Illinois Annual Air Quality Report

Illinois Annual Air Quality Report 2002

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A Message from the Director

The 32nd Annual Air Quality Report contains information gathered in 2002 from the Illinois EPA's statewide air-monitoring network comprised of more than 200 monitors measuring pollutants and air toxic compounds. The data contained in the report indicates that outdoor air quality in Illinois remained good or moderate 89 percent of the time.

The year 2002 was significant, as it followed a three-year period when air-monitoring equipment in the Illinois portion of the Chicago Metropolitan area did not register any exceedances or ozone levels above the federal one-hour health standard for ozone (smog). Monitoring data was closely observed in 2002 to determine if the area was able to continue to meet the standard. However, as a result of emissions and high temperatures experienced over a short period of time, exceedances were recorded at critical monitoring sites in the region and attainment was not reached.

In 2002, air-monitoring equipment recorded six days when ozone levels exceeded the one-hour standard for ozone. Two of the days occurred in the Metro East region, and the remaining four occurred in the Chicago metropolitan area. According to the Air Quality Index (AQI), Illinois had 4 days when air quality was considered "red" or "unhealthy" and 34 days when air quality was considered "orange" or "unhealthy for sensitive groups" in one or more portions of the State in 2002. Of the 34 "orange" days, 30 were for 8-hour ozone, 11 were for PM2.5 (fine particles), and 7 were both PM2.5 and ozone. The AQI includes both the 1-hour and 8-hour ozone standards and the fine particulate (PM2.5) standards. (Note: the 8-hour ozone and fine particulate standards have yet to be implemented by the U.S. Environmental Protection Agency.)

Generally speaking, the highest levels of air pollution are found in largely populated areas. In Illinois, those primary areas include the Greater Chicagoland area and the St. Louis Metro East regions. Ozone, which is formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react with sunlight, is of particular concern as it has been linked to respiratory problems for humans, especially children and elderly residents. However, it should be noted that the U.S. Environmental Protection Agency recently compared metropolitan areas across the nation based on unhealthy air quality days for the years 2000-2002. In the comparison, the Chicago metropolitan area ranked 40th out of 50 with 45 unhealthy days. Also included in the comparison was the St. Louis area, ranking 17th with 69 unhealthy days. The top ranking area in the nation was Riverside-San Bernardino, California, which recorded 445 unhealthy air quality days for the same time period, significantly higher than both the Chicago and St. Louis regions.

The Illinois Environmental Protection Agency has monitored air pollution levels for more than twenty years, and recognized the on-going trend of decreased ozone and fine particulate matter levels. However, work must continue to further improve air quality for all Illinois residents.

Since the formation of the Illinois EPA in 1970, the Agency has been commitment to improving air quality. In addition to the Agency main role as a regulator of air pollution sources, it continues to develop other initiatives to further reduce air pollution. Two of the well-recognized programs include Ozone Action Days and Green Pays on Green Days. Both programs were created by the Illinois EPA and the Partners for Clean Air coalition to encourage individual citizens and businesses to pledge to reduce pollution when ozone levels are high. As a result of such programs, it is estimated that volatile organic compounds are reduced by more than 20 tons per day.

The 2002 Annual Air Quality report is intended to provide information to businesses, organizations and individual citizens. Let us all recognize the achievements made in recent years and further commit to continue our work together to improve air quality in Illinois. Please contact the Illinois EPA with comments and/or questions regarding this report or air pollution control programs.

Renee Cipriano

Director

Executive Summary

This report presents a summary of air quality data collected throughout the State of Illinois during the calendar year - 2002. 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, and volatile organic compounds. Monitoring was conducted at over 90 different site locations collecting data from more than 200 instruments.

In terms of the Air Quality Index (AQI) air quality during 2002 was either good or moderate more than 89% of the time throughout Illinois. There were 4 days (all due to ozone) when air quality in some part of Illinois was considered Unhealthy (category Red). Additionally, there were 34 days (30 for 8-hour ozone and 11 for PM2.5, 7 days were high for both ozone and PM2.5) when air quality in some part of Illinois was considered Unhealthy for Sensitive Groups (category Orange). This compares with 40 Unhealthy for Sensitive Groups days in 2001. The increase in unhealthy ozone days (34 in 2002 versus 17 in 2001) is primarily due to 2002 being more conducive than normal in terms of weather patterns associated with elevated ozone than an indication of worsening air quality. 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 1993 - 2002 are as follows: Particulate Matter (PM10) 11% decrease, Sulfur Dioxide 31% decrease, Nitrogen Dioxide 4% decrease, Carbon Monoxide 44% decrease, Lead 53% decrease, and Ozone 6% 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, 2002. Emission estimates are for the calendar year 2001 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.