Release Date: September 11, 2000

The Energy Department is expanding its efforts to collect data on microscopic airborne particles to the deep South.

The department will award Southern Research Institute (SRI), Birmingham, AL, a $750,000 contract to augment an air monitoring station in Alabama with new capabilities to study fine particulate matter called PM2.5. The term stands for particulate matter with a diameter less than 2.5 micrometers, or about 1/30th the width of a human hair.

The effort is intended to assist the Environmental Protection Agency (EPA), state agencies and the energy industry in gauging the level and sources of the tiny particles which are now regulated under new federal air quality standards.

The Energy Department's funding will enable SRI to augment an existing site, operated by the Jefferson County Health Department in North Birmingham. Among the new instruments to be installed will be sensors that will provide for the near-continuous characterization of PM2.5 chemical composition, along with surface meteorology.

Prior to this new effort, the Energy Department had focused its PM2.5 analyses on the Ohio River basin. Locating additional monitoring equipment in the deep South will fill an important gap in the national particulate monitoring effort. The region's topography, weather patterns, and variety of emission sources may affect the chemical make-up and airborne transport of fine particles in ways that are different than in other parts of the country.

PM2.5 was identified when EPA revised the National Ambient Air Quality Standards in 1997. Previously, emissions of larger diameter particles had been regulated, but the new standards focused on much smaller particles that have been linked to respiratory ills, regional haze and other problems. The new standards ultimately could require state government to put into place compliance plans for reducing the release of these particles.

Meeting the new air quality targets is complicated because the tiny particles can be emitted from a variety of sources, ranging from coal-burning power plants, industrial factories, automobiles, agricultural practices and even forest fires.

Unlike most other air pollutants, PM2.5 particles typically consist of hundreds of chemical compounds. In addition, a high percentage of the particles is formed from atmospheric reactions between various gases. Therefore, to identify sources of PM2.5 according to specific components, both the mass and composition of the tiny particles must be measured, along with the concentrations of precursor gases and other co-pollutants.

The Energy Department's National Energy Technology Laboratory - the lead fossil energy research laboratory in the federal government - is supporting the two-year project. The monitoring site will become part of an 8-station regional air-monitoring network named SEARCH (Southeastern Aerosol Research and Characterization) supported by the Electric Power Research Institute, Southern Company, and other companies.

Beginning this fall, the station will also be core monitoring site in a larger, nationwide network EPA is establishing to determine the mass and chemical composition of PM2.5.

By developing a more complete and accurate picture of PM2.5 particles in southern states, SRI's efforts could lead to a better understanding of which industries and activities are most responsible for the particulates, and in turn, allow regulatory authorities to implement controls in the most cost-effective manner.

When the new equipment is installed at the North Birmingham station, researchers will be able to monitor particle size distribution (0.2 to 10 microns), organic and elemental carbon, ammonium, nitrate, and sulfate levels. The researchers will use a detailed database of near-continuous measurements to support subsequent studies that locate emission sources, time/transport properties, and management strategies for fine particulate emissions in the region.