When we think about helping students learn, we often focus on great teachers, strong curriculum and supportive families. Though those things are important, the quality of the air they breathe may be just as big of a factor in their success in the classroom.
Students spend about six to eight hours each day at school. If the air is stuffy or contains high levels of carbon dioxide, particulate matter, dust, mold or other allergens and pollutants, it can greatly affect their health and academic performance. Because children’s lungs are still developing, they breathe more rapidly and inhale more air for their body size than adults; they can be especially sensitive to the harmful effects of indoor air pollution.
Cleaner Air Means Fewer Sick Days
Students can’t learn if they consistently miss school because of illness. One of the biggest benefits of good indoor air quality is better health, resulting in fewer sick days.
Asthma, a common chronic disease in children, is one of the leading reasons students miss school. Poor indoor air quality (IAQ) can trigger asthma flare-ups, making it harder for students to stay healthy and attend class regularly. Dampness and mold in schools can increase asthma-related health effects by 30% to 50%.
One study found that higher levels of particle pollution (PM2.5) were linked to more missed school days and more student behavior problems that required disciplinary action. Teachers and staff were also more likely to miss work because of illness related to air pollution. These findings show that cleaner air can help create a healthier, more productive learning environment for students, teachers and staff.
“Something as simple as a classroom air purifier increases air changes to reduce airborne particles and germs, which means fewer sick days,” said Brian Clark, the school administrator at Star of the North Academy, in Minnesota. “Fewer absences means more time learning for our students and less strain on families who would otherwise miss work to care for a sick child.”
Clean Air Helps Students Focus and Concentrate
Research shows that good indoor air quality is not just a building issue; it is an education issue.
Imagine a fifth-grade classroom just after lunch. The students return inside after recess, and it's time for a math lesson. In one classroom, the air feels fresh because the ventilation system is working well and air pollutants are kept to a minimum. Students can pay attention to the teacher's instructions, stay focused during independent work and make fewer mistakes.
In another classroom, stale, stuffy air makes some students feel tired, distracted or uncomfortable. With poor ventilation, carbon dioxide levels rise, students begin to rub their eyes, cough and have trouble concentrating on the lesson. The teacher spends more time redirecting attention and repeating instructions.
Just like it's easier to think clearly after getting a good night's sleep, clean air helps students' brains get the oxygen they need to stay alert and focused. When the air is cleaner, students can spend more energy learning and less energy dealing with discomfort or breathing issues.
Higher pollution levels are linked to more behavior problems and disciplinary referrals in schools.
Better Air Quality Supports Learning
Besides improving focus, better ventilation is also linked to stronger cognitive performance, including attention, memory and decision-making. In that same math class, students need to listen to directions, remember the steps for solving a problem and decide which strategy to use. In a classroom with good ventilation and fresh air, students are more likely to stay attentive, retain information and think through problems effectively. Better air quality helps support the cognitive skills that learning depends on, including attention, memory and decision-making.
Many studies support this claim, including one Harvard study that found that lower carbon dioxide (CO2) levels were associated with higher test scores, improved thinking, attention and problem solving that can impact overall learning. Another study looked at students' test scores in relation to ventilation rates and temperatures. The results showed that students in classrooms with more air flow earned better scores in reading, math and science than students in classrooms with less fresh air. These studies and more have led to the EPA findings that report children in classrooms with higher outdoor air ventilation rates score 14% to 15% higher on standardized tests as compared to those with lower ventilation rates.
Teachers and Staff Benefit from Clean Air Too
Students are not the only people affected by indoor air quality. Teachers spend long hours in school buildings and can also experience negative effects from poor air quality. Bad air can lead to headaches, fatigue, allergies and respiratory symptoms and more missed workdays. When teachers and staff are healthy and in school more consistently, students benefit from stable instruction and stronger relationships with their teachers.
Ways Schools Can Improve Air Quality
Schools face unique challenges because classrooms can be crowded, used for many different activities, and often they have to operate on a limited budget. The good news is, improving indoor air quality can be simple and does not always require major renovations. Many practical and low-cost improvements can provide meaningful benefits for students and staff.
“There is space in the middle between all or nothing where transformation can begin. That takes the pressure off trying to be perfect or making big leaps in a short amount of time,” explained Julie Lundgren, administrator at Lakes International Language Academy.
Simple, low-cost steps schools can take to improve indoor air quality are:
- Monitor carbon dioxide levels and improve ventilation and airflow when levels rise.
- Ensure fresh air vents are not blocked by desks, bookshelves, doors or any other furniture.
- Utilize MERV13 air filters and replace on schedule.
- Fix water leaks quickly to prevent mold growth.
- Reduce dust and other particulate matter in the air.
- Reduce the number of volatile organic compounds used in the school’s cleaning products.
- Ensure school buses and other vehicles do not idle close to the building’s clean air intake vents.
- Use walk-off mats at each school door entrance to capture dirt, pollen and other allergens brought into the school.
Blog last updated: November 9, 2026
