New study reveals how many layers of face masks are needed to be effective against COVID-19

A recent study done in Australia has suggested that when it comes to face masks/covers, the more layers there are, the better protection the mask will provide. Face masks are suggested to be one of the most effective ways to protect yourself from COVID-19 infection. However, the mask type and effectiveness have been constantly questioned, even after all these months into the pandemic. At first, it was suggested to wear masks only if you have symptoms or are caring for a coronavirus positive person. Then, in the month of June, the World Health Organisation declared that anyone (healthy or sick) in a COVID-19 affected area should wear a three-layer mask/cover. The mask should have a hydrophobic layer on the outside, a water-absorbing layer on the inside and a filter layer in between the two. The Centers for Disease Control and Prevention, US, has suggested a two-layer homemade mask on their website. Guidelines on making a face mask at home by the Indian government has no mention of the ideal number of layers. One layer is still better than no layer at all For the study, the researchers used a special LED lighting system and a high-speed camera to observe the spread of the droplets released on talking, sneezing and coughing while wearing different types of face masks. A healthy volunteer was taken for the study. For the cloth covering, a 175GSM cotton fabric was used with a thread count of 170TPI and the surgical mask was a 3-ply mask. It was found that a two-layer face mask was better than one layer mask in stopping the spread of droplets. However, one layer was still better than no mask at all and a surgical mask was better than a two-layer mask. Previous evidence Previous studies have also suggested something similar when it comes to face masks. A study done at the Florida Atlantic University College of Engineering indicated that when uncovered, the droplets from a person can spread up to 8 feet and a single bandana or a T-shirt with a thread count of around 85 can reduce this distance to between 3 and 7 feet. A stitched mask made of quilting cotton was found to be the best in this study – it could reduce the droplet spread to 2.5 inches. In another study, a 12-layer cotton mask was suggested to be as effective as a surgical mask. The latest study suggested that there are various factors that determine the efficacy of a cloth mask like the number of layers, the fabric used, and how frequently the mask is washed. Hence, it is suggested that the guidelines for making face covers at home should at least include instructions to include three layers or more. For more information, read our article on  Face covers to battle COVID-19 Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health.