As the new crown pneumonia epidemic continues to spread, masks have become a mandatory public health necessity in many parts of the world. Due to the dwindling supply of medical surgical masks and N95 masks (they are being properly transferred to medical care facilities), the general public is often urged to cover their mouth and nose with anything that can be used when going out to public places. Ideally, self-made masks should have two to three layers, but in the absence of any better options, health departments around the world propose to use headscarves, scarves, or neck sleeves as substitutes for masks. Some experts agreed: "Any mask or covering is better than nothing."
Eric Westman of Duke University School of Medicine is trying to figure out which masks should be purchased for a non-profit organization that helps local communities at risk. He quickly realized that the market was full of products claiming to be extraordinary, but there was no testing process to verify the efficacy of these masks. Not surprisingly, a properly sized N95 mask can reduce spray droplets most effectively, followed by surgical masks. However, most of the cotton masks tested performed well, and the blocking rate of droplets was not far from that of medical surgical masks.
Unfortunately, not all types of mouth and nose coverings can effectively reduce spray droplets. In terms of reducing the droplets emitted by the speaker, the effect of knitted fabrics and squares is particularly poor. But what really surprised the researchers was the test results of the cashmere neck sleeve.
When talking about the test results of the cashmere neck sleeve, Westman said: "The idea that' nothing is better than nothing' is not valid." Under the circumstances, the droplets sprayed during the benchmark test are similar.
He explained: "We attribute this to the fact that cashmere and textiles break down those large particles into many small particles. They tend to stay in the air longer and are easier to spread in the air."
This study believes that wearing such a mask may eventually be counterproductive, causing a greater risk of transmission than not wearing a mask. However, this conclusion is still hypothetical, and this study does not clearly prove that cashmere neck sleeves can aggravate the spread of the virus. On the contrary, this research suggests that the frequently used adage "something is better than nothing" may be wrong.