A study at the University of Wisconsin-Madison shows the material and the fit of a mask determine how effective it is.
An engineering professor says the disposable, surgical-style masks are the most effective because they filter the droplets released when people breathe out. He says a well-fitting cloth mask is also effective, but they aren’t as good at protecting people from breathing in outside particles. The study finds that while masks help prevent the spread of COVID-19, physical distancing is the best method.
