Currently, Pitkin County Public Health strongly recommends that anyone over the age of 2 wear face masks in all indoor public places. In addition, universal masking is required in all schools in accordance with the current public health order.
That said, below is a brief summary of the scientific evidence from the Centers for Disease Control and Prevention (CDC) on how masks work and how well they work. This information, along with our current level of risk, helps determine mask orientations.
COVID-19 infection is spread primarily by inhaling respiratory droplets generated when people cough, sneeze, sing, talk or breathe. The masks are primarily intended to reduce the emission of droplets containing the virus, which is especially relevant for asymptomatic or presymptomatic infected mask wearers who feel well and may be unaware of their infectivity to others. These individuals are estimated to account for over 50% of transmissions.
In a laboratory evaluation of the effectiveness of the masks, studies found that multi-layered fabric masks prevent 50-70% of aerosols from the wearer. Wearing a mask can also help prevent germs from another person’s respiratory droplets from entering your nose and mouth.
In addition, at least ten community-level analytical studies show that following guidance from organizational and political leaders for universal masking, new COVID-19 infections have declined significantly – in some cases by as much as 79%. . Two studies have also shown a reduction in death rates due to masking.
Please consult these CDC sources for more information on the science of masking and a brief on the scientific evidence for masks. Our public health team continues to gather studies and data on this important topic, so stay tuned for more.