What HVAC measures have been taken to provide maximum air filtration and ventilation in school buildings? Why is HCPSS monitoring the carbon dioxide (CO2) concentration in school cafeterias? What is considered an elevated CO2 concentration? What causes an elevated CO2 concentration in schools? What are the risks associated with elevated CO2 concentration to students and staff in the building? Are HEPA filtration units and other mitigation efforts helping to ease CO2 concentration or possibly contributing to it? How will parents/guardians be notified if their child's school experiences elevated CO2 concentration? Where can I find Indoor Environmental Quality (IEQ) information?