(Press-News.org) A team of researchers studying the effectiveness of different types of face masks has found that in order to provide the best protection against COVID-19, the fit of a mask is as important, or more important, than the material it is made of.
The researchers, from the University of Cambridge, carried out a series of different fit tests, and found that when a high-performance mask - such as an N95, KN95 or FFP2 mask - is not properly fitted, it performs no better than a cloth mask. Minor differences in facial features, such as the amount of fat under the skin, make significant differences in how well a mask fits.
The results, published in the journal PLoS ONE, also suggest that the fit-check routine used in many healthcare settings has high failure rates, as minor leaks may be difficult or impossible to detect by the wearer. While the sample size was small, the researchers hope their findings will help develop new fit tests that are quick and reliable, in the case of future public health emergencies. The current study only evaluated the impact of fit on the wearer of the mask - the team will evaluate how fit impacts the protection of others in future research.
The COVID-19 pandemic has made well-fitting face masks a vital piece of protective equipment for healthcare workers and civilians. While the importance of wearing face masks in slowing the spread of the virus has been demonstrated, there remains a lack of understanding about the role that good fit plays in ensuring their effectiveness.
"We know that unless there is a good seal between the mask and the wearer's face, many aerosols and droplets will leak through the top and sides of the mask, as many people who wear glasses will be well aware of," said Eugenia O'Kelly from Cambridge's Department of Engineering, the paper's first author. "We wanted 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."
For the study, seven participants first evaluated N95 and KN95 masks by performing a fit check, according to NHS guidelines. Participants then underwent quantitative fit testing - which uses a particle counter to measure the concentration of particles inside and outside the mask - while wearing N95 and KN95 masks, surgical masks, and fabric masks. The results assessed the protection to the mask wearer, which is important in clinical settings.
N95 masks - which are a similar standard to the FFP3 masks available in the UK and the rest of Europe - offered higher degrees of protection than the other categories of masks tested; however, most N95 masks failed to fit the participants adequately.
In their study, the researchers found that when fitted properly, N95 masks filtered more than 95% of airborne particles, offering superior protection. However, in some cases, poorly-fitted N95 masks were only comparable with surgical or cloth masks.
"It's not enough to assume that any single N95 model will fit the majority of a population," said O'Kelly. "The most widely-fitting mask we looked at, the 8511 N95, fit only three out of the seven participants in our study."
One observation the researchers made during their study was the width of the flange of the mask - the area of the material which comes in contact with the skin - may be a critical feature to fit. Masks which fit the greatest number of participants tended to have wider, more flexible flanges around the border.
In addition, small facial differences were observed to have a significant impact on quantitative fit. "Fitting the face perfectly is a difficult technical challenge and, as our research showed, small differences such as a centimetre wider nose or slightly fuller cheeks can make or break the fit of a mask," said O'Kelly.
Self-performed fit-checks are attractive because they save on time and resources, and are often the only method of fit testing available. However, this study, and studies of fit-check systems in other countries, indicate that such fit-check systems are not reliable.
The researchers hope that their results will be of use for those who are working on new technologies and programmes to assess fit, so that healthcare and other frontline workers are adequately protected in the case of any future pandemics. Additionally, they hope these results will bring attention to the importance of fit in clinical-grade masks, especially if such masks are to be widely used by the public. This study did not evaluate the impact of fit on protecting others, which is a future area of research.
INFORMATION:
Current electronic components in computers, mobile phones and many other devices are based on microstructured silicon carriers. However, this technology has almost reached its physical limits and the smallest possible structure sizes.
Two-dimensional (2D) materials are therefore being intensively researched. One can imagine these materials as extremely thin films consisting of only one layer of atoms. The best known is graphene, an atomically thin layer of graphite. For its discovery, Andre Geim and Konstantin Novoselov received the Nobel Prize in Physics in 2010.
While ...
Our world needs reliable telecommunications more than ever before. However, classic devices have limitations in terms of size and cost and, especially, power consumption - which is directly related to greenhouse emissions. Graphene could change this and transform the future of broadband. Now, Graphene Flagship researchers have devised a wafer-scale fabrication technology that, thanks to predetermined graphene single-crystal templates, allows for integration into silicon wafers, enabling automation and paving the way to large scale production.
This work, published in the prestigious journal ACS Nano, is a great example of a collaboration fostered by the ...
During the first confinement (18 March to 10 May 2020), people who reported worse sleep quality during a night also reported an increase in negative mood, psychotic-type like experiences and somatic complaints on the next day. Furthermore, daily reports of deaths caused by Covid-19 predicted psychological symptoms on the same day and sleep quality the following night. This is the result of research carried out in three countries (Belgium, Hungary, Spain) under direction of Peter Simor with researchers at the Université libre de Bruxelles (ULB), Rebeca Sifuentes-Ortega, Ariadna Albajara Saenz, Oumaïma Benkirane, Anke Van Roy and Philippe Peigneux from the CRCN (Center for Research in Cognition and Neurosciences) and the UNI (ULB Neurosciences Institute) ...
Personality traits such as conscientiousness or sociability are patterns of experience and behavior that can change throughout our lives. Individual changes usually take place slowly as people gradually adapt to the demands of society and their environment. However, it is unclear whether certain personality traits can also be psychologically influenced in a short-term and targeted manner.
Researchers from the universities of Zurich, St. Gallen, Brandeis, Illinois, and ETH Zurich have now investigated this question using a digital intervention. In their study, around 1,500 participants were provided with a specially developed smartphone app for three months and the researchers then assessed whether and ...
A mathematician from RUDN University suggested a stable difference scheme for solving inverse problems for elliptic-telegraph and differential equations that are used to describe biological, physical, and sociological processes. The results of the study were published in the Numerical Methods for Partial Differential Equations journal.
Elliptic equations are a class of differential equations in partial derivatives that are used, among other things, to model time-independent processes. Telegraph equations are presented in a nonstationary form. They were initially obtained for a telegraph communication line, but today they are also used to model the movement of insects, the flow of blood ...
PHOENIX -- A Mayo Clinic team, led by Rahmi Oklu, M.D., Ph.D., a vascular and interventional radiologist at Mayo Clinic, in collaboration with Samir Mitragotri, Ph.D., of Harvard University, report the development of a new ionic liquid formulation that killed cancer cells and allowed uniform distribution of a chemotherapy drug into liver tumors and other solid tumors in the lab. This discovery could solve a problem that has long plagued drug delivery to tumors and provide new hope to patients with liver cancer awaiting a liver transplant. The preclinical study results are published in Science Translational Medicine.
Dr. Oklu, study author and director of Mayo Clinic's ...
Two international studies of a consortium including more than a dozen institutions the world over, including Empa, published today in the journal Nature show levels of CFC-11 emissions, one of many chlorofluorocarbon (CFC) chemicals once widely used in refrigerators and insulating foams, are back on the decline - less than two years after their shock resurgence in the wake of suspected rogue production in eastern China was widely publicized.
"The findings are very welcome news and hopefully mark an end to a disturbing period of apparent regulatory breaches", says Luke Western from the University of Bristol, a ...
Cerebral small vessel disease (SVD) is characterized by damage to the blood vessels and parenchyma in the brain. It presents as a multitude of symptoms, which makes the diagnosis difficult. Matters are complicated further when SVD sets in along with other comorbidities with similar symptoms. Therefore, accurate diagnosis at an early stage of disease progression helps in defining better prognosis and management strategies for patients with cerebral SVD.
A team of researchers from the United Kingdom set out to review more than 10,000 studies on clinical diagnosis, risk factors, progression, and intervention ...
Experts have spent decades warning us about the rising rates of childhood obesity, which has become an epidemic among recent generations in many places around the world, including Spain. The transition from the traditional Mediterranean diet to the consumption of processed foods with low nutritional value is a key contributor, with child-targeted advertising also partly to blame. According to the Breakfast Food Advertisements in Mediterranean Countries: Products' Sugar Content in Adverts from 2015 to 2019 report produced by UOC Faculty of Information and Communication Sciences professor and researcher, Mireia Montaña, the majority of breakfast products ...
In recent years, active, self-propelled particles have received growing interest amongst the scientific community. Examples of active particles and their systems are numerous and very diverse, ranging from bacterium films to flocks of birds or human crowds. These systems can demonstrate unusual behavior, which is challenging to understand or model.
To this end, large-scale models of active particles were being scrutinised by experts at Leicester, in order to understand basic principles underlying active particle dynamics and apply them in a scenario of an evacuation strategy for customers in crowded place. Unexpectedly, the 'super-particles' milling in a circular motion were stumbled upon ...
