What is Reactive Nitrogen?

atomic structure of nitrate

Reactive nitrogen is all biologically, chemically, and radiatively active nitrogen in the environment. This includes inorganic forms of nitrogen, such as ammonia (NH3) and ammonium (NH4+), nitric oxide (NO), nitrogen dioxide (NO2), nitric acid (HNO3), nitrous oxide (N2O), and nitrate (NO3-), and organic compounds such as urea, amines, proteins and nucleic acids.

Why is Reactive Nitrogen Increasing?

increasing reactive nitrogen

Reactive nitrogen in the environment is increasing due to the use of synthetic fertilizers and the combustion of fossil fuels. The input of nitrogen to the environment from these two sources now exceeds that from all natural sources.

What are the Impacts of Reactive Nitrogen?

1) Reactive nitrogen can be lost from the soil by moving to surface or groundwater, potentially decreasing the quality of drinking water and promoting eutrophication in coastal waters.

2) Reactive nitrogen in soils and water bodies can also return to the atmosphere, where the portion that is not reduced to N2 gas contributes to both the greenhouse effect and stratospheric ozone depletion.

3) Reactive nitrogen in the troposphere can lead to acid deposition, which can damage infrastructure, acidify soils and water bodies, and saturate soils with nitrogen.

4) Reactive nitrogen in the troposphere can also lead to higher levels of ozone, which can damage human health and vegetation.

Counties of the United States that violated the 8-hour ozone safety standard of the United States Environmental Protection Agency, as of June 2007, or are designated as "maintenance" areas.


Prof. Bob Howarth's Intro to Reactive N


Critical needs for reducing reactive Nitrogen in New York State: A policy brief from NYSWRI (2009) [link]

New York

Reactive N Links

Acid Lakes

NYS Department of Environmental Conservation (NYS DEC) (link)

United States Environmental Protection Agency (USEPA) (link)

NYSERDA Environmental Monitoring, Protection, & Evaluation (link)

Upper Susquehanna

Upper Susquehanna Coalition (link)

Chesapeake Bay Program (link)

Peconic Estuary

EPA - National Estuary Program (link)

Long Island Sound Study (link)

Peconic Estuary Program (link)