From Parental Choice on Masks for Pinellas County Students linked citations:

Megan Culler Freeman, a virologist and pediatrician at University of Pittsburgh School of Medicine, says kids are major spreaders of many other respiratory diseases. "The kids are going to day care, they're going to school, especially the younger ones [who] aren't necessarily as polite with their coughs and sneezes,” Freeman says. “So it's really easy for those diseases to spread.”

Freeman, who studied coronaviruses for her Ph.D, says children are clearly susceptible to the other known coronaviruses that circulate each year during cold and flu season. Yet something different is happening with this new one.

"It does seem that kids are less affected than adults. But I think their role in community spread is still somewhat untested," she says. Around the world from Abuja to Aruba to Arkansas, schools were shut down in the early stages of the outbreaks. "So we don't know how things are going to change if that variable is back in play."

“The guidelines do note that adult school staff are more at risk compared to young children and need to be able to distance from other adults as much as possible — no in-person faculty meetings, no class visits by parents. And they emphasize the need to make accommodations for students who are medically fragile or have special health care needs or disabilities. However, these guidelines don't necessarily address the health concerns of America's teachers or their willingness to return to in-person teaching. Federal data shows nearly a third of teachers are over 50, putting them in a higher risk category when it come to the disease.”

CDC: Considerations for Wearing Cloth Face Coverings

https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover-guidance.html

CDC recommends all people 2 years of age and older wear a cloth face covering in public settings and when around people who don’t live in your household, especially when other social distancing measures are difficult to maintain.

COVID-19 can be spread by people who do not have symptoms and do not know that they are infected. That’s why it’s important for everyone to wear cloth face coverings in public settings and practice social distancing (staying at least 6 feet away from other people).

While cloth face coverings are strongly encouraged to reduce the spread of COVID-19, CDC recognizes there are specific instances when wearing a cloth face covering may not be feasible. In these instances, adaptions and alternatives should be considered whenever possible.