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1909 photograph by Frederick McKay of Greene Vardiman Black (left) and Isaac Burton and F.Y. Wilson, studying the Colorado Brown Stain. [8]Community water fluoridation in the United States is partly due to the research of Dr. Frederick McKay, who pressed the dental community for an investigation into what was then known as "Colorado Brown Stain."
During the 1950s and 1960s, conspiracy theorists baselessly claimed that fluoridation was a communist plot to undermine American public health. [11] In recent years, water fluoridation has become a prevalent health and political issue in many countries, resulting in some countries and communities discontinuing its use while it has expanded in ...
Substituting a fluorine into a para position, however, protects the aromatic ring and prevents the epoxide from being produced. [13] Adding fluorine to biologically active organic compounds increases their lipophilicity (ability to dissolve in fats), because the carbon–fluorine bond is even more hydrophobic than the carbon–hydrogen bond.
In September 1948, he presented a series of papers at a Fluorocarbon Symposium by the American Chemical Society. [4] On 29 November 1948 he filed an application to patent the electrochemical process of making fluorine-containing carbon compounds with two others from the Minnesota Mining & Manufacturing Company , St. Paul, Minnesota, which he ...
Fluoride monitor (at left) in a community water tower pumphouse, Minnesota, 1987 Fluoridation does not affect the appearance, taste, or smell of drinking water. [1] It is normally accomplished by adding one of three compounds to the water: sodium fluoride, fluorosilicic acid, or sodium fluorosilicate.
Fluorine is a chemical element; it has symbol F and atomic number 9. It is the lightest halogen [note 1] and exists at standard conditions as pale yellow diatomic gas. Fluorine is extremely reactive as it reacts with all other elements except for the light inert gases. It is highly toxic.
The most common F-gases are hydrofluorocarbons (HFCs), which contain hydrogen, fluorine, and carbon. They are used in a multitude of applications including commercial refrigeration, industrial refrigeration, air-conditioning systems, heat pump equipment, and as blowing agents for foams, fire extinguishants, aerosol propellants, and solvents.
Moissan's fluorine cell, from his 1887 publication. Fluorine is a relatively new element in human applications. In ancient times, only minor uses of fluorine-containing minerals existed. The industrial use of fluorite, fluorine's source mineral, was first described by early scientist Georgius Agricola in the 16th century, in the context of ...