What the air quality index means to families


May 2, 2016

The quality of air can impact the health of children and the elderly. Learn who is vulnerable to poor air quality.

Do you know what the air quality index values mean and how they affect the health of your family? It’s important to understand, especially if you have family members in the “sensitive” groupings.


First, what is the Air Quality Index?

AirNow defines it as “an index for reporting daily air quality. It tells you how clean or unhealthy your air is, and what associated health effects might be a concern. The AQI focuses on health effects you may experience within a few hours or days after breathing unhealthy air.”

The air quality index is divided into six levels of health concern: Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy and Hazardous.

More details on the categories:


  1. Good: The index value for your community is between 0 and 50. Air quality is satisfactory and poses little or no health risk.
  2. Moderate: The index is between 51 and 100. Air quality is acceptable; however, pollution in this range may pose a moderate health concern for a very small number of individuals. People who are unusually sensitive to ozone or particle pollution may experience respiratory symptoms.
  3. Unhealthy for Sensitive Groups: When index values are between 101 and 150, members of sensitive groups may experience health effects, but the general public is unlikely to be affected.
    • Ozone: People with lung disease, children, older adults and people who are active outdoors are considered sensitive and therefore at greater risk.
    • Particle pollution: People with heart or lung disease, older adults and children are considered sensitive and therefore at greater risk.
  1. Unhealthy: Everyone may begin to experience health effects when index values are between 151 and 200. Members of sensitive groups may experience more serious health effects.
  2. Very Unhealthy: Index values between 201 and 300 trigger a health alert, meaning everyone may experience more serious health effects.
  3. Hazardous: Index values over 300 trigger health warnings of emergency conditions. The entire population is even more likely to be affected by serious health effects.


Ozone is a gas found in the air we breathe. But depending on where it occurs, it can be good or bad. When bad ozone forms — which is more likely to happen during warmer months — it can make the symptoms of asthma, bronchitis or emphysema worse. It can also cause:

  • Coughing and pain when taking a deep breath
  • Lung and throat irritation
  • Wheezing and trouble breathing during exercise or outdoor activities


What can you do?

Be aware and watch for warnings on your local news and radio stations. The Centers for Disease Control and Prevention advise that when ground-level ozone levels are high, take steps to limit the amount of air you breathe in while you’re outside. The CDC recommends you:

  • Think about spending more time indoors, where ozone levels are usually lower.
  • Choose easier outdoor activities (like walking instead of running) so you don’t breathe as hard.
  • Plan outdoor activities at times when ozone levels are lower (usually in the morning and evening).

Want to learn more about the air quality in your area? Visit AirNow to search for local conditions.