A Message from the Director

Since 1970, the Clean Air Program at the Illinois Environmental Protection Agency (EPA) has been working to combat air pollution. To comply with the federal Clean Air Act and its amendments, the Agency issues permits to air pollution sources and works to reduce air pollutants. Clean air efforts have progressed to creating partnerships that encourage both voluntary pollution-reducing activities and that promote preventing pollution before it starts.

Our remaining major air pollution problem affects a substantial portion of Illinois’ population. Both the Chicago and East St. Louis metropolitan regions still do not meet the federal air quality standard for ozone (smog), which is associated with human respiratory problems as well as ecosystem damage. There were six occurrences of unhealthful air quality in one or more portions of Illinois during 1997 — five due to ozone and one due to particulate matter — compared with 6 in 1996 and 11 in 1995.

Although this document shows that the trend in Illinois air pollution has been a steady decrease in emissions, there is still much to do to ensure that our residents enjoy the best air quality possible. Recent efforts to combat ozone include asking residents and businesses in the Chicago ozone non-attainment areas for help by voluntarily altering their activities that contribute to ozone formation on Ozone Action Days. Surveys show that about more than 70 percent of Chicago-area citizens heard about Ozone Action Days and of those, about 65 percent took actions to reduce ozone.

This 27th Annual Air Quality Report highlights information obtained in 1997 from the Bureau of Air’s statewide air monitoring network, which incorporates more than 300 monitors that track the measurements of a variety of pollutants and air toxic compounds, has a 90 percent efficiency in collecting data. We hope you find this report helpful.

We welcome any comments or questions you may have so that we can better address your information needs.

Mary A. Gade
Director

Executive Summary

This report presents a summary of air quality data collected throughout the state of Illinois during calendar year 1997. Data is presented for the six criteria pollutants (those for which air quality standards have been developed — particulate matter, ozone, sulfur dioxide, nitrogen dioxide, carbon monoxide, and lead) along with some heavy metals, nitrates, sulfates, volatile organic compounds, and PM 2.5 . Monitoring was conducted at more than 100 different site locations collecting data from more than 200 instruments.

In terms of the Pollutant Standards Index, air quality during 1997 was either good or moderate more than 98 percent of the time throughout Illinois. There were six days statewide that exceeded an air quality standard for any pollutant — one for particulate matter and five for ozone. These exceedances occurred in Cook, Lake, Jersey and Madison counties (ozone) and Madison County (particulate matter). Air quality trends for the criteria pollutants are continuing to show downward trends or stable trends well below the level of the standards.

In 1997 monitoring was conducted at nine locations in Cook and Madison counties for PM 2.5 (fine particulate matter of size less than 2.5 microns). In July 1997 the U.S. EPA finalized new ambient air quality standards for particulate matter that included the fine particulates as measured by PM 2.5. The monitoring network to fully assess these standards will be phased in during 1998 and 1999. Data is also included for the first time for mercury sampling at two locations in Cook County.

Stationary point source emission data has again been included. The data in the report reflects information contained in the Emission Inventory System as of Dec. 31, 1997. Emission estimates are for the calendar year 1997 and are for the pollutants: particulate matter, volatile organic material, sulfur dioxide, nitrogen oxides and carbon monoxide. Emission trends of these pollutants has been given for the years 1981 to the present. Emissions reported with the Annual Emissions Report have been provided starting with 1992. In general there has been a trend toward decreasing emissions over this time period.

These are Adobe Acrobat PDF files. You will need the free Acrobat Reader software, available from Adobe's web site, to view them.

You can download the full report or individual sections.

Full Report (112 pages, 626K)

Cover, Contents, and Executive Summary (46K)

Sections

1. Air Pollutants: Sources, Health and Welfare Effects (38K)
2. Statewide Summary of Air Quality for 1997 (199K)
3. Pollutant Standards Index (32K)
4. Statewide Summary of Point Source Emissions (49K)

Appendices

1. Air Sampling Network (106K)
2. Air Quality Data Summary Tables (130K)
3. Precision and Accuracy Data Summary and Tables (19K)
4. Point Source Emission Inventory Summary Table (32K)
5. Illinois EPA Bureau of Air/Division of Air Pollution Control (17K)