Studies Say a Breath of Fresh Air Leads to Good Grades

Poor classroom air quality leads to lower attendance, a decline in grades, and a higher risk of illness.

By: Hilary Van Hoose

A Google map of Los Angeles shows varying air quality levels from Oct. 9

Students have grown so used to stale classroom air that many overlook its impact on cognitive performance. However, improving air quality through filtration or even basic ventilation can lead to significant gains in focus and learning.

A study in PLOS ONE found not only that a combination of ventilation and cooling reduced illness-related absences and down-time, but also increased test scores significantly.

A study published in Environment International found that even small changes in indoor air quality can have a significant impact on student absences. For every tiny increase in indoor particle pollution (PM2.5) by 1 microgram per cubic meter (µg/m³), the number of school days missed increased by 7.37 per year. On the other hand, improving ventilation—by increasing the amount of fresh air by just 1 liter per second per person—led to a 5.59-day reduction in absences each year.

Long-term exposure to polluted air also has cumulative effects on health. Many recent and past studies show that exposure to the kinds of PM2.5 you find in urban areas like Los Angeles increase rates of cerebrovascular damage like strokes and neurological disorders like dementia, Alzheimer’s disease, and Parkinson’s disease.

In addition to ventilation, air filtration is also a vital factor in both student health and academic performance.

A working paper by NYU’s Michael Gilraine outlined how caution following the 2015 gas leak in Aliso Canyon prompted all LAUSD schools within five miles to place air filters in every classroom, office, and common area – resulting in math and English scores increasing by about the same amount as results from reducing class sizes by one third.

While industrial air filters cost approximately $1,000 per class per year, more affordable options exist. The Environmental Protection Agency and the UConn Indoor Air Quality Initiative found that $60 DIY “Corsi-Rosenthal Box” filters are 99% effective at removing infectious aerosols from classroom air.

Reducing levels of CO2 and PM2.5 are not the only benefits to filtration and ventilation either. Viral infections such as COVID-19 cause a drop in intelligence and cognitive ability.

A recent study in the New England Journal of Medicine found that those who have recovered from a mild COVID-19 infection have a 3 point drop in IQ, each reinfection causes a 2 point reduction, those with long-covid experience a 6-point drop, and those with severe infection lose 9 points.

Given that HEPA filters effectively remove PM2.5 but not CO2, one might wonder if using an air purifier alongside open windows negates benefits. However, a study published in Building and Environment revealed that the reduction rate of PM2.5 was only slightly higher with windows closed, suggesting that the advantages of purifiers still hold with windows open.

Student GPAs would skyrocket and absences would drop significantly if Valley College and other schools in the LACCD system followed common sense guidelines on implementing filtration and ventilation to make the indoor air in classrooms and common areas cleaner.