Natural fluoridation

Fluoride is well established as effective for the prophylaxis of dental caries and has been under investigation for the treatment of osteoporosis. Both therapeutic applications originated from epidemiologic observations that subjects living in areas with naturally fluoridated water (1-2 ppm) had less dental caries and fewer vertebral compression fractures than subjects living in nonfluoridated water areas. Fluoride is accumulated by bones and teeth, where it may stabilize the... 

The term semi-clathrate refers to solid inclusion compounds where, in addition to non-bonded, clathrate interactions, there is a contribution of chemical bonding. In the example used above, this chemical contribution is of ionic nature fluoride anion from the ammonium salt is incorporated into the water host framework linked via hydrogen bonds. Thus, the host has anionic character and guest-host interactions have ionic component. 

Naturally fluoridated foods and water have been ingested for decades with no serious side effects. In addition, public fluoridation has been widespread in this country for over 30 years without serious adverse effects. The incidence of mottled enamel, one of the earliest and most sensitive signs of fluoride toxicity, has not increased significantly in the past 15 years of water fluoridation. The safety and efficacy of fluoride has definitely been established, with no scientific evidence against fluoridation. 

The administration of fluoride in drinking water at concentrations of approximately 1 ppm significantly reduces dental caries. The anticaries benefits are similar to those due to natural fluoride in drinking water. Fluoridated drinking water produces the following a 60% lower dental caries rate, a 75% decrease in the loss of 6-year molars, and a 90%i reduction in the incidence of proximal caries of the four upper anterior teeth. 

Introduction Natural Fluoridation Controlled Fluoridation Dry Feeders Saturators... 

Drs. H. V. Smith, M. C. Smith, E. M. Lantz, Researchers at University of Arizona Reported that experimental results showed that dental mottling occurred in rats that were fed concentrated naturally fluoridated water and rats fed a diet high in fluorides. 

Because all water supplies contain measurable amounts of fluoride, it can be said that all water supplies are fluoridated. However, those water supplies containing naturally occurring fluoride concentrations greater than 0.7 ppm and less than 1.5 ppm have appreciable dental significance, and are the ones we refer to as being naturally fluoridated. 

Therefore, an upflow saturator could also be utilized in this application. If there is an appreciable natural fluoride level in the untreated water, that amount should be added to the calculated level based on fluoride added. Similarly, when calculating feed rates, the natural fluoride concentration should be subtracted from the desired level in order to determine the quantity to be added. 

A small community in the Midwestern US wants to fluoridate their potable water system. The community has a population of approximately 1700 and serves a large rural school with an equivalent school population of 2667. The community has two wells that are located 2 miles apart and are automatically controlled with pressure switches. Each well has a well house that contains bleach, polyphosphate, and soda ash storage and feed systems. Average daily production from both weUs is 0.210 MGD. The water has natural fluoride level of 0.13 mg/L. The optimal fluoride level for this community system is 0.8 mg/L. Determine (a) the feed rate and annual amount of sodium fluoride and (b) the feed rate and annual amount of fluorosiUcic acid solution, (c) Provide the advantages and disadvantage of each chemical feed system. 

However, in 1886, American engineer Charles Martin Hall and French engineer Paul Heroult simultaneously but independently announced that they had discovered how to electrowin aluminum metal from alumina. Because aluminum oxide melts at such a high temperature (i.e., 2030 C) and is a nonionic (i.e., nonconductive) Hquid, electrolysis of the molten oxide is not feasible. What both Hall and Heroult discovered was that a natural fluoride mineral called cryolite (i.e., Na AlF, monoclinic), which occurs naturally in Greenland and melts at only 1009 C, would act as fluxing agent and easily dissolve purified aluminum oxide. This molten salt mixture could then be electrolyzed using carbon electrodes. 

Footnote It is interesting to note that the incidence of osteoporosis has been reported to be lower in areas where the natural fluoride content of the water is high. 

CZJ Natural fluoride ixxicecittaticxis rattge from 1—3 ppm in grains and 1-36 ppm in forages with a mean of less than 4 pprri. 

---