Is a Mask That Covers the Mouth and Nose Free from Undesirable Side Effects in Everyday Use and Free of Potential Hazards?

Which Mask, N95 or Surgical Mask, Causes Hoarseness in Healthcare Workers?

OBJECTIVES

This study aimed to determine the impact of different types of masks on the voices of healthcare professionals who had to wear masks for an extended amount of time during the pandemic period and had a healthy voice.

METHODS

Our research included 41 healthcare workers. The participants were separated into two groups: surgical (n = 21) and N95 mask users (n = 20). Healthcare workers evaluated masks before and after wearing them for at least 8 hours throughout the workday. All subjects had a videolaryngoscopic examination; the Voice Handicap Index-10 (VHI-10), GRBAS, acoustic voice analysis (F0, jitter%, shimmer%, noise/harmonic ratio, relative average perturbation [RAP]), aerodynamic measures (maximum phonation time, MPT), and blood oxygen saturation were evaluated.

RESULTS

Although both groups' VHI-10 scores increased after using the mask, this rise was not statistically significant in our research. According to the GRBAS classification, voice quality deterioration was identified in 9.6% (mild-moderate) of the group using surgical masks and 15% (mild) of the group wearing N95. Only the jitter and RAP values of individuals wearing both surgical and N95 masks were determined to be statistically significant. There was no significant change in MPT following mask wear in either group. Both the surgical and N95 mask-using groups showed a substantial drop in blood oxygen saturation before and after mask usage.

CONCLUSION

There was no change in voice quality between healthcare workers wearing surgical and N95 masks. It has been noticed that voice perception and quality are affected by the mask's barrier effect rather than the kind of mask.

Protective face mask: an effective weapon against SARS-CoV-2 with controlled environmental pollution

Masks are face coverings that give protection from infectious agents, airborne pathogens, bacteria, viruses, surgical fog, dust, and other chemical hazards by acting as a barrier between the wearer and the environment. In the COVID-19 pandemic, this major personal protective equipment's became essential part of our daily life. The aim of this review is to analyze and discuss the different types of masks with their pros and cons, manufacturing procedures, evaluation criteria, and application with some of the sterilization process for reuse and smart mask. The review used a thorough examination of the literature to analyze the preventive effects of surgical, N95, smart mask, and potential environmental damage from those masks. Several studies and evidence were also examined to understand the efficiency of different mask on different environment. N95 respirators are capable of filtering out non-oil-based 95% air-born particles, and surgical masks act as a protective barrier between the wearer and the environment. The application of spoon bond and melt blown techniques in the fabrication process of those masks improves their protective nature and makes them lightweight and comfortable. But the high demand and low supply forced users to reuse and extend their use after sterilizations, even though those masks are recommended to be used once. Universal masking in the SARS-COV-2 pandemic increased the chance of environmental pollution, so the application of smart masks became essential because of their high protection power and self-sterilizing and reusing capabilities.

Wearing face masks while climbing stairs influences respiratory physiology

During the COVID-19 pandemic wearing face masks was mandatory. Nowadays, face masks are still encouraged indoors, especially in hospitals. People climbing stairs with masks describe unpredictable dyspnea. In this study, healthy adults climbed 5 floors with and without a mask. Various cardio-respiratory parameters were measured, including O2-saturation (O2-Sat) and end-tidal CO2(EtCO2), at baseline and on the top floor. Subjective indexes, such as Borg's scale, were evaluated. Thirty-two volunteers (16 males), median age 39 years (IQR 32.5-43), median BMI = 23.6 (IQR 21.5-25.1), with good fitness levels, participated. Comparing baseline to end-activity, median (IQR): O2-Sat change was -1.0% (-2-0) without mask, versus -3.0% (-4-0) with mask,p= 0.003; EtCO2+ 7.0 (+3.3-+9) without mask, versus +8.0 (+6-+12) with mask,p= 0.0001. Hypercarbia was seen in 5 (15.6%) participants without mask, median = 48 mmHg (IQR 47.5-51), and in 11 (34%) participants with mask, median = 50 mmHg (IQR 47-54),p< 0.001. Desaturation (O2-Sat < 95%) was seen in 5 (15.6%) participants without mask, median = 94% (IQR 93%-94%), and in 10 (31%) participants with mask, median = 91.5% (IQR 90%-93%),p= 0.06. Regression analysis demonstrated that only male sex was significantly associated with abnormal EtCO2(OR = 26.4, 95% CI = 1.9-366.4,p= 0.005). Ascent duration increased from median (IQR) of 94 s (86-100) without mask to 98 s (89-107) with mask,p< 0.001. Borg's scale of perceived exertion (range 0-10) increased from median (IQR) of 3.0 (2.5-3.87) without mask to 4.0 (3.0-4.37) with mask,p< 0.001. To conclude, during routine daily activities, such as stair-climbing, face masks cause dyspnea, and have measurable influences on ventilation, including true desaturation and hypercapnia, especially in males.

Wearing face masks as a potential source for inhalation and oral uptake of inanimate toxins - A scoping review

BACKGROUND

From 2020 to 2023 many people around the world were forced to wear masks for large proportions of the day based on mandates and laws. We aimed to study the potential of face masks for the content and release of inanimate toxins.

METHODS

A scoping review of 1003 studies was performed (database search in PubMed/MEDLINE, qualitative and quantitative evaluation).

RESULTS

24 studies were included (experimental time 17 min to 15 days) evaluating content and/or release in 631 masks (273 surgical, 228 textile and 130 N95 masks). Most studies (63%) showed alarming results with high micro- and nanoplastics (MPs and NPs) release and exceedances could also be evidenced for volatile organic compounds (VOCs), xylene, acrolein, per-/polyfluoroalkyl substances (PFAS), phthalates (including di(2-ethylhexyl)-phthalate, DEHP) and for Pb, Cd, Co, Cu, Sb and TiO2.

DISCUSSION

Of course, masks filter larger dirt and plastic particles and fibers from the air we breathe and have specific indications, but according to our data they also carry risks. Depending on the application, a risk-benefit analysis is necessary.

CONCLUSION

Undoubtedly, mask mandates during the SARS-CoV-2 pandemic have been generating an additional source of potentially harmful exposition to toxins with health threatening and carcinogenic properties at population level with almost zero distance to the airways.

Ethics of Nudging in the COVID-19 Crisis and the Necessary Return to the Principles of Shared Decision Making: A Critical Review

Nudging, a controversial technique for modifying people's behavior in a predictable way, is claimed to preserve freedom of choice while simultaneously influencing it. Nudging had been largely confined to situations such as promoting healthy eating choices but has been employed in the coronavirus disease 2019 (COVID-19) crisis in a shift towards measures that involve significantly less choice, such as shoves and behavioral prods. Shared decision making (SDM), a method for direct involvement and autonomy, is an alternative approach to communicate risk. Predominantly peer-reviewed scientific publications from standard literature databases like PubMed, PsycInfo, and Psyndex were evaluated in a narrative review. The so-called fear nudges, as well as the dissemination of strongly emotionalizing or moralizing messages can lead to intense psycho-physical stress. The use of these nudges by specialized units during the COVID-19 pandemic generated a societal atmosphere of fear that precipitated a deterioration of the mental and physical health of the population. Major recommendations of the German COVID-19 Snapshot Monitoring (COSMO) study, which are based on elements of nudging and coercive measures, do not comply with ethical principles, basic psychological principles, or evidence-based data. SDM was misused in the COVID-19 crisis, which helped to achieve one-sided goals of governments. The emphasis on utilitarian thinking is criticized and the unethical behavior of decision makers is explained by both using the concept of moral disengagement and the maturity level of coping strategies. There should be a return to an open-ended, democratic, and pluralistic scientific debate without using nudges. It is therefore necessary to return to the origins of SDM.

Effective volume of rebreathed air during breathing with facepieces increases with protection class and decreases with ambient airflow

Wearing facepieces is discussed in the context of increasing the volume of rebreathed air. We hypothesized that rebreathed air volume increases with increasing filtering facepiece (FFP) class and that persons breathing via facepieces compensate for the additional dead-space. We have determined the effective amount of rebreathed air for a surgical masks and FFP2 and FFP3 respirators in a physical model and determined tidal volumes, breathing frequency, blood oxygen saturation, and transcutaneously measured blood carbon dioxide partial pressure (PCO2) in lung-healthy subjects breathing without and with facepieces at rest and during exercising on a recumbent ergometer. Rebreathed air volume increased with the facepieces' protection class and with increasing inspiration volume by 45 ± 2 ml to 247 ± 1 ml. Ambient airflow reduced rebreathed air volume by 17% up to 100% (all p < 0.001). When wearing facepieces, subjects increased tidal volume (p < 0.001) but not breathing frequency. Oxygen saturation was not influenced by facepieces. With FFP3 respirators PCO2 increased by up to 3.2 mmHg (p < 0.001) at rest but only up to 1.4 mmHg (p < 0.001) when exercising. Discomfort of breathing increased with increasing protection class of the facepiece but was consistently perceived as tolerable. We conclude that the amount of rebreathed air increases with increasing protection class of facepieces. Healthy adults were capable to compensate the facepieces' dead-space by adapting tidal volume at rest and during physical activity; thereby they tolerated moderate increases in PCO2. Ambient airflow may considerably reduce the amount of facepiece related rebreathed air.

Eustachian tube dysfunction after using different types of masks during the coronavirus disease 2019 pandemic

OBJECTIVE

This study aimed to investigate the relationship between the use of different types of masks (N95/filtering facepiece type 2, surgical) and Eustachian tube dysfunction in healthcare workers.

METHODS

The study included 37 healthcare workers using N95/filtering facepiece type 2 masks and 35 using surgical masks for at least 6 hours per day, and 42 volunteers who are not healthcare workers using surgical masks for less than 6 hours per day. Participants' demographic features, clinical data and Eustachian Tube Dysfunction Questionnaire scores were compared.

RESULTS

The frequencies of autophony and aural fullness were significantly higher in the healthcare workers using N95/filtering facepiece type 2 masks. Autophony and aural fullness were significantly greater in the post-mask period than the pre-mask period. Middle-ear peak pressures and Eustachian Tube Dysfunction Questionnaire scores were higher in healthcare workers who used N95/filtering facepiece type 2 masks.

CONCLUSION

Healthcare workers who used N95/filtering facepiece type 2 masks had worsened middle-ear pressures and Eustachian Tube Dysfunction Questionnaire scores. Use of N95/filtering facepiece type 2 masks was associated with higher rates of autophony, aural fullness and higher Eustachian Tube Dysfunction Questionnaire scores in the post-mask period.

Expert consensus on the diagnosis, treatment, and prevention of respiratory syncytial virus infections in children

BACKGROUND

Respiratory syncytial virus (RSV) is the leading global cause of respiratory infections and is responsible for about 3 million hospitalizations and more than 100,000 deaths annually in children younger than 5 years, representing a major global healthcare burden. There is a great unmet need for new agents and universal strategies to prevent RSV infections in early life. A multidisciplinary consensus development group comprising experts in epidemiology, infectious diseases, respiratory medicine, and methodology aims to develop the current consensus to address clinical issues of RSV infections in children.

DATA SOURCES

The evidence searches and reviews were conducted using electronic databases, including PubMed, Embase, Web of Science, and the Cochrane Library, using variations in terms for "respiratory syncytial virus", "RSV", "lower respiratory tract infection", "bronchiolitis", "acute", "viral pneumonia", "neonatal", "infant" "children", and "pediatric".

RESULTS

Evidence-based recommendations regarding diagnosis, treatment, and prevention were proposed with a high degree of consensus. Although supportive care remains the cornerstone for the management of RSV infections, new monoclonal antibodies, vaccines, drug therapies, and viral surveillance techniques are being rolled out.

CONCLUSIONS

This consensus, based on international and national scientific evidence, reinforces the current recommendations and integrates the recent advances for optimal care and prevention of RSV infections. Further improvements in the management of RSV infections will require generating the highest quality of evidence through rigorously designed studies that possess little bias and sufficient capacity to identify clinically meaningful end points.

Evaluation of health worker acceptance and tolerance of respirators in clinical practice-An Australian perspective

BACKGROUND

One of the main infection prevention and control measures introduced during the COVID-19 pandemic was the focused application of respiratory protection to ensure health worker safety and the effective use of personal protective equipment. However, user acceptance of these strategies is paramount in sustainable compliance. This study explores various aspects of respirator use and provides recommendations to improve and maximize health worker safety. The aim of this study was to understand the relationship between respirator (P2/N95) comfort and user experience toward respiratory protection. The aim of this study was to understand the relationship between respirator (P2/N95) comfort and user experience toward respiratory protection.

METHODS

The nonexperimental cross-sectional design study was conducted in New South Wales, Australia between November and December 2022 using an anonymous self-administered online questionnaire in Microsoft Forms.

RESULTS

Of 2,514 respondents, 65% reported to have used a respirator every working day with only a few using a respirator once weekly or less (9%). Almost all respondents had completed at least one quantitative fit test (96%) prior to the survey. Fifty-nine percent reported to have experienced discomfort from wearing a respirator and the most reported adverse effect was difficulty communicating (64%), followed by skin irritation or acne (62%) and headache (56%).

CONCLUSIONS

Despite somewhat less favorable ratings on comfort and communication, health workers are in favor of respiratory protection. However, a focus on tolerance of respirators and strategies to address adverse effects from prolonged respirator use must be considered when implementing policies and procedures. Moreover, resources must be allocated to improve the design, breathability, and sustainability of a respirator along with education and training on how to use respiratory protection safely and effectively.

Self-Perceived Voice Handicap During COVID19 Compulsory Facemask Use: A Comparative Study Between Portuguese and Spanish Speakers

This study investigates self-perceptions of voice-related handicap as a function of facemask use in the general working population during the COVID19 outbreak, using the Voice Handicap Index (VHI). Each VHI item was answered twice in a row; the first answer referred to the condition of not wearing a facemask (henceforth, the Without condition) and the second to the condition of using a facemask (henceforth, the With condition). VHI scores were collected via Google Forms (Google, Mountain View, California), targeting 2 groups of speakers of different nationalities, Portuguese (n = 261) and Spanish (n = 297). A Wilcoxon test was carried out to compare VHI scores between With and Without conditions for each group of speakers; a Mann-Whitney U test was used to compare groups within each condition. Results suggested that VHI overall scores and scores for all dimensions were higher for the With condition, for both Portuguese and Spanish speakers. When comparing groups of speakers, Spanish speakers presented higher scores for functional and emotional dimensions, for both With and Without conditions. In addition, the overall score for the Without condition was higher for Spanish speakers. No differences between groups were found for the total VHI score for the With condition. When comparing overall VHIdiff between speakers, that is, the difference in the VHI total score between With and Without conditions, no significant differences could be found. Thus, a multiple regression analysis was carried out between the VHIdiff and the independent variables of interest: age, sex, smoking habits, professional occupation, nationality, facemask type and its hours of use. The resulting model providing the highest association suggested that 2.5% of the variation in overall VHIdiff total score could be associated with sex, smoking habits, and professional level. Female smokers who use their voices during prolonged hours at work (e.g., teachers, lawyers, sales people) presented a higher VHI total score when wearing a mask. Future voice-related health interventions should address preventive strategies towards speaking behaviors leading to vocal fatigue and vocal effort as a consequence of compulsory facemask use, especially with respect to female professional voice users who smoke.

Prolonged mask wearing changed nasal microbial characterization of young adults during the COVID-19 pandemic in Shanghai, China

Background

Face masks have become a common sight during the Coronavirus Disease 2019 (COVID-19) pandemic in many countries. However, the impact of prolonged face mask wearing on nasal microbiota of healthy people is not fully understood.

Methods

In this study, we compared the nasal microbiota of 82 young adults who wore face masks for an extended period of time to 172 mask-free peers from the same school recruited before the COVID-19 pandemic via 16S ribosomal RNA gene sequencing. Diversity, composition, and function of nasal microbiota between the two groups were analyzed. Prevalence of commensal bacteria colonized in the nasal cavity was determined by culture-based analysis.

Results

We observed that prolonged face mask wearers had significantly different nasal microbial characterization and metabolic function compared to mask-free controls from 2018. Specifically, the nasal microbiota of the prolonged mask wearers displayed increased abundance of Staphylococcus, Pseudoalteromonas, Corynebacterium, etc. Meanwhile, the abundance of several genera including Bacteroides, Faecalibacterium, and Agathobacter was decreased. Moreover, we observed that COVID-19 infection history did not affect the composition of nasal microbiota significantly. Additionally, the culture-based analysis revealed that Staphylococcus aureus and Corynebacterium accolens increased, and Staphylococcus epidermidis decreased in the nasal cavity of prolonged mask wearers.

Conclusions

Overall, our study suggests that prolonged face mask wearing can significantly alter the nasal microbiota.

Revisiting the rationale of mandatory masking

In this perspective, we review the evidence for the efficacy of face masks to reduce the transmission of respiratory viruses, specifically severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and consider the value of mandating universal mask wearing against the widespread negative impacts that have been associated with such measures. Before the SARS-CoV-2 pandemic, it was considered that there was little to no benefit in healthy people wearing masks as prophylaxis against becoming infected or as unwitting vectors of viral transmission. This accepted policy was hastily reversed early on in the pandemic, when districts and countries throughout the world imposed stringent masking mandates. Now, more than three years since the start of the pandemic, the amassed studies that have investigated the use of masks to reduce transmission of SARS-CoV-2 (or other pathogens) have led to conclusions that are largely inconsistent and contradictory. There is no statistically significant or unambiguous scientific evidence to justify mandatory masking for general, healthy populations with the intention of lessening the viral spread. Even if mask wearing could potentially reduce the transmission of SARS-CoV-2 in individual cases, this needs to be balanced against the physical, psychological and social harms associated with forced mask wearing, not to mention the negative impact of innumerable disposed masks entering our fragile environment. Given the lack of unequivocal scientific proof that masks have any effect on reducing transmission, together with the evident harms to people and the environment through the use of masks, it is our opinion that the mandatory use of face masks in the general population is unjustifiable and must be abandoned in future pandemic countermeasures policies.

Does mask wearing affect skin health? An untargeted skin metabolomics study

Wearing masks is used as an effective way to prevent the spread of viruses. However, the effect of wearing masks on skin health requires further assessment. In this study, a non-invasive D-squame sampling method coupled with an untargeted metabolomics analysis by liquid chromatography high-resolution mass spectrometry was developed to identify the changes in the skin metabolome caused by wearing masks. D-squame method was found to have advantages over the commonly used sterile gauze method, especially for the lipids and lipid-like molecules. A total of 356 skin metabolites were putatively identified from the stratum corneum of 10 volunteers, and 17 differential metabolites were significantly downregulated after wearing surgical masks or N95 respirators. The downregulation of metabolites such as phosphatidylethanolamine and sphingomyelin might be related to hypoxia or increased skin moisture caused by wearing masks. Changes in skin metabolomics indicated a potential risk of skin barrier disruption and skin inflammation. Intermittent removal of the masks can effectively alleviate changes in the skin metabolome.

Mask wearing provides psychological ease but does not affect facial expression intensity estimation

During the COVID-19 pandemic, wearing a face mask became a global daily practice. Japanese people were already accustomed to wearing masks due to their collectivistic culture, which prioritizes conformity and group harmony. In such a culture, where individuals are concerned about how others perceive them and their actions, wearing masks can be a self-protective action to prevent, escape, or reduce the severity of perceived negative feelings. Previous studies indicate that people experiencing anxiety tend to have negative biases when evaluating emotional expressions on faces. Therefore, we hypothesized that wearing a mask can reduce the negative feelings caused by social pressure, emotion processing, especially intensity perception. While our findings confirmed that wearing a mask reduced negative feelings caused by social pressure, there was no significant change in emotion intensity recognition performance. This null result might be attributed to the small effect size of the association between negative bias in emotion processing and an individual's state. In future studies, it would be valuable to include participants from non-collectivistic cultures to gain a broader understanding of the impact of wearing masks on emotion processing.

Oral microbiome of the inner surface of face masks and whole saliva during the COVID-19 pandemic

Wearing a face mask was strongly recommended during the COVID-19 pandemic. The purpose of this study was to investigate the diversity of the oral microbiome, the abundance of each bacterium on the inner surface of the mask, and the effects of xerostomia on the microbiota. The study was conducted on 55 generally healthy adults (45 women and 10 men, mean age 38.18 ± 12.49 years). Unstimulated flow rate (UFR) and stimulated flow rate (SFR) were measured in whole saliva samples collected for each condition. The 14 major oral bacterial species, including Porphyromonas gingivalis (P. gingivalis), Lactobacillus casei (L. casei), Tannerella forsythia (T. forsythia), and Treponema denticola (T. denticola) on the inner surface of the mask and in the UFR and SFR samples, were analyzed by real-time PCR. We found that the total DNA copy number of oral bacteria was significantly higher in UFR and SFR than in the mask (p < 0.001). On the inner surface of the mask, P. gingivalis and L. casei were the most abundant Gram-negative and Gram-positive species, respectively. The oral microbiome profile of the mask differed from that of the UFR and SFR samples. Shannon's diversity index was also significantly higher in the UFR and SFR than in the mask (2.64 ± 0.78, 2.66 ± 0.76, and 1.26 ± 1.51, respectively, p < 0.001). Shannon's diversity index of UFR and SFR had a significant positive correlation with each other (r = 0.828, p < 0.001), but there was no significant relationship with Shannon's diversity index of mask. Red complex abundance, including P. gingivalis, T. forsythia, and T. denticola, was significantly higher in UFR than in the mask. Interestingly, the DNA copy number of each of the 14 bacteria, the total bacterial amount, and Shannon's diversity index did not differ in the absence or presence of xerostomia (p > 0.05). In summary, oral bacteria migrated to and existed on the inside of the mask, and the presence of xerostomia did not affect the bacterial profiles. The inner surface of the mask had an independent oral microbiome profile, although this showed lower quantity and diversity than the UFR and SFR samples.

Capillary carbon dioxide tension increases in hospital staff wearing filtering facepiece masks: a prospective crossover study

Background

The COVID-19 pandemic has changed worldwide hygiene practices. In particular, the use of filtering face piece (FFP) masks markedly increased. Concerns have been raised regarding possible negative respiratory effects of wearing FFP masks. The aim of this study was to investigate gas exchange and subjective breathing effort in hospital personnel wearing FFP2 or FFP3 masks.

Methods

In this prospective, single-centre, crossover study, 200 hospital workers were assigned to alternately wear FFP2 or FFP3 masks for 1 h during routine activities. Capillary blood gas analysis was performed to evaluate gas exchange while wearing the FFP masks. The primary end-point was the change in capillary partial pressure of carbon dioxide (P_cCO2). In addition, capillary partial pressure of oxygen (P_cO2), respiratory rate and subjective breathing effort were assessed at the end of each hour. Changes between time points and study groups were estimated using univariate and multivariate models.

Results

P_cCO2 increased from 36.8±3.5 to 37.2±3.3 mmHg (p=0.047) and 37.4±3.2 mmHg (p=0.003) in individuals wearing FFP2 or FFP3 masks, respectively. Age (p=0.021) and male sex (p<0.001) were significantly associated with increased P_cCO2. Similarly, the P_cO2 increased from 70.7±8.4 to 73.4±8.8 mmHg (p<0.001) and 72.8±8.5 mmHg (p=0.004) in individuals wearing FFP2 or FFP3 masks, respectively. Respiratory rate and subjective breathing effort increased significantly while wearing FFP2 and FFP3 masks (p<0.001 for all analyses). The order of wearing FFP2 or FFP3 masks did not significantly affect the results.

Conclusions

An hour of wearing FFP2 or FFP3 masks increased P_cCO2 values, respiratory rate and subjective breathing effort in healthcare personnel performing routine activities.

Physiologic effects of surgical masking in children versus adults

Background

Surgical masks remain a focal part of the CDC guidelines to decrease COVID-19 transmission. Evidence refuting significant effects of masking on ventilation is mostly limited to small studies, with a paucity of studies on children, and none comparing children to adults.

Methods

A total of 119 subjects were enrolled (71 adults, 49 children) in a prospective interventional study with each subject serving as their own mask-free control. End tidal CO2 (ETCO2), inspired CO2 (ICO2), and respiratory rate were measured by nasal cannula attached to an anesthesia machine D-fend module. Pulse oximetry and heart rate were also followed. After the mask-free period, an ASTM Level 3 disposable surgical mask was donned and 15 min of mask-worn data were collected.

Results

A steady state was confirmed for ETCO2 and ICO2 over the masked period, and mean ICO2 levels rose significantly (p < 0.001) after masking in all age groups. The increase in ICO2 for the 2- to 7-year-old group of 4.11 mmHg (3.23-4.99), was significantly higher (p < 0.001) than the final ΔICO2 levels for both the 7- to 14-year-old group, 2.45 mmHg (1.79-3.12), and adults, 1.47 mmHg (1.18-1.76). For the pediatric group there was a negative, significant correlation between age and ΔICO2, r = -0.49, p < 0.001. Masking resulted in a statistically significant (p < 0.01) rise in ETCO2 levels of 1.30 mmHg in adults and 1.36 mmHg in children. The final respective ETCO2 levels, 34.35 (33.55-35.15) and 35.07 (34.13-36.01), remained within normal limits. Pulse oximetry, heart rate, and respiratory rate were not significantly affected.

Discussion

The physiology of mechanical dead space is discussed, including the inverse relationship of subject age vs ICO2. The methodology and results are compared to previously published studies which detracted from the physiologic safety of surgical masking.

Conclusions

The wearing of a surgical mask results in a statistically significant rise in ICO2 and a smaller rise in ETCO2. Because ETCO2 and other variables remain well within normal limits, these changes are clinically insignificant.

Effect of extreme temperatures on asthma hospital visits: Modification by event characteristics and healthy behaviors

Although ambient temperature has been linked to asthma exacerbation, impacts associated with extreme temperature events remain unclear. This study aims to identify the events characteristics that elevate risk of asthma hospital visits, and to assess whether healthy behavior changes due to the COVID-19 prevention and control policy may modify the relationships. Data of asthma hospital visits from all medical facilities in Shenzhen, China during 2016-2020 were assessed in relation to extreme temperature events using a distributed lag model. Stratified analysis was conducted by gender, age and hospital department to identify susceptible populations. Through events defined by various duration days and temperature thresholds, we explored the modification by events intensity, length, occurrence time and healthy behaviors. The cumulative relative risk of asthma during heat waves compared to other days was 1.06 (95%CI: 1.00-1.13) and for cold spells was 1.17 (95%CI: 1.05-1.30), and that of males and school-aged children were generally higher than other sub-groups. There were significant effects of heat waves and cold spells on asthma hospital visits when the mean temperature was above 90th percentile (30 °C) and below 10th percentile (14 °C) respectively, and the relative risks were higher when events lasted longer, became stronger, occurred in daytime and in early summer or winter. During the healthy behaviors maintaining period, the risk of heat waves increased whilst the risk of cold spells reduced. Extreme temperatures may pose considerable impact on asthma and the health effect can be modified by the event characteristics and anti-epidemic healthy behaviors. Strategies of asthma control should consider the heightened threats of the intense and frequent extreme temperature events in the context of climate change.

Influence of Face Masks on Physiological and Subjective Response during 130 Min of Simulated Light and Medium Physical Manual Work-An Explorative Study

BACKGROUND

Undesirable side effects from wearing face masks during the ongoing COVID-19 pandemic continue to be discussed and pose a challenge to occupational health and safety when recommending safe application. Only few studies examined the effects of continuously wearing a face mask for more than one hour. Therefore, the influence of wearing a medical mask (MedMask) and a filtering facepiece class II respirator (FFP2) on the physiological and subjective outcomes in the course of 130 min of manual work was exploratively investigated. Physical work load and cardiorespiratory fitness levels were additionally considered as moderating factors.

METHODS

Twenty-four healthy subjects (12 females) from three different cardiorespiratory fitness levels each performed 130 min of simulated manual work with light and medium physical workload using either no mask, a MedMask or FFP2. Heart rate, transcutaneous oxygen and carbon dioxide partial pressure (P_tcO₂, P_tcCO₂) as well as perceived physical exertion and respiratory effort were assessed continuously at discrete time intervals. Wearing comfort of the masks were additionally rated after the working period.

RESULTS

There was no difference in time-dependent changes of physiological outcomes when using either a MedMask or a FFP2 compared to not wearing a mask. A stronger increase over time in perceived respiratory effort occurred when the face masks were worn, being more prominent for FFP2. Physical workload level and cardiorespiratory fitness level were no moderating factors and higher wearing comfort was rated for the MedMask.

CONCLUSION

Our results suggest that using face masks during light and medium physical manual work does not induce detrimental side effects. Prolonged wearing episodes appeared to increase respiratory effort, but without affecting human physiology in a clinically relevant way.

Physio-metabolic and clinical consequences of wearing face masks—Systematic review with meta-analysis and comprehensive evaluation

Background

As face masks became mandatory in most countries during the COVID-19 pandemic, adverse effects require substantiated investigation.

Methods

A systematic review of 2,168 studies on adverse medical mask effects yielded 54 publications for synthesis and 37 studies for meta-analysis (on n = 8,641, m = 2,482, f = 6,159, age = 34.8 ± 12.5). The median trial duration was only 18 min (IQR = 50) for our comprehensive evaluation of mask induced physio-metabolic and clinical outcomes.

Results

We found significant effects in both medical surgical and N95 masks, with a greater impact of the second. These effects included decreased SpO2 (overall Standard Mean Difference, SMD = −0.24, 95% CI = −0.38 to −0.11, p &lt; 0.001) and minute ventilation (SMD = −0.72, 95% CI = −0.99 to −0.46, p &lt; 0.001), simultaneous increased in blood-CO2 (SMD = +0.64, 95% CI = 0.31–0.96, p &lt; 0.001), heart rate (N95: SMD = +0.22, 95% CI = 0.03–0.41, p = 0.02), systolic blood pressure (surgical: SMD = +0.21, 95% CI = 0.03–0.39, p = 0.02), skin temperature (overall SMD = +0.80 95% CI = 0.23–1.38, p = 0.006) and humidity (SMD +2.24, 95% CI = 1.32–3.17, p &lt; 0.001). Effects on exertion (overall SMD = +0.9, surgical = +0.63, N95 = +1.19), discomfort (SMD = +1.16), dyspnoea (SMD = +1.46), heat (SMD = +0.70), and humidity (SMD = +0.9) were significant in n = 373 with a robust relationship to mask wearing (p &lt; 0.006 to p &lt; 0.001). Pooled symptom prevalence (n = 8,128) was significant for: headache (62%, p &lt; 0.001), acne (38%, p &lt; 0.001), skin irritation (36%, p &lt; 0.001), dyspnoea (33%, p &lt; 0.001), heat (26%, p &lt; 0.001), itching (26%, p &lt; 0.001), voice disorder (23%, p &lt; 0.03), and dizziness (5%, p = 0.01).

Discussion

Masks interfered with O2-uptake and CO2-release and compromised respiratory compensation. Though evaluated wearing durations are shorter than daily/prolonged use, outcomes independently validate mask-induced exhaustion-syndrome (MIES) and down-stream physio-metabolic disfunctions. MIES can have long-term clinical consequences, especially for vulnerable groups. So far, several mask related symptoms may have been misinterpreted as long COVID-19 symptoms. In any case, the possible MIES contrasts with the WHO definition of health.

Conclusion

Face mask side-effects must be assessed (risk-benefit) against the available evidence of their effectiveness against viral transmissions. In the absence of strong empirical evidence of effectiveness, mask wearing should not be mandated let alone enforced by law.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021256694, identifier: PROSPERO 2021 CRD42021256694.

Possible toxicity of chronic carbon dioxide exposure associated with face mask use, particularly in pregnant women, children and adolescents - A scoping review

Introduction

During the SARS-CoV-2-pandemic, face masks have become one of the most important ubiquitous factors affecting human breathing. It increases the resistance and dead space volume leading to a re-breathing of CO2. So far, this phenomenon and possible implications on early life has not been evaluated in depth.

Method

As part of a scoping review, literature was systematically reviewed regarding CO2 exposure and facemask use.

Results

Fresh air has around 0.04% CO2, while wearing masks more than 5 min bears a possible chronic exposure to carbon dioxide of 1.41% to 3.2% of the inhaled air. Although the buildup is usually within the short-term exposure limits, long-term exceedances and consequences must be considered due to experimental data. US Navy toxicity experts set the exposure limits for submarines carrying a female crew to 0.8% CO2 based on animal studies which indicated an increased risk for stillbirths. Additionally, mammals who were chronically exposed to 0.3% CO2 the experimental data demonstrate a teratogenicity with irreversible neuron damage in the offspring, reduced spatial learning caused by brainstem neuron apoptosis and reduced circulating levels of the insulin-like growth factor-1. With significant impact on three readout parameters (morphological, functional, marker) this chronic 0.3% CO2 exposure has to be defined as being toxic. Additional data exists on the exposure of chronic 0.3% CO2 in adolescent mammals causing neuron destruction, which includes less activity, increased anxiety and impaired learning and memory. There is also data indicating testicular toxicity in adolescents at CO2 inhalation concentrations above 0.5%.

Discussion

There is a possible negative impact risk by imposing extended mask mandates especially for vulnerable subgroups. Circumstantial evidence exists that extended mask use may be related to current observations of stillbirths and to reduced verbal motor and overall cognitive performance in children born during the pandemic. A need exists to reconsider mask mandates.

Efficacy of Surgical Masks Versus N95 Respirators for the Prevention of COVID-19 in Dental Settings: A Systematic Review

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2. (SARS-CoV-2). It spreads mainly through saliva droplets or nasal discharge. Dentists are among the professionals with the greatest risk of contracting and transmitting COVID-19. We compared the efficacy of surgical masks versus N95 respirators in preventing COVID-19 infection in dental settings. PubMed, Scopus, Web of Science, and Cochrane Library databases were searched. Search terms corresponded to a predefined PICOS (patient/population, intervention, comparison, and outcomes) question. The risk of bias was evaluated using AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews-2), ROBIS (Risk of Bias in Systematic Reviews), and Health Evidence tools. A total of 191 articles were screened, and nine of them were further evaluated for eligibility, of which five articles (fulfilled the selection criteria) and were included in this study. Two studies concluded that surgical masks could provide equivalent protection to N95 respirators. Another study found that N95 respirators were superior to surgical masks. The fourth study found that better protection can be achieved when using surgical masks by the aerosol source than when the recipient uses an N95 respirator, while the last study concluded that surgical masks or N95 respirators alone do not provide full protection. Thus, according to this systematic review, N95 respirators provide better protection against COVID-19 infection compared to surgical masks.

Effect of short-term use of FFP2 (N95) masks on the salivary metabolome of young healthy volunteers: a pilot study

The use of face masks has become an integral part of public life in the post-pandemic era. However, the understanding of the effect of wearing masks on physiology remains incomplete and is required for informing public health policies. For the first time, we report the effects of wearing FFP2 masks on the metabolic composition of saliva, a proximal matrix to breath, along with cardiopulmonary parameters. Un-induced saliva was collected from young (31.2 ± 6.3 years) healthy volunteers (n = 10) before and after wearing FFP2 (N95) masks for 30 minutes and analyzed using GCMS. The results showed that such short-term mask use did not cause any significant change in heart rate, pulse rate or SpO₂. Three independent data normalization approaches were used to analyze the changes in metabolomic signature. The individuality of the overall salivary metabotype was found to be unaffected by mask use. However, a trend of an increase in the salivary abundance of L-fucose, 5-aminovaleric acid, putrescine and phloretic acid was indicated irrespective of the method of data normalization. Quantitative analysis confirmed increases in concentrations of these metabolites in saliva of paired samples amid high inter-individual variability. The results showed that while there was no significant change in measured physiological parameters and individual salivary metabotypes, mask use was associated with correlated changes in these metabolites plausibly originating from altered microbial metabolic activity. These results might also explain the change in odour perception reported to be associated with mask use. Potential implications of these changes on mucosal health and immunity warrants further investigation to evolve more prudent mask use policies.

Face mask use to prevent COVID-19 in clinical practice. Using a review of reviews to improve decision-making and transparency

BACKGROUND

The COVID-19 pandemic has highlighted the importance of transparency and scientific rigour in the development of clinical guidance. Rapid review methodologies were widely used in the development of guidance, and in the United Kingdom, COVID-19 guidance was criticized for methodological inadequacy and erroneous conclusions.

AIMS

To summarize the evidence looking at the use of face masks to prevent COVID-19 infection in clinical practice areas, and to show how this can be used in decision-making.

DESIGN

Overview of systematic reviews.

METHOD

Systematic reviews which included meta-analyses were sought, and data on the protective effect of face masks on COVID-19 transmission were extracted. A total of 15 papers yielded 44 effect sizes suitable for quantitative presentation, which showed wide variation in effect depending on the outcome and intervention chosen.

CONCLUSIONS

Guideline development groups need to take care to choose outcomes that are of most importance to those who are the target of guidance. Quantification of the protective effect of interventions such as different types of face mask will help nurses and others decide on the utility of their use, alongside consideration of the other factors that go into informing clinical recommendations.

IMPLICATIONS FOR PATIENT CARE AND THE PROFESSION

COVID-19 has been an unprecedented public health issue, but much clinical guidance was lacking in transparency. Nurses and other healthcare professionals have often expressed a lack of confidence in guidance. Systematic reviews reported a wide range of effect sizes. However, there was a high degree of indirectness and heterogeneity in methods and findings. To produce transparent guidance, those for whom guidance is intended should have evidence of effect where this is available.

IMPACT

Guideline authors should reflect these outcomes in their recommendations, clearly balancing both the benefits and harms of recommending face masks to prevent COVID-19.

Development and evaluation of a fluidic facemask for airborne transmission mitigation

Recently, a fluidic facemask concept was proposed to mitigate the transmission of virus-laden aerosol and droplet infections, such as SARS-CoV-2 (COVID-19). This paper describes an experimental investigation of the first practical fluidic facemask prototype, or "Air-Screen". It employs a small, high-aspect-ratio, crossflow fan mounted on the visor of a filter-covered cap to produce a rectangular air jet, or screen, in front of the wearer's face. The entire assembly weighs less than 200 g. Qualitative flow visualization experiments using a mannequin clearly illustrated the Air-Screen's ability to effectively block airborne droplets (∼10⁰ µm) from the wearer's face. Quantitative experiments to simulate droplets produced during sneezing or a wet cough (∼10² µm) were propelled (via a transmitter) at an average velocity of 50 m/s at 1 m from the mannequin or a target. The Air-Screen blocked 62% of all droplets with a diameter of less than 150 µm. With an Air-Screen active on the transmitter, 99% of all droplets were blocked. When both mannequin and transmitter Air-Screens were active, 99.8% of all droplets were blocked. A mathematical model, based on a weakly-advected jet in a crossflow, was employed to gain greater insight into the experimental results. This investigation highlighted the remarkable blocking effect of the Air-Screen and serves as a basis for a more detailed and comprehensive experimental evaluation.

The impact of wearing powered air purifying respirators or N95 masks on the olfactory function in healthcare workers: A randomized controlled trial

BACKGROUND

With the Coronavirus disease 2019 epidemic, wearing a mask has become routine to prevent and control the virus's spread, especially for healthcare workers. However, the impact of long-term mask wear on the human body has not been adequately investigated. This study aimed to investigate whether Powered Air Purifying Respirators and N95 masks impact the olfaction in healthcare workers.

METHODS

We recruited fifty-six healthcare workers and randomly divided them into 2 groups, wearing a powered air purifying respirator (PAPR) (experiment group, N = 28) and an N95 mask (control group, N = 28). Olfactory discrimination and threshold tests were performed before and after wearing the masks. SPSS 26.0 (SPSS Inc., Chicago, Illinois) software was used for the statistical analyses.

RESULTS

There was a statistical difference in the olfactory threshold test after wearing the mask in both PAPR Group (Z = -2.595, P = .009) and N95 Group (Z = -2.120, P = .034), with no significant difference between the 2 (χ2 = 0.29, P = .589). There was no statistical difference in the discrimination test scores in both 2 groups after wearing the masks.

CONCLUSION

Wearing a mask affects the healthcare workers' olfaction, especially odor sensitivity. Healthcare workers have a higher olfactory threshold after long-term mask wear, whether wearing PAPRs or N95 masks.

Geographical, Sex, Age, and Seasonal Differences in Serum Manganese Status Among Chinese Adults with Hypertension

BACKGROUND

Manganese (Mn) is an essential trace metal element required for optimal human health. However, few studies have assessed the Mn status in hypertensive patients, especially in China. Moreover, factors associated with Mn status have not yet been thoroughly explored. Therefore, we aimed to assess the serum Mn status of adults with hypertension in China and its association with demographic factors.

METHODS

An observational, cross-sectional study was conducted to assess serum Mn concentrations in 14 provinces of China. A total of 2597 patients with hypertension were randomly identified by sex, age, and district, and serum Mn concentrations were quantified using inductively coupled plasma mass spectrometry (ICP-MS).

RESULTS

In our study population, the median serum Mn levels were 1.60 (interquartile range (IQR), 0.94-2.85) µg/L for males and 1.51 (IQR, 0.86-2.69) µg/L for females. In adjusted linear regression models, significantly higher serum Mn concentrations were found in summer (compared with spring, β, 1.06 µg/L, 95% CI: 0.62 to 1.50), and those living in Guangxi (compared with Heilongjiang, β, 0.81, 95% CI: 0.06 to 1.56), Shanxi (compared with Heilongjiang, β, 0.75, 95% CI: 0.01 to 1.50), and Liaoning (compared with Heilongjiang, β, 1.65, 95% CI: 0.91 to 2.38), and significantly lower serum Mn concentrations were found in patients who aged 60-70 years (compared with those aged < 60 years, β, - 0.40 μg/L, 95% CI: - 0.76 to - 0.05).

CONCLUSION

Our findings observed high serum Mn status among Chinese adults with hypertension, and revealed the association between terms of age, region, and season with serum Mn.

Evaluation of face masks as a valuable forensic DNA evidence in the post-COVID era

After the onset of COVID-19 pandemic, a sharp surge in the usage of the face-masks throughout the globe has been observed. Pre-experiment survey of 252 individuals indicated a higher use of cotton-make masks (41%), followed by N-95 make (31%), and surgical disposable masks (26%). It was also further revealed that a higher fraction of individuals wear a face-mask more than 3 times (37%) before its disposal. In order to assess the potential usability of different mask types as forensic DNA evidence, a study was conducted on 50 healthy individuals. DNA content of different fractions such as the portion of mask covering the mouth region and the ear-piece showed a good source of host DNA. Though no statistically significant difference (P < 0.05) was found in the DNA quantity obtained from different face mask types, an increasing trend was obtained in the order: cloth make type (7.031 ± 0.31 ng), N-95 make (4.711 ± 0.15 ng), and surgical disposable type (2.17 ± 0.13 ng). The time of wearing of a face-mask showed a positive correlation with the yield of DNA irrespective of the face-mask type used. Samples retrieved from both the portions covering the mouth area and the ear-piece showed a good source of genomic DNA yielding an average of 4.82 ± 0.11 ng and 4.44 ± 0.10 ng of DNA, respectively. Irrespective of the face-mask types, number of reuse, and the portion of the mask, 66.66-96.11% of samples showed a complete autosomal STR DNA profile. This suggests that if a face-mask is found at the crime scene, it should be collected and preserved as a potential source of DNA evidence for routine forensic DNA analysis.

Effect of face masks on salivary parameters and halitosis: Randomized controlled crossover trial

BACKGROUND

Face masking is associated with self-perceived dry mouth and halitosis. Aim of the study was to measure the effect of different face masks on salivary parameters and halitosis.

METHODS

The randomized controlled crossover clinical trial with four periods included 40 oral healthy participants using different face masks (cloth mask, surgical mask, filtering facepiece 2 [FFP2] mask) or no mask (control) for 4 h in random order. Unstimulated salivary flow rate (primary outcome) and stimulated salivary flow rate, salivary pH and buffer capacity of stimulated and unstimulated saliva (secondary outcomes, blinded), and volatile sulfur compounds (secondary outcome) were measured before and after the 4-h periods. Statistical analysis was performed by repeated measures ANOVA (p < 0.05).

RESULTS

Of 40 randomized participants, 39 completed the study. Unstimulated salivary flow rate prior to face masking amounted to 0.6 ± 0.3 ml/min. Face masking had no significant effect on unstimulated salivary flow (p = 0.550). Face masking had also no significant effect on the other salivary parameters (p ≥ 0.518). The concentration of volatile sulfur compounds (VSC) prior to face masking amounted to 157.3 ± 59.7 ppb. After face masking, the concentration of VSC increased slightly, but not significantly (p = 0.055): 168.1 ± 76.3 ppb (control), 199.3 ± 132.7 ppb (cloth masks), 188.5 ± 101.1 ppb (surgical masks), and 189.7 ± 90.1 ppb (FFP2 masks).

CONCLUSION

Four hours of face masking did not change the salivary flow rate, pH, and buffer capacity, and had no significant effect on VSC's levels. Wearing face masks does not seem to result in measurable side-effects on salivary parameters such as a reduced salivary flow rate or VSC's levels.

CLINICAL TRIAL REGISTRATION

The protocol was prospectively registered at ClinicalTrials.gov (NCT04914208) on June 4, 2021.

Does Prolonged FFP2 Mask Use Cause Changes in Nasal Cytology? A Pilot Observational Study on Healthcare Workers

TheCOVID-19 pandemic has rapidly spread worldwide. Individual prevention approaches include FFP2/N95 mask use. Healthcare (HC) workers wear face masks for a long time during their work shifts and often complain of nasal symptoms. Current data on mask-associated symptoms or upper airway epithelium transformations are limited. Nasal cytology (NC) is a useful, non-invasive diagnostic method to assess cellular alterations. The aim of this study is to compare NC in HC workers before and after the continuous wearing of FFP2 face masks. We conducted a pilot observational study on 10 volunteer HC workers, who continuously used FFP2 masks during the work shift. All subjects underwent NC at the beginning (T0) and at the end of their workshift (T1) and the cytological findings were compared. Moreover, nasal symptoms were collected. Rare inflammatory cells were detected at T0 and, comparing cytological data about T0 and T1, no significant differences were observed. The most reported nasal symptoms were itching (70%) and a dry nose (60%). Difficulty of breathing and nasal blockage were not relevant. These preliminary data seem to suggest that wearing an FFP2 mask does not determine observable alterations in NC in daily work. However, further studies on a larger population for a longer period are needed.

The Difference in Electromyographic Activity While Wearing a Medical Mask in Women with and without Temporomandibular Disorders

Wearing a medical mask influences resting activity of the temporalis anterior and masseter muscles in healthy young women. However, no studies link medical mask-wearing with masticatory muscle activity in patients with temporomandibular disorders (TMDs). Therefore, this study aims to compare electromyographic patterns while wearing a medical mask between women with and without temporomandibular disorders. Based on the Research Diagnostic Criteria for Temporomandibular Disorders, 115 adult women qualified for the study. Participants were divided into the following two groups: diagnosed TMDs (n = 55; mean age: 23.5 ± 2.3 years) and healthy women (n = 60; mean age: 23.7 ± 2.6 years). Examinations of the resting and functional electromyographic activity of the temporalis anterior (TA), superficial masseter (MM), anterior bellies of the digastric muscle (DA), and the middle part of the sternocleidomastoid muscle (SCM) were carried out using the BioEMG III™. Both groups showed statistically significant decreases in resting masticatory muscle activity during medical mask examination compared to no mask measurement. The significant differences in no mask measurement between both groups were noted regarding resting masticatory activity, clenching in the intercuspal position, and clenching on dental cotton rollers. During medical mask examination, women with TMDs showed differences in resting masticatory activity and clenching on dental cotton rollers compared to the healthy group. In all analyzed variables, both groups showed similar electromyographic patterns in the maximum mouth opening measurement during medical mask and no mask examination. A medical mask influences the resting bioelectric activity of the masticatory muscles in women with temporomandibular disorders and healthy women. We observed differences and some similarities in resting and functional electromyographic patterns within masticatory and neck muscles in both groups during medical mask and no mask examination.

The pharmaceutical industry is dangerous to health. Further proof with COVID-19

Background:

The COVID-19 period highlights a huge problem that has been developing for decades, the control of science by industry. In the 1950s, the tobacco industry set the example, which the pharmaceutical industry followed. Since then, the latter has been regularly condemned for illegal marketing, misrepresentation of experimental results, dissimulation of information about the dangers of drugs, and considered as criminal. Therefore, this study was conducted to show that knowledge is powerfully manipulated by harmful corporations, whose goals are: 1/financial; 2/to suppress our ability to make choices to acquire global control of public health.

Methods:

Pharmaceutical industry techniques for manipulating science and COVID-19 reporting were reviewed. Several sources of official documents were used: PubMed; National Institutes of Health resources; pharmaceutical companies; policy documents; national newspapers and news agencies; and books by prominent professionals (scientific and legal). A few studies have not been published in peer-reviewed journals; however, they have been conducted by reputable scientists in their respective fields.

Results:

Since the beginning of COVID-19, we can list the following methods of information manipulation which have been used: falsified clinical trials and inaccessible data; fake or conflict-of-interest studies; concealment of vaccines’ short-term side effects and total lack of knowledge of the long-term effects of COVID-19 vaccination; doubtful composition of vaccines; inadequate testing methods; governments and international organizations under conflicts of interest; bribed physicians; the denigration of renowned scientists; the banning of all alternative effective treatments; unscientific and liberticidal social methods; government use of behavior modification and social engineering techniques to impose confinements, masks, and vaccine acceptance; scientific censorship by the media.

Conclusion:

By supporting and selecting only the one side of science information while suppressing alternative viewpoints, and with obvious conflicts of interest revealed by this study, governments and the media constantly disinform the public. Consequently, the unscientifically validated vaccination laws, originating from industry-controlled medical science, led to the adoption of social measures for the supposed protection of the public but which became serious threats to the health and freedoms of the population.

Nanotechnology Transition Roadmap toward Multifunctional Stimuli-Responsive Face Masks

In recent times, the use of personal protective equipment, such as face masks or respirators, is becoming more and more critically important because of common pollution; furthermore, face masks have become a necessary element in the global fight against the COVID-19 pandemic. For this reason, the main mission of scientists has become the development of face masks with exceptional properties that will enhance their performance. The versatility of electrospun polymer nanofibers has determined their suitability as a material for constructing "smart" filter media. This paper provides an overview of the research carried out on nanofibrous filters obtained by electrospinning. The progressive development of the next generation of face masks whose unique properties can be activated in response to a specific external stimulus is highlighted. Thanks to additional components incorporated into the fiber structure, filters can, for example, acquire antibacterial or antiviral properties, self-sterilize the structure, and store the energy generated by users. Despite the discovery of several fascinating possibilities, some of them remain unexplored. Stimuli-responsive filters have the potential to become products of large-scale availability and great importance to society as a whole.

Effects of Wearing FFP2 Masks on SARS-CoV-2 Infection Rates in Classrooms

In this retrospective cohort study involving 614 secondary school students, the likelihood of becoming infected with SARS-CoV-2 in schools with different focus (sports focus vs. general branch; the only difference in the sports focus school was that PE was allowed at all times without restrictions) and different prevailing restrictions were compared. A significantly higher likelihood of infection with SARS-CoV-2 was found in sports classes during the period with a strict FFP-2 mask requirement compared to general branch classes (for Delta from November 2021 to December 2021, and for Omicron from January 2022 to February 2022). The higher likelihood of infection was observed both during the Delta and the Omicron wave. After the relaxation of the mitigation measures, however, students in general branch classes showed a clear "catch-up" of infections, leading to a higher incidence of infections during this phase. By the end of the observation period (30 April 2022), only a small difference in cumulative SARS-CoV-2 infection rates (p = 0.037, φ = 0.09) was detected between classes with a sports focus and those without a sports focus. The results suggest that SARS-CoV-2 transmission can be reduced in school classes by mandatory FFP-2 mask use. In many cases, however, infection appears to be postponed rather than avoided.

Commitment to protective measures during the COVID-19 pandemic in Syria: A nationwide cross-sectional study

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 continues to impose itself on all populations of the world. Given the slow pace of vaccination in the developing world and the absence of effective treatments, adherence to precautionary infection control measures remains the best way to prevent the COVID-19 pandemic from spiraling out of control. In this study, we aim to evaluate the extent to which the Syrian population adheres to these measures and analyze the relationship between demographic variables and adherence.

METHODS

This cross-sectional study took place in Syria between January 17 and March 17, 2021. A structured self-administered questionnaire was used to collect the data. The questionnaire was distributed in both electronic and printed versions. Our sample consisted of 7531 individuals. Collected data were analyzed using SPSS v.25. The chi-square test was used to address the correlation between adherence and demographic variables.

RESULTS

Of the 10083 reached out, only 8083 responded, and 7531 included in the final analysis with an effective response rate of 74.7%. Of them, 4026 (53.5%) were women, 3984 (52.9%) were single, and 1908 (25.3%) had earned university degrees. 5286 (70.25) were in the high level of adherence category to protective measures. Statistically significant differences were documented when investigating the correlation between commitment to preventive measures and age, sex, marital status, financial status, employment, and educational attainment. Furthermore, those who believed that COVID-19 poses a major risk to them, or society were more committed to preventive measures than those who did not.

CONCLUSION

The participants in this study generally showed a high level of adherence to the preventive measures compared to participants in other studies from around the world, with some concerns regarding the sources of information they depend on. Nationwide awareness campaigns should be conducted and focus on maintaining, if not expanding, this level of commitment, which would mitigate the pandemic's impact on Syrian society.

Effect of Face Masks on Physiological and Perceptual Responses during 30 Minutes of Self-Paced Exercise in Older Community Dwelling Adults

This study examined the effects of different types of masks (no mask, surgical mask (SM), and N95-mask) on physiological and perceptual responses during 30-min of self-paced cycle ergometer exercise. This study was a prospective randomly assigned experimental design. Outcomes included workload (Watts), oxygen saturation (SpO₂), end-tidal carbon dioxide (PetCO₂), heart rate (HR), respiratory rate (RR), rating of perceived exertion (RPE), and rating of perceived dyspnea (RPD). Volunteers (54-83 years (n = 19)) completed two familiarization sessions and three testing sessions on an air braked cycle ergometer. No significant difference was found for condition x time for any of the dependent variables. RPE, RPD, and PetCO₂ were significantly higher with an N95-mask vs. no mask (NM) ((p = 0.012), (p = 0.002), (p < 0.001)). HR was significantly higher with the SM compared to the NM condition (p = 0.027) (NM 107.18 ± 9.96) (SM 112.34 ± 10.28), but no significant difference was found when comparing the SM to the N95 condition or when comparing the N95condition to the NM condition. Watts increased across time in each condition (p = 0.003). Initially RR increased during the first 3 min of exercise (p < 0.001) with an overall gradual increase noted across time regardless of mask condition (p < 0.001). SpO₂ significantly decreased across time but remained within normal limits (>95%). No significant difference was found in Watts, RR, or SpO₂ regardless of mask condition. Overall, the N95mask was associated with increased RPE, RPD, and PetCO₂ levels. This suggests trapping of CO₂ inside the mask leading to increased RPE and RPD.

Health hazards related to using masks and/or personal protective equipment among physicians working in public hospitals in Dhaka: A cross-sectional study

Background

Wearing masks or personal protective equipment (PPE) has become an integral part of the occupational life of physicians due to the coronavirus disease 2019 (COVID-19) pandemic. Most physicians have been developing various health hazards related to the use of different protective gears. This study aimed to determine the burden and spectrum of various health hazards associated with using masks or PPE and their associated risk factors.

Methods

This cross-sectional survey was conducted in Dhaka Medical College from March 01–May 30, 2021, among physicians from different public hospitals in Dhaka, Bangladesh. We analyzed the responses of 506 physicians who completed case record forms through Google forms or hard copies.

Findings

The mean (SD) age of the respondents was 35.4 [7.7], and 69.4% were men. Approximately 40% were using full PPE, and 55% were using N-95 masks. A total of 489 (96.6%) patients experienced at least one health hazard. The reported severe health hazards were syncope, severe dyspnea, severe chest pain, and anaphylaxis. Headache, dizziness, mood irritation, chest pain, excessive sweating, panic attack, and permanent facial disfigurement were the minor health hazards reported. Extended periods of work in the COVID-19-unit, reuse of masks, diabetes, obesity, and mental stress were risk factors for dyspnea. The risk factors for headaches were female sex, diabetes, and previous primary headaches. Furthermore, female sex and reusing masks for an extended period (> 6 h) were risk factors for facial disfigurement. The risk factors for excessive sweating were female sex and additional evening office practice for an extended period.

Conclusions

Healthcare workers experienced several occupational hazards after using masks and PPE. Therefore, an appropriate policy is required to reduce such risks.

Quantifying protocols for safe school activities

By the peak of COVID-19 restrictions on April 8, 2020, up to 1.5 billion students across 188 countries were affected by the suspension of physical attendance in schools. Schools were among the first services to reopen as vaccination campaigns advanced. With the emergence of new variants and infection waves, the question now is to find safe protocols for the continuation of school activities. We need to understand how reliable these protocols are under different levels of vaccination coverage, as many countries have a meager fraction of their population vaccinated, including Uganda where the coverage is about 8%. We investigate the impact of face-to-face classes under different protocols and quantify the surplus number of infected individuals in a city. Using the infection transmission when schools were closed as a baseline, we assess the impact of physical school attendance in classrooms with poor air circulation. We find that (i) resuming school activities with people only wearing low-quality masks leads to a near fivefold city-wide increase in the number of cases even if all staff is vaccinated, (ii) resuming activities with students wearing good-quality masks and staff wearing N95s leads to about a threefold increase, (iii) combining high-quality masks and active monitoring, activities may be carried out safely even with low vaccination coverage. These results highlight the effectiveness of good mask-wearing. Compared to ICU costs, high-quality masks are inexpensive and can help curb the spreading. Classes can be carried out safely, provided the correct set of measures are implemented.

The World Bank-UNESCO-UNICEF report [1] estimates that learning losses from the COVID-19 pandemic could cost this generation $17 trillion dollars in lifetime earnings. Despite the surging pressure to keep schools open, many countries lack guidelines for safe school activities. Using the empirical transmission level for closed schools as a baseline, we quantify the impact of distinct non-pharmaceutical interventions (NPIs) on infection rates and different values of vaccine coverage. Strikingly, we show that classes can be kept safe, provided the correct wearing of good quality masks together with to the proper combination of other NPIs. In such scenarios, the increase in infections can be kept below 20% compared to suspending classes.

Factors associated with anxiety symptoms among medical laboratory professionals in Khobar: Single institution study

Background

A clinical professional has a challenging role during the coronavirus disease (COVID-19) pandemic in providing timely and accurate results with limited resources and a rapid increase in the number of samples to be tested. However, during the ongoing pandemic, the anxiety level of Medical Laboratory Professionals (MLT) has not been studied in Saudi Arabia within the hospital environment.

Aim

To determine the associated factors related with anxiety level of MLT at King Fahd Hospital of the University (KFHU) during the COVID-19 pandemic.

Methods

The study design was a cross-sectional quantitative study. Data were collected by administering a paper-based questionnaire that was distributed among MLT at KFHU. The questionnaire consisted of three sections. The first two sections were prepared by the researchers and included participant demographics and questions related to COVID-19. The third section used the Hamilton Anxiety Scale to assess anxiety levels.

Result

The study revealed that 70.4% of MLT showed no signs of anxiety, while 19.2% showed mild/moderate anxiety levels, and approximately 10.4% showed severe to extreme anxiety levels. In addition, a significant association between the anxiety level and difficulty breathing among MLT wearing personal protective equipment was observed. Moreover, a significant association between sex and anxiety level was identified. Females MLT had higher percentages of severe anxiety (12.8% vs. 5.1%) and mild/moderate anxiety (24.4 vs. 7.7%) than males.

Conclusions

Protecting the mental health status of MLT is an essential part of public health measures to fight the COVID-19 pandemic.

Carbon dioxide rises beyond acceptable safety levels in children under nose and mouth covering: Results of an experimental measurement study in healthy children

Nose and mouth covering (NMC) has been made compulsory for children in many countries during the Covid-19 pandemic. We wanted to determine the average CO₂ levels in inhaled air with NMC in children between age 6 and 17. We used short term measurements under surgical masks and FFP2 masks according to European norm EN 149, compared to baseline in an experimental, intra-individually controlled study over 25 min. CO₂ content was measured every 15 s using an automated dual-wavelength infrared CO₂ measurement device (G100, Geotech, Leamington Spa, UK) over 25 min in a short-term experimental setting, with children seated. After baseline measurement children were provided with two types of commonly worn NMC: surgical masks and FFP2--masks in randomized sequence for 3 min each. We kept ambient CO₂-levels below 1000 parts per million (ppm) through frequent ventilation. We measured breathing frequency and pulse as potential physiological moderator variables. Forty-five children, 25 boys, 20 girls, with a mean age of 10.7 years (standard deviation 2.6) were measured. We measured 13,100 ppm (SD 380) under surgical mask and 13,900 ppm (SD 370) under FFP2 mask in inhaled air. A linear model with age as a covariate showed a highly significant effect of the condition (p < 1*10^-9). We measured 2,700 ppm (SD 100) CO₂ at pre-baseline and 2,800 ppm (SD 100) at post-baseline, a non-significant small difference. Appropriate contrasts revealed that the change was due to the masks only and the difference between the two types of masks was small and not significant. Wearing of NMC (surgical masks or FFP2- -masks) raises CO₂ content in inhaled air quickly to a very high level in healthy children in a seated resting position that might be hazardous to children's health.

Blepharoconjunctivitis and Otolaryngological Disease Trends in the Context of Mask Wearing during the COVID-19 Pandemic

(1) Purpose: In 2020, wearing of face masks was mandated in the United States in an effort to lessen transmission of the novel 2019 coronavirus disease (COVID-19) pandemic; however, long-term mask wearing may present with unintended side-effects in both ophthalmic and otolaryngologic clinical practice. This study aims to examine if mask wearing increased the incidence of primarily chalazion, blepharoconjunctivitis, and rhinitis occurrence during the mask-mandated COVID-19 pandemic period. (2) Methods: Medical records from tertiary academic center clinics were analyzed for incidence of ophthalmic and otolaryngologic diagnoses of interest (blepharoconjunctivitis- and rhinitis-related disorders). Data were collected from a pre-pandemic (March 2019–February 2020) and a mid-pandemic window (March 2020–February 2021) during which widespread mask mandates were implemented in Texas. Comparison was performed using a t-test analysis between incidence of chosen diagnoses during the described time periods. (3) Results: Incidence of ophthalmic disorders (primarily blepharoconjunctivitis and chalazion) in the pre-pandemic versus mid-pandemic windows did show a significant difference (p-value of 0.048). Similarly, comparison of otolaryngologic diagnoses (primarily rhinitis and related conditions) between the two time periods showed a significant difference (p-value of 0.044) as well. (4) Conclusion: Incidence of the chosen ophthalmic and otolaryngologic disorders did increase during periods of mask mandates. While these findings are preliminary, further studies are warranted to understand other factors that may have played a role in eye and nose pathology.

Myths and misconception of COVID-19 among hospital sanitary workers in Pakistan: Efficacy of a training program intervention

Objective

Hospital sanitary workers are among the prime source to disseminate information at a massive level, however they received least attention during the pandemic COVID-19. The study was designed to investigate the prevailing myths and misconceptions of the coronavirus pandemic among the sanitary workers of health care system. Further, a systematic training program is devised and tested to demystify the false myths with discerning truth and awareness-raising in hospital sanitary workers.

Method

A pre-post face-to-face intervention design was opted and the intervention was conducted at five locations by the project team. The intervention consisted a 3 days training program to target myths and misconceptions of hospital sanitary workers. The study was completed in 8 months starting from August, 2019 to March, 2020. Participants were recruited from local hospitals having a specialized indoor COVID treatment facility. The sample consisted of 82 participants (n = 25, 30.09% females) with age ranging from 18 to 60 years (M ± SD = 37.41 ± 10.09).

Findings

The results indicated that 86.4% of the participants never heard the name of the coronavirus before the pandemic in Pakistan. A majority of the participants (> 50%) believed on a very alarming but unrealistic rate of mortality i.e., 30–60%. The pre-testing showed a high prevalence of myths in all four domains (i.e., popular treatments = 24.44, conspiracy myths = 7.93, home remedies = 16.46, and COVID-reliance = 7.82). The pre and post comparison of individual myths showed significant improvement on 24 of the 26 myths with a decline ranging from 0.18 to 1.63. Overall, the intervention significantly decreased scores on all four domains of coronavirus myths.

Conclusion

The training intervention appeared to effectively reduce myths and misconceptions of sanitary staff workers and is advised to be included as a standard training program for sanitary workers of health care system.

Future Acceptability of Respiratory Virus Infection Control Interventions in General Population to Prevent Respiratory Infections

Background and Objectives: In both pandemic and non-pandemic situations, nonpharmaceutical public health measures may offer easy, low-cost, and effective means of reducing the spread and impact of acute respiratory infections. It is unknown whether such measures would be acceptable to the Saudi community beyond the current pandemic. Materials and Methods: A validated survey was used to test community acceptance of the measures. Respondents were asked which infection control practices they planned to maintain and which they believed should be policies for the community as a whole after the COVID-19 pandemic has subsided. Results: The survey was completed by 2057 people (95% completion rate), 1486 (72%) of whom were female, 259 (12.5%) of whom were current smokers, and 72 (3.5%) of whom had chronic lung disease. The most prevalent age groups were 18−30 years (933; 45.4%) and 31−40 years (483; 23.5%), with 641 individuals over 40 years old. Of the responses, 93% indicated that they would continue washing their hands more often; 92% wanted both clinicians and patients to wear masks in hospitals; 86% would continue avoiding smoking in indoor and outdoor areas; 73% would continue wearing a face covering on public transportation; 70% indicated that they would continue wearing a face covering in indoor public places. Regarding the respiratory virus infection control measures, 85% (11/13) received significant support (≥70% acceptability level) for continuation as policies in the future. Wearing face coverings outdoors and social distancing outdoors received little support (45% and 66%, respectively). Of the respiratory virus infection control measures, 54% received less support from current smokers than non-smokers (acceptability level < 70%). People with chronic respiratory disease supported 77% of the measures being regarded as policies in the future. Conclusion: The Saudi community supports nonpharmacological respiratory infection control measures that reduce the likelihood of infection. Public health campaigns should target smokers to increase awareness of the importance of these measures in lowering infections. Based on the findings of this study, nonpharmacological treatments should be presented and included in future recommendations for both the public and patients diagnosed with chronic respiratory diseases.

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.

Orthodontic Adolescent Patients’ Attitudes toward Protective Face Mask Wearing during the COVID-19 Pandemic

Background and Objectives: The COVID-19 pandemic led to restrictive measures, which aimed to limit the spread of the SARS-CoV-2 virus. These restrictions impacted all areas of life, including the activity of dental offices. For patients with orthodontic appliances, closing the dental offices was a major issue, as most orthodontic treatments last for more than a year and require regular checkups. The aim of this research was to assess the impact that the restrictive measures that were imposed during the COVID-19 pandemic, and, especially, wearing a face mask had on a sample of Romanian teenagers undergoing fixed orthodontic treatment. Material and Methods: The study group consisted of 277 orthodontic patients, with ages between 12 and 17.9 years, from North-Western Romania. They completed a 9-item questionnaire. The control group consisted of 231 participants, with ages between 12 and 17.9 years. They completed an 8-item questionnaire. Results: Most patients from the study group were not worried that wearing a protective face mask would hide their braces (never—49.5%; rarely—26.7%), and their desire to undergo an orthodontic treatment was not affected by the compulsoriness of face mask wearing (never—51.6%; rarely—26%). In contrast to that, in the control group, more than 50% of the participants were worried to some degree that wearing a protective face mask would hide their smile (occasionally—29.9%; frequently—18.2%; very frequently—2.2%). The majority of the participants from the study group did not consider interrupting the orthodontic treatment due to the COVID-19 pandemic (62.5%), and the majority of the participants from the control group did not consider not going to the dentist due to the COVID-19 pandemic (70.6%). Most of the participants from the study group were not happy that they had to wear a face mask, which covered their orthodontic appliances, during the orthodontic treatment (68.6%). The attitude was similar to that of the participants from the control group, who were not happy that they had to wear a face mask, that covered their smile (51.1%). In the study group, most patients did not want face mask wearing to continue to be compulsory, given the fact that their orthodontic appliances were no longer visible (52%). In the control group, the attitude was similar, with 48.1% of the participants not wanting face mask compulsoriness to be maintained. Conclusions: In conclusion, although, most patients would not like to continue wearing a face mask as a mandatory regulation, they were not concerned or negatively affected by wearing a protective face mask, even though face masks hid their braces.

Medical/Surgical, Cloth and FFP/(K)N95 Masks: Unmasking Preference, SARS-CoV-2 Transmissibility and Respiratory Side Effects

Background: Social distancing and mask-wearing were recommended and mandatory for people during the COVID-19 pandemic. Methods: A web-based questionnaire was disseminated through social media assessing mask type preference and COVID-19 history amongst tertiary sector services and the rates of the triad of respiratory symptoms in each mask type, along with other respiratory-related parameters. Results: Amongst 4107 participants, 63.4% of the responders, mainly women, preferred medical/surgical masks; 20.5%, mainly men, preferred cotton cloth masks; and 13.8% preferred FFP/(K)N95 masks. COVID-19 history was less common in FFP/(K)N95 compared to medical/surgical (9.2% vs. 15.6%, p < 0.001) or cloth masks (9.2% vs. 14.4%, p = 0.006). Compared to the control group (rare mask-wearing, nonsmokers and without lung conditions), those wearing one medical mask were more likely to report frequent sputum production (4.4% vs. 1.9%, p = 0.026) and frequent cough (4.4% vs. 1.6%, p = 0.013), and those wearing FFP/(K)N95 masks were more likely to report frequent cough (4.1% vs. 1.6%, p = 0.048). Compared to the control group, those preferring cotton cloth masks were more likely to report a frequent cough (7.3% vs. 1.6%, p = 0.0002), sputum production (6.3% vs. 1.9%, p = 0.003) and dyspnea (8% vs. 1.3%, p = 0.00001). Conclusions: Safe mask-wearing should be in parallel with a more personalized and social interaction approach.