How and Why Nitrogen Pollution Impacts Public Health and the Environment

Agriculture-based nitrogen pollution impacts public health, drinking water, air quality, fisheries and the environment.

“Air pollution kills people, and compromises millions of lives. And nitrogen is a big part of that problem. ” – Alan Townsend, University of Colorado Professor of Ecology and Evolutionary Biology

Nitrous oxide is 300 times more potent than carbon as a greenhouse gas.

Everyone knows the story of carbon: the tale of a naturally occurring substance, crucial for life to exist at all, that human interference has turned into a threat to long-term life on earth through climate change. But nearly nobody knows the similarly troubling story of one of the other building blocks of life: nitrogen.

You can’t live without Nitrogen. If you don’t get enough Nitrogen, you die. It is written into every strand of our DNA. It makes up 80 percent of the earth’s atmosphere. But not a single atom of the N-rich air we breathe in and out can nourish us, or any plant or animal. In this “inert” form, it is inaccessible.

All life needs Nitrogen in a different “fixed” form that is far less abundant in the natural world. The amount of available fixed nitrogen acted as a limiting factor for life on earth – dictating the amount of plant/crop growth that is possible, and thus the amount of food we could grow. This “cap” on life existed until humans discovered a way to manufacture fixed Nitrogen.

This has allowed food production to keep up with the steadily increasing human population (at least 2 billion humans would starve today without it). But we’re conducting a global science experiment: all this extra nitrogen is causing dramatic environmental changes, poisoning rivers and lakes, killing huge sections of the ocean and boosting global warming.

This is a major untold story and one of the biggest environmental problems we face.

Here are the major reasons why:

Water Quality:

Increased use of nitrogen fertilizers means higher nitrate levels in rivers, lakes and aquifers. In California’s San Joaquin Valley for example, residents of farm communities are forced to buy bottled water because their wells exceed safe nitrate levels. Click here for more information on California nitrate contamination from University of California, Davis.

Climate Change:

Pound for pound, nitrous oxide is 300 times more potent than carbon as a greenhouse gas.

Dead Zones:

Areas of the ocean that are choked of oxygen and lifeless, caused in most cases by nitrogen fertilizer runoff from agricultural areas, are increasing everywhere. Worldwide, the number has gone from 146 in 2004 to 405 in 2008. In the United States an annual dead zone in the Gulf of Mexico that fluctuates between 3,000 and 8,000 square miles has hammered the region’s $2.8 billion fisheries. In June 2008, a task force set a goal of reducing the dead zone to a five-year average of 2,000 square miles by 2015.

Ozone Pollution:
Nitrogen pollution in the form of nitrous oxide increases ground level ozone, leading to a host of human health problems including cardiac and respiratory disease.