Study Investigates Association of Air Pollution and Health Effects.

Scientists with the Electric Power Research Institute (EPRI) have been conducting a two-year, $7 million, state-of-the-art study on air quality and human health, The Aerosol Research Inhalation Epidemiological Study (ARIES) is taking place in Atlanta and is the most comprehensive and lengthy assessment of air quality conducted in any location to date. Focusing specifically on coronary and respiratory diseases, scientists have examined relationships between air pollution components and a number of health outcomes ranging from unscheduled physician visits to emergency-room admissions to death. In addition to measuring pollutant gases (sulfur dioxide, carbon monoxide, etc.), the scientists measured fine particles ([PM.sub.2.5]) in the air and components of those particles, such as organic compounds, aero-allergens, sulfates, and trace metals. They also studied the ultrafine particles to see if one or more of the components could explain the results of previous studies.

Atlanta was chosen as a study location because it is a major city that has exceeded U.S. Environmental Protection Agency (U.S. EPA) air quality standards and because its pollution comes from many different sources. The large population and high pollution levels make it easier to detect health effects.

Preliminary findings are that carbonaceous compounds are as prevalent in the mix of fine particles as are sulfur compounds. "This is particularly significant, "according to Ron Wyzga, EPRI's area manager of air quality health and risk assessment, "because we have found no association between sulfur compounds (sulfates) and health effects to date at the levels measured in Atlanta."

Wyzga added that cardiovascular diseases and air pollution do appear to be linked, as shown by emergency-room admissions for all cardiovascular diseases and for abnormal heart rhythms. The pollutants most associated with these diseases appear to be carbon monoxide, elemental carbon, organic carbon, and large ("coarse") particulates. Since many of the compounds linked to cardiovascular problems contain carbon, EPRI's scientific team will try to identify specific compounds in the carbon fractions and try to discern which components are related to adverse cardiovascular effects.

So far, scientists have examined more than a million hospital admission records and over 12,000 death reports. They expect to complete the study and publish final results by this summer. Data are currently being published in peer-reviewed journals and will provide scientific input into the regulatory and standard-setting process.