Fluoride - toxic and pathologic aspects: review of current literature on some aspects of fluoride toxicity.

Humans are exposed to fluorides, which are ubiquitous compounds, primarily through water, food, dental products, and air. The use of fluoridated water in the preparation of foods and beverages at commercial establishments and at home, coupled with fluoride in dental products, has led to increased consumption of fluorides. Fluorides can produce wide-ranging effects on many tissues, organs, and systems in the body. Fluorides are toxic at high concentrations, but at low concentrations they are added to drinking water to prevent the formation of dental caries. In mammals, fluorides have a high affinity for teeth and bones. Consumption of excess fluoride during the time of tooth enamel formation in children can cause dental fluorosis, marked by discoloured or "mottled" teeth. Skeletal fluorosis, marked by symptoms ranging from slight pain to crippling deformities, is an additive disease, for which daily consumption of high levels of fluoride for many years is usually required. In addition to teeth and bones, fluoride can also affect kidneys, lungs, and the nervous system, and it can disturb hormones and possibly change genetics. Treatment of male animals with high levels has indicated that fluoride can affect testicular production in mice and rabbits, but not always in rats. Treatment of female rats and rabbits with sodium fluoride during several generations failed to produce reproductive effects, but a high concentration of fluoride decreased bone ossification in rats.