Release Date: March 29, 2000

DOE Supports Air Quality Studies to Assess Airborne Fine Particle Levels and Links to Personal Exposure

Tiny airborne particles, so small that 30 side-by-side would barely equal the width of a human hair, have come under the regulatory microscope in recent years. The Environmental Protection Agency (EPA) has revised air quality standards to limit them, and States face the likelihood of having to regulate them.

But scientists are still unsure of the linkage between levels of these microscopic particles floating in the outside air and the amount that humans actually are exposed to while inside their homes.

	PM2.5 particles are so small that 30 of them side-by-side would barely equal the width of a human hair.

To help evaluate this linkage, the Department of Energy and the Ohio Department of Development's Coal Development Office (OCDO) have begun working together in an air monitoring program to compare outside air with the air people in the Steubenville, Ohio, area breathe in their homes.The Energy Department is funding about $3 million of the $5 million program that will be conducted during the next three years. Co-funders include the Electric Power Research Institute, OCDO, CONSOL Energy's subsidiary CONSOL Inc., the National Mining Association, the American Iron and Steel Institute, and the American Petroleum Institute.The Steubenville Comprehensive Air Monitoring Program will measure concentrations and compositions of fine particulate matter known as PM2.5, as well as coarser particles, weather, and priority gaseous pollutants. PM2.5 is the term given to airborne particles that have a diameter on average of 2.5 micrometers or smaller in size. A variety of natural and man-made sources - such as erosion of the earth's crust, forest fires, motor vehicle exhaust, and industries such as electric power plants - can produce fine particles. In July 1997, EPA revised the National Ambient Air Quality Standard to limit the allowable ambient air concentrations of these fine particles and established a nationwide network of PM2.5 monitoring sites to identify areas that did or did not meet the new standard. The 1997 standard stipulates that no more than 15 micrograms of PM2.5 particles may exist in one cubic meter of air on average over a three-year period. EPA will re-evaluate this standard in 2002. EPA standards for fine particulate ultimately could require that state governments implement compliance plans that call for reductions from stationary and mobile sources. Therefore, it is critical for state and federal environmental agencies to determine which pollutants have the most significant impact on human health and the environment so that the maximum public benefit can be obtained by reducing emissions of those pollutants or their precursors.The 1998 National Research Council review of EPA's PM2.5 program underscored the need for additional study of ambient air quality and human health. As part of an effort to gain a better understanding of the chemical constituents of ambient PM2.5 and other co-pollutants (gases, pollen, etc.) at ambient monitoring sites, DOE launched a two-year air-monitoring program in 1999 that targets PM2.5 and co-pollutants in the Ohio River Valley.Last year the National Research Council said the DOE air-monitoring program in the Ohio River Valley would be strengthened if it included a personal exposure study. It recommended expanding upon the Upper Ohio River Valley Project, which includes the region around Steubenville.The Upper Ohio River Valley Project has a primary monitoring site in downtown Pittsburgh 40 miles to the east of Steubenville. Two additional monitoring sites are located directly south of Pittsburgh by 61 and 78 miles and one site 195 miles southwest of Pittsburgh in Ohio - 155 miles beyond Steubenville. Monitoring at these four locations differs in intensity with the most frequent testing and the more extensive analysis being done at the Pittsburgh monitoring station. The National Research Council's recommendation paved the way for the Steubenville study. Frequency of sampling and types of analyses planned for Steubenville will be similar to those being done at Pittsburgh, but the Steubenville study will build on the Upper Ohio River Valley Project by creating a second high-intensity air-monitoring location in the Upper Ohio River Valley region and also linking outdoor air-monitoring with an indoor personal exposure study. CONSOL Inc. is the primary contractor for the Steubenville study and will provide the necessary coordination and data integration. The Energy Department's Office of Fossil Energy is funding the outdoor study, which includes measuring PM2.5 and various other pollutants at a central urban site, four remote sites and outside the homes of people who have agreed to participate in the program. The Energy Department's research in fine particulate matter will play a key role in developing processes and technologies to avoid or reduce emissions from coal-based power systems such as electric utilities. The indoor analysis, funded by OCDO, is being performed mainly by the Harvard University School of Public Health under subcontract to CONSOL. This study will measure most of the same pollutants inside the homes of participants, and will collect data from personal samplers worn by the participants. The personal samplers will be worn by a panel of older adults during the summer of 2000 and the winter of 2001, and by a panel of children during the winter and summer of 2001. An additional panel of older adults may be monitored in the summer of 2000.

Specifically, the study's results will be used to:

• determine how the concentration and composition of PM2.5 vary with location, time, season and weather conditions,
• establish the correlation between PM2.5 concentrations and compositions experienced by "at risk" groups (children and older adults) and the PM2.5 concentrations and compositions measured by a centrally located outdoor monitor,
• establish the correlation between PM2.5 concentrations and compositions and co-pollutants
• provide a comprehensive data base for use in epidemiological studies, long-range transport studies, and State Implementation Program compliance.

DOE's National Energy Technology Laboratory (NETL) is managing both the Steubenville Program and the Upper Ohio River Valley Project. Although the two projects will operate independently, ambient air quality data from each project will be made readily available to the other through the projects' respective technical advisory committees. This will greatly facilitate the interpretation of data by both sets of researchers. The combined data will also be available to the EPA and other researchers as an invaluable basis for future health-related studies.