Which policy or behavior is recommended to improve indoor air quality in schools?

• A. Increase use of scented cleaners and close windows.
• B. Use low-VOC materials and increase ventilation with outdoor air.
• C. Seal buildings completely and reduce ventilation.
• D. Rely solely on HEPA filters without ventilation changes.

Answer: (B)

Indoor air quality improves most when pollutants are kept low at the source and the air is actively refreshed with outdoor air. Using low-VOC materials means paints, adhesives, and cleaning products emit fewer harmful gases, so the indoor environment stays cleaner from the moment buildings are used. Increasing ventilation with outdoor air dilutes whatever pollutants are present, lowering their concentrations and improving oxygen levels for occupants. It’s important to balance ventilation with outdoor air quality and energy use, but the general principle is that bringing in fresh air plus reducing pollutant sources gives the strongest benefit for students and staff.

Fluids such as scented cleaners raise VOC levels, and closing windows or sealing buildings completely reduces air exchange, allowing pollutants to accumulate. Relying only on HEPA filtration helps remove particulates but does not address gases and does not replace the need for outdoor air exchange.