Effectiveness of face masks for the population.

Background: Health authorities and organizations consider non-medical face masks as an additional passive means to prevent virus diffusion. Communication strategies disseminate information among the population that such masks are essential for mitigating virus diffusion. However, scientific studies are not conclusive in showing the undisputed filtration efficiency of fabric/cloth facial masks (both commercial and homemade). Objectives: This study examines scientific data about the effectiveness of face masks before and during the COVID-19 emergency. Present trends in the making of commercial and homemade fabric/cloth face masks are also examined. Methods: Statistical data of published studies are analyzed and compared. Main considerations and sugge-stions are also extracted and discussed. Current approaches are examined for assessing the characteristics and effectiveness of fabric/cloth commercial and homemade face masks intended for the population. Results: Conflicting data exist as to whether non-medical masks have a protective effect from the spread of respiratory viruses. Both medical masks (MDs) and respiratory personal protection equipment (PPE) show a given effectiveness value. Conclusion: Concerning commercial and homemade fabric/cloth masks, giving general indications on the choice of materials and their assemblage is difficult as it is not possible to assess the effectiveness of the filter media with respect to the kind of multiphase fluid that may be emitted upon breathing, sneezing, or coughing under different environmental conditions. This is particularly important because airflow rate, temperature, humidity, and duration of use will affect the performance of filter media. Moreover, while a mask may have excellent filter media, droplets may leak into the face-piece unless there is an adequate facial seal. In the presence of leaks, any type of mask may actually offer less protection independently of its nominal filtering effìciency.

Review of the Breathability and Filtration Efficiency of Common Household Materials for Face Masks.

The World Health Organization and the United States Centers for Disease Control have recommended universal face masking by the general public to slow the spread of COVID-19. A number of recent studies have evaluated the filtration efficiency and pressure differential (an indicator of breathability) of various, widely available materials that the general public can use to make face masks at home. In this review, we summarize those studies to provide guidance for both the public to select the best materials for face masks and for future researchers to rigorously evaluate and report on mask material testing. Of the tested fabric materials and material combinations with adequate breathability, most single and multilayer combinations had a filtration efficiency of <30%. Most studies evaluating commonly available mask materials did not follow standard methods that would facilitate comparison across studies, and materials were often described with too few details to allow consumers to purchase equivalent materials to make their own masks. To improve the usability of future study results, researchers should use standard methods and report material characteristics in detail.

Efficacy of cloth face mask in prevention of novel coronavirus infection transmission: A systematic review and meta-analysis.

INTRODUCTION: Novel coronavirus is believed to be tiny enough (0.08-0.14 µm) to penetrate through face mask, thus protection offered by cloth mask may be too low. However, the use of cloth face mask in community has been recommended by the United States Centre for Disease Control and Prevention and regulatory bodies of other countries. There is paucity of literature on efficacy of cloth face mask in preventing SARS-CoV-2 infection transmission; thus, this review aims to update the available most recent evidences on efficacy of cloth face masks in prevention of viral infection transmission. METHODS: We searched MEDLINE, EMBASE, and Clinical Trials Register for identifying studies related to this review using free-text terms and MeSH terms. Both experimental and observational studies on efficacy of cloth masks which were published in English language have been included in this review except expert opinions, commentaries, editorials, and review articles. Twelve studies were eligible to be included in review for data extraction and qualitative synthesis was carried out from extracted data but quantitative analysis (meta-analysis) could not be performed because of serious heterogeneity between the studies. RESULTS: Cloth face masks show minimum efficacy in source control than the medical grade mask. The efficacy of cloth face masks filtration varies and depends on the type of material used, number of layers, and degree of moisture in mask and fitting of mask on face. CONCLUSION: Cloth face masks have limited efficacy in combating viral infection transmission. However, it may be used in closed, crowded indoor, and outdoor public spaces involving physical proximity to prevent spread of SARS-CoV-2 infection.

Safety code blue! Assessing the use of blue surgical sterilization wrap for homemade respirator masks during the COVID-19 crisis.

The use of surgical sterilization wrap for respirator masks during the COVID-19 crisis has become a popularized personal protective equipment alternative option due to claims supporting its ability to meet N95 standards. This study sought to assess these claims using standardized filter testing. The tested material failed to meet N95 standards and suggests its use may place medical personnel at increased risk of harm when managing COVID-19 patients.

Pretreated household materials carry similar filtration protection against pathogens when compared with surgical masks.

OBJECTIVE: The past 4 months, the emergence and spread of novel 2019 SARS-Cov-2 (COVID-19) has led to a global pandemic which is rapidly depleting supplies of personal protective equipment worldwide. There are currently over 1.6 million confirmed cases of COVID-19 worldwide which has resulted in more the 100,000 deaths. As these numbers grow daily, hospitals are being forced to reuse surgical masks in hopes of conserving their dwindling supply. Since COVID-19 will most likely have effects that last for many months, our nationwide shortage of masks poses a long term issue that must be addressed immediately. METHODS: Based on a previous study by Quan et al., a salt-based soaking strategy has been reported to enhance the filtration ability of surgical masks. We propose a similar soaking process which uses materials widely available in anyone's household. We tested this method of pretreating a variety of materials with a salt-based solution by a droplet test using fluorescently stained nanoparticles similar in size to the COVID-19 virus. RESULTS: In this study, we found that paper towels and surgical masks pretreated with the salt-based solution showed a noticeable increase in filtration of nanoparticles similar in size to the COVID-19 virus. We also show that the TWEEN20 used by Quan et al. is not a critical component for the solution, and using salt alone in solution still provides a dramatically increased level of protection. CONCLUSIONS: We believe this method will allow for healthcare workers to create a disposable added layer of protection to their surgical masks, N95s, or homemade masks by using household available products. Adoption of this method may play an essential role in ensuring the safety of healthcare workers during the COVID-19 pandemic and any pandemics that may arise in the future.