Effects of Various Fluorine Compounds on the Albino Rat

At the beginning of the 19th century, an Italian chemist demonstrated the presence of fluorine in the teeth of both man and animals. This discovery created considerable interest at that time and can probably be considered the initial step in stimulating research on the problem.

In the light of our present day knowledge, there is evidence that the ingestion of small amounts of fluorine may be distinctly beneficial to livestock. However, the primary problem in animal nutrition is concerned with definitely harming effects resulting from an excessive intake.

It was only a few years ago that farmers were using raw rock phosphate as a mineral supplement in rations for livestock. Although raw rock phosphate might supply the desired mineral ingredients at a lower cost than they might be obtained from other sources, it was learned that rock phosphate produced abnormal calcification of the teeth and possibly other changes which greatly limited its usage. These changes were the same as could be produced experimentally by using a chemically pure fluorine salt.

Observations in Europe, and in recent years in this country, show that cattle grazing near industrial plants which give off fluorine in the smoke, such as aluminum or superphosphate plants, show excessive wear on the teeth, decrease in the rate of growth, and in some cases cause premature death.

Since Tennessee is one of the largest phosphate producing states, and since industrial plants have started a rather rapid program of expansion, there is a need for more information on the problem of chronic fluorosis.

The experiments reported in this thesis were designed primarily to study the relative toxicity of various fluorine compounds in the albino rat. Experiments have been conducted to study the concentration of sodium fluoride and length of time of feeding necessary to produce fluorsis; to biologically test the fluorine concentration of samples of hay obtained near industral plants known to give off fluorine substances; and to investigate substances in the ration which might offer promise of alleviating the toxic effects of fluorine in the albino rat.