الفهرس 
Materials and methodsOnly 14 pages are availabe for public view
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Abstract
Fluoride is ubiquitous in the environment and it is one of the most abundant elements on earth’s crust. Fluorine is never found free in nature. Fluorine in drinking water is totally in an ionic form and hence, it rapidly, totally and passively passes through the intestinal mucosa and interferes with major metabolic pathways of the living system.
Fluorine is often called a two-edge sword because in small doses it has remarkable prophylactic influence on the dental system by inhibiting dental caries , while in higher doses it causes dental and skeletal fluorosis ( shanthakumari et al 2004 ) , These range from mild dental fluorosis to crippling skeletal fluorosis as the level and period of exposure increases. Crippling skeletal fluorosis is a significant cause of morbidity in a number of regions of the world.
High concentration of fluorine is a noxious environment affecting the health of human and animals. There are two patterns of fluoride toxicity in the world,
endemic fluorosis and industrial fluorosis. Endemic fluorosis is related to the high concentration of fluoride present in the drinking water, while industrial fluorosis is mainly due to air pollution of fluorine (Saralakumari and Ramakrishna Rao 1991).
He and cher (2006) reported that fluoride is an essential trace element for human beings and animals and Suwalsky et al (2004) stated that fluoride is a normal component of body fluids, soft tissues and particularly of bones and teeth.
Fluoride is found in all natural waters at some concentration. Seawater typically contains about 1mg/l while rivers and lakes generally exhibit concentrations of less than 0.5 mg/l. In groundwaters, however, low or high concentrations of fluoride can occur, depending on the nature of the rocks and the occurrence of fluoride-bearing mineral (Edmunds and Smedley, 1996).