Currently, Pitkin County Public Health strongly recommends everyone over 2 years of age wear masks in all public indoor settings. In addition, universal masking is required in all schools per the current public health order.
With that said, below you will find a short summary of scientific evidence from the Centers for Disease Control and Prevention (CDC) on how masks work and their effectiveness. This information coupled with our current risk level helps determine mask guidance.
COVID-19 infection is transmitted predominately by inhalation of respiratory droplets generated when people cough, sneeze, sing, talk, or breathe. Masks are primarily intended to reduce the emission of droplets containing virus, which is especially relevant for asymptomatic or presymptomatic infected mask wearers who feel well and may be unaware of their infectiousness to others. These individuals are estimated to account for more than 50% of transmissions.
In a laboratory assessment of masks effectiveness, studies found that multi-layer cloth masks prevent 50-70% of aerosols coming from the wearer. Wearing a mask can also help prevent germs that come from another person’s respiratory droplets from getting into your nose and mouth.
In addition, at least ten studies in community level analysis show that following directives from organizational and political leadership for universal masking, new COVID-19 infections fell significantly – in some cases up to 79%. Two studies also showed a reduction in mortality rates due to masking.
Please review these CDC sources for more information on the science of masking and a brief about the scientific evidence for masks. Our Public Health team continues to gather studies and data on this important topic so please stay tuned for more information.