ASU efforts heighten visibility of global elemental shortages


Margaret Coulombe

ASU limnologist James Elser, a Regents' and Parents Association Professor in the School of Life Sciences in ASU's College of Liberal Arts and Sciences, is concerned; so concerned, that he is one of three scientists who founded the Sustainable Phosphorus Initiative at ASU. The initiative is the only effort in the America's working to shed light on the complex issues surrounding the shrinking reserves of phosphorus in the United States and globally.

Elser's initiative and research were profiled in the November issue of The Scientist.

Why is phosphorus important? It is a key elemental component of life, from the "phospho" in phospholipid membranes on our cells and organelles to "the business end of the adenosine triphosphate (ATP) coenzyme that drives cellular machinery, and part of the backbone of every DNA and RNA molecule. Life is simply not possible without phosphate."

Phosphorus use in fertilizers and agriculture fueled the "Green Revolution" of the mid-20th century, but along with increased productivity in farmers' fields, came runoff of excess phosphorus into streams, rivers and coastal areas that created choked waterways and dead zones, the report said. The piece also referenced the imbalance in use internationally, where "corn growers in Kenya apply just 8 kg of phosphate fertilizer per hectare per year, and Chinese farmers use 10 times that amount, 92 kg; way more than what the plants can use," ecologist Peter Vitousek of Stanford University is quoted as saying.

The article notes that humans use more than 150 million tons of phosphate rock per year, mined from a limited number of sources. In the United States, phosphorus-bearing rock comes from Florida, North Carolina and Idaho, but is expected to dwindle in the next 50 years. That would force the U.S. to shift to importation from mines in Morocco or China, which harbor the largest reported reserves of the element, or other foreign sources.

Elser, along with Dan Childers, a professor with ASU's Global Institute of Sustainability and Mark Edwards, a professor with the W.P. Carey School of Business, launched the Sustainable Phosphorus Initiative on Earth Day to alert national decision-makers, farmers and sustainability experts, and the public to the need for smarter agricultural practices, reclamation from waste streams, and changes in diets.

In an effort to increase awareness internationally, ASU will host the Sustainable Phosphorus Summit, Feb. 3-5, 2011. Some of the top experts in the world will gather to discuss the complex dynamics of phosphorus as a limited resource, from development of sustainable practices to national security issues ( 

In addition to Elser's studies of phosphorus limitation in fresh water lakes and its impact on fauna, The Scientist article examines work by Roberto Gaxiola, a plant physiologist at ASU who researches ways to improve food crop efficiency in poor soils, and John Nagy, an ASU alumnus and mathematical biologist at Scottsdale Community College, who worked with Elser to analyze the role of phosphorus in tumor growth in humans. The role of phosphorus in health and its connection to cancer was also examined, with the focus on studies by George Beck, a molecular biologist at Emory University School of Medicine. Reference was also made to findings by Mohammed Razzaque, a cell biologist at Harvard School of Dental Medicine, who discovered that high-phosphate diets in mice led to premature aging. Another colleague of Elser's, Valeria Souza, a microbial ecologist with the National Autonomous University of Mexico, has found in Cuatro Cienegas, a series of ancient hot springs in Mexico, that limited phosphorus can lead to limitations in genome size, and diversification in microbial species.

The importance of phosphorus, from evolution and health to agriculture is summed up by a quote from Dana Cordell, "There is nothing on the market that can replace phosphorus on the scale that we need it." Cordell is an environmental scientist at the University of Technology in Sydney whose work first spurred Elser's interest in how phosphorus limitation could impact human systems. Cordell will be one of the key speakers at ASU's Sustainable Phosphorus Summit in 2011.