<P> The high energy beta particles from 32 P penetrate skin and corneas and any 32 P ingested, inhaled, or absorbed is readily incorporated into bone and nucleic acids . For these reasons, Occupational Safety and Health Administration in the United States, and similar institutions in other developed countries require personnel working with 32 P to wear lab coats, disposable gloves, and safety glasses or goggles to protect the eyes, and avoid working directly over open containers . Monitoring personal, clothing, and surface contamination is also required . Shielding requires special consideration . The high energy of the beta particles gives rise to secondary emission of X-rays via Bremsstrahlung (braking radiation) in dense shielding materials such as lead . Therefore, the radiation must be shielded with low density materials such as acrylic or other plastic, water, or (when transparency is not required), even wood . </P> <P> In 2013, astronomers detected phosphorus in Cassiopeia A, which confirmed that this element is produced in supernovae as a byproduct of supernova nucleosynthesis . The phosphorus - to - iron ratio in material from the supernova remnant could be up to 100 times higher than in the Milky Way in general . </P> <P> At 0.099%, phosphorus is the most abundant pnictogen in the Earth's crust but it is not found free in nature; it is widely distributed in many minerals, mainly phosphates . Inorganic phosphate rock, which is partially made of apatite (a group of minerals being, generally, pentacalcium triorthophosphate fluoride (hydroxide)), is today the chief commercial source of this element . According to the US Geological Survey (USGS), about 50 percent of the global phosphorus reserves are in the Arab nations . Large deposits of apatite are located in China, Russia, Morocco, Florida, Idaho, Tennessee, Utah, and elsewhere . Albright and Wilson in the UK and their Niagara Falls plant, for instance, were using phosphate rock in the 1890s and 1900s from Tennessee, Florida, and the Îles du Connétable (guano island sources of phosphate); by 1950 they were using phosphate rock mainly from Tennessee and North Africa . </P> <P> Organic sources, namely urine, bone ash and (in the latter 19th century) guano, were historically of importance but had only limited commercial success . As urine contains phosphorus, it has fertilising qualities which are still harnessed today in some countries, including Sweden, using methods for reuse of excreta . To this end, urine can be used as a fertiliser in its pure form or part of being mixed with water in the form of sewage or sewage sludge . </P>

A pale green mineral the major source of phosphorus