Impact of structural features on dynamic breathing resistance of healthcare face mask

Functionalized Face Masks as Smart Wearable Sensors for Multiple Sensing

Wearable sensors provide continuous physiological information and measure deviations from healthy baselines, resulting in the potential to personalize health management and diagnosis of diseases. With the emergence of the COVID-19 pandemic, functionalized face masks as smart wearable sensors for multimodal and/or multiplexed measurement of physical parameters and biochemical markers have become the general population for physiological health management and environmental pollution monitoring. This Review examines recent advances in applications of smart face masks based on implantation of digital technologies and electronics and focuses on respiratory monitoring applications with the advantages of autonomous flow driving, enrichment enhancement, real-time monitoring, diversified sensing, and easily accessible. In particular, the detailed introduction of diverse respiratory signals including physical, inhalational, and exhalant signals and corresponding associations of health management and environmental pollution is presented. In the end, we also provide a personal perspective on future research directions and the remaining challenges in the commercialization of smart functionalized face masks for multiple sensing.

An antimicrobial zinc ion fiber for COVID-19 prevention in nonwoven face coverings for healthcare settings

The COVID-19 pandemic created an unprecedented increase in the usage of personal protective equipment (PPE) in the healthcare industry, especially in the form of face coverings. Subsequently, guidelines related to breathability and wear comfort were published by the Centers for Disease Control (CDC) as an influx of various new materials entered the PPE market. This study evaluated a proprietary, novel, zinc-ion embedded fiber with the ability to deactivate bacteria and viruses, including SARS-COV-2, for its wear comfort in a nonwoven disposable mask in comparison to a commercially available surgical face mask which served as the control. Ten healthy, full-time, career, firefighters participated in this study wearing both masks in a randomized fashion. A medical task simulation (MTS) protocol was developed to replicate nursing task metabolic rates, per the compendium of physical activities, via a graded treadmill walking exercise. Participant ratings including ease of mask fit, overall mask comfort, facial comfort, breathability, and facial temperature sensation were recorded before, during, and after the 50-minute protocol in a controlled environmental chamber. The 100% nylon, zinc ion mask was rated as slightly cooler at the beginning of the trial (at 0.8 vs. 1.3), than the commercially available polypropylene mask. The polypropylene mask also reached a perceived mask facial comfort (MFC) rating of 1.6 just 35 min into the protocol whereas the zinc ion mask did not reach a rating of slight discomfort until the end of the exercise. Findings indicate the novel zinc-ion embedded mask was as comfortable, if not more so, than the commercially available nonwoven mask with more favorable ratings for longer durations. Not only do the zinc properties provide enhanced protection, but they maintain, if not improve, wearer comfort.

8-hour performance of loose-fitting powered air-purifying respirators in simulated hospital and coal mine environments

Loose-fitting powered air-purifying respirators (LF-PAPRs) are increasingly used in hospitals and coal mines because of their high comfort and protection level, but the utilization faces the challenges of 8-hr continuous high protection requirements in the hospital environment and the coupling effects of high temperature, high humidity, high dust concentration in coal mines. Based on the self-developed powered air-purifying respirator simulation test system, this study explores the 8-hr changes of supplied airflow, the relative air pressure inside the inlet covering (ΔP), and total inward leakage (TIL) of four models of LF-PAPRs in simulated hospital and coal mine environments. Results show that: (1) In a simulated hospital environment, all four LF-PAPRs showed filter cartridge blockage within 5 ∼ 6 hr of continuous operation; while in the simulated coal mine, three models of LF-PAPRs showed filter cartridge blockage within 3 hr. (2) In both the hospital and coal mine environments, there are cases where the supplied airflow of LF-PAPRs dropped below 170 L/min within 3 hr. (3) In a simulated hospital environment, the ΔP of all LF-PAPRs maintained positive within 5-6 hr; while in the simulated coal mine, the ΔP of two LF-PAPRs, respectively, appeared negative after 1 hr and 1.6 hr operation. (4) The maximum TIL of the tested LF-PAPRs, respectively ranged from 0.5-0.9% and 1.4-3% in simulated hospital and coal mine environments. (5) In both hospital and coal mine environments, the supplied airflow and ΔP of each LF-PAPR showed a decreasing trend with increasing test duration, while the TIL significantly increased with testing time. (6) The supplied airflow, ΔP, and TIL of each LF-PAPR in the simulated hospital environment performed better than those in the coal mine. This study evaluated the performance of PAPR under the most severe operating conditions, and respirator performance may differ under in-situ conditions.

Thermal responses of face-masked pedestrians during summer: An outdoor investigation under tree-shaded areas

During the SARS-CoV-2 (COVID-19) pandemic, most citizens were cooperative towards the face-masking policy; however, undeniably, face masking has increased complaints of thermal discomfort to varying degrees and resulted in potential health hazards during summer. Thus, a thermal comfort survey was conducted under tree-shaded areas generally preferred by pedestrians to explore the thermal response of face-masked pedestrians. Thirty-two subjects, with and without masks, participated in walking experiments, and their thermal parameters and physiological indicators were recorded; moreover, the subjects were asked to fill in subjective questionnaires. The results showed that although tree shades significantly reduced the average radiant temperature, dampness in the mask may cause some discomfort symptoms, among which intense sweating (54.55%) and tachycardia (42.18%) accounted for the largest proportion. Based on thermal indices, it could be concluded that face-masking does not significantly affect the thermal comfort of subjects walking in shaded areas. Notably, a 30-min walk in tree-shaded areas with face masking does not adversely affect human health or quality of life. Thus, the present assessment of the thermal safety of humans in shaded environments provides reference data for determining thermal comfort levels during outdoor walking with face masking.

A Review of Filtration Performance of Protective Masks

Masks are essential and effective small protective devices used to protect the general public against infections such as COVID-19. However, available systematic reviews and summaries on the filtration performance of masks are lacking. Therefore, in order to investigate the filtration performance of masks, filtration mechanisms, mask characteristics, and the relationships between influencing factors and protective performance were first analyzed through mask evaluations. The summary of filtration mechanisms and mask characteristics provides readers with a clear and easy-to-understand theoretical cognition. Then, a detailed analysis of influencing factors and the relationships between the influencing factors and filtration performance is presented in. The influence of the aerosol size and type on filtration performance is nonlinear and nonconstant, and filtration efficiency decreases with an increase in the gas flow rate; moreover, fitness plays a decisive role in the protective effects of masks. It is recommended that the public should wear surgical masks to prevent COVID-19 infection in low-risk and non-densely populated areas. Future research should focus on fitness tests, and the formulation of standards should also be accelerated. This paper provides a systematic review that will be helpful for the design of masks and public health in the future.

A review on the effectiveness of various masks in protection against COVID-19

As of June1st 2021, more than 17 crore people have been infected with COVID-19 across the globe, and almost 3 crore people have been infected in India. The virus can spread through even normal actions like talking with particle emission rates inversely correlating with word frequency and volume, which can be reduced by covering the mouth. However, there is debate concerning the effectiveness of the various face mask types in preventing respiratory infections. Many have reported that wearing a mask is uncomfortable, especially when worn for long hours and while performing strenuous activities. Another disease that has raised its head is mucormycosis. However, COVID-19 can be a serious infection in many, with many fatalities. It is not yet clear how much protection vaccines give, and in a hugely populated country like India, it may be very difficult to vaccinate the whole population. Moreover, the vaccination for pediatric groups has just started. So, it is imperative to wear masks that can be protective against infection. However, some people believe that a straightforward cotton mask is insufficient. We set out to analyze the efficacy of masks through this investigation. According to the results of this systematic review, there are no studies that give conclusive evidence that using face masks as recommended by current public health guidelines will stop this condition. This is a significant discovery that should be communicated to the scientific community and calls into question the rationale for inconsistent and differing public health recommendations.

Design of a Low Respiratory Resistance Mask for COVID-19

Observational evidence suggests that mask-wearing mitigates transmission of COVID-19; at the same time high respiratory resistance leads to an unwillingness to wear masks. This paper proposed a respiratory drive structure to reduce the air resistance of a mask. This structure provides different shapes during expiration and inspiration while focusing on filtering dust, bacteria, or viruses. Meanwhile, the assembled system on the mask can be disassembled and replaced. Then porous media simulation is used to verify the model effect. Experimental results of a new mask show that the ventilation resistance is reduced by 20%, and the bacterial filtration efficiency meets the requirements of YY 0469–2011.

Comparison of filtration efficiency and respiratory resistance of COVID-19 protective masks by multi-national standards

Background

Face masks from worldwide satisfy different standards during the COVID-19 pandemic, which led to the public misunderstanding of the concepts.

Methods

We systematically evaluated the quality of face masks provided by different companies according to multi-national standards, including EN 149-2001+A1: 2009, GB 2626-2019 and NIOSH 42 CFR Part 84-2019, focusing particularly on the particulate filtration efficiency (PFE) and respiratory resistance performance.

Results

Three types of masks (planar, folding and cup type masks) were measured based on different standard protocols. The results indicated that the PFE of the mask decreased in sequence of folding mask ≈ cup type mask > planar mask. The respiratory resistance of the masks ranked as follows: cup type mask > folding mask> planar mask. Overall, when PFE was used as the quality indicator, all the masks have a higher chance of meeting criteria of the EN149-2001+A1:2009, followed by the stricter standard set by the GB2626-2019 and NIOSH 42 CFR Part84-2019. Conversely, the respiratory resistance of the masks fulfilled the highest requirement of the EN149-2001+A1:2009 standard, while it is easier to satisfied the standard of GB 2626-2019 and NIOSH 42 CFR Part 84-2019.

Conclusions

We believe that our study provides effective guidance for customers worldwide to choose proper face masks under different epidemic situations.

A Physical Analog to Assess Surgical Face Mask Air Flow Resistance During Tidal Ventilation

A large variety of disposable face masks have been produced since the onset of the COVID-19 pandemic. Decreased resistance to inspiration improves adherence to the use of the mask; the so called breathability is usually estimated by the measurement of air flow across a section of the tissue under a given pressure difference. We hypothesized that the mask pressure—flow relationship studied in conditions that mimic tidal breathing could allow a more comprehensive characterization of airflow resistance, a major determinant of mask comfort. A physical analog was made of a plaster cast dummy head connected through a pneumotachograph to a series of bellows inflated/deflated by a respirator. Pressure was measured at the mock airway opening over which the mask was carefully secured. The precision of the measurement equipment was quantified using two estimates of measurement error: repeatability coefficient (RC) and within-mask coefficient of variation (CV_wm). The airflow resistance of 10 surgical masks was tested on 4 different days. Resistance means did not differ significantly among four repeated measures (0.34 hPa.s.L⁻¹; 0.37 hPa.s.L⁻¹; 0.37 hPa.s.L⁻¹; and 0.37 hPa.s.L⁻¹; p = 0.08), the estimated RC was 0.08 hPa.s.L⁻¹ [95%CI: 0.06–0.10 hPa.s.L⁻¹], and CV_wm was 8.7% [95%CI: 1.5–12.2%]. Multiple comparisons suggest the presence of a learning effect by which the operator reduced the error over the course of repetitive resistance measurements. Measurement precision improved considerably when the first set of measures was not taken into account [RC ~ 0.05 hPa.s.L⁻¹ (95%CI: 0.03–0.06 hPa.s.L⁻¹); CV_wm~4.5% (95%CI: 1.9–6.1%)]. The testing of the face mask resistance (R) appears simple and highly repeatable in conditions that resemble tidal breathing, once operator training was assured. The procedure adds further to the current standard assessment of breathability and allows estimating the maximal added respiratory load, about 10–20% of the respiratory resistance reported in heathy adult subjects.

A First Assessment of an Aerodynamic Barrier Layer for Filtering Airborne Hygroscopic Particles

In this work, consideration is given to an aerodynamic concept to boost the filtration in face masks of airborne hygroscopic particles such as those caused by an infected person when coughs or sneezes. Nowadays, increasing the filtration efficiency of face masks implies either increasing the number of crisscrossing fiber layers or decreasing the equivalent hydraulic diameter of the pore, however, both measures are in clear detriment of its breathability. Here, a novel strategy is proposed in which the filtration of an airborne particle is boosted by increasing its diameter. We called properly this concept as the aerodynamic barrier layer. In this concept, a traditional crisscrossing fiber layer is replaced by a parallel rearranged of the fibers in the direction of the flow. This rearrangement will promote central lift forces which will push the particles toward the center of the channel where after clustering they will coalesce resulting in a bigger particle that can be now easily captured by a conventional fiber crisscrossing layer. Utilizing a simplified geometrical model, an expression for the required length of the aerodynamic barrier layer was derived. It is shown that an aerodynamic barrier layer with a length of only a few millimeters can aerodynamically focus water droplets around 1 μm-diameter and the penetration of airborne particles can be reduced up to 55%.

Photoaging Characteristics of Disposable Masks under UV Irradiation

The global outbreak of Corona Virus Disease 2019 (COVID-19) has led to an extreme increase in the use of disposable masks. If the used disposable masks are not appropriately disposed of, they will enter the natural environment and lead to environmental pollution. In order to understand the impacts of disposable masks after being disposed of into the natural environment, aging experiments with simulated natural conditions were performed on the outer, inner, and middle layers of the masks to verify the aging characteristics of disposable masks. We analyzed the mechanical behavior, surface morphology, and Fourier Transform Infrared Spectroscopy (FT-IR) spectra of disposable masks treated with different levels of UV irradiation to understand the possible changes in the masks under UV. Results showed that the elongation at break, tensile strength, and maximum force of all three polypropylene (PP) mask layers decreased after UV irradiation, indicating chemical bond breakage. In the process of photoaging, each layer of the disposable masks showed a different degree of microscopic surface changes after UV irradiation, and these changes gradually intensified with the extension of UV exposure time. FT-IR results showed that functional groups, such as hydroxyl and carbonyl groups increased in each layer after UV irradiation. The results of this study support that, although the different layers of the disposable masks are all made of PP, they age differently in the environment. With the ever-increasing number of disposable masks in the environment, we need to further study the aging and degradation of disposable masks to better understand their potential impacts on the environment in the future.

[Vocal tract discomfort and wellbeing of caregivers for the elderly during the pandemic]

BACKGROUND

During the Sars-CoV2-pandemic, people working in healthcare such as caregives for the elderly face additional burden, e.g. by the use of face masks.

METHODS

In a prospective study, the emotional and physical wellbeing as well as the vocal tract discomfort of caregivers of two municipal homes for the elderly were assessed by questionnaires, the Mini-SCL and the Vocal Tract Discomfort Scale (VTDS), and one on personal data (sex, age, lung disease, previous SARS-CoV2-infection) and on voice symptoms.

RESULTS

67% of the questionnaires were answered by 56 women and 11 men aged 45.2 ± 11.5. In the Mini-SCL, increased scores were found in depression in 23.8%, anxiety in 49.3%, somatization in 55.2% and in the global score in 44.7%. 52%. showed increased scores in the VTDS Significant correlations were found in between the subscales of the Mini-SCL and the VTDS as well as to dysphonia symptoms.

DISCUSSION

Psychological problems, somatization and vocal tract discomfort is more frequently reported by caregivers for the elderly than in the normal population. The VTDS, voice symptoms and the Mini-SCL scales are significantly related. Training on vocal hygiene should be included in workplace health promotion during the pandemic.

Processing and Quality Control of Masks: A Review

It is clear that viruses, especially COVID-19, can cause infection and injure the human body. These viruses can transfer in different ways, such as in air transfer, which face masks can prevent and reduce. Face masks can protect humans through their filtration function. They include different types and mechanisms of filtration whose performance depends on the texture of the fabric, the latter of which is strongly related to the manufacturing method. Thus, scientists should enrich the information on mask production and quality control by applying a wide variety of tests, such as leakage, dynamic respiratory resistance (DBR), etc. In addition, the primary manufacturing methods (meltblown, spunlaid, drylaid, wetlaid and airlaid) and new additive manufacturing (AM) methods (such as FDM) should be considered. These methods are covered in this study.

What We Are Learning from COVID-19 for Respiratory Protection: Contemporary and Emerging Issues

Infectious respiratory diseases such as the current COVID-19 have caused public health crises and interfered with social activity. Given the complexity of these novel infectious diseases, their dynamic nature, along with rapid changes in social and occupational environments, technology, and means of interpersonal interaction, respiratory protective devices (RPDs) play a crucial role in controlling infection, particularly for viruses like SARS-CoV-2 that have a high transmission rate, strong viability, multiple infection routes and mechanisms, and emerging new variants that could reduce the efficacy of existing vaccines. Evidence of asymptomatic and pre-symptomatic transmissions further highlights the importance of a universal adoption of RPDs. RPDs have substantially improved over the past 100 years due to advances in technology, materials, and medical knowledge. However, several issues still need to be addressed such as engineering performance, comfort, testing standards, compliance monitoring, and regulations, especially considering the recent emergence of pathogens with novel transmission characteristics. In this review, we summarize existing knowledge and understanding on respiratory infectious diseases and their protection, discuss the emerging issues that influence the resulting protective and comfort performance of the RPDs, and provide insights in the identified knowledge gaps and future directions with diverse perspectives.

The impact of surgical masks on the nasal function in the COVID-19 era

BACKGROUND

The Covid-19 pandemics has obliged to using different types of personal protective devices (PPD) for a prolonged time of the day, especially in the Health Centers, with preference of surgical masks (SM) during the first pandemic waves.

AIMS/OBJECTIVES

This study was designed to assess the eventual changes of the nasal respiratory condition during continuous SM wearing.

MATERIAL AND METHODS

Fourteen healthcare professionals filled a visual analogue scale (VAS) questionnaire for the detection of eventual nasal breathing impairment or symptoms. Nasal resistance and flow values were obtained via the active anterior rhinomanometry (AAR) that was performed under the basal condition, as well as immediately after wearing the surgical mask (SM) and 3 h after its continuous use.

RESULTS

The increase of inspiratory resistance was significantly correlated to the reduction of the maximum flux, when comparing SM parameters to the basal ones (r = -0.70, p < .05). At VAS evaluation, SM wearing showed to induce itching in 70% of the subjects, nasal dryness in 55%, nasal blockage in 50%, headache in 39%, watery nasal discharge in 20% and sneezing in 18%.

CONCLUSIONS AND SIGNIFICANCE

The SMs do not induce evident physiological variations of the nasal function due to a compensatory respiratory mechanism that, despite a progressive increase of nasal resistances, is not inducing significant changes of the nasal fluxes.

Potential biodegradable face mask to counter environmental impact of Covid-19

On the eve of the outbreak of the COVID-19 pandemic, there is a tremendous increase in the production of facemasks across the world. The primary raw materials for the manufacturing of the facemasks are non-biodegradable synthetic polymers derived from petrochemicals. Disposal of these synthetic facemasks increases waste-load in the environment causing severe ecological issues for flora and fauna. The synthesis processes of the polymers from the petrochemical by-products were also not eco-friendly, which releases huge greenhouse and harmful gases. Therefore, many research organizations and entrepreneurs realize the need for biodegradable facemasks to render similar performance as the existing non-biodegradable masks. The conventional textile fabrics made of natural fibers like cotton, flax, hemp, etc., can also be used to prepare facemasks with multiple layers in use for general protection. Such natural textile masks can be made anti-microbial by applying various herbal anti-microbial extracts like turmeric, neem, basil, aloe vera, etc. As porosity is the exclusive feature of the masks for arresting tiny viruses, the filter of the masks should have a pore size in the nanometre scale, and that can be achieved in nanomembrane manufactured by electrospinning technology. This article reviews the various scopes of electrospinning technology for the preparation of nanomembrane biomasks. Besides protecting us from the virus, the biomasks can be useful for skin healing, skincare, auto-fragrance, and organized cooling which are also discussed in this review article.

Disposable face masks and reusable face coverings as non-pharmaceutical interventions (NPIs) to prevent transmission of SARS-CoV-2 variants that cause coronavirus disease (COVID-19): Role of new sustainable NPI design innovations and predictive mathematical modelling

Best-published evidence supports the combined use of vaccines with non-pharmaceutical interventions (NPIs), to reduce the relative risk of contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes COVID-19; this will enable a safe transition to achieving herd immunity. Albeit complex, the strategic public health goal is to bundle NPIs to keep the basic reproduction number R₀ below one. However, validation of these NPIs is conducted using random clinical trials, which is challenging in a swiftly moving pandemic given the need for recruiting large participant cohort over a longitudinal analysis period. This review highlights emerging innovations for potentially improving the design, functionality and improved waste management of disposable face masks such as filtering facepiece (FFPs) respirators, medical masks, and reusable face coverings to help prevent COVID-19. It describes use of different mathematical models under varying scenarios to inform efficacy of single and combined use of NPIs as important counter-measures to break the cycle of COVID-19 infection including new SARS-CoV-2 variants. Demand for face masks during COVID-19 pandemic keeps increasing, especially for FFPs worn by medical workers. Collaborative and well-conducted randomised controlled trials across borders are required to generate robust data to inform common and consistent policies for COVID-19 and future pandemic planning and management; however, current use of systematic reviews of best available evidence can be considered to guide interim policies.

Quantitative fit testing of filtering face-piece respirators during the COVID-19 pandemic reveals anthropometric deficits in most respirators available in Iran

PURPOSE

Frontline health care workers (HCWs) must wear a standard N95 or FFP2 respirator during worldwide pandemics of respiratory diseases including COVID-19 to protect against airborne infectious pathogens when performing care activities. This study aimed to quantitatively investigate the fit of most of the common FFRs used during the COVID-19 pandemic in Iran.

METHODS

A total of 37 volunteers were fit tested in 20 selected FFRs in a randomized order. The selected FFRs were underwent quantitative fit testing by PortaCount® model 8038. To determine the effects of face sizes on respirator fit, the participants' facial dimensions were measured using a digital caliper.

RESULTS

The rate of passing fit tests for the studied FFRs were surprisingly low with 11 out of 20 FFRs having less than 10% passing fit tests and the best performers having only 43% and 27% passing fit tests (brands 2 and 20, respectively). Cup-shaped respirators provided significantly greater fit than the vertical flat-fold ones (p < 0.001). A significantly different FFs were found among the respirator brands (F = 13.60, p < 0.001).

CONCLUSION

Overall, unacceptably low fit factors were obtained from the studied FFRs. The main reasons for this are suspected to single size and style for each studied FFR. It confirms the importance and requirement of the proper respirator selection in that way fitted optimally into facial dimensions, appropriate usage, and properly performing the fit testing procedure. A unique fit test panel should be developed to guide respirator wearers in selecting the appropriate FFR for their specific face sizes.

Advances in Facemasks during the COVID-19 Pandemic Era

The outbreak of coronavirus disease (COVID-19) has transformed the daily lifestyles of people worldwide. COVID-19 was characterized as a pandemic owing to its global spread, and technologies based on engineered materials that help to reduce the spread of infections have been reported. Nanotechnology present in materials with enhanced physicochemical properties and versatile chemical functionalization offer numerous ways to combat the disease. Facemasks are a reliable preventive measure, although they are not 100% effective against viral infections. Nonwoven materials, which are the key components of masks, act as barriers to the virus through filtration. However, there is a high chance of cross-infection because the used mask lacks virucidal properties and can become an additional source of infection. The combination of antiviral and filtration properties enhances the durability and reliability of masks, thereby reducing the likelihood of cross-infection. In this review, we focus on masks, from the manufacturing stage to practical applications, and their abilities to combat COVID-19. Herein, we discuss the impacts of masks on the environment, while considering safe industrial production in the future. Furthermore, we discuss available options for future research directions that do not negatively impact the environment.

Vocal tract discomfort in caregivers for the elderly during an interval of the COVID-19 pandemic

BACKGROUND

During the coronavirus disease 2019 (COVID-19) pandemic, professional caregivers caring for the elderly may experience more vocal tract problems in addition to regular high vocal demands while wearing face masks/coverings.

METHODS AND PARTICIPANTS

Vocal tract discomfort (VTD) was assessed in 64 caregivers in one home for the elderly (64% participation rate) in June 2020 using the German version of the VTD scale.

RESULTS

More than one-half of the participating caregivers experienced VTD, described mostly as dryness, irritability, and tightness. Approximately, 80% reported that sensations were not perceived before enhanced infection prevention standards were implemented.

CONCLUSIONS

Among caregivers caring for the elderly during the COVID-19 pandemic, special care should be focused on the voice and vocal tract well-being.

About the Acceptance of Wearing Face Masks in Times of a Pandemic

Wearing face masks in times of COVID-19 is one of the essential keystones for effectively decreasing the rate of new infections and thus for mitigating the negative consequences for individuals as well as for society. Acceptance of wearing masks is still low in many countries, making it extremely difficult to keep the pandemic at bay. In an experimental study, participants (N = 88) had to assess how strange they felt when wearing a face mask while being exposed to displays of groups of varying numbers of mask wearers. Three different types of face masks were shown: simple homemade masks, FFP2 masks, and loop scarfs. The higher the frequency of people wearing masks in the displayed social group, the less strange the participants felt about themselves, an essential precondition for accepting wearing masks. This effect of a descriptive social norm was particularly effective when people saw others wearing less intrusive masks, here, simple homemade masks.

Challenges, Strategies, and Recommendations for the Huge Surge in Plastic and Medical Waste during the Global COVID-19 Pandemic with Circular Economy Approach

After December 2019, the globe was affected by a new coronavirus (SARS-CoV-2) that causes severe respiratory illnesses, which is responsible for increasing environmental problem consequences related to the extra consumption of medical waste and single-use plastics (such as personal protective equipment (PPE) and packaging plastics). Although the consumption of these plastics protects our life during this crisis, it is pivotal to move toward plastic recycling processes and environmentally friendly and sustainable alternatives, like bio-based degradable plastics with a circular economy perspective. This review article collected scattered information and provided a future perspective on how worldwide COVID-19 disruption can perform as a catalyst to improve plastic and medical waste management. Additionally, this paper illustrates the most effective disinfection technologies for COVID-19 wastes, such as high/low heat technologies and chemical disinfection, and PPE reusing processes, including dry heat, vaporized hydrogen peroxide, ozone, and UV light during the outbreak. In this vein, medical waste treatment facilities must be more automatic, with a minimum of personnel involved. Moreover, some recent valid guidelines from different international organizations and countries, future outlook, and practical recommendations that could be effective during this epidemic or even in the post-pandemic world for plastic and medical waste management were provided. Ultimately, governments should improve their waste management because of the potential of pathogen transmission or increased plastic and medical waste generation and try to enhance the environmental knowledge of society. People also should revise their viewpoints on plastic consumption by elevating sustainable behaviors, abandoning old habits, and adjusting to novel ones.

Personal Protective Equipment (PPE) in COVID 19 Pandemic: Related Symptoms and Adverse Reactions in Healthcare Workers and General Population

OBJECTIVES

To assess prevalence of Personal Protective Equipment (PPE)-related symptoms and adverse reactions during Coronavirus Disease 2019 pandemics.

METHODS

We conducted an observational study among people exposed to various degree of infectious risk. Data were collected with a self-administered online questionnaire.

RESULTS

The entire cohort complained about a wide range of adverse reactions: respiratory symptoms affected 80.3% of respondents, 68.5% referred pressure-related skin lesions, fewer manifested a dermatosis of different grade or ocular symptoms. Most of the affected individuals belonged to healthcare staff and manifestations were predicted by wearing time (more than 6 h/d). Moreover, symptoms were higher in the healthcare staff wearing N95/FFP2 respirator mask.

CONCLUSIONS

Given the crucial role of PPE to contain the pandemic infection, more attention has to be paid to exposed categories, establishing preventive measure of side effects to ensure total safety.

An overview of filtration efficiency through the masks: Mechanisms of the aerosols penetration

The masks have always been mentioned as an effective tool against environmental threats. They are considered as protective equipment to preserve the respiratory system against the non-desirable air droplets and aerosols such as the viral or pollution particles. The aerosols can be pollution existence in the air, or the infectious airborne viruses initiated from the sneezing, coughing of the infected people. The filtration efficiency of the different masks against these aerosols are not the same, as the particles have different sizes, shapes, and properties. Therefore, the challenge is to fabricate the filtration masks with higher efficiency to decrease the penetration percentage at the nastiest conditions. To achieve this concept, knowledge about the mechanisms of the penetration of the aerosols through the masks at different effective environmental conditions is necessary. In this paper, the literature about the different kinds of face masks and respiratory masks, common cases of their application, and the advantages and disadvantages of them in this regard have been reviewed. Moreover, the related mechanisms of the penetration of the aerosols through the masks are discussed. The environmental conditions affecting the penetration as well as the quality of the fabrication are studied. Finally, special attention was given to the numerical simulation related to the different existing mechanisms.

The Physiological Impact of Masking Is Insignificant and Should Not Preclude Routine Use During Daily Activities, Exercise, and Rehabilitation

PURPOSE

Masking has been employed as a strategy for reducing transmission of a variety of communicable diseases. With the outbreak of SARS-CoV-2, many countries have implemented mandatory public masking. However, the perceived impact of mask use on pulmonary function has been a deterrent to public compliance with recommendations. COVID-19 has shed light on the impact that comorbid cardiac and pulmonary conditions may have on disease severity. This knowledge has led to increased primary and secondary prevention efforts for which exercise and rehabilitation are central. The importance of safe methods of exercise while mitigating risk of viral transmission is paramount to global recovery from the pandemic and prevention of future outbreaks.

METHODS

We constructed a focused literature review of the impact of various masks on pulmonary function at rest and with exercise. This was then incorporated into recommendations for the integration of masks with exercise and rehabilitation in the COVID-19 era.

RESULTS

While there is a paucity of evidence, we identified the physiological effects of masking at rest and during exercise to be negligible. The perceived impact appears to be far greater than the measured impact, and increased frequency of mask use leads to a physiological and psychological adaptive response.

CONCLUSIONS

Masking during daily activities, exercise, and rehabilitation is safe in both healthy individuals and those with underlying cardiopulmonary disease. Rehabilitation participants should be reassured that the benefits of masking during COVID-19 far outweigh the risks, and increased frequency of mask use invokes adaptive responses that make long-term masking tolerable.

Meltblown fabric vs nanofiber membrane, which is better for fabricating personal protective equipments

The coronavirus disease 2019 (COVID-19) pandemic has led to a great demand on the personal protection products such as reusable masks. As a key raw material for masks, meltblown fabrics play an important role in rejection of aerosols. However, the electrostatic dominated aerosol rejection mechanism of meltblown fabrics prevents the mask from maintaining the desired protective effect after the static charge degradation. Herein, novel reusable masks with high aerosols rejection efficiency were fabricated by the introduction of spider-web bionic nanofiber membrane (nano cobweb-biomimetic membrane). The reuse stability of meltblown and nanofiber membrane mask was separately evaluated by infiltrating water, 75% alcohol solution, and exposing under ultraviolet (UV) light. After the water immersion test, the filtration efficiency of meltblown mask was decreased to about 79%, while the nanofiber membrane was maintained at 99%. The same phenomenon could be observed after the 75% alcohol treatment, a high filtration efficiency of 99% was maintained in nanofiber membrane, but obvious negative effect was observed in meltblown mask, which decreased to about 50%. In addition, after long-term expose under UV light, no filtration efficiency decrease was observed in nanofiber membrane, which provide a suitable way to disinfect the potential carried virus. This work successfully achieved the daily disinfection and reuse of masks, which effectively alleviate the shortage of masks during this special period.

The need for fully bio-based facemasks to counter coronavirus outbreaks: A perspective

The onset of coronavirus pandemic has sparked a shortage of facemasks in almost all nations. Without this personal protective equipment, healthcare providers, essential workers, and the general public are exposed to the risk of infection. In light of the aforementioned, it is critical to balance the supply and demand for masks. COVID-19 will also ensure that masks are always considered as an essential commodity in future pandemic preparedness. Moreover, billions of facemasks are produced from petrochemicals derived raw materials, which are non-degradable upon disposal after their single use, thus causing environmental pollution and damage. The sustainable way forward is to utilise raw materials that are side-stream products of local industries to develop facemasks having equal or better efficiency than the conventional ones. In this regard, wheat gluten biopolymer, which is a by-product or co-product of cereal industries, can be electrospun into nanofibre membranes and subsequently carbonised at over 700 °C to form a network structure, which can simultaneously act as the filter media and reinforcement for gluten-based masks. In parallel, the same gluten material can be processed into cohesive thin films using plasticiser and hot press. Additionally, lanosol, a naturally-occurring substance, imparts fire (V-0 rating in vertical burn test), and microbe resistance in gluten plastics. Thus, thin films of flexible gluten with very low amounts of lanosol (<10 wt%) can be bonded together with the carbonised mat and shaped by thermoforming to create the facemasks. The carbon mat acting as the filter can be attached to the masks through adapters that can also be made from injection moulded gluten. The creation of these masks could simultaneously be effective in reducing the transmittance of infectious diseases and pave the way for environmentally benign sustainable products.

Can respirator face masks in a developing country reduce exposure to ambient particulate matter?

Respirator face masks (RFMs) as a personal-level intervention is increasingly being utilized to reduce ambient particulate matter (PM) exposure, globally. We tested the effectiveness of 50 commercially available ones in reducing the exposure of ambient particle number concentrations (PNC), PM₁₀, PM_2.5, and PM₁ (PM ≤ 10, 2.5, and 1 μm in diameter, respectively) in a traffic-affected urban site in Tehran. To examine the efficiency of RFMs, we applied a specific experimental setup including vacuum pumps, dummy heads, connecting tubes, glass chambers, and GRIMM Aerosol Spectrometer to measure all metrics after dummy heads. The average effectiveness of RFMs was in the range of 0.7-83.5%, 3.5-68.1%, 0.8-46.1%, and 0.4-32.2% in reducing ambient PNC, PM₁₀, PM_2.5, and PM₁, respectively. Considering all metrics, the highest effectiveness was observed always for Biomask, followed by 3 M 9332, due to their well-designed physical characteristics (e.g., adjustable nose clip for any face/nose shape, and size, soft inner material in the nose panel to provide a secure seal against leakage, adjustable or elasticated straps/ear loops to better adjust on any face). Biomask reduced ambient PM₁₀ with a mean value of 94.6 μg m^-3 (minimum-maximum: 51.7-100.3 μg m^-3), whereas it filtered on average just 29.0 μg m^-3 (25.7-43.5 μg m^-3) of ambient PM_2.5 and 18.2 μg m^-3 (14.7-21.8 μg m^-3) of PM₁. A fuzzy analytical hierarchy process to find the most important design-related factors of RFMs affecting their effectiveness, which showed the exhalation valve and its diaphragm (20.4%), nose clip (19.7%), and cheek flaps (18.6%) are ranked as the main design-related variables. The fuzzy technique for order preference by similarity to ideal solution indicated that Biomask and 3M 9332 had scores of 1 and 0.97, the highest scores compared with other RFMs. This study provides crucial evidence-based results to elucidate the effectiveness and design-related factors of RFMs in real-environmental circumstances.