Polluted Precipitation

Identifying the source of pollutants can be difficult. Often airborne pollutants are carried many miles from their source.

USGS Study Identifies Major Source of Nitrate in Precipitation

Released: 10/19/2007 2:55:35 PM
Contact Information:
U.S. Department of the Interior, U.S. Geological SurveyOffice of Communication119 National CenterReston, VA 20192
Emily Elliott Phone: 412-624-8882
Denver Makle Phone: 703-648-4732

Nitrate found in precipitation occurring in rural areas of the Northeastern and Midwestern United States is primarily caused by emissions from stationary sources located hundreds of miles away, according to a new U.S. Geological Survey (USGS) study.

Stationary sources include coal-burning power plants and other industrial facilities. Although vehicles are the single largest emission source of nitrogen oxides in this region, distant stationary sources may have a greater impact on nitrate found in rain and snow.

"These results demonstrate that we have a new chemical analysis tool for tracing the influence of emissions from stationary sources. This could be a powerful method for monitoring the effects of stationary source emission reductions slated for this region over the next 8 years," says Emily Elliott, former USGS scientist and current assistant professor at the University of Pittsburgh.

The study, published in the journal Environmental Science and Technology, presents the first large-scale investigation of nitrogen isotopes in precipitation. The authors analyzed stable nitrogen isotopes at 33 long-term...(complete article here).