Illinois Air Quality Report 2010

A Message from the Director

The Illinois EPA presents this 40th Annual Air Quality Report to summarize air quality data collected in calendar year 2010. This report includes monitoring data for a number of air pollutants as well as some heavy metals.

Air quality is an important issue for all Illinois residents, especially those with chronic lung and heart disorders. Since the creation of the Illinois EPA in 1970, we have learned a great deal about what is in the air we breathe and what we can do to make the air cleaner. The Illinois EPA focuses on many environmental issues, but providing a healthy, clean environment for Illinois citizens has always been and will continue to remain a top priority.

Data in the 2010 Air Quality Report show the air quality was either good or moderate 91 percent of the time through Illinois. There were no days when the air quality was considered to be Unhealthy (category red) according to the national Air Quality Index.

Over the past decade (2001-2010), coarse particulate matter (PM10) has decreased 25 percent, fine particulate matter (PM2.5) decreased 24 percent and carbon monoxide decreased 52 percent.

The Illinois EPA strives to provide a healthy environment for all citizens. Data are not only collected and analyzed; they are made available to the public on a daily basis through the Agency’s website Air Quality Menu web page.  The information can be critical to individuals with lung and heart disorders. The Illinois EPA will continue this essential service as it works toward further improvements in air quality.

If you have any questions and/or comments regarding the 2010 Annual Air Quality Report or air pollution control programs, please feel free to contact the Illinois EPA.


John J. Kim
Interim Director

Executive Summary

This report presents a summary of air quality data collected throughout the State of Illinois during the calendar year - 2010.  Data is presented for the six criteria pollutants (those for which air quality standards have been developed - particulate matter (PM10 and PM2.5), ozone, sulfur dioxide, nitrogen dioxide, carbon monoxide, and lead) along with some heavy metals, nitrates, sulfates, volatile organic and toxic compounds. Monitoring was conducted at over 80 different site locations collecting data from more than 200 instruments.

In terms of the Air Quality Index (AQI) air quality during 2010 was either good or moderate 91 percent of the time throughout Illinois. There were no days when air quality in some part of Illinois was considered Unhealthy (category Red). This compares with one Unhealthy day in 2009. There were 32 days (22 for 8-hour ozone, 9 for PM2.5 and 1 for both 8-hour ozone and PM2.5) when air quality in some part of Illinois was considered Unhealthy for Sensitive Groups (category Orange). This compares with 13 Unhealthy for Sensitive Groups days reported in 2009. Air quality trends for the criteria pollutants are continuing to show downward trends or stable trends well below the level of the standards. Percentage changes over the ten year period 2001 – 2010 are as follows: Particulate Matter (PM10) 25 percent decrease, Particulate Matter (PM2.5) 24 percent decrease, Sulfur Dioxide 43 percent decrease, Nitrogen Dioxide 25 percent decrease, Carbon Monoxide 52 percent decrease, Lead 33 percent decrease, and Ozone 19 percent decrease.

Stationary point source emission data has again been included.  The data in the report reflects information contained in the Emission Inventory System (EIS) as of December 31, 2010. Emission estimates are for the calendar year 2010 and are for the pollutants: particulate matter, volatile organic material, sulfur dioxide, nitrogen oxides and carbon monoxide. Emission trends of these pollutants have been given for the years 1998 to the present. Emissions reported with the Annual Emissions Report have been provided starting with 1998 and are currently available through 2009. In general there has been a trend toward decreasing emissions over this time period.