How Your School’s Indoor Air Quality Affects Health and Learning

The EPA estimates that up to half of all schools have problems linked to indoor air quality. Unlike homes, schools are places where many children and staff are crowded into small spaces. In fact, schools may have four times as many people per square foot as offices. This poor indoor air quality does affect the health and learning of students and staff.

Poor indoor air quality can have short and long-term health effects for both students and staff. But children, whose bodies and lungs are still developing, are especially vulnerable to the health impacts of air pollution. Indoor air quality problems in schools have been linked to drowsiness, headaches, concentration problems, academic performance, asthma and COPD symptoms, as well as absences due to respiratory infections or allergic reactions to chemicals used in schools. Furthermore, growing up breathing high levels of air pollution can affect how children's lungs develop, putting them at greater risk of lung disease as they age. 

Studies have shown that children in classrooms with higher outdoor air ventilation rates and cleaner indoor air quality tend to achieve higher standardized test scores in comparison with children in poorly ventilated classrooms. This is due to the lower carbon dioxide levels in the classroom and reduced transmission and spread of infectious disease. Unfortunately, the same study found that ventilation rates in classrooms regularly fall below the minimum standard needed for healthy indoor air, and many schools have HVAC (heating, ventilating and air-conditioning) systems that need updates and are failing.

What Impacts a School’s Indoor Air Quality?

A school’s #1 priority is to provide a quality education in a safe environment. But a schools’ indoor air quality can be impacted by a variety of factors including the building’s location, airflow and ventilation, temperature and humidity, building maintenance, cleaning products and practices and even occupant behavior. 

A school’s location can contribute to air pollution when they are located near pollutions sources. For instance, schools located near highways, factories, power plants, oil and gas operations, etc., can have poor indoor air quality caused by these outdoor air pollutants getting into the school. Unfortunately, there are limited state and federal standards for school air quality so these problems may go unchecked. 

The building temperature can impact a school’s air quality drastically as well. For instance, when temperatures rise, so does the concentration of carbon dioxide emitted by each person in the building. High temperature and humidity levels can increase concentrations of other pollutants as well because many bacteria strains and viruses, as well as mold, thrive in high humidity.

Unfortunately, tight school budgets can mean indoor air quality is not a priority. In these cases, building maintenance of ventilation system updates may have been deferred leading to a variety of problems, including: 

• Poor ventilation and air flow leading to headaches, drowsiness, poor academic performance, and increased absenteeism. 
• Uncontrolled classroom temperatures which can have health and performance impacts.
• If buses are idling nearby, pollution and diesel emissions, which studies have shown are detrimental to children’s brains and respiratory systems. 
• If very outdated, the appearance of harmful substances that were used during building but are now banned, like asbestos. 
• The use of cleaning products and other chemicals inside the building that may be harmful to individuals with asthma or chemical sensitivities.  

Steps to Improve Your School’s Air Quality

The approach to improve indoor air quality is the same for homes, work, schools, and other buildings and includes source control, ventilation, and air cleaning.  Not all schools will have the bandwidth to make big changes, but here are some low-cost, practical first steps that schools can take to improve indoor air quality:

1. Test your school for radon. Seek expert advice on where to place the test kits including all occupied and intended to be occupied rooms in contact with the ground and some upper floor rooms. Follow-up testing by continuous radon monitoring should be completed in rooms that have elevated radon levels. Establish a baseline of indoor air pollution and determine where improvements are needed. This includes measuring the temperature, humidity, air movement and airflow volume, and using a carbon dioxide (CO2) monitor is useful for indicating when outdoor air ventilation may be inadequate.
2. Assess your school for common allergens and asthma triggers and remove them. This could include mouse droppings, pets in the classroom, dust, strong fragrances and cleaning products.  
3. Consider a low/no chemical policy at your school including limiting the use of fragrances, scents, air fresheners and strong cleaning chemicals.
4. Improve ventilation to increase circulation of fresh air in the classroom and reduce indoor air pollutants by: 
   • Ensure classroom air ducts are open and not blocked by desks or bookshelves. 
   • Open classroom windows for at least 10 minutes each day to increase fresh outdoor air flow.
   • Leave classroom doors open when students leave the room for lunch, recess or another class.
   • Use fans to exhaust classroom air to the outdoors and to get a crosswind.
5. See if your school budget allows the purchase of indoor air quality measuring devices. Wireless, battery-operated indoor air quality devices can monitor a wide array of air quality issues (e.g. temperature, humidity, CO2, radon). If you cannot afford these on your own, your school may be eligible to borrow equipment from an EPA Regional Office. Find your EPA Regional Offices.

Schools should be safe and healthy learning environments for all students and staff. Learn more about improving air quality by visiting our How to Know if There is a Problem page and Healthy Air Tools for Schools and Districts page.