News Releases - 2000

Preliminary Chicago Urban Air Sampling Results Announced

Springfield, Ill. -- Air samples from the first three months of the Chicago Urban Air Toxic Monitoring Program, including two new sampling sites near O'Hare International Airport, showed levels similar to other sites in the urban metropolitan area.

"Although we are relieved that no levels were detected so far that are unusually high, it should be emphasized this is only limited, preliminary data and no final conclusions should be reached." said Illinois EPA Director Tom Skinner. "We will continue to collect and analyze air samples in order to determine whether this first set of results is representative."

The program is funded for a six-month sampling period through a $200,000 appropriation obtained by Sen. David Sullivan, R-Park Ridge. The preliminary results for 23 chemical compounds in the air are the result of six separate 24-hour samples taken in June, July and August.

The four new air monitoring stations included in the program are located in Bensenville and Schiller Park, near O'Hare, and for comparison purposes in Northbrook and in a highly industrialized location in Southeast Chicago. Four of the compounds, acetaldehyde, benzene, formaldehyde and 1,3-butadiene, pose the greatest potential public health concern and were specifically targeted for analysis. They are generally released through various types of combustion, including burning of fuels in autos, trucks and aircraft, tobacco smoking, and various industrial processes.

Although the U.S. EPA has not established specific health standards for these compounds, the concentrations detected in the June-August sampling were below peak levels detected in previous sampling at various locations in the Chicago metro area. They are also comparable to or below levels reported in other urban areas, such as Milwaukee, Detroit, New York City and Houston.

The average concentrations of the target compounds near O'Hare Airport are comparable to lower than those values measured in other areas of the Chicago region. The highest formaldehyde and acetaldehyde concentrations have been found near the downtown area, measured at the Chicago Jardine water plant near Navy Pier. Those levels are comparable or below downtown concentrations reported in 1999 for Detroit, Houston, Milwaukee and New York City, however.

In addition, compared to other urban areas, the average concentrations in the June through August sampling for the target compounds, except 1,3-butadiene, were significantly lower around O'Hare Airport and were below those found in Detroit, Milwaukee, New York City and Houston. The 1,3-butadiene levels were comparable to those cities.

A more detailed analysis based on the six months of air sampling should be available in the spring of 2001.