonomy to classify such studies by methodology, study population (subjects, experimental vs. observational methodology, comparator, specificity, and timeframe) to facilitate synthesis. (2) Objective measures of increased heat and humidity within the mask are well documented. (3) Frequency and characteristics of dermatologic effects have been insufficiently evaluated. (4) Physical mask designs are varied, making generalizations challenging. (5) More studies of impact on work performance and communication are needed. (6) Studies of effect of FFR design and accompanying training materials on ease and consistency of use are needed.

Effects of face masks on fairness in on-site personnel selection during a pandemic

Introduction

Despite significant challenges, personnel selection procedures had to continue as on-site testing in the Covid-19 pandemic. Health and safety measures and specifically the use of face masks threaten to limit the fairness of cognitive testing and behavioral observation in the assessment center.

Methods

In this study, we compare the performance and pass rates of pilot selection under three different conditions in the selection campaigns of 2019 (pre-pandemic), 2020 (health and safety measures without mask), and 2021 (health and safety measures with mask).

Results

Mask wearing and other health and safety measures had no influence on the objective parameters of pilot selection. However, for some of the areas of competence in the assessment center subjective observability was rated lower for the condition with face masks.

Discussion

We conclude that the fairness and precision of selection processes are not compromised by wearing face masks and that a high degree of standardization in diagnostic instruments prevents a partially reduced subjective observability from affecting the selection's outcome.

Influence of face masks on the subjective impairment at different physical workloads

To quantify the subjective and cognitive impairment caused by wearing face masks at work, 20 men and 20 women (median age 47 years, range 19-65) were tested under different ergometer workloads while wearing surgical mask, community mask, FFP2 respirator or no mask in a randomized and partially double-blinded design. Masks were worn also at the workplace for four hours. Subjective impairment was recorded by questionnaires. Cognitive performance was tested before and after the workplace examination. Subjective feeling of heat, humidity, and difficult breathing increased with rising physical exertion and wearing time for all three mask types, most notably for FFP2. Even when blinded, participants with FFP2 reported difficult breathing already at rest. During physical exertion, individuals with low tolerance to discomfort reported significantly stronger impairment (OR 1.14, 95% CI 1.02-1.27). Regarding light work, older subjects (OR 0.95, 95% CI 0.92-0.98) and women (OR 0.84, 95% CI 0.72-0.99) showed significantly lower and atopic subjects stronger impairment (OR 1.16, 95% CI 1.06-1.27). No significant influence of mask wearing was detected on cognitive performance. Wearing a mask had no effect on cognitive performance, but led to discomfort which increased with physical exertion and wearing time. Individuals who tolerate discomfort poorly felt more impaired by wearing a mask during physical exertion.

A pilot study to evaluate the changes in venous blood gas parameters and hypoxia biomarkers in health care workers using different kinds of masks

Background

The study is aimed to investigate the metabolic alterations and changes in biochemical parameters associated with extended mask.

Methods

It was a prospective comparative study conducted on 129 participants comprised of 37 healthy controls and 92 health care workers using different kind of masks like, cloth mask, surgical masks and N95-FFR/PPE. Two samples on day-1 and day-10 were collected for analysis of blood gas parameters, serum hypoxia-inducible factor-α (HIF-α), and erythropoietin (EPO).

Results

Oxygen saturation percentage (sO2) of 72.68 (P = 0.033) was significantly low, whereas, Na+ (P = 0.05) and Ca2+ (P < 0.001) were raised in exposed individuals than the healthy controls. The serum HIF-α level of 3.26 ng/mL, was considerable higher in the exposed individuals than controls (P = 0.001). pO2 and sO2 were the lowest and HIF-α and EPO were raised in N95-FFR/PPE of all mask users (P < 0.01). A significant difference was evidenced for pCO2, pH, Na+, Ca2+, and EPO in the exposed group. A positive correlation between the duration of mask use (in hours) with HIF-α (r = 0.247, P = 0.005) and Ca2+ (r = 0.306, P < 0.001) was observed. The major complaints in N95-FFR/PPE users were headache (15.2%) and polydipsia (33.3%).

Conclusion

The study findings depicted a significant metabolic alterations in PPE/N95 users which could be due to chronic hypoxic exposure of the tissues.

Effects of cloth face masks on physical and cognitive performance during maximal exercise testing

Wearing a cloth face mask has been shown to impair exercise performance; it is essential to understand the impact wearing a cloth face mask may have on cognitive performance. Participants completed two maximal cardiopulmonary exercise tests on a cycle ergometer (with and without a cloth face mask) with a concurrent cognitive task. Blood pressure, heart rate, oxygen saturation, perceived exertion, shortness of breath, accuracy, and reaction time were measured at rest, during each exercise stage, and following a 4-minute recovery period. The final sample included 35 adults (age = 26.1 ± 5.8 years; 12 female/23 male). Wearing a cloth face mask was associated with significant decreases in exercise duration (-2:00 ± 3:40 min, P = 0.003), peak measures of maximal oxygen uptake (-818.9 ± 473.3 mL/min, -19.0 ± 48 mL·min^-1·kg^-1, P < 0.001), respiratory exchange ratio (-0.04 ± 0.08, P = 0.005), minute ventilation (-36.9 ± 18 L/min), oxygen pulse (-3.9 ± 2.3, P < 0.001), heart rate (-7.9 ± 12.6 bpm, P < 0.001), oxygen saturation (-1.5 ± 2.8%, P = 0.004), and blood lactate (-1.7 ± 2.5 mmol/L, P < 0.001). While wearing a cloth face mask significantly impaired exercise performance during maximal exercise testing, cognitive performance was unaffected in this selected group of young, active adults.

The effect of masks on cognitive performance

The use of face masks has been a key response to the COVID-19 pandemic in almost every country. However, despite widespread use of masks in classrooms and offices around the world, almost nothing is known about their effects on cognitive performance. Using a natural experiment, I show that mandatory mask wearing has a negative causal effect on the cognitive performance of competitive chess players. I analyzed the quality of almost 3 million chess moves played by 8,531 individuals (ages 5-98 y) in 18 countries before and during the pandemic. Wearing a mask decreased the quality of players' decisions-a measure of their cognitive performance-by approximately one-third of an SD. However, the disruptive effect of masks is relatively short-lived, gradually weakening such that there is no measurable disadvantage from wearing a mask after roughly 4 h of play. The mask effect is driven by a large, negative effect for experts, with minimal change in performance at lower levels, and is stronger in high-incentive competitions. I provide support for a distraction mechanism whereby masks interfere with performance when working memory load is high.

The Effect of Face Masks on Physiological Data and the Classification of Rehabilitation Walking

Gait analysis and the assessment of rehabilitation exercises are important processes that occur during fitness level monitoring and the treatment of neurological disorders. This paper presents the possibility of using oximetric, heart rate (HR), accelerometric, and global navigation satellite systems (GNSSs) to analyse signals recorded during uphill and downhill walking without and with a face mask to find its influence on physiological functions during selected walking patterns. The experimental dataset includes 86 signal segments acquired under different conditions. The proposed methodology is based on signal analysis in both the time and frequency domains. The results indicate that face mask use has a minimal effect on blood oxygen concentration and heart rate, with the average mean changes of these parameters being less than 2%. The support vector machine, a Bayesian method, the k -nearest neighbour method, and a two-layer neural network showed very good separation abilities and successfully classified different walking patterns only in the case when the effect of face mask wearing was not included in the classification process. Our methodology suggests that artificial intelligence and machine learning tools are efficient methods for the assessment of motion patterns in different motion conditions and that face masks have a negligible effect for short-duration experiments.

Bayesian network meta-analysis of face masks' impact on human physiology

Several concerns regarding the safety of face masks use have been propounded in public opinion. The objective of this review is to examine if these concerns find support in the literature by providing a comprehensive overview of physiological responses to the use of face masks. We have performed a systematic review, pairwise and network meta-analyses to investigate physiological responses to the use of face masks. The study has been registered with PROSPERO (C RD42020224791). Obtained results were screened using our exclusion and inclusion criteria. Meta-analyses were performed using the GeMTC and meta R packages. We have identified 26 studies meeting our inclusion and exclusion criteria, encompassing 751 participants. The use of face masks was not associated with significant changes in pulsoxymetrically measured oxygen saturation, even during maximal-effort exercises. The only significant physiological responses to the use of face masks during low-intensity activities were a slight increase in heart rate, mildly elevated partial pressure of carbon dioxide (not meeting criteria for hypercarbia), increased temperature of facial skin covered by the mask, and subsequent increase of the score in the rating of heat perception, with N95 filtering facepiece respirators having a greater effect than surgical masks. In high-intensity conditions, the use of face masks was associated with decreased oxygen uptake, ventilation, and RR. Face masks are safe to use and do not cause significant alterations in human physiology. The increase in heart rate stems most likely from increased respiratory work required to overcome breathing resistance. The increase in carbon dioxide is too small to be clinically relevant. An increased rating of heat perception when using face masks results from higher temperature of facial skin covered by the mask.