The Biology Book: From the Origin of Life to Epigenetics, 250 Milestones in the History of Biology (2015)

Phosphorus Cycle

Hennig Brand (c. 1630–c. 1692), Carl Wilhelm Scheele (1742–1786), Johan Gottlieb Gahn (1745–1818)


Phosphorus was the first element discovered that was not known in the ancient world. In 1669, the German alchemist Hennig Brand was searching for the philosopher’s stone, which could transform base metals, such as lead, into gold or silver. He boiled down urine, yielding solid phosphorus, which emitted a pale-green glow. One hundred years later, Johan Gottlieb Gahn, a Swedish chemist-metallurgist, extracted phosphorus from calcium phosphate in bone, which became its major source until the 1840s. At about the same time, another Swede, the pharmacist Carl Wilhelm Scheele, discovered a method for mass-producing phosphorus, which enabled Sweden to become one of the world’s principal manufacturers of matches.

Phosphorus is essential for living organisms. It is a component of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), as well as adenosine triphosphate (ATP), involved in energy transfer. In combination with lipids to form phospholipids, it is the core of cell membranes. Calcium phosphate provides strength to bones and teeth.

Of all the biosphere’s recycled elements, phosphorus is the scarcest. Much of the earth’s phosphorus is found as a phosphate (phosphorus + oxygen) in rock and sedimentary deposits from which it is released into the sea by weathering and mining. Whereas inadequate phosphorus slows or stunts the growth of algae, excess phosphorus causes an uncontrolled overgrowth.

Humans added phosphates to household detergents and fertilizers in the mid-twentieth century, which had a major negative impact that disrupted the natural balance of the phosphate cycle. Phosphate runoffs into lakes and streams can cause algal blooms—rapidly growing dense populations of algae. When algae die, they are consumed by bacteria, a process that depletes vast amounts of oxygen from the water and leads to the death of fish and other aquatic organisms from oxygen starvation. Outflows from municipal sewage treatment plants also contribute phosphates to water. US states began to ban this household use of phosphates in the 1970s.

SEE ALSO: Prokaryotes (c. 3.9 Billion BCE), Algae (c. 2.5 Billion BCE), Land Plants (c. 450 Million BCE), Coral Reefs (c. 8000 BCE), Deoxyribonucleic Acid (DNA) (1869), Biosphere (1875), Energy Balance (1960), Silent Spring (1962).

“The hand that rocks the cradle can also rock the Axis.” This 1942 photograph shows a woman supporting the wartime effort by making dies for bombs. During World Wars I and II, incendiary weapons containing white phosphorus were used.