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1.
MMWR Morb Mortal Wkly Rep ; 70(7): 254-257, 2021 Feb 19.
Article in English | MEDLINE | ID: covidwho-1089245

ABSTRACT

Universal masking is one of the prevention strategies recommended by CDC to slow the spread of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) (1). As of February 1, 2021, 38 states and the District of Columbia had universal masking mandates. Mask wearing has also been mandated by executive order for federal property* as well as on domestic and international transportation conveyances.† Masks substantially reduce exhaled respiratory droplets and aerosols from infected wearers and reduce exposure of uninfected wearers to these particles. Cloth masks§ and medical procedure masks¶ fit more loosely than do respirators (e.g., N95 facepieces). The effectiveness of cloth and medical procedure masks can be improved by ensuring that they are well fitted to the contours of the face to prevent leakage of air around the masks' edges. During January 2021, CDC conducted experimental simulations using pliable elastomeric source and receiver headforms to assess the extent to which two modifications to medical procedure masks, 1) wearing a cloth mask over a medical procedure mask (double masking) and 2) knotting the ear loops of a medical procedure mask where they attach to the mask's edges and then tucking in and flattening the extra material close to the face (knotted and tucked masks), could improve the fit of these masks and reduce the receiver's exposure to an aerosol of simulated respiratory droplet particles of the size considered most important for transmitting SARS-CoV-2. The receiver's exposure was maximally reduced (>95%) when the source and receiver were fitted with modified medical procedure masks. These laboratory-based experiments highlight the importance of good fit to optimize mask performance. Until vaccine-induced population immunity is achieved, universal masking is a highly effective means to slow the spread of SARS-CoV-2** when combined with other protective measures, such as physical distancing, avoiding crowds and poorly ventilated indoor spaces, and good hand hygiene. Innovative efforts to improve the fit of cloth and medical procedure masks to enhance their performance merit attention.


Subject(s)
/prevention & control , Masks/standards , /epidemiology , Centers for Disease Control and Prevention, U.S. , Humans , Masks/statistics & numerical data , United States/epidemiology
2.
MMWR Morb Mortal Wkly Rep ; 70(6): 208-211, 2021 Feb 12.
Article in English | MEDLINE | ID: covidwho-1079854

ABSTRACT

Approximately 41% of adults aged 18-24 years in the United States are enrolled in a college or university (1). Wearing a face mask can reduce transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19) (2), and many colleges and universities mandate mask use in public locations and outdoors when within six feet of others. Studies based on self-report have described mask use ranging from 69.1% to 86.1% among adults aged 18-29 years (3); however, more objective measures are needed. Direct observation by trained observers is the accepted standard for monitoring behaviors such as hand hygiene (4). In this investigation, direct observation was used to estimate the proportion of persons wearing masks and the proportion of persons wearing masks correctly (i.e., covering the nose and mouth and secured under the chin*) on campus and at nearby off-campus locations at six rural and suburban universities with mask mandates in the southern and western United States. Trained student observers recorded mask use for up to 8 weeks from fixed sites on campus and nearby. Among 17,200 observed persons, 85.5% wore masks, with 89.7% of those persons wearing the mask correctly (overall correct mask use: 76.7%). Among persons observed indoors, 91.7% wore masks correctly. The proportion correctly wearing masks indoors varied by mask type, from 96.8% for N95-type masks and 92.2% for cloth masks to 78.9% for bandanas, scarves, and similar face coverings. Observed indoor mask use was high at these six universities with mask mandates. Colleges and universities can use direct observation findings to tailor training and messaging toward increasing correct mask use.


Subject(s)
Masks/statistics & numerical data , Masks/standards , Public Health/legislation & jurisprudence , Students/psychology , Universities/legislation & jurisprudence , Adolescent , /prevention & control , Humans , Students/statistics & numerical data , United States/epidemiology , Young Adult
3.
J Infect Dev Ctries ; 15(1): 51-57, 2021 Jan 31.
Article in English | MEDLINE | ID: covidwho-1079733

ABSTRACT

BACKGROUND: COVID-19 is a global pandemic. The virus spreads through respiratory droplets and close contact. Therefore, the availability of personal protective equipment (PPE) for healthcare professionals is essential. 3D printing technology could represent a valid option to ameliorate PPE shortages. METHODOLOGY: Custom-made face mask were designed on the basis of facial scan and then 3D-printed. The whole protocol is executed with freeware software and only required a 3D printer. Six healthcare workers wore the device weekly thus expressing a judgment regarding quality of work, respiratory and skin comfort. RESULTS: The estimated total cost of a single mask is approximately 5 USD. The virtual design of a complete mask lasted 68 minutes on average. Most healthcare workers rated comfort as very good. CONCLUSIONS: Based on the encouraging results obtained, we can confidently confirm that custom-made masks are novel and useful devices that may be used in the fight against COVID-19.


Subject(s)
/prevention & control , Equipment Design/methods , Masks/standards , Printing, Three-Dimensional , Equipment Design/instrumentation , Female , Health Personnel/statistics & numerical data , Humans , Male , Masks/economics , Printing, Three-Dimensional/economics
4.
Int J Environ Res Public Health ; 18(4)2021 02 08.
Article in English | MEDLINE | ID: covidwho-1079658

ABSTRACT

BACKGROUND: During the SARS-CoV-2 pandemic, there was shortage of the standard respiratory protective equipment (RPE). The aim of this study was to develop a procedure to test the performance of alternative RPEs used in the care of COVID-19 patients. METHODS: A laboratory-based test was developed to compare RPEs by total inward leakage (TIL). We used a crossflow nebulizer to produce a jet spray of 1-100 µm water droplets with a fluorescent marker. The RPEs were placed on a dummy head and sprayed at distances of 30 and 60 cm. The outcome was determined as the recovery of the fluorescent marker on a membrane filter placed on the mouth of the dummy head. RESULTS: At 30 cm, a type IIR surgical mask gave a 17.7% lower TIL compared with an FFP2 respirator. At 60 cm, this difference was similar, with a 21.7% lower TIL for the surgical mask compared to the respirator. When adding a face shield, the TIL at 30 cm was further reduced by 9.5% for the respirator and 16.6% in the case of the surgical mask. CONCLUSIONS: A safe, fast and very sensitive test method was developed to assess the effectiveness of RPE by comparison under controlled conditions.


Subject(s)
/prevention & control , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Masks/standards , Personal Protective Equipment/standards , Respiratory Protective Devices/standards , Aerosols/adverse effects , Humans , Occupational Exposure/prevention & control , Ventilators, Mechanical , Water
5.
Pan Afr Med J ; 37(Suppl 1): 47, 2020.
Article in English | MEDLINE | ID: covidwho-1069980

ABSTRACT

The recent Coronavirus disease (COVID-19) caused by the novel strain of coronavirus (SARS-CoV-2 virus) has become a worldwide public health crisis with associated high mortality rates globally. Human to human transmission of the infection emphasizes the importance of adhering to public and social measure to halt its spread. However, the recent #ENDSARS protests led by angry youths in Nigeria resulted to complete flouting of all WHO guidelines meted to curb the spread of the virus. Given that the nation is the most populous African country with over 50 percent of her population been youths, this situation has huge implications for the country and Africa as a whole. The risk of community transmission occasioned by the protest, coupled with travels and active mobility across countries within the continent increases the risk of community transmission with possible increases in new cases over the next few weeks to months. From the foregoing, it is expedient to increase awareness and enforcement of the use of personal protective equipment especially use of nose masks, face shields and frequent hand washing or sanitizing in public places. These individual-targeted measures will go a long way to curtail the imminent community transmission of COVID-19 across Nigeria. It is therefore recommended that Government and non-governmental agencies across the region actively engage to increase collaborative efforts; screening facilities and access to these services across the country, as well as accentuate regular adherence to preventive measures to the general public.


Subject(s)
/prevention & control , Civil Disorders , Public Health , Adolescent , Africa/epidemiology , /transmission , Cooperative Behavior , Hand Disinfection/standards , Health Services Accessibility , Humans , Masks/standards , Nigeria/epidemiology , Personal Protective Equipment
6.
Pan Afr Med J ; 37(Suppl 1): 46, 2020.
Article in English | MEDLINE | ID: covidwho-1069979

ABSTRACT

Introduction: on January 30, 2020, the World Health Organization declared the novel coronavirus outbreak a Public Health Emergency of International Concern. As of October 5, 2020, there were over 34.8 million reported cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and more than 1 million reported deaths from coronavirus disease 2019 (COVID-19), globally. Non-pharmaceutical interventions, such as social distancing policies, hand hygiene, and mask use, are key public health measures to control COVID-19. In response to, or in some cases even before, the first wave of SARS-CoV-2 infections were reported in their countries, policy makers across Africa issued various social distancing policies. Methods: we describe social distancing policies issued from March 1 to April 24, 2020 in 22 Anglophone countries of sub-Saharan Africa. We reviewed policies identified online. Results: though all 22 countries closed schools and banned gatherings, they took a variety of approaches to sizes of gatherings banned and to stay-at-home orders, with 13 countries issuing national stay-at-home orders, four issuing subnational stay-at-home orders, and five not issuing stay-at-home orders. Enforcement provisions varied by country, as did funeral and health care exceptions. Conclusion: movement restrictions, business restrictions, and school closures can have substantial negative impacts on economies, education, nutrition, and routine health care. Yet easing or lifting of COVID-19 social distancing policies can lead to increased transmission. Our review documents a wide variety of policy alternatives used in Africa and can inform future adjustments as countries ease, lift, and reapply measures in response to their evolving epidemics.


Subject(s)
/prevention & control , Health Policy , Africa , Hand Hygiene/standards , Humans , Masks/standards , Public Health
7.
Health Sociol Rev ; 29(2): 158-167, 2020 07.
Article in English | MEDLINE | ID: covidwho-1066140

ABSTRACT

Shortages of personal protective equipment (PPE) and medical devices needed during the COVID-19 pandemic were widely reported in early 2020. In response, civic DIY volunteers explored how they could produce the required equipment. Members of communities such as hacker- and makerspaces employed their skills and tools to manufacture, for example, face shields and masks. The article discusses these civic innovation practices and their broader social implications by relating them to critical making theory. Methodologically, it is based on a digital ethnography approach, focusing on hacker and maker communities in the UK. Communities' DIY initiatives display characteristics of critical making and 'craftivism', as they assessed and counteracted politicised healthcare supply shortages. It is argued that their manufacturing activities during the COVID pandemic relate to UK austerity politics' effects on healthcare and government failure to ensure medical crisis supplies. Facilitated by open source design, communities' innovation enabled healthcare emergency equipment. At the same time, their DIY manufacturing raises practical as well as ethical issues concerning, among other things, efficacy and safety of use.


Subject(s)
/prevention & control , Masks/supply & distribution , Personal Protective Equipment/supply & distribution , Protective Devices , Equipment Design , Humans , Masks/standards , Personal Protective Equipment/standards , Private Sector
8.
Epidemiol Infect ; 149: e24, 2021 01 14.
Article in English | MEDLINE | ID: covidwho-1065752

ABSTRACT

The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) is highly contagious, and the coronavirus disease 2019 (COVID-19) pandemic caused by it has forced many countries to adopt 'lockdown' measures to prevent the spread of the epidemic through social isolation of citizens. Some countries proposed universal mask wearing as a protection measure of public health to strengthen national prevention efforts and to limit the wider spread of the epidemic. In order to reveal the epidemic prevention efficacy of masks, this paper systematically evaluates the experimental studies of various masks and filter materials, summarises the general characteristics of the filtration efficiency of isolation masks with particle size, and reveals the actual efficacy of masks by combining the volume distribution characteristics of human exhaled droplets with different particle sizes and the SARS-CoV-2 virus load of nasopharynx and throat swabs from patients. The existing measured data show that the filtration efficiency of all kinds of masks for large particles and extra-large droplets is close to 100%. From the perspective of filtering the total number of pathogens discharged in the environment and protecting vulnerable individuals from breathing live viruses, the mask has a higher protective effect. If considering the weighted average filtration efficiency with different particle sizes, the filtration efficiencies of the N95 mask and the ordinary mask are 99.4% and 98.5%, respectively. The mask can avoid releasing active viruses to the environment from the source of infection, thus maximising the protection of vulnerable individuals by reducing the probability of inhaling a virus. Therefore, if the whole society strictly implements the policy of publicly wearing masks, the risk of large-scale spread of the epidemic can be greatly reduced. Compared with the overall cost of social isolation, limited personal freedoms and forced suspension of economic activities, the inconvenience for citizens caused by wearing masks is perfectly acceptable.


Subject(s)
/epidemiology , Masks/standards , Aerosols , Humans , Nasopharynx/virology , Oropharynx/virology , Particle Size , Viral Load
9.
Int J Environ Res Public Health ; 18(4)2021 02 04.
Article in English | MEDLINE | ID: covidwho-1063402

ABSTRACT

The first wave of the COVID-19 pandemic brought about a broader use of masks by both professionals and the general population. This resulted in a severe worldwide shortage of devices and the need to increase import and activate production of safe and effective surgical masks at the national level. In order to support the demand for testing surgical masks in the Italian context, Universities provided their contribution by setting up laboratories for testing mask performance before releasing products into the national market. This paper reports the effort of seven Italian university laboratories who set up facilities for testing face masks during the emergency period of the COVID-19 pandemic. Measurement set-ups were built, adapting the methods specified in the EN 14683:2019+AC. Data on differential pressure (DP) and bacterial filtration efficiency (BFE) of 120 masks, including different materials and designs, were collected over three months. More than 60% of the masks satisfied requirements for DP and BFE set by the standard. Masks made of nonwoven polypropylene with at least three layers (spunbonded-meltblown-spunbonded) showed the best results, ensuring both good breathability and high filtration efficiency. The majority of the masks created with alternative materials and designs did not comply with both standard requirements, resulting in suitability only as community masks. The effective partnering between universities and industries to meet a public need in an emergency context represented a fruitful example of the so-called university "third-mission".


Subject(s)
/prevention & control , Laboratories , Masks/standards , Pandemics , Humans , Italy
10.
Adv Respir Med ; 88(6): 638-639, 2020.
Article in English | MEDLINE | ID: covidwho-1058966

ABSTRACT

Performing medical procedures with the use of personal protective equipment may reduce the efficiency of medical procedures performed, for example, as with the current use of respiratory protection devices, including N95 or surgical masks. Healthcare workers (HCWs) using N95 respirators or medical masks may experience discomfort associated with wearing a mask when performing medical procedures, in particular those associated with increased physical activity, causing increased respiratory effort.


Subject(s)
/prevention & control , Infection Control/methods , Occupational Exposure/prevention & control , Emergency Medical Services , Humans , Masks/standards
11.
Enferm Clin ; 31 Suppl 1: S73-S77, 2021 Feb.
Article in English, Spanish | MEDLINE | ID: covidwho-1046465

ABSTRACT

The main element of personal protective equipment against the SARS-CoV-2 pandemic are masks, which protect against droplets and aerosols that can remain suspended in the air. The objective of this study is to summarize the existing evidence on the filtration of different materials for the manufacture of masks. A scoping review or exploratory review has been carried out in the PubMEd and Scopus databases, using the terms "respirator", "mask", "facemask", "material", and "tissue", combined with Boolean operators. The results show some of the materials used for the manufacture of masks, both surgical masks and medium-high filtration masks, as well as materials used for the manufacture of household masks. As a conclusion, it is necessary to know the characteristics of the different materials as well as their properties to guarantee an adequate use according to the specific needs in each context, being fundamental the application of particle filtration systems as well as support materials that comply with current recommendations.


Subject(s)
/prevention & control , Masks/standards , /epidemiology , Cellulose/standards , Equipment Design/methods , Filtration/instrumentation , Filtration/standards , Health Personnel , Humans , Masks/supply & distribution , Pandemics , Personal Protective Equipment/supply & distribution , Polypropylenes/standards , Static Electricity , Textiles/standards
12.
PLoS One ; 16(1): e0245688, 2021.
Article in English | MEDLINE | ID: covidwho-1043475

ABSTRACT

INTRODUCTION: The COVID-19 pandemic has made well-fitting face masks a critical piece of protective equipment for healthcare workers and civilians. While the importance of wearing face masks has been acknowledged, there remains a lack of understanding about the role of good fit in rendering protective equipment useful. In addition, supply chain constraints have caused some organizations to abandon traditional quantitative or/and qualitative fit testing, and instead, have implemented subjective fit checking. Our study seeks to quantitatively evaluate the level of fit offered by various types of masks, and most importantly, assess the accuracy of implementing fit checks by comparing fit check results to quantitative fit testing results. METHODS: Seven participants first evaluated N95 and KN95 respirators by performing a fit check. Participants then underwent quantitative fit testing wearing five N95 respirators, a KN95 respirator, a surgical mask, and fabric masks. RESULTS: N95 respirators offered higher degrees of protection than the other categories of masks tested; however, it should be noted that most N95 respirators failed to fit the participants adequately. Fit check responses had poor correlation with quantitative fit factor scores. KN95, surgical, and fabric masks achieved low fit factor scores, with little protective difference recorded between respiratory protection options. In addition, small facial differences were observed to have a significant impact on quantitative fit. CONCLUSION: Fit is critical to the level of protection offered by respirators. For an N95 respirator to provide the promised protection, it must fit the participant. Performing a fit check via NHS self-assessment guidelines was an unreliable way of determining fit.


Subject(s)
/prevention & control , Masks , Textiles , Adolescent , Adult , Aged , Female , Humans , Male , Masks/standards , Masks/virology , Middle Aged , /virology , Occupational Exposure/prevention & control , Textiles/virology , Young Adult
13.
Ann Fam Med ; 19(1): 55-62, 2021.
Article in English | MEDLINE | ID: covidwho-1024391

ABSTRACT

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic has led at times to a scarcity of personal protective equipment, including medical masks, for health care clinicians, especially in primary care settings. The objective of this review was to summarize current evidence regarding the use of cloth masks to prevent respiratory viral infections, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), among health care clinicians. METHODS: We searched 5 databases, the Centers for Disease Control and Prevention website, and the reference lists of identified articles on April 3, 2020. All identified publications were independently screened by 2 reviewers. Two authors independently extracted data and graded the studies. Randomized control trials (RCTs) were graded using the Consolidated Standards of Reporting Trials (CONSORT) checklist, and observational and nonhuman subject studies were graded using 11 domains common across frequently used critical appraisal tools. All discrepancies were resolved by consensus. RESULTS: Our search identified 136 original publications. Nine studies met inclusion criteria. We performed a qualitative synthesis of the data from these studies. Four nonrandomized trials, 3 laboratory studies, 1 single-case experiment, and 1 RCT were identified. The laboratory studies found that cloth materials provided measurable levels of particle filtration but were less efficacious at blocking biologic material than medical masks. The RCT found that cloth masks were associated with significantly more viral infections than medical masks. CONCLUSIONS: The current literature suggests that cloth materials are somewhat efficacious in filtering particulate matter and aerosols but provide a worse fit and inferior protection compared to medical masks in clinical environments. The quality and quantity of literature addressing this question are lacking. Cloth masks lack evidence for adequate protection of health care clinicians against respiratory viral infections.


Subject(s)
/prevention & control , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Masks/standards , Textiles , Equipment Design , Humans , Masks/supply & distribution , Materials Testing , Personal Protective Equipment/supply & distribution , United States
15.
Rev. enferm. UERJ ; 28: e51476, jan.-dez. 2020.
Article in English, Portuguese | LILACS (Americas) | ID: covidwho-1016414

ABSTRACT

Objetivo: desenvolver um modelo de máscara de tecido, com aplicação do elemento filtrante em celulose, para fins de utilização como barreira física segura para aerossóis, como estratégia de resposta emergencial à pandemia provocada pelo SARS-CoV-2. Método: pesquisa laboratorial realizada por meio de protótipos, testagens empíricas e análises e discussões junto a expertises. Resultados: a condução da pesquisa demonstrou que os aerossóis são retidos pela barreira física de celulose introduzida à estrutura das máscaras, o que motivou a segunda fase do estudo em unidade da Rede Brasileira de Laboratórios Analíticos de Saúde sobre a eficácia desses materiais. Conclusão: a confecção de máscaras de tecido é um fenômeno mundial importante e urgente frente à pandemia da COVID-19. Em função da crise de abastecimento e dos parâmetros ressaltados neste estudo, acredita-se que o uso desse equipamento possa ser estendido a setores não críticos de unidades de saúde, além da população em geral.


Objective: to develop a model of fabric mask, with the application of a cellulose filter element, for use as a safe physical barrier for aerosols, as an emergency response strategy for the SARS-CoV-2 pandemic. Method: laboratory research carried out by means of prototypes, empirical tests and analyses, and discussions with experts. Results: the research demonstrated that aerosols are retained by the physical cellulose barrier introduced into the structure of the masks, which motivated the second phase of the study into the effectiveness of these materials at a unit of the Brazilian Analytical Health Laboratories Network. Conclusion: the making of fabric masks is an important and urgent worldwide phenomenon in tackling the COVID-19 pandemic. In view of the supply crisis and the parameters highlighted in this study, it is believed that the use of this equipment can be extended to non-critical sectors of health units, as well as to the general population.


Objetivo: desarrollar un modelo de mascarilla de tela, con la aplicación de un elemento filtrante de celulosa, para su uso como barrera física segura para aerosoles, como estrategia de respuesta de emergencia para la pandemia SARS-CoV-2. Método: investigación de laboratorio realizada mediante prototipos, pruebas y análisis empíricos y discusiones con expertos. Resultados: la investigación demostró que los aerosoles son retenidos por la barrera física de celulosa introducida en la estructura de las máscaras, lo que motivó la segunda fase del estudio sobre la efectividad de estos materiales en una unidad de la Red Brasileña de Laboratorios Analíticos de Salud. Conclusión: la fabricación de máscaras de tela es un fenómeno mundial importante y urgente para hacer frente a la pandemia de COVID-19. Ante la crisis de oferta y los parámetros resaltados en este estudio, se cree que el uso de este equipamiento puede extenderse a sectores no críticos de las unidades de salud, así como a la población en general.


Subject(s)
Humans , Coronavirus Infections/prevention & control , Personal Protective Equipment/standards , Betacoronavirus , Masks/standards , Materials Testing , Brazil , Cellulose , Filters , Surge Capacity , Pandemics/prevention & control
17.
Future Microbiol ; 16: 5-11, 2021 01.
Article in English | MEDLINE | ID: covidwho-993128

ABSTRACT

Aim: Face masks are an important addition to our arsenal in the fight against COVID-19. The aim of this study is to present a novel method of measuring mask performance which can simultaneously assess both fabric penetration and leakage due to poor fit. Materials & methods: A synthetic aerosol is introduced into the lung of a medical dummy. A conical laser sheet surrounds the face of the dummy where it illuminates the aerosol emitted during a simulated breath. The system is demonstrated with five mask types. Conclusions: The curved laser sheet highlights both penetration through the mask fabric and leakage around the edges of the mask. A large variation in both material penetration and leakage was observed.


Subject(s)
/prevention & control , Masks/standards , Textiles , Aerosols/analysis , Clothing , Equipment Design , Humans , Materials Testing , Particle Size , Personal Protective Equipment/standards , Sodium Chloride
19.
J Occup Environ Hyg ; 18(2): 72-83, 2021 02.
Article in English | MEDLINE | ID: covidwho-975161

ABSTRACT

Simple plastic face shields have numerous practical advantages over regular surgical masks. In light of the spreading COVID-19 pandemic, the potential of face shields as a substitution for surgical masks was investigated. In order to determine the efficacy of the protective equipment we used a cough simulator. The protective equipment considered was placed on a manikin head that simulated human breathing. Concentration and size distribution of small particles that reached the manikin respiration pathways during the few tens of seconds following the cough event were monitored. Additionally, water sensitive papers were taped on the tested protective equipment and the manikin face. In the case of frontal exposure, for droplet diameter larger than 3 µm, the shield efficiency in blocking cough droplets was found to be comparable to that of regular surgical masks, with enhanced protection for portions of the face that the mask does not cover. Additionally, for finer particles, down to 0.3 µm diameter, a shield blocked about 10 times more fine particles than the surgical mask. When exposure from the side was considered, the performance of the shield was found to depend dramatically on its geometry. While a narrow shield allowed more droplets and aerosol to penetrate in comparison to a mask under the same configuration, a slightly wider shield significantly improved the performance. The source control potential of shields was also investigated. A shield, and alternatively, a surgical mask, were placed on the cough simulator, while the breathing simulator, situated 60 cm away in the jet direction, remained totally exposed. In both cases, no droplets or particles were found in the vicinity of the breathing simulator. Conducted experiments were limited to short time periods after expiratory events, and do not include longer time ranges associated with exposure to suspended aerosol. Thus, additional evidence regarding the risk posed by floating aerosol is needed to establish practical conclusions regarding actual transmittance reduction potential of face shields and surgical face masks.


Subject(s)
/prevention & control , Inhalation Exposure/analysis , Masks/standards , Personal Protective Equipment/standards , /isolation & purification , Aerosols/analysis , Air Microbiology , Cough/virology , Environmental Monitoring , Humans , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Inhalation Exposure/prevention & control , Materials Testing , Occupational Exposure/analysis , Occupational Exposure/prevention & control
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