Phosphorus is one of the most essential minerals that is necessary for the sustenance of human life. In the human body, there is no substitute for phosphorus. In various forms it is a component of DNA, a player in cellular energy transport, and a building block in cell membranes and bone. (1) The key fuel on which all the rest of our body cellular chemistry depends is adenosine triphosphate (ATP). Every day our bodies synthesize and break down about 3 grams of ATP for every gram of dry body weight. Four separate Nobel Prizes have been awarded for ATP-related discoveries. (2)
Table 1 provides information on phosphorus in the human body. Phosphorus is a dietary requirement, the recommended intake being 800 milligrams per day, but it is not something that a person need worry about. A normal diet provides between 1000 and 2000 milligrams per day, depending on the extent to which phosphate-rich foods are consumed. These include tuna, salmon, sardines, liver, turkey, chicken, eggs and cheese, all of which have more than 200 milligrams per 100 grams. (3)
Table 1- Phosphorus in the human body (3)
Blood -- 345 ppm
Bone -- ~70,000 ppm (7%)
Tissue -- 3000-8000 ppm (0.3-0.8%)
Total amount in body -- ~780 grams
Agriculture
People acquire the phosphorus they need from food, and phosphorus is a key ingredient in processed fertilizers containing nitrogen, phosphorus, and potassium. There is no alternative to phosphorus in agriculture. To sustain one person’s balanced diet, modern agriculture requires mining 22.5 kilograms of phosphate rock a year. David Vaccari reports, “As complex as the chemistry of life may be, the conditions for the vigorous growth of plants often boil down to three numbers, 19-12-5. Those are the percentages of nitrogen, phosphorus and potassium, prominently displayed on every package of fertilizer. In the 20th century the three nutrients enabled agriculture to increase its productivity and the world’s population to grow more than six-fold.” (4)
Some scientists want concern for the world’s dwindling phosphorus supply tacked onto the world’s list of environmental hazards with potentially global implications. The Global Phosphorus Research Initiative reports that studies suggest current high-grade reserves will be depleted within 50-100 years. While the exact timing might be disputed, it is widely accepted that the quality of phosphate rock is decreasing and costs increasing. In mid 2008 the price of phosphate rock reached a peak 800% higher than early 2007. (5)
Catherine Clabby observes, “The demand for phosphorus increased sharply in the mid-20th century with the success of the Green Revolution, when plant breeders successfully produced higher-yield versions of familiar field crops. Those higher yield versions required larger doses of fertilizer. An estimated 17 million tons of processed phosphorus were used on the world’s farm fields in 2010, with demand only expected to rise. (1)
The fact that so few countries have phosphorus mines stirs more concern. About 90 percent of the world’s known reserves are located in or are controlled by five countries: Morocco, Jordan, South Africa, the United States and China. And China, which recently raised its tariffs on phosphorus, is expected to keep more at home. The declining quality, or purity, of known phosphate rock sources is only heightening anxiety. (1)
The US is the world’s second-largest producer of phosphorus (after China), at 19 percent of the total. Meanwhile, nearly 40 percent of global reserves are controlled by a single country, Morocco, sometimes referred to as the ‘Saudi Arabia of phosphorus.’ Although Morocco is a stable, friendly nation, the imbalance makes phosphorus a geo-strategic ticking time bomb. (4)
Of the US total phosphorus production, 70 percent comes from a single source: pit mines near Tampa, FL, but there has been some litigation. The Sierra Club and local environmentalists slammed the brakes on an 11,000 acre mine extension after securing a court injunction in July 2010. The environmental groups argued in federal court that phosphorus mining extracts too high a price in lost wetlands, soiled water supplies and ruined farmland. (6)
Some settlements were made in 2012. Craig Pittman reports, “The world's largest phosphate miner has cut a deal with the environmental groups that sued it in 2010. In exchange for allowing mining to proceed near Fort Meade in Hardee County, Mosaic Fertilizer will buy a 4,400 acre ranch and donate it for use as a new state park. In addition, the company has agreed to pull back its mining from the Peace River, which supplies water to people in Sarasota and Charlotte counties. The company will preserve 400 acres of land between the southwest mine border and the river, and also preserve about 70 acres of a type of wetlands known as bayheads that are difficult to re-create or restore. Environmental groups hailed the settlement as a major victory.” (7)
The Downside of Phosphorus
Too much phosphorus from eroded soil and from human and animal waste ends up in lakes and oceans, where it spurs massive, uncontrolled blooms of cyanobacteria (also know as blue-green algae) and algae which starve other organisms of oxygen, creating ‘dead zones’ and contributing to the depletion of fisheries. (4)
The Florida Everglades are clearly the best example of the downside of too much phosphorus. The phosphorus, which comes from fertilizer, sewage, and animal wastes, triggers massive harmful algal blooms that foul beaches, kill fish and smother sawgrass. Unnaturally high levels of phosphorus fuel the growth of cattails which forces out sawgrass and other natural habitat vital to the survival of the Everglades. (8)
The state and federal government are in the midst of a long-term multibillion dollar effort (the most expensive and comprehensive environmental repair in history) to clean up Everglades water pollution and get more water flowing in Florida's famed River of Grass. However, the Everglades are still threatened by excess nutrients. (9)
To try and solve the problem, The Everglades Foundation announced in September 2014 The Grand Challenge, which will pay $10 million (provided by a single donor) to an individual or team who can develop a process to remove phosphorus from waterways and recycle it to be used as fertilizer for the world's food supply. The Grand Challenge will be formally launched in February 2015 and Everglades Foundation officials expect the prize to be awarded by 2022. (10)
Another example of phosphorus pollution is Lake Erie. In the decades leading up to the 1970s, loadings of nutrients, particularly phosphorus from municipal sewage treatment plants and other anthropogenic sources, visibly degraded Lake Erie. This excessive nutrient enrichment, known as eutrophication, resulted in severe algal fouling of the lake, which in turn created aesthetic, taste and odor problems, reduced available oxygen and led to fish die-offs. The primary sources of phosphorus loading to Lake Erie in the decades leading up to The Great Lakes Water Quality Agreement of 1972 were municipal sewage plants. The Agreement, a bi-national pact to protect the Great Lakes limits the amount of phosphorus that can be discharged into the lake to 11,000 metric tons per year. Despite meeting this target for all but five years since 1984, harmful algal blooms have reemerged. The development of new targets, and measures to implement, gained more urgency in August 2014 after a harmful algal bloom contaminated the water supply for more than 400,000 people in Toledo, Ohio. (11)
One other source of phosphorus: each human being excretes a minimum of 1.5 grams of phosphorus per day; this converts to an annual input of around three billion pounds of phosphate as P2O5. (12)
Substitutes
In 2010, many states enacted a ban on phosphates in detergents, both laundry and dishwasher, under the guise that the new formulations were better for the environment. But, as phosphate free formulas began to hit the shelves in 2011, many consumers were less than thrilled with the results. Although Consumer Reports tested 24 top-rated phosphate-free detergents and rated several as very good, none of them cleaned as well as the top-rated phosphate products. Green detergents also often cost more. (13)
This underscores the tradeoffs that people often face today in a more environmentally conscious marketplace. From hybrid cars to solar panels, environmentally friendly alternatives can cost more. They can be less convenient and they can prove less effective, like some of the new cleaning products: cleaner for the environment, not the dishes.
Lastly, The European Union has also adopted a ban on phosphates in household detergents. (14)
References
- Catherine Clabby, “Scientists make the case that easily accessible supplies of an essential element are being depleted,” American Scientist
- Peter W. Huber and Mark P. Mills, The Bottomless Well, (New York, Basic Books, 2005), 174
- John Emsley, Nature’s Building Blocks, (Oxford, Oxford University Press, 2001), 310
- David A. Vaccari, “Phosphorus: A Looming Crisis,” Scientific American, 300, 54, June 2009
- “Phosphorus,” The Global Policy Research Institute, Accessed October 7, 2014
- Mike Esterl, “Miners Dig In For a Fight,” The Wall Street Journal, November 30, 2010
- Craig Pittman, “Phosphate mining giant cuts deal with environmentalists that allows mining but saves wetlands,” Tampa Bay Times, February 21, 2012
- Andy Reid, “Sugar industry accused of dodging Everglades clean-up costs,” articles.sun-sentinel.com, June 15, 2014
- Atreyee Bhattacharya, “The Everglades are still threatened by excess nutrients,” Transactions American Geophysical Union, 93, 424, October 16, 2012
- “Remove phosphorus, win $10 million,” news-press.com, September 23, 2014
- Codi Kozacek, “Lake Erie algae blooms prompt new international targets of phosphorus,” circleofblue.org, August 9, 2014
- William McGucken, Lake Erie Rehabilitated, (University of Akron Press, Akron, OH, 2000), 75
- Bryan Walsh, “Banning phosphates in detergents makes for cleaner water if not always cleaner dishes,” Time, 126, 90, November 22, 2010
- “EU-wide ban on phosphates in household detergents adopted,” accessed October 7, 2014
