Phosphorus

Phosphorus is an element in the Periodic Table, with the symbol P and the atomic number 15. Phosphorus exists in at least four allotropic forms: white (or yellow), red, and black (or violet). Phosphorus is found commonly in nature, as it is an essential chemical in living systems. "Phosphate rock, which contains the mineral apatite, an impure tri-calcium phosphate, is an important source of the element. Large deposits are found in Russia, in Morocco, and in Florida, Tennessee, Utah, Idaho, and elsewhere." In humans, it is found in nervous tissues, bones, and cell protoplasm.

White phosphorus is dangerously reactive in air, so it should be kept under water. When exposed to sunlight or heated in its own vapor to 250C, white phosphorus converts to the red variety. Red phosphorus will not spontaneously ignite.

Uses
Red phosphorus is used in safety matches, pyrotechnics, pesticides, incendiary shells, smoke bombs, and tracer bullets.

Concentrated phosphoric acids, containing up to 75% P2O5, are used in agriculture as fertilizer. Phosphates are also used in special types of glass, like those used for sodium lamps.

Bone-ash (calcium phosphate) is used in fine china and to produce mono-calcium phosphate, which is used in baking powder. Phosphorus is also used in manufacturing steels. Trisodium phosphate is used as a cleaning agent, a water softener, and to prevent boiler scale and corrosion of pipes and boiler tubes.

In the Environment
Phosphorus occurs commonly in the natural world, but never in its pure form - only as phosphates. Phosphates consist of a phosphorus atom bonded with four oxygen atoms. In minerals, this exists as a negatively charged phosphate ion (PO43-), but in organophosphates, there are organic molecules attached to one, two, or three of the oxygen atoms.

Phosphorus is naturally present in many foods, especially tuna, salmon, sardines, liver, turkey, chicken, eggs and cheese.

In Sewage Sludge
In the Targeted National Sewage Sludge Survey, a 2009 test of 84 samples of sewage sludge from around the U.S., the EPA found phosphorus in every sample in concentrations ranging from 2,620 to 118,000 parts per million.

Health Effects
Humans are frequently exposed to phosphates through their food, as it is an essential mineral. Phosphates are part of DNA materials and they also take part in energy distribution. However, too much phosphate can cause health problems, including kidney damage and osteoporosis.

If ingested, white phosphorus is severely poisonous. Before people die of from ingesting white phosphorus, they experience nausea, stomach cramps, and drowsiness. Additionally, white phosphorus can cause severe burns if it comes in contact with skin.

Related SourceWatch articles

 * Biosolids
 * Sewage sludge
 * Food Rights Network

External resources

 * Public Health Statement for White Phosphorus, Agency for Toxic Substances & Disease Registry.