Fluoride pollution may become a serious threat to mammals as it is capable of distorting the skeleton which may change an individual into a useless hump of flesh and blood. Minerals like Fluor-spar (CaF2), Fluor-apatite [Caf2, 3Ca2 (P04)2] and Cryolite (Na3 AIF6) are the main source of fluorine in nature.
In India, fluor-apatite and cryolite are fairly common. The disintegration and decay of these minerals bring fluorides into the soil. From the soil fluorides are absorbed by plants which may contain about 0.1%) of fluorine in their ash content as fluorides. Fluoride particles may get air-borne as well.
Fluoride pollution in India is generally caused by waters which permeating through fluorine bearing strata or detritus and alluvia may acquire as much as 15-22 ppm of fluorine content. Such waters if supplied to the city may cause mass scale fluorine toxicity.
Fluorides are taken up by living organisms through lungs and intestines. Only a fraction of fluorides absorbed is excreted-most of it is retained inside. Fluorine is an important constituent of harder portions of bones, such as ball and socket joints, enamel of teeth etc. However, it is present in very small quantities about 0.1 to 0.3 ppm in human body. Its deficiency induces osteoporosis, dental caries and bones lose their rigidity.
But there is a very thin line demarkating deficient, sufficient and conditions of excess supply as the presence of about 5-12 ppm of this element becomes toxic. Plants take up fluorides more readily from water than from the soil and accumulate it forming fluoracetate and fluorcitrate. It enters livestock through the vegetation. As a matter of fact fluoride toxicity has done more damage to livestock on worldwide basis than any other type of pollution.
Higher fluoride concentration has deleterious effect on teeth and bones. It interferes with calcium and phosphorus metabolism. Teeth acquire a dull white coating and brown patches. Enamel becomes brittle and may break away.
Bones lose their elasticity and arthritic conditions follow. Bones become prone to fractures. Fluorine is an effective inhibitor of many enzymes, notable among them are encloses which are important constituent of the glycolytic pathway. Its presence in toxic concentrations impairs glycolysis which disturbs the overall metabolism of an individual.