Cuts in air pollution increased pollution at ground level

Written by
John Sullivan
John Sullivan, School of Engineering and Applied Science
Aug. 22, 2024

The United States has slashed smog-causing pollutants like airborne sulfur dioxide in the past 20 years, but the cuts have unintentionally increased ground and water pollution in some local areas, according to research from Princeton and Colorado State University.

In an article published June 20 in the journal Nature Geoscience, researchers found that decreased atmospheric levels of sulfur dioxide and a group of nitrogen oxide pollutants called NOx (including NO and NO2) have led to increased nitrogen deposits in forests and streams in various parts of the country. These increased deposits, linked to environmental problems, are found in areas connected to high levels of ammonia emissions, which are generally from agriculture and have not been directly regulated in the United States.

“The novelty of this work is constraining particle formation through a suite of direct observations, and the results show the benefits of using observations to identify key pollutants to improve air quality and decrease nitrogen deposition on seasonal and regional scales,” said Mark Zondlo, a principal researcher on the project and professor of civil and environmental engineering at Princeton. 

Environment Tags
Research Themes