Know Your Colors: Air Quality Index Helps Determine Outdoor Activity Health Risks


June 6, 2012, Portage, IN – From a very young age, children can recognize and name colors. However, when it comes to the air quality in local communities, it’s up to the parent to check the “color of the day” – a measurement of pollutants in the air know as the Air Quality Index (AQI), which is translated into colors associated with the air quality of each day. By using the AQI, you can better determine whether or not it’s a good day to go for a bike ride, spend an afternoon in the park, or head to one of the many beaches along Lake Michigan’s southern shoreline.

The Air Quality Index (AQI) tells you how clean or polluted your air is and what associated health effects might be a concern for you. The U.S. Environmental Protection Agency (EPA) calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For each of these pollutants, the EPA has established national air quality standards to protect public health. Unhealthy levels of ground-level ozone can impact the health of family members and coworkers – especially children, the elderly, and individuals with heart or lung ailments.

“Two of my three kids have been affected by asthma from a very young age,” commented Meredith Seymour of Valparaiso, Indiana. “And, when school is out and kids want to play outdoors, I regularly check the AQI to see if their activity might lead to respiratory problems or a full-blown asthma attack.”

How Does the AQI Work?

An easy way to understand how the AQI works is like this: think of the AQI as a yardstick that runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern. For example, an AQI value of 50 represents good air quality with little potential to affect public health, while an AQI value over 300 represents hazardous air quality.

To make it easy for everyone to understand, the AQI numbers are associated with colors:

Each category corresponds to a different color and a different level of health concern. The six colors and what they mean are:

  • Green is “Good.” Air quality is considered satisfactory, and air pollution poses little or no risk.
  • Yellow is “Moderate.” Air quality is acceptable; however, people who are unusually sensitive to ozone may experience respiratory symptoms.
  • Orange is “Unhealthy for Sensitive Groups” Although the general public is not likely to be affected at this AQI range, people with lung disease, older adults, and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air.
  • Red is “Unhealthy.” Everyone may begin to experience some adverse health effects, and members of the sensitive groups may experience more serious effects.
  • Purple is “Very Unhealthy.” This would trigger a health alert signifying that everyone may experience more serious health effects.
  • Maroon is “Hazardous.” This would trigger a health warning of emergency conditions. The entire population is more likely to be affected.

Northwest Indiana Air Quality & Your Health

You most likely know someone, if not yourself, that is affected by some form of lung disease. Across the three counties of Northwest Indiana, recent studies from the American Lung Association show that:

  • 9% of adults suffer from asthma
  • 4% live with chronic bronchitis
  • 38% have a form of cardio-vascular disease
  • 10% of the children in Lake and LaPorte counties struggle with pediatric asthma

The number of adults with asthma is nearly that of adults with diabetes. Consider how diabetics make adjustments to their diet in order to be as healthy as possible.

NWI Indiana Clean Air, an initiative developed by the Northwestern Indiana Regional Planning Commission (NIRPC) is a partnership between the people and businesses of Northwest Indiana to help all residents Think Green & Breathe Easy – understanding and inspiring actions to improve the air quality of this unique region.

“Everyone can make ‘lifestyle’ adjustments to the air quality in Northwest Indiana,” commented Kathy Luther, Director of Environmental Programs, NIRPC. “It’s carpooling in your daily commute, combining everyday errands so get more done while driving less, avoiding the wait time at drive-thru windows…it’s the small things that can make a big difference in the quality of the air we breathe.”

“I know that I can change some habits to make a difference in our air quality,” concluded Mike Dobis of Merrillville. “I’ve talked to my employer, my coworkers, friends, and family to let them know how they can do their share. I’m ‘walking the talk’ and trying to get others to do the same.”

For more information on how individuals and businesses can join the efforts of NWI Clean Air, visit today.

Northwest Indiana – where it all adds up to cleaner air. Brought to you by Northwestern Indiana Regional Planning Commission, a clean air leader.


For more information:
Kathy Luther,
Director of Environmental Programs
Northwestern Indiana Regional Planning Commission

6100 Southport Road
Portage, IN 46368
219-763-6060 x 127