Friend and Foe: Nitrogen Pollution: Little-Known Environmental and Human Health Threats


The Green Revolution prevented a predicted global famine in the 20th century, caused by low agricultural yields and increasing population. The term “Green Revolution” was first used in 1968 by William Gaud, formerly of USAID. That revolution greatly increased worldwide agricultural production. The “Father of the Green Revolution,” Norman Borlaug, lead the development of “high-yielding varieties of cereal grains, expansion of irrigation infrastructure, modernization of management techniques, distribution of hybridized seeds, synthetic fertilizers, and pesticides to farmers.” (Wikipedia)

Billions of people would otherwise have eventually starved, but the technologies of the Green Revolution prevented that expected catastrophe. Nitrogen fertilizers were a big part of that agricultural technology revolution, but those life-saving fertilizers have become a major environmental problem. It is a problem that now threatens human health and welfare, according to Alan Townsend, Ph.D.

Townsend is a Professor in the Department of Environmental Studies at the University of Colorado, Boulder.

Speaking in a symposium at the 242nd National Meeting & Exposition of the American Chemical Society, Townsend said “It’s been said that nitrogen pollution is the biggest environmental disaster that nobody has heard of.” Townsend is an authority on how human activity changed the natural cycling of nitrogen. He says it has created a friend-turned-foe problem, and he is calling for focused global action to control it.

The Green Revolution refers to a series of research, and development, and technology transfer initiatives, occurring between the 1940s and the late 1960s, that increased agricultural production worldwide, particularly in the developing world, beginning most markedly in the late 1960s. The initiatives, led by Norman Borlaug, credited with saving over a billion people from starvation, involved the development of high-yielding varieties of cereal grains, expansion of irrigation infrastructure, modernization of management techniques, distribution of hybridized seeds, synthetic fertilizers, and pesticides to farmers.Wikipedia

The symposium included almost reports by ten experts. Abstracts of each presentation can be seen in a release at Newswise.

Broadcast live streaming video on Ustream

Professor Townsend says nitrogen pollution is a hidden problem and is little-recognized as an environmental problem, because it is invisible. He says “People can see an oil slick on the ocean, but hundreds of tons of nitrogen spill invisibly into the soil, water and air every day from farms, smokestacks and automobile tailpipes. But the impact is there – unhealthy air, unsafe drinking water, dead zones in the ocean, degraded ecosystems and implications for climate change. But people don’t see the nitrogen spilling out, so it is difficult to connect the problems to their source.”

Describing the scope and the intensification of the nitrogen pollution problem as “startling,” Townsend said that over the past hundred years, worldwide nitrogen inputs to the environment have doubled largely due to the invention and use of synthetic fertilizer. This is the “magic” of the green revolution in play.

There are two types of nitrogen, “reactive” and “inert.” The air we breathe contains nitrogen, approximately 78 percent by volume. Airborne nitrogen is not used by plants as a nutrient, because it is the inert type. There is a way to convert this inert nitrogen into the reactive type, discovered by Fritz Haber almost 100 years ago, in 1909. By 2005, Townsend says human activity was producing 400 billion pounds of reactive nitrogen annually.

This reactive nitrogen contributes to air pollution, degradation of ecosystems, water pollution, loss of some plant species, and some human health concerns.

Professor Townsend says excess nitrogen can enters the atmosphere as the greenhouse gas nitrous oxide, increasing the warming effect, but it also fuels plant growth and forms reflective aerosols in the atmosphere, reflecting heat.

According to Professor Townsend, the effects of nitrogen vary, and they are not well understood. Currently, it may be causing minor cooling. More worrying is that it increases air and water pollution.

New measurement technologies, new techniques to help diagnose nitrogen’s effects and new technologies to reduce its impact should help to recognize the scope of the problem, Townsend says.

Alan Gray is the Publisher and Editor-in-Chief of NewsBlaze Daily News and other online newspapers. He prefers to edit, rather than write, but sometimes an issue rears it’s head and makes him start pounding the keyboard. Alan has a fascination with making video and video editing, so watch out if he points his Canon 7d in your direction.