An Essential Element for Life

Many studies report beneficial effects of trivalent chromium. The element is described by WHO [24.5] as essential owing to its ability to strengthen the activity of in-suHn and its influence on carbohydrate and Upid metaboHsm. Biological systems commonly contain chromium as Cr in small concentrations [24.6]. It is thought, but disputed, that chromium is essential for life and involved in human glucose metaboHsm [24.7]. Chromium intake has been shown to be positive for humans and decreases the symptoms of diabetes in people with glucose intolerance [24.8]. An adequate intake of chromium for an adult is 50-200 pg/day and the content of chromium in tissues is 100-1000 pg/kg dry weight. 

ICDA Statistical Bulletin, International Chromium Development Association, Paris, 2001, Volume 11, July. 

Lofthouse, The World of Chromium Metal in the report of the ICDA South Africa Conference 2003, Paris 2003 G. Dubpemell, Chromium in Modem Electroplating, (ed. F.A. Lowenheim). 3 edn, John Wiley Sons, New York, 1974, p. 98 

U S Environmental Protection Agency EPA TTNWeb EMC, 2003, http // www.epa.gov/ttn/emc/software.html WHO, Trace elements in human nutrition and health, Geneva, 1996 (Referred from E. Walterson, Chromium, Nickel and 

Molybdenum in society and in the environment (in Swedish), Jernkontoret, Stockholm, p. 171) 

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Potassium is an essential element for life. It is found in great abundance in potatoes and especially in bananas. 

Diatomic nitrogen makes up about 79 percent of Earth s atmosphere. Nitrogen is an essential element for life, yet only a few organisms can use atmospheric nitrogen directly. A few species of soil bacteria can produce ammonia, NH, from atmospheric nitrogen. Other species of bacteria can then convert the ammonia into nitrite and nitrate ions, which can be absorbed and used by plants. 

Because of its ionic nature magnesium forms very few coordination compounds. Donor-acceptor species in aqueous solutions are short-lived, but magnesium bromide and iodide have sufficient acceptor properties to dissolve in donor solvents such as alcohols and ketones. Magnesium appears to be an essential element for life, occurring in chlorophyll. 

Phosphorus (P) is one of the most widely distributed elements on Earth. It s found as phosphate in almost all igneous and sedimentcuy rocks. It s also an essential element for life and provides energy when adenosine triphosphate (ATP) is converted to adenosine diphosphate (ADP) within the cells of your body. It can be found in bones, in DNA, and nucleic acids. Today, it can be found frequently in soda drinks in the form of phosphoric acid. On its own, however, phosphorous is a hazardous material, cmd prolonged exposure can lead to severe burns and illness. 

Cobalt is a metal with magnetic properties similar to those of iron. Its salts give glass a beautiful deep-blue colon Cobalt-based alloys have long been used in the manufacturing industry. An addition of 20% cobalt to chromium-nickel-based alloys, used for turbine blades and burner lines in aircraft engines, improves the high-temperature properties. Cobalt powder is an important component in cemented carbides (hard metals). Cobalt is also an essential element for life and important for humans and animals. It is present mainly in the form of vitamin Bjj. The artificially produced isotope Co is used as a source of intense g-radiation. It is used in industry and in radioisotope therapy. 

The applications of boron in medicine are not limited to the development of new chemotherapeu-tics, but also include diagnostics and the modulation of many metabolic processes through dietary boron. The discovery of polyhedral boron compounds added new dimensions to the medicinal chemistry of boron, facilitating the quest for biologically active molecules containing boron clusters rather than only a single boron atom per molecule. Thus, boron is an essential element for life and living. 

Water is an essential element for life. Life, especially extraterrestrial life is discussed in many textbooks. Astrophysical and astrochemical insights into the origin of life were reviewed by Ehrenfreund et al., 2002 [114] and Chyba and Hand, 2005 [68]. In this chapter we will outline how life can be defined and has evolved on Earth and the role of water for this process. 

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