Tag: masks

Children Struggle to Recognise Expressions of People with Facemasks

Image by pedro_wroclaw from Pixabay

sA new study has shown that children between the ages of 3 and 5 have difficulty in recognising the emotions of people wearing surgical masks. This collateral effect from this  measure to prevent COVID transmission could influence the correct development of children’s capabilities of social interaction.

To provide guidance for decision-makers, the World Health Organization (WHO) and UNICEF compiled a document discouraging exposure to the use of facemasks when dealing with children aged up to five years old. In addition, even for older children, WHO recommends weighing up the benefits of wearing facemasks in against potential negative impacts that could include social and psychological problems, and difficulties in communication and learning.

To investigate such possible negative impacts, a study was carried out by the U-Vip (Unit for Visually Impaired People) research team led by Monica Gori at the IIT- Istituto Italiano di Tecnologia (Italian Institute of Technology). The findings were published in Frontiers in Psychology.

A research team led by Monica Gori at the Istituto Italiano di Tecnologia (IIT) focused on the pre-school age group, helping define the measures that can be taken to reduce the impact of the use of surgical masks amongst children. While the wearing of facemasks is not mandatory from 3 to 5 years of age, children are in any case exposed to the use of such preventive measures in various everyday social and educational contexts.

The IIT researchers prepared a quiz containing images of people with and without facemasks, and displayed them on screens to 119 individuals comprising 31 children aged between 3 and 5 years old, 49 children between 6 and 8 years old, and 39 adults between 18 and 30 years old. The participants, independently or with parental assistance in the case of the youngest participants, were asked to try to recognise the faces’ expressions, with and without facemask, conveying different emotions such as happiness, sadness, fear and anger.

When those faces were covered with a facemask, the 3-5 years olds only managed to recognise facial expressions conveying happiness and sadness 40% of the time. The percentages were higher for other age groups: 6-8 years olds had a 55-65% success rate, and 70-80% adults. Generally, however, all age groups displayed some difficulty in interpreting these emotions expressed while the face was partially covered by a facemask. There were better results with other expressions, but the pre-school age children still had the greatest difficulty.

“The experiment was performed in the earliest phases of the 2020 pandemic, and at that time facemasks were still a new experience for everyone,” said Monica Gori. “Children’s brains are highly flexible, and at the moment we are performing tests to ascertain whether children’s understanding of emotions has increased or not.”

“In the study, we worked with children and adults with no forms of disability”, explained Maria Bianca Amadeo, IIT researcher, “of course, these observations are even more important when considering children affected by disabilities.” 
“Indeed”, added co-author Lucia Schiatti, IIT researcher, “for example visual impairment implies difficulties in social interaction. For such individuals in particular, it will be even more necessary to concentrate on possible preventive measures or specific rehabilitation activities”.

Further research is needed over the next few years to assess the actual impact of this mask wearing on the ability of children with and without disabilities to interact. In the meantime, the findings suggest the use of transparent facemasks for all operators in contact with children in the 3-5 year-old age group, or developing training activities to teach children how to recognise emotions by looking at the eyes.

Source: News-Medical.Net

Journal information: Gori, M., et al. (2021) Masking Emotions: Face Masks Impair How We Read Emotions. Frontiers in Psychology. doi.org/10.3389/fpsyg.2021.669432.

Normal Breathing Can Transport Viruses Over 2 Metres

Researchers have demonstrated that normal breathing can transport viruses in saliva droplets up a distance of up to 2.2 metres in 90 seconds.

The World Health Organization and the Centers for Disease Control recommend social distancing to prevent the spread of COVID. The distances are estimated from various studies, but there is a need for further research into how viruses are transported from one person to another. 
Previous studies considered aerosol transport after coughing or sneezing, while this study focused on normal human breathing, using computer simulations with a more realistic model than prior studies. A normal breath produces periodic jet flows that contain saliva droplets, but those jets’ velocity is less than a tenth that of a cough or sneeze.

Wearing a face mask greatly reduces the distance which these droplets can travel. Saliva droplets restricted by a mask had travelled only 0.72 metres after two minutes, far short of the distance of 1.8 metres suggested by the CDC.

The investigators found even normal breathing produces a complex field of vortices that can move saliva droplets away from the person’s mouth. The role of these vortices has not previously been understood.

Study author, Ali Khosronejad, American Institute of Physics said: “Our results show that normal breathing without a facial mask generates periodic trailing jets and leading circular vortex rings that propagate forward and interact with the vortical flow structures produced in prior breathing cycles.”

This complex vorticity field can enable the transport of aerosol droplets over long distances despite the slow speeds. A face mask serves to dissipate the kinetic energy of the jet produced by an exhaled breath, thereby disrupting the vortices and limiting the travel of virus-laden droplets.

The researchers also took into account evaporation of the saliva droplets. With no mask, they found the saliva droplets near the front of the plume of exhaled breath had partially evaporated, reaching a size of only one-tenth of a micrometre. In stagnant indoor air, it would take days for droplets this small to settle to the ground.

Masks partially redirect the exhaled breath downward, significantly restricting forward motion of the plume, so the risk of suspended droplets remaining in the air is substantially reduced.

“To simplify the breathing process, we did not consider the flow of air-saliva mixture through the nose and solely accounted for the flow through the mouth,” Khosronejad said. “In future studies, we will explore the effect of normal breathing via both the nose and mouth.”

Source: News-Medical.Net

Journal reference: Khosronejad, A., et al. (2021) A computational study of expiratory particle transport and vortex dynamics during breathing with and without face masks. Physics of Fluids. doi.org/10.1063/5.0054204.

As Lockdowns Ease, Masks and Social Distancing are Still Needed

A new model suggests that as lockdowns ease, other control measures such as mask use must be enhanced in order to prevent additional COVID outbreaks.

The mathematical model, developed by scientists at the Universities of Cambridge and Liverpool, provides general insights about how COVID will spread under different potential control scenarios.

They considered ‘non spatial’ control measures involving facemasks, handwashing and metre-scale social distancing can all limit the number of virus particles being spread between people. The other, ‘spatial’ control measures included lockdown and travel restrictions, which reduce how far virus particles can spread. Different combinations of COVID control measures showed that non-spatial control needs to be ramped up as lockdown is lifted.

“More effective use of control measures like facemasks and handwashing would help us to stop the pandemic faster, or to get better results in halting transmission through the vaccination programme. This also means we could avoid another potential lockdown,” said Dr. Yevhen Suprunenko, a Research Associate in the University of Cambridge’s Department of Plant Sciences and first author of the paper. The authors stress that their predictions rely on such non-spatial control measures being implemented effectively.

Their model took into account the socio-economic impact of the measures. The costs of spatial measures of lockdown increased over time, while costs for non-spatial measures decreased due to falling prices and greater availability of items such as masks, and usage becoming a habit.

“Measures such as lockdowns that limit how far potentially infected people move can have a stronger impact on controlling the spread of disease, but methods that reduce the risk of transmission whenever people mix provide an inexpensive way to supplement them,” explained co-author Dr Stephen Cornell at the University of Liverpool.

The model was derived from identifying control strategies for plant diseases threatening staple crops. Instead of the usual computer simulation model, mathematical approach allowed the authors to identify insights on how to control newly emerging infectious diseases of plants and animals.

“Our new model will help us study how different infectious diseases can spread and become endemic. This will enable us to find better control strategies, and stop future epidemics faster and more efficiently,” said co-author Professor Chris Gilligan in the University of Cambridge’s Department of Plant Sciences.

Source: Medical Xpress

Journal information: Analytical approximation for invasion and endemic thresholds, and the optimal control of epidemics in spatially explicit individual-based models, Journal of the Royal Society Interface,rsif.royalsocietypublishing.or … .1098/rsif.2020.0966

As COVID Variants Dominate, Better Mask Use is Needed

Evidence is accumulating that COVID is commonly transmitted through small aerosolised droplets emitted during regular speaking and breathing—a problem compounded by the enhanced contagiousness of variants such as 501Y.V2, the strain which dominates in South Africa.

Masks have become ubiquitous in the pandemic-struck world, and even fashionable, with many different types available. However, their effectiveness varies considerably from top-of-the-range N95 masks to a pulled-up shirt which offers very little protection.
“How well a mask works depends on two things: filtration and fit,” said Professor Linsey Marr, who studies airborne disease transmission at Virginia Tech .

“Good filtration removes as many particles as possible, and a good fit means that there are no leaks around the sides of your mask, where air—and viruses—can leak through,” she said, noting that even a small gap could result in a 50% reduction in effectiveness.

We do not recommend wearing more than two masks. Adding more layers proves diminishing returns and can compromise breathability. It must remain easy to breathe through the layers; otherwise, air is more likely to leak in around the sides of the mask.

Wearing a cloth mask over a surgical mask, or ‘double masking’ does improve effectiveness as it serves to tighten the surgical mask’s fit. Air escapes around the corners and edges of the mask, as anyone who has worn glasses and had them fog up in the cold can attest to.

While N95 masks are the best available, there are also equivalents such as KN95 or FFP2.

“They all provide a similar level of filtration, meaning protection of particles going in and out,” said Ranu Dhillon, a global health physician at Brigham and Women’s Hospital and Harvard Medical School. Dhillon is frustrated at the lack of transparency and education for the public about masks.

Health care workers, for example, get their masks tested for fit, something which could be also done by members of the public.

Donald Milton, a professor of environmental health at the University of Maryland, said that the key to understanding the COVID airborne transmission threat is to treat it like cigarette smoke. Ventilation helps, but if you have someone between you and an exhaust vent, then masks will definitely help.

Before the pandemic, Milton and Dhillon courted controversy by demonstrating that most viral transmission was in the form of small droplets emitted when speaking or breathing, and the contribution to transmission by coughing and sneezing was smaller than previously thought. The two researchers are hopeful that their findings will find their way into official COVID policy, and future research may even see masks becoming a common sight during peak flu seasons.

Source: Japan Times