Indiana has a large network of outdoor monitors which measure for six common pollutants. These pollutants include carbon monoxide (CO), lead (Pb), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM), and sulfur dioxide (SO2). This page provides reports on long-term trends.
IDEM divided the state into eight regions to provide readers with a more detailed breakdown of data where they live and work. The regions are not tied to policies or laws. Each report covers a period of 30 years. A region may not monitor for all six pollutants. All available data is included for each region.
Historical Air Quality Data
- Northwest Indiana Trend Reports [ZIP]
- North Central Indiana Trend Reports [ZIP]
- Northeast Indiana Trend Reports [ZIP]
- West Central Indiana Trend Reports [ZIP]
- Central Indiana Trend Reports [ZIP]
- East Central Indiana Trend Reports [ZIP]
- Southwest Indiana Trend Reports [ZIP]
- Southeast Indiana Trend Reports [ZIP]