I am undertaking a study on fluoride in drinking water in the south central hydrographic region of Haiti. The concentration of fluoride in drinking water varies from place to place. I would like to know what could be the cause of this.
Hello Cajouste, Many factors can modify the concentration of fluoride in drinking water such as the geology and hydrogeology of the area, the temperature, the anthropogenic activities… I suggest you to consult this document: Edmunds M., Smedley P. (2005) Fluoride in natural waters. IN: Selinus O., Alloway J. B., Centeno A. J., Finkelman B. R., Fuge R., Lindh U.,Smedley P. Essentials of Medical Geology. London: Elsevier Academic Press, pp. 301-329. ISBN: 0-12-636341-2.
thank for the answer I think the depth of the phreatic groundwater and soil porosity could be a crucial role in the variation of concentration of fluoride in drinking water in these areas.
Dear Cajouste
The literature has reported the concentration of fluoride tends to increase in depth of groundwater. Why does fluoride’s concentration increase in depth of groundwater?
Concentration increase due to depth and change in ground water table, because soil starta having all kind of metal and metloied, Fluoride is one of them
Fluoride is considered as one of the biggest geogenic contaminant in the semi-arid hard rock terrains. Fluoride-rich minerals such as Fluorite- micas- apatite-amphiboles etc. are abundant in granitic rocks and act the major source of F in the groundwater (Reddy et al. 2010). However, a minor contribution may be derived from the agricultural fertilizers and combustion (Brindha et al. 2011). Since it has a natural origin, the variation in hydrogeochemical conditions in the aquifer may affect the mobility of F in groundwater. A number factors including availability and solubility of F-minerals, pH, temperature, anion exchange capacity of aquifer materials, residence time, porosity, structure, depth, groundwater age, concentration of bicarbonates (Apambire et al. 1997). The determination of international standard of F in the drinking water is done by WHO as 1.5 mg/L. However, this value may be waived accordingly with different climatic regions, since the amount of water consumed and consequent fluoride ingested are influenced primarily by air temperature (Bell and Ludwig, 1970). In India, Bureau of Indian Standards (BIS, 1992) specifies the maximum permissible limit of fluoride in the drinking water is 1.2mg/L and the most desirable limit being 0.6—1.2 mg/L.
To get more information please follow the links
http://link.springer.com./article/10.1007/s00128-012-0929-8
http://link.springer.com./article/10.1007/s00128-012-0638-3
Hallow Cajouste Tony Jean-Pierre,
One of the prime causes of varying concentration of Fluoride in underground water from place to place is the availability of Granite (felsper, fluroapatite etc.) rock formation, from where leaching of Fluoride takes place.
Another major factor might be the richness of Calcium in the water bearing Aquifer, due to which Fluoride in water reacts with Calcium to form insoluble Calcium Fluoride, Eventually the Fluoride concentration in underground water is reduce.
Thanking you.
With Regards.
Nripendra Kumar Sarma
Guwahati, Assam, India
In the literature it's reported that the calcuim is an antagonist of fluoride in a ground water rich in calcuim we will attend at a very low ppm fluoride ion in drinking water.
Apart from calcium, the other ion that control the mobility of fluoride in groundwater is HCO3. If the concentration of HCO3 is high, the formation of Ca+HCO3=>CaCO3 will be the dominant the reaction than Ca+F2=>CaF2. This competitive behaviour of HCO3 will reduce the Ca level in groundwater thereby the concentration of F remains high.
Ca has an ability to reduce the fluoride level in groundwater, on the other hand elevated Na concentration will have positive effect on F enrichment . In this context, I was trying to relate the high Na discharged by the tannery industries with the F dynamics. This study was successful and I have proved that the tannery effluent (anthropogenic) has not only spoiled the groundwater with high salinity, but also acting as a catalyst to trigger the Fluoride (geogenic) contamination.
This article is published in Environmental contamination and Toxicology (see the link below)
http://link.springer.com/article/10.1007%2Fs00128-012-0929-8
By following the link you can download the Medical Geology book by Selinus et al. https://dl.dropboxusercontent.com/u/6749523/Essentials%20of%20Medical%20Geology%2C%20Selinus.pdf The reason for sharing is the following: Two years ago (or so) Elsevier did not want to print any more books although there was a demand for new prints. In fact one of the authors encouraged me to share the book to students etc. But, a revised edition has now been published by Springer and I encourage those who can afford to get it or recommend it to university libraries etc. http://www.springer.com/earth+sciences+and+geography/geology/book/978-94-007-4374-8 or http://www.amazon.co.uk/Essentials-Medical-Geology-Revised-Edition/dp/9400743742/ref=sr_1_2?ie=UTF8&qid=1366828887&sr=8-2&keywords=medical+geology
Thanks for the referral I already read it on this books on the page 301 to 341
Hello Peltola! I really appreciate your information. I wonder if you can help me about information that I would like to know.
Magnesium is the antagonist of calcium. However, calcium interfere magnesium’s absorption in high concentration. How can you explain that? What should be the calcium value to interfere the absorption of magnesium?
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