The Illinois Environmental Protection Agency (IEPA) released the 2012 Air Quality Report on December 31, 2013 . This report has been published for more than forty (40) years. The unusual weather patterns in the Illinois and the rest of the country have led to elevated air pollution levels for 2012. However, the past ten year trends have shown that air quality is improving and the IEPA hopes that this will continue. Some notable observations included:

  • Warmest year record for Chicago and Metro-East St. Louis
  • Second warmest year on record for Springfield
  • Twenty-three (23) consecutive days of 90+ oF and ten (10) consecutive days of 100+ oF
  • Multiple days of ‘Red’ or ‘Unhealthy’ category for Air Quality Index (AQI)

In terms of AQI, the air quality in 2012 in Illinois was either “good” or “moderate” 86% of the time with eleven (11) days of category ‘Red’ [zero (0) days in 2011] and forty (40) days of category ‘Orange’ [thirty-one (31) days in 2011]. The air quality trends for the criteria pollutants standards over a ten (10) year period from 2003-2012 show the following changes:

  • 24-hr PM10 – 8% decrease
  • Annual PM2.5 – 21% decrease
  • 1-hr SO2 – 50% decrease
  • Annual NO2 – 30% decrease
  • 8-hr CO – 48% decrease
  • Lead – 5% decrease
  • 8-hr O3 – 1% decrease