Poor ventilation in school buildings across the U.S. will limit the ability of in-person instruction to resume safely.
As a new school year approaches amid the coronavirus pandemic, she and her colleagues are threatening not to return unless it's repaired.
Nationwide, an estimated 41% of school districts need to update or replace their heating, ventilation and cooling systems in at least half their schools, according to a federal report issued in June.
Stephen Murley, the school superintendent in Green Bay, Wisconsin, said most of his district's 42 campuses have older air systems.
Brian Toth, superintendent of the Saint Marys Area School District in northern Pennsylvania, said his districts five schools air systems have no exit vents to circulate fresh air in and the virus out.