Fluoride levels in seven commercial phosphate fertilizers (four single superphosphate samples, two diammonium phosphate samples, and one ammonium nitrophosphate sample) were analyzed independently at three laboratories employing the techniques of ion chromatography and ion-selective electrode. The results were consistent for aqueous solutions containing 100?mg?L?1 (ppm) of fertilizer. The average values of fluoride from four different studies varied from 0.140?±?0.006–1.33?±?0.158% (w/w) for the seven fertilizer samples. The [P2O5]/[F] ratios (w/w) were computed for all the seven samples and the values were in the range of 13.79–328.57. By comparing these values with the average [P2O5]/[F] ratio in phosphate rock, it was inferred that 3–75% of fluoride originally present in rock remained in the fertilizers. IR spectral data revealed a small peak at 716?cm?1 – indicative of SiF62? – in the sample containing lowest fluoride which may be on account of fluoride stripping of intermediate phosphoric acid with reactive silica in this case. Considering 15 MMT (million metric tons) of annual consumption of phosphate fertilizers in India, the incremental load of fluoride in agricultural fields was estimated to be 127,650?±?14,550 MTy?1 based on the grand average fluoride content of 0.851?±?0.097% (w/w). While a part of this fluoride would likely get discharged into oceans through run-off, the remainder may persist in the soil, some amount may accumulate in vegetation, and a part might find its way into fresh water bodies, thereby aggravating the fluoride problem in the Country. The problem of non-point source pollution can be reduced by eliminating fluoride at source, and utilizing the recovered fluoride as feedstock. This could, in principle, satisfy the entire requirement of the fluorochemicals industry in India. Environmental costs need to be factored in while making an assessment of the viability of fluoride recovery and reuse in this manner compared to production from virgin sources of fluoride.
A young woman presented with a novel multisystem disease: painful periostitis, osteosclerosis, hypertension, and renal dysfunction. The similarity of some of this clinical picture to fluoride intoxication led to the discovery of massively elevated fluoride levels in serum, urine, and bone. Although initially an enigma, the source of fluoride was
Risk assessment of fluoride daily intake from preference beverage.
Background/purpose Tea, coffee and alcohol beverages are called preference beverage and are drunk habitual and in large quantities. Therefore, there is a high possibility that a health risk is caused by the contained components, and risk assessment of intake is essential. However, the risk assessment of fluoride intake from preference beverages
Black tea amelioration of sodium fluoride-induced alterations of DNA, RNA, and protein contents in the cerebral hemisphere, cerebellum, and medulla oblongata regions of mouse brain.
Summary: Oral administration of sodium fluoride (NaF, 6 and 12 mg/kg body weight/day) to Swiss male albino mice for 30 days caused significant, dose-dependent reduction in DNA, RNA, and protein contents in cerebral hemisphere, cerebellum, and medulla oblongata of the brain. After 30 days of NaF treatment, followed by withdrawal
Comparative efficacy of a hydroxyapatite and a fluoride toothpaste for prevention and remineralization of dental caries in children.
Abstract Objective This in situ study compared the effectiveness of two toothpastes containing hydroxyapatite or 500 ppm fluoride in promoting remineralization and inhibiting caries development. Materials and methods Two enamel blocks (human primary teeth), one sound and one with artificially-produced caries lesion, were exposed to toothpaste containing either 10% hydroxyapatite or 500 ppm F-
Pharmacokinetic aspects of topical fluorides
Pharmacokinetic studies have revealed quantitative information about the bioavailability, rate of absorption, distribution, and clearance of fluoride following the use of fluoride-containing dentifrices, gels, varnishes, and solutions. It is concluded that following the use of topical fluoride products, variable amounts of fluoride are swallowed and absorbed into the systemic circulation--amounts which may be sufficient to produce acute
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