Biological Role
Chlorine plays a major biological role in most higher animal life as acqueous choride anions, as part of the electrolyte makeup of inter- and intra-cellular fluids. It has been noted that the ionic strength and composition of these fluids is often similar to sea water. In humans, chloride is most commonly obtained in the diet from table salt. Excess salt intake can have health implications. Iodine are needed by our bodies in trace amounts, particularly by the thyroid gland. Its definiciency can cause goitre. The other three halogens have no known biological role.
Read more about this topic: Halogen
Famous quotes containing the words biological and/or role:
“Although there is no universal agreement as to a definition of life, its biological manifestations are generally considered to be organization, metabolism, growth, irritability, adaptation, and reproduction.”
—The Columbia Encyclopedia, Fifth Edition, the first sentence of the article on “life” (based on wording in the First Edition, 1935)
“Totalitarianism is never content to rule by external means, namely, through the state and a machinery of violence; thanks to its peculiar ideology and the role assigned to it in this apparatus of coercion, totalitarianism has discovered a means of dominating and terrorizing human beings from within.”
—Hannah Arendt (1906–1975)