Abstract

1. The 30-day LC₅₀ of sodium fluoride administered in the drinking water was 205 ppm fluoride in the weanling rat. Death generally occurred between the third and fifth day after administration was begun. When levels of 150–250 ppm fluoride were administered in the water, 30–40% of the surviving rats showed a renal lesion consisting of dilatation of the tubules at the corticomedullary junction.

2. Levels of 0, 1, 5, 10, 25, 50, and 100 ppm fluoride were administered in the drinking water to rats for 6 months. No growth depression was seen, even at 100 ppm, but mortality was slightly increased in males and females ingesting 50 ppm and males ingesting 100 ppm. The only pathologic changes were seen in the kidney and the bone. Two of the 12 rats receiving 100 ppm for 6 months showed a marked dilatation of the tubules in the corticomedullary region of the kidneys. The lesion was accompanied by a high water consumption and urine output. Radiographically, an increase in the deposition of trabecular bone was seen in the rats ingesting 100 ppm fluoride. A slight increase was also seen in the males ingesting 50 ppm fluoride.

3. Balance studies showed that rats retained about 50% of the ingested fluoride after 3 months on fluoridated water. Seventy-five to 80% of the ingested fluoride was absorbed, and 65–70% of the absorbed fluoride was retained. After 6 months, the male rats retained 45% of the ingested fluoride, the females about 60%. Both males and females absorbed 80% of the ingested fluoride. The males retained 60% of the absorbed fluoride; the females, 80%. The percentage fluoride retained was independent of the fluoride level in the water. The increased age of the rats did not alter fluoride retention, except that the females retained a higher percentage of the ingested fluoride than the males after 6 months.

4. The fluoride concentration in the femur ash of the rats ingesting fluoridated water for 3 months was directly proportional to the fluoride level in the water, even with a level of 100 ppm. After 6 months, the fluoride concentration was directly proportional to the fluoride level in the water at levels of 50 ppm and less. The rats ingesting 100 ppm fluoride in the water had a lower concentration than would be expected from this proportionality.

5. The natural fluoride present in a stock animal ration such as Purina Fox Chow Meal was of limited availability. Only 10–15% of this fluoride was metabolized by the rat.

• Related Studies :

  • Health effects of fluoride pollution caused by coal burning

    Recently a huge amount of fluoride in coal has been released into indoor environments by the combustion of coal and fluoride pollution seems to be increasing in some rural areas in China. Combustion of coal and coal bricks is the primary source of gaseous and aerosol fluoride and these forms

  • The effect of 0.05 percent dietary sodium fluoride on the rat kidney

    Two hundred and twenty-six white rats were given a diet containing 0.05 per cent sodium fluoride (226 ppm) for periods ranging from 3 to 56 days. It was established that changes in the kidneys occurred regularly after 21-28 days on the diet. The kidney changes consisted primarily in dilatation of the

  • Evaluation of serum lipoprotein and tissue antioxidant levels in sheep with fluorosis

    The aim of this study was to evaluate serum lipoprotein and tissue antioxidant levels of sheep with and without fluorosis living in a volcanic area of Turkey. Fifteen Akkaraman sheep with fluorosis in the A?ri region north of Lake Van and 10 Akkaraman sheep without fluorosis in the Van region

  • Changes of acute harmful effects and fluoride kinetics after single intravenous injection of sub-toxic hydrofluoric acid in rats-Renal dysfunction, abnormal serum electrolytes, metabolic acidosis and fluoride kinetics.

    Hydrofluoric acid (HFA) is used widely in many industrial processes. There have been many reports on the acute lethal effects of HFA in relation to occupational accidents. This study was designed to investigate the time-dependent harmful effects after exposure of sub-toxic doses. The serum fluoride ion (F) kinetics is also

  • Vitamin D deficiency, rickets, and fluorosis in India

    Data on the vitamin D status of the populations in a tropical country like India have seldom been documented. Vitamin D deficiency is presumed to be rare. Population studied by the author and others in the country has proved otherwise. Studies were carried out to document the dietary habits, serum

• Related FAN Content :

  • Fluoride Gels & Kidney Function

    Scientists have found that the application of "Fluoride Gels" at the dental office causes very high spikes in the blood fluoride level. The high spikes in blood fluoride levels are a result of three factors: the high concentration of fluoride in the gel (= 12.3 mg of fluoride in each

  • Fluoride & Kidney Stones

    It has long been suspected that fluoride may contribute to the formation of kidney stones. This suspicion has recently gained support from a study of an American man with skeletal fluorosis. According to the authors: "A new, important, medical problem (that seemed temporally related to cessation of fluoride exposure and subsequent negative calcium

  • Fluoride as a Cause of Kidney Disease in Humans

    Because the kidney is exposed to higher concentrations of fluoride than all other soft tissues (with the exception of the pineal gland), there is concern that excess fluoride exposure may contribute to kidney disease - thus initiating a "vicious cycle" where the damaged kidneys increase the accumulation of fluoride, causing

  • Fluoridation of drinking water and chronic kidney disease: Absence of evidence is not evidence of absence

    A fairly substantial body of research indicates that patients with chronic renal insufficiency are at an increased risk of chronic fluoride toxicity. Patients with reduced glomerular filtration rates have a decreased ability to excrete fluoride in the urine. These patients may develop skeletal fluorosis even at 1 ppm fluoride in the drinking water.

  • Fluoride as a Cause of Kidney Disease in Animals

    Because the kidney is exposed to higher concentrations of fluoride than all other soft tissues (with the exception of the pineal gland), there is concern that excess fluoride exposure may contribute to kidney disease - thus initiating a "vicious cycle" where the damaged kidneys increase the accumulation of fluoride, causing in