Ecosystems and Air Quality

Researchers are exploring the dynamic interrelationships between natural ecosystems and air quality—advancing our understanding of how air pollution can negatively impact forests, lakes, and other natural ecosystems and the benefits they provide.

A robust body of research links the negative impacts that air pollution can have on natural ecosystems. For example: pollutants such as sulfur can lead to excess levels of acid in lakes and streams, and damage trees and forest soils; atmospheric nitrogen can reduce the biodiversity of plant communities and harm fish and other aquatic life; ozone damages tree leaves and negatively affects scenic vistas in protected natural areas; mercury and other heavy metal compounds emitted as exhaust from fuel combustion can eventually accumulate in plants and animals, some of which are consumed by people.

EPA research on the environmental impacts of air quality supports the Secondary National Ambient Air Quality Standards (NAAQS), set under the Clean Air Act to protect animals, soil, crops, vegetation, water and buildings from the impacts of air pollution. (The Primary NAAQS protect public welfare.) To support the review of the NAAQS, EPA prepares Integrated Science Assessments (ISAs), which contain a concise evaluation and synthesis of the most policy-relevant science for reviewing the NAAQS.

The research improves the understanding of the pathways and magnitude of ecosystem exposure to nitrogen and sulfur; assesses the impacts of excessive atmospheric nitrogen deposition on ecosystems; identifies how wildfires impact ecosystems; and evaluates the environmental impacts of the nation’s mix of energy use, including air and water quality, among other activities.