Asthma Capitals: Poor Air Quality

In AAFA's Asthma Capitals ReportDownload PDF, we looked at eight risk factors that can affect asthma rates: poverty, lack of health insurance, poor air quality, pollen counts, long-term control medicine use, quick-relief medicine use, smoking laws and access to specialists.

Air pollution is a mixture of natural and man-made substances in the air we breathe. It is typically separated into outdoor and indoor pollution.1 Air pollution includes gases, smoke from fires, volcanic ash, dust particles and other substances that are irritating to the lungs. Research shows that air pollution can cause and worsen asthma.

Ozone, a gas, is one of the most common air pollutants. Ozone contributes to what we typically experience as “smog” or haze. It is most common in cities where there are more cars. It is also more common in the summer when there is more sunlight and low winds. Ozone triggers asthma because it is irritating to the lungs and airways.

Other forms of air pollution can also trigger asthma. Small particles in the air can pass through your nose or mouth and get into your lungs. Airborne particles, found in haze, smoke and airborne dust, present serious air quality problems. People with asthma are at greater risk from breathing in small particles. The particles can make asthma worse.

Many sources, including local TV weather forecasts, report the expected air quality for the next day or two. This information can help you know when the air quality may trigger an asthma episode and allow you to plan accordingly.

Poor air quality

California dominates this list because of wildfires. Smoke from wildfires contains tiny particles that affect air quality. These particles can irritate your eyes, nose, throat and lungs. Poor air quality can worsen asthma symptoms. Children and people with respiratory disease like asthma are at high risk for asthma episodes when the air quality is poor.

Wildfires do not only affect people in the immediate fire area. Smoke can blow many miles away and impact people hundreds of miles away. Smoke and ash contain harmful particles that can irritate even healthy lungs. The impact on those with asthma can be serious.

The Environmental Protection Agency (EPA) tracks and reports daily air quality around the country using the Air Quality Index (AQI). The AQI is a measure of air pollution to indicate the safety of the air and possible health effects. Those with asthma can watch air quality on to help them manage their symptoms.

AQI values are color coded by level of health concern. Green (AQI value of 0-50) means air quality is good. When the air quality reaches yellow (AQI value of 51-100) or higher, those who are sensitive to air pollution need to take caution, especially when outside.


poor air quality index

Air pollution is also connected to the development of asthma.2 Asthma rates are higher in polluted areas. Young children are particularly vulnerable when they live in areas with poor air quality.3

This underscores the need to protect the Clean Air Act and enact policies that combat climate change. As temperatures rise, the risk of wildfires increases, and high-pressure weather systems trap ozone and other pollutants closer to the ground. Recently, the Environmental Protection Agency (EPA) disbanded a panel of air pollution experts who were responsible for reviewing air pollution standards and their impact on health.



1. National Institute of Environmental Health Sciences. (2018). Air pollution. Retrieved March 26, 2019, from
2. Gehring, U., Wijga, A. H., Hoek, G., Bellander, T., Berdel, D., Brüske, I., . . . Brunekreef, B. (2015). Exposure to air pollution and development of asthma and rhinoconjunctivitis throughout childhood and adolescence: A population-based birth cohort study. The Lancet Respiratory Medicine,3(12), 933-942. doi:10.1016/s2213-2600(15)00426-9
3. The Effect of Air Pollution on Lung Development from 10 to 18 Years of Age. (2005). New England Journal of Medicine,352(12), 1276-1276. doi:10.1056/nejm200503243521230