Abstract

The effects of calcium ion and broad pH ranges on free fluoride ion aqueous concentrations were measured directly and computed theoretically. Solubility calculations indicate that blood fluoride concentrations that occur in lethal poisonings would decrease calcium below prevailing levels. Acute lethal poisoning and also many of the chronic effects of fluoride involve alterations in the chemical activity of calcium by the fluoride ion. Natural calcium fluoride with low solubility and toxicity from ingestion is distinct from fully soluble toxic industrial fluorides. The toxicity of fluoride is determined by environmental conditions and the positive cations present. At a pH typical of gastric juice, fluoride is largely protonated as hydrofluoric acid HF. Industrial fluoride ingested from treated water enters saliva at levels too low to affect dental caries. Blood levels during lifelong consumption can harm heart, bone, brain, and even developing teeth enamel. The widespread policy known as water fluoridation is discussed in light of these findings

• Related Studies :

  • Environmental and physiological factors affecting dental fluorosis

    In addition to differences in fluoride intake and possibly to calcium deficiency or malnutrition, there are several factors which may account for individual differences in the occurrence of dental fluorosis. Disorders in acid-base balance affect the renal handling of fluoride such that, in acidosis, the excretion rate is diminished and,

  • Effects of plasma fluoride and dietary calcium concentrations on GI absorption and secretion of fluoride in the rat

    This 30-day balance study with weanling rats was designed to determine the effects of plasma fluoride and dietary calcium concentration and their interaction on the absorption, balance, and tissue concentrations of fluoride. The three major groups differed according to the total exposure and plasma concentrations of fluoride. One group received

  • Modulation of fluoride toxicity in rats by calcium carbonate and by withdrawal of fluoride exposure.

    In order to assess the effect of calcium on the toxic effects of fluoride, adult female Wistar rats were treated with sodium fluoride (NaF, 500 ppm in drinking water) alone or in combination with calcium carbonate (CaCO3, 50 mg/kg by oral intubation) daily for 60 days. Food, water and fluoride

  • Fluoride metabolism

    Knowledge of all aspects of fluoride metabolism is essential for comprehending the biological effects of this ion in humans as well as to drive the prevention (and treatment) of fluoride toxicity. Several aspects of fluoride metabolism - including gastric absorption, distribution and renal excretion - are pH-dependent because the coefficient

  • Sodium Fluoride F 18: Summary of Use during Lactation.

    Drug Levels and Effects Information in this record refers to the use of sodium fluoride F 18 as a diagnostic agent. The manufacturer recommends withholding breastfeeding for 24 hours after a diagnostic dose of 300-450 MBq (8 to 12 mCi); however, this time might be longer than necessary given the minimal

• Related FAN Content :

  • Nutrient Deficiencies Enhance Fluoride Toxicity

    It has been known since the 1930s that poor nutrition enhances the toxicity of fluoride. As discussed below, nutrient deficiencies have been specifically linked to increased susceptibility to fluoride-induced tooth damage (dental fluorosis), bone damage (osteomalacia), neurotoxicity (reduced intelligence), and mutagenicity. The nutrients of primary importance appear to be calcium,

  • Fluoride Exposure Increases Metabolic Requirement for Calcium & Vitamin D

    It is well known that individuals with nutrient deficiencies are more susceptible to fluoride toxicity, including fluoride's bone effects. As discussed in the following studies, fluoride increases the skeleton's need for calcium (and vitamin D) by increasing the amount of unmineralized tissue (osteoid) in the bone. When insufficient calcium and

  • Fluoride Exposure Increases Metabolic Requirement for Magnesium

    Fluoride's toxicity is significantly enhanced in the presence of nutritional deficiencies. Similarly, fluoride exposure increases the body's requirement for certain nutrients. An individual with a high intake of fluoride, for example, will need a proportional increase in calcium to avoid the mineralization defects (e.g., osteomalacia) that fluoride causes to bone

  • Fluoridation of drinking water and chronic kidney disease: Absence of evidence is not evidence of absence

    A fairly substantial body of research indicates that patients with chronic renal insufficiency are at an increased risk of chronic fluoride toxicity. Patients with reduced glomerular filtration rates have a decreased ability to excrete fluoride in the urine. These patients may develop skeletal fluorosis even at 1 ppm fluoride in the drinking water.

  • Kidney Patients Are at Increased Risk of Fluoride Poisoning

    It is well established that individuals with kidney disease are susceptible to suffering bone damage and other ill effects from low levels of fluoride exposure. Kidney patients are at elevated risk because when kidneys are damaged they are unable to efficiently excrete fluoride from the body. As a result, kidney patients