Healthy Schools - Outdoor Air Quality

kids sitting outside

How can air pollution affect students?

Air pollution problems near schools can increase long- and short-term health problems for students.  Good indoor air quality is an important piece to a healthy environment and can help schools complete their primary goal of educating children.  Poor outdoor air quality around schools can lead to health problems such as: 

·         Asthma attacks
·         Wheezing and cough
·         Shortness of breath
·         Headaches
·         Eye irritation
·         Susceptibility to infections

EPA’s Air Quality Flag Program for Schools webpage provides information and recommendations for outdoor activity guidance at schools.  

Why is outdoor air quality important to student health?

Students, teachers and staff who have breathing difficulties are at increased risk of respiratory stress or asthma attacks when outdoor air
quality is bad.    

Air pollution reduces air quality and thus is a major risk to health.  Air pollution causes to a number of health concerns such as asthma, allergies, lung disease, anxiety and depression.  Young children, teenagers and people with preexisting respiratory medical conditions are especially vulnerable to air pollution.

The types and amount of air pollution you may breathe will vary by your location, the time of day, the temperature and the weather.

Some sources of air pollution are natural such as smoke from wildfires, pollen from plants, dander from pets, or spores from molds.  Other sources of air pollution are from burning coal, driving cars and trucks, and incinerating garbage.

When should schools pay close attention to poor outdoor air quality and temperatures?

Students, teachers, and staff who have breathing difficulties are at increased risk of respiratory stress or asthma attacks when outdoor air quality is bad.  Some situations are more likely to trigger respiratory distress or asthma attacks.  Outside temperatures can definitely have an effect on breathing difficulties as seen in the following information.

High Temperatures

Built to retain heat in the winter, many northern U.S. schools are 50 years old and lack proper infrastructure and heating, ventilation and air conditioning equipment to cope with high outdoor temperatures. Southern schools may be more prepared, but long-term use and poorly maintained HVAC systems can negatively impact their ability to respond to high temperatures as well. The need for cooling strategies, such as air conditioning, or school designs that enhance natural ventilation has become more evident due to the increase in frequency and severity of extreme heat events in the United States in the past few years.

The U.S. Environmental Protection Agency’s Indoor Air Division found more than 30 research articles showing that high temperatures influence student health, thinking and performance.

Student Health: High temperatures and humidity have been associated with adverse impacts on physical education by triggering cough and asthma. Warmer classrooms have been associated with worse indoor air quality perceptions and self-reported eye, throat and nose irritation.

Student Thinking: Heat impacts cognitive function acutely and chronically, including reaction time, information processing, memory and reasoning. A recent study found young adults living in non-air-conditioned dormitories performed worse in two cognitive tests measuring selective attention, reaction time and accuracy.

Student Performance: High school students in New York state were more likely to fail standardized testing when outdoor temperatures were 90°F or higher. Another study found for each 1°F increase in average temperature throughout the academic year, students without air conditioning experienced a 1 percent deficit in their learning; this effect was tripled among minorities. The good news is that access to air conditioning mitigated up to 78 percent of the observed effects.

Cooling the air during extreme heat events is a priority to preserve school health. However, AC is not necessarily a “one size fits all” solution. Aging infrastructure limits the ability to retrofit old buildings, increasing energy bills absorb money from tight school budgets, and air conditioning units can sometimes impact other aspects of indoor environments, such as acoustics and indoor air quality.

Low Temperatures

Schools in the northern U.S. were built to cope with low outdoor temperatures.  They are usually well insulated and have robust heating systems.  Southern schools may be less prepared.  As with higher temperatures, long-term use and poorly maintained HVAC systems in southern schools can also negatively impact their ability to respond to low temperatures.  

Because they are less able to regulate their body temperature than adults, children exposed to extreme cold can quickly develop a dangerously low body temperature (i.e., become hypothermic).  Children and adults respond to cold extremes by shivering, developing "goose bumps", and experiencing lethargy and a slow heart rate.

The definition of extreme cold can vary across different regions of the country and there are no local or national temperature standards or specific rules about when students should be kept indoors. While most students can spend short periods outdoors if they are dressed appropriately, prolonged exposure to below-freezing temperatures can lead to serious conditions such as frostbite or hypothermia.

The decision to modify or cancel outdoor physical activities due to weather conditions should be made by school administrators using a “common sense” approach, with consideration given to risk factors of the student population at each school.

Young children, those with health conditions such as asthma, and those who are not dressed appropriately for the cold weather are at greatest risk of health complications in cold temperatures. Environmental risk factors include air temperature, wind chill factor, relative humidity, amount of time spent outdoors, etc.

When a decision is made to allow students to participate in outdoor recess or physical education in cold weather conditions, the following preventative measures are essential to protecting their health and safety:

  1. Dress Warmly and Stay Dry  ̶  Adults and children should wear: a hat, scarf or knit mask to cover face and mouth, mittens, water-resistant coats and boots, sleeves that are snug at the wrist, and several layers of loose clothing.
  2. Be Aware of the Wind Chill Factor  ̶  Wind chill is the temperature the body feels when the air temperature is combined with wind speed. As the speed of the wind increases, it can “carry away” heat from the body and cause skin temperature to drop to dangerously low levels, even when the weather is only cool.
  3. Prevention is the Key  ̶  Do not ignore shivering! It is the first sign that the body is losing heat and serves as a signal that the student should return indoors.  Students should be Supervised closely and ensure supervisory staff is trained to recognize and respond to symptoms of cold exposure, including hypothermia and frostbite.  Students who are known to have medical disabilities or diagnoses should be checked on regularly.

What are common outdoor air pollutants?

Common outdoor air pollutants include byproducts from smokestack or automobile emissions like particulate matter (PM), nitrogen dioxide (NO2), sulfur dioxide (SO2) and ozone (O3).  Other outdoor air pollutants are allergens like pollen and mold.  There has been a lot of study about adverse health effects of ground-level ozone and particulate pollution.

Why is ground-level ozone a health concern?

Ground-level ozone is an air pollutant.  The ozone layer in Earth’s upper atmosphere is good.  Ozone in the lower atmosphere close to ground in the air that we breathe can be a health hazard.  Ozone can be created when other air pollutants react with sunlight. Common symptoms of ozone exposure are coughing and pain when taking a deep breath, lung and throat irritation, or wheezing and trouble breathing.  Ozone effects are often more severe when breathing deeply such as when doing strenuous activities or exercising.  Ozone is more common in warmer months; unfortunately the same months of the year when people tend to be more active outdoors.  For people with asthma, bronchitis, emphysema or other respiratory illness, symptoms of exposure to ozone in the air are often worse and can lead to more medical emergencies.

Why is particulate pollution a health concern?

Particulate pollution includes dust, dirt, soot, smoke or drops of liquid.  This form of air pollution is often called particulate matter or PM for short.  Some particles are big enough or dark enough to see in the air while many particles are too small or too light to see with your eyes.  The bigger particles are often called PM10 and the smaller particles PM2.5.  The smaller particles are considered to be more dangerous as these tiny PM2.5 particles can get farther into your lungs.  Common symptoms of exposure to particle pollution are eye irritation, lung and throat irritation, trouble breathing, lung cancer, or problems with babies at birth like low birth weight.  For people with heart disease, particle pollution can cause serious health problems like a heart attack.

What is the Air Quality Index?

The Air Quality Index is a reporting system for quickly sharing the amount of air pollution forecast for an area.  The AQI uses a color system to make it easy for people to quickly determine if air quality is reaching levels that might be unhealthy for them to be working, playing or exercising outdoors.

Air Quality Flag Program

What is the School Air Quality Flag Program?

As student achievement is directly connected to health, monitoring outdoor air quality can help prepare students for days when their health could be adversely affected by poor air quality.  The Environmental Protection Agency's Air Quality Flag Program matches air quality forecasts with actions to protect health. Flags that are color coded to match the air quality forecasting system are flown in a visible location to remind people about the outdoor air quality. 

This allows people who have respiratory medical conditions or other physical limitations to plan their actitivies to minimize respiratory distress or asthma attacks.

The American Lung Association has a complimentary Flag Program.  The ALA Tennessee chapter has additional educational information and resources for schools about air quality.

Government partners

Tennessee Department of Environment and Conservation
Division of Air Pollution Control

Environmental Protection Agency
Air Quality Flag Program

Other partners

American Lung Association of Tennessee
Air Quality Flag Program Sign Up Form
Healthy Air Outdoors

Additional resources

American Academy of Pediatrics
Extreme Temperatures:  Heat and Cold