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.
Mouthwash ingestion by preschool children
Even though fluoride provides a significant contribution in dental caries prevention, it is known that its random employment may lead to enamel alterations such as dental fluorosis, besides the possibility of severe systemic alterations. The aim of this study was to evaluate the ingestion of mouthwashes administered to preschool children. It was
Salivary fluoride concentration and retention after rinsing with 0.05 and 0.2% sodium fluoride (NaF) compared with a new high F rinse containing 0.32% NaF.
Objective To compare salivary fluoride (F) concentration and F retention after rinsing with a new 0.32% sodium fluoride (NaF) rinse and conventional 0.05 and 0.2% NaF rinses. Methods Seventeen subjects (aged 22–26 years), with normal salivary secretion rates, participated in a double blind, cross-over study. In three separate sessions with a minimum washout
Fluoride in tea--its dental significance: a review.
It has long been accepted that fluoride accumulates in the leaves of the tea plant. Camellia sinensis. In addition it is known that some of this fluoride is released into the infusion which is drunk as tea. The exact concentration of fluoride in a cup of tea and the effects
Fluorosis is linked to anaemia.
We report here a simple, easy-to-practice treatment procedure for anaemia, by focusing on withdrawal of fluoride consumption and promotion of nutrients through diet. The approach to improve nutrient intake as supplementation of iron and folic acid or iron tonic does not yield beneficial results. The reason being highly destructive F–
A review of fluoride in African groundwater and local remediation methods.
Groundwater is the major source of drinking water supply in the bulk of African urban and rural communities. However, groundwater in some parts of the African countries contains fluoride in concentrations exceeding the 1.5 mg/L permissible limit established by the WHO. No confirmed data are available on the number of people
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