Indoor Air Quality Affecting Student Attendance: Insights from a Research Study

In a groundbreaking recent study primarily supported by the U.S. EPA and conducted across 31 schools in the Midwestern United States, researchers have shed light on the profound impact of indoor environmental quality on student attendance. The findings not only underscore the importance of adequate ventilation but also emphasize the role of indoor air quality in shaping the educational landscape (here you can read more on HVAC in schools).

This comprehensive study spanned two years and meticulously monitored indoor environmental data in 144 classrooms from elementary and secondary schools and more than 3,000 students. It's worth noting that all the classrooms featured mechanical ventilation systems with recirculation, and none had operable exterior windows or doors.

The main takeaways can be summarized as follows:

  • Ventilation rates matter, a lot
    One of the most striking revelations from the study was the direct correlation between ventilation rates and student attendance. In brief, for every 1 liter per second per person increase in ventilation rate, there is a 0.15% increase in the annual daily attendance rate.
  • The important role of PM2.5
    The study also highlighted the significance of indoor particulate matter (PM2.5) levels. For every additional 1 microgram per cubic meter (μg/m³) of indoor PM2.5, there was a 0.19% decrease in the annual daily attendance rate.
  • Implications for education and beyond
    Reduced absence rates are not just about ensuring students are in their seats; they translate into socioeconomic benefits and improved academic achievements. Moreover, higher ventilation rates and cleaner indoor air can contribute to reducing health risks.


This research serves as a call for schools and institutions to prioritize indoor air quality and ventilation systems. By doing so, they not only enhance the learning environment but also nurture healthier, more engaged, and academically successful students.


Read the full study here