Researchers Discover Adverse Effects of Nitrogen in National Parks

A study by Harvard researchers found that nitrogen-based compounds are negatively affecting the ecosystems of U.S. National Parks, and that there is no existing policy to curtail this trend, The paper concludes that nitrogen deposition is a serious problem for ecosystems in the U.S., and in particular for national parks that are supposed to be maintained in their pristine state.

According to co-author Daniel J. Jacob, a professor of atmospheric chemistry and environmental engineering, the paper’s principal discovery is that “a major contribution to this nitrogen deposition comes from agriculture, which emits ammonia and in its present state is totally unregulated in the United States,” he said.

The paper cites power plants, automobile exhaust, and industrial agriculture as the foremost means of disrupting the ecosystems, particularly their soil nutrient concentrations, algal growth, and aquatic pH levels.

While the paper focuses on the magnitude of the adverse effects of nitrogen deposition in the U.S., Jacob added that the issue is a global one.

“The Europeans have a much worse problem than we do, but they’ve been acting on it,” Jacob said. “They have strong controls on ammonia emissions. It’s a tremendous problem in India, China, and in places like Brazil with a lot of cattle.”


Co-author Raluca Ellis, a former postdoctoral fellow in environmental science and engineering, addressed the research’s policy implications.

“This work suggests that to keep our National Parks unchanged, as is mandated by law, we need to reduce our emission of nitrogen-based compounds (nitrogen oxides and ammonia),” Ellis wrote in an email to The Crimson.

One obstacle to this political goal is that ammonia emissions have never been regulated in the past. While the two main processes by which ammonia is emitted--the application of fertilizer and the use of manure--have been unregulated in the U.S., they have been increasingly and successfully regulated in Europe.

The main reason that ammonia regulations have been nonexistent is that the Environmental Protection Agency regulates environmental activity based on public health concerns. While ammonia has some impacts on public health, Jacob said that “they are slightly muted. It’s more questionable to control just on public health concerns, whereas the effects on ecosystems are obvious.”

Reduction does not have to be publicly mandated. Some farms are beginning to limit ammonia emissions, and better farming practices and technology are other means of ammonia reduction.


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