For Immediate Release January 17, 2012
Alan Townsend, Professor, Dept. of Ecology and Evolutionary Biology,
University of Colorado, 303-819-1691
Eric Davidson, Executive Director, The Woods Hole Research Center 774-392-4599
Penelope Whitney, Resource Media 415-397-5000 x 313
New report reviews U.S. nitrogen pollution impacts & solutions
Widespread effects on U.S. health, environment and economy
The nitrogen cycle has been profoundly altered by human activities, and that in turn is affecting human health, air and water quality, and biodiversity in the U.S., according to a multi-disciplinary team of scientists writing in the 15th publication of the Ecological Society of America’s Issues in Ecology. In “Excess Nitrogen in the U.S Environment: Trends, Risks, and Solutions,” lead author Eric Davidson and 15 colleagues from universities, government, and the private sector review the major sources of reactive nitrogen in the U.S., resulting effects on health and the environment, and potential solutions. The report can be viewed at http://www.esa.org/science_resources/issues/FileEnglish/issuesinecology15.pdf
“Nitrogen pollution touches everyone’s lives,” said Eric Davidson, director of Woods Hole Research Center. “This report highlights the latest understanding of how it’s harming human health, choking estuaries with algal growth, and threatening biodiversity. It’s even changing how quickly trees such as red maple grow in our forests.”
There is good news: effective air quality regulation has reduced nitrogen pollution from U.S. energy and transportation sectors. On the other hand, agricultural emissions are increasing. Ammonia, a byproduct of livestock waste, remains mostly unregulated and is expected to increase unless better controls on ammonia emissions from livestock operations are implemented. Additionally, crop production agriculture is heavily dependent on synthetic nitrogen fertilizer to increase crop yields, but approximately half of all nitrogen fertilizer applied is not taken up by crops and is lost to the environment.
The report cites the following impacts from nitrogen pollution:
- More than 1.5 million Americans drink well water contaminated with nitrate, a regulated drinking water pollutant, either above or near EPA standards, potentially placing them at increased risk of birth defects and cancer, which are noted in the report.
- Agricultural and sewage system nutrient releases are likely linked to coral diseases, bird die-offs, fish diseases, and human diarrheal diseases and vector-borne infections transmitted by insects such as mosquitos and ticks.
- Two-thirds of U.S. coastal systems are moderately to severely impaired due to nutrient loading. There are now nearly 300 hypoxic (low oxygen) zones along the U.S. coastline.
- Air pollution continues to reduce biodiversity, with exotic, invasive species dominating native species that are sensitive to excess reactive nitrogen. For example, in California, airborne nitrogen is impacting one third of the state’s natural land areas, and the expansion of N-loving, non-native, highly flammable grasses in the western U.S. has increased fire risk.
The report reviews agricultural solutions, and notes that applying current practices and technologies can reduce nitrogen pollution from farm and livestock operations by 30 to 50 percent. “We know a lot about how to solve the problem. We need the political and economic will to make it happen,” said Davidson. “We need more support from Congress to expand – not cut – funding to the USDA’s Natural Resources Conservation Service for programs like the Environmental Quality Incentives Program,” said Mark David, a University of Illinois researcher. “They support farmers in reducing nitrogen losses from their fields and livestock operations.”
The report can be viewed at