RTI International, IMPROVE Monitoring Network Celebrate 25 Years of Measuring Air Quality of U.S. National Parks

RESEARCH TRIANGLE PARK, N.C.—For 25 years, scientists at RTI International have supported federal efforts to protect and enhance the scenic beauty and air quality of U.S. national parks by analyzing air samples collected through a nationwide network of air monitoring devices.

The team recently won a contract to continue their work. As part of the five-year, $2.6-million contract, RTI researchers, led by Eva Hardison of Environmental and Industrial Sciences Division, will continue providing ions analysis of filters collected as part of the Interagency Monitoring of Protected Visual Environments (IMPROVE) program.

The IMPROVE program, begun in 1985, implemented an extensive long-term monitoring program designed to establish the current visibility conditions, track changes in visibility, and determine causal mechanisms for visibility impairment in the National Parks and Wilderness Areas.

Last October, researchers from RTI and the other three major contractors for the IMPROVE program attended the IMPROVE Steering Committee Meeting in the Columbia River Gorge, Washington, where they celebrated the 25th anniversary of the program.

"We are proud to have been a part of this important program for the past 25 years, and look forward to making significant contributions in the next five," Hardison said. "I hope someone from RTI will attend the 50th anniversary of IMPROVE."

RTI has conducted analyses for the National Park Service since the IMPROVE program began. Over that time, the number of monitoring sites in the program has expanded from 20 sites to 170 sites monitored today. Data supplied by RTI researchers has assisted with improving air quality policies in those areas.

RTI scientists analyze air samples for chloride and for sulfur and nitrogen compounds that indicate acid in the atmosphere in such well-known and heavily visited national parks as the Grand Canyon, Yosemite and Great Smoky Mountains National Park.

RTI scientists have supported special studies to correlate individual pollutant sources, such as power generation plants, with decreased visibility in specific national parks. They have also monitored the air for harmful ozone levels that damage vegetation and ecosystems and can trigger a variety of health problems including chest pain, coughing, congestion and reduced lung function.

Air quality affects the longevity of cultural and geological landmarks in our national parks as well as the health of visitors, plants and animals.

RTI researchers have found that the air quality in national parks often rivals pollution levels of urban areas. However, analytical data trends from the program indicate that pollution control measures in place today are making a difference in our parks. Those data indicate a statistically significant decline in the concentrations of sulfur dioxide and sulfate, with lesser declines in nitrogen.