The Office of Sustainability collects ambient air quality data in and around Marion County for pollutants which have National Ambient Air Quality Standards (NAAQS). These pollutants are referred to as the criteria pollutants and include Carbon Monoxide (CO), Ozone (O3), Sulfur Dioxide (SO2), Nitrogen Dioxide (NO2), Particulate Matter 10 micron (PM10), Particulate Matter 2.5 micron (Fine Particles), and Lead (Pb).
The air quality standards are set at levels to protect the public health. Air monitoring is conducted by the Indiana Department of Environmental Management (IDEM) to assure compliance of those standards. The gaseous pollutants (CO, O3, SO2) are measured 24 hours a day, 7 days a week by IDEM staff. The particulate type pollutants (Fine Particles, PM10, Pb) are collected over a 24 hour period and measured once every day to every 6th day (PM10 and Pb). Each year the agency collects nearly 160,000 total air measurements in central Indiana.
Up to the hour air quality information and readings can also be checked by calling our air quality phone line at 317-327-4AIR. Forecasted AQI levels are also reported.