A view of downtown Indianapolis with a blue sky

What is Knozone?

Knozone is an initiative to make Central Indiana one of the Midwest’s most sustainable, livable regions. Through education, resources and guidance for taking action, Knozone works with residents, schools, and businesses to improve our region’s air quality, making Central Indiana a great place to live, work and visit.

Take the Pledge

Current Conditions forAir Quality Index (AQI)

Ozone is a highly reactive molecule made of three oxygen atoms. Ozone that forms naturally in the Earth’s upper atmosphere (stratosphere) absorbs most of the sun’s radiation. In the Earth’s lower atmosphere (troposphere), ozone forms as a result of manmade pollution. When ozone forms in the troposphere it can lead to health complications.


Particulate matter (PM) 2.5 is the term used to describe particle pollution found in the air that is smaller than 2.5 micrometers. Manmade and natural sources emit particles of dust, dirt, soot, smoke and other pollutants that are suspended in the air. Particle pollution can cause smog and lead to health complications when inhaled.


Unhealthy for Sensitive Groups
Very Unhealthy
A view of the Indianapolis skyline

Approximately 45% of Ozone causing pollution is produced by motor vehicles

Only 12% can be attributed to power plants and large factories

Learn how you can help
Click here to view the IDEM report