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How many layers does one need for protection against Covid-19?
Caution: While double-masking may improve the effectiveness of the mask, Dickson Aruhomukama, a clinical microbiology researcher at Makerere University College of Health Science, says it seems overly dramatic and not really necessary. PHOTO/NET.
The continued presence of Covid-19 has caused fear and anxiety among many people. This has caused many to adopt certain behaviours such as wearing more than one mask. But is this more helpful? Experts explain.
With the onset of Covid-19, Centres for Disease Control and Prevention established that the respiratory disease was majorly transmitted when droplets from infected persons were generated through sneezing, talking or breathing.
Their website recommended the use of multi-layer cloth masks to prevent transmission of the virus. “Masks were primarily intended to reduce the emission of virus-laden droplets.”
Dickson Aruhomukama, a clinical microbiology researcher at Makerere University College of Health Science, says with regards to the fight against Covid-19, when we use masks, we intend to achieve four things:
● You need a mask that sits well on your face, covers your nose and mouth and does not have pockets on the sides to allow external air to enter and air breathed out to escape into the external air.
● Whichever mask you wear, you should be able to breathe easily through it.
● The mask should be efficient to keep out organisms which include among others bacteria and viruses. As such, it must have good filtration efficiency.
● The reusability of the mask should also be taken into consideration. Is it a one-use mask or can it be used multiple times? That matters a lot because some are disposable while others can be reused.
Research
Basing on a study he and his team have carried out (Assessing knowledge, attitudes, perceptions and skills towards the use of face-masks in Kampala, Uganda: a community-level perspective), they believe one can use a single mask. “Then, in design, change the number of layers it has. For example, your single mask could have three or four layers,” he says.
The first layer, which sits on the face is designed to improve the fit of the mask. The material used must allow breathability irrespective of whether it is heavy or light. More to that, it ought to be flexible to easily and comfortably sit on the face without pockets.
Then the one or two layers in between could be filters and can be as rigid as can be as long as they do not allow organisms to escape. The outer one will cover the filters but also improve the design in regards to the features of the mask discussed earlier. Here, he says, one mask with several layers affords you all the features of a good mask.
Materials
The study, which also tested and compared various materials and forms of face-masks for filtration efficiency, breathability, microbial cleanliness, distance-dependent fitness, and re-usability of different face-masks procured from face-mask vendors in Kampala, examined each to see if they are as effective as surgical masks.
“The findings were that some of these are great alternatives to the medical ones, even when washed,” he says.
That said, some are single layered and Dr David Musoke, a researcher at Makerere University School of Public Health, says such are not as protective as a double layered one, hence not recommended. “Double masking would be appropriate if the filtration capabilities of one mask are wanting. That said, rather than wear two masks, wear one that is appropriate,” Musoke says.
Wearing them right
While double masking may increase protection, Aruhomukama says it really depends on which one you are going to put on top of the other.
“When done, the recommended outermost mask should be the surgical mask. However, the challenge is in distinguishing the masks as some think that a disposable mask is the same as a surgical mask.
Most Ugandans would not afford double masking as surgical masks are more expensive,” he adds.
That said, when double masking, if the masks do not conform to the required standards, even if one used 10, he says, they will not achieve much.
Home made masks
Dr Musoke says if one cannot access a face mask made to the required specifications, homemade masks are a great alternative.
“A double layered kitengi mask that fits well, keeps organisms out and allows breathability works just fine. However, ensure it is washed and treated (say, through ironing), to keep germs at bay,” he says.
