A new study shows that using cheap and widely available tools, scientists have developed a simple method to visually assess how different types of masks effectively prevent the spread of droplets that may contain SARS-CoV-2 virus particles .
Although the authors point out that their work is still in the early stages, and so far, their method has only been tested in a small number of people, but these preliminary proof-of-principle results show that professional-grade N95 masks, surgical or polypropylene masks, and when When the wearer speaks, hand-made cotton masks may block most of the spray. However, turbans and neck fleece may provide little protection because researchers have observed that more droplets are expelled from these materials, most likely because these materials break down larger droplets as they pass through the material. Emma Fischer and colleagues suggest that non-experts can easily construct and operate this setting to evaluate masks at the community level, so that mask manufacturers can use the method to optimize mask design, while education and community Outreach organizations can demonstrate proper mask installation procedures.
As countries around the world formulate mask directives to curb the spread of COVID-19, in the face of unprecedented demand, global commercial suppliers are experiencing shortages. To make up for this, many people turn to homemade masks and mask substitutes, but these “do it yourself” versions have not yet been systematically tested. In order to evaluate the effectiveness of 14 different types of masks and other masks that are frequently changed, Fischer Wait. A simple method was devised in which one male speaker, or in some cases, four speakers, each mask should be worn when standing in a dark environment. The speaker will say five times in the direction of the laser beam “Keep healthy, man”, which will scatter the light in the droplets released during the speech.
The mobile phone camera recorded the droplets and counted them through a simple computer algorithm. The installer has been carefully designed to be simple and cheap, so it can be copied by non-experts-the hardware it requires (including laser equipment) is usually available and can be purchased for less than $200. Although the researchers acknowledged the need for further testing, Fischer Wait.The findings show that N95 masks without valves can best prevent the spread of droplets, but surgical or polypropylene masks and handmade cotton masks are also effective. Early findings indicate that turbans and fleece (like balaclavas) may provide little protection.
The corresponding author of the study, Martin Fischer, wrote in a Q&A: “Our work is just a demonstration of a simple measurement method, not a systematic mask study.” “More work is needed. Study the changes in masks, speakers, and the way people wear them. We also hope to extend our method to other droplet-generating actions, such as coughing and sneezing. In addition, we want to explore the effects of incorrect placement and saturation of humidity.”