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OK. Now that we have established that tap water with natural and adjusted fluoride are identical, how do you explain the lack of problems in comminities with naturally fluoridated water?

Since a solution of calcium fluoride will be limited to a maximum solubility of 16 ppm, there will ONLY be 16 ppm of fluoride ions available in blood if the solute is calcium fluoride. With a maximum solubility of 42,200 ppm for sodium fluoride, the concentration of fluoride ions available could increase to 42,200 ppm, although a human would die well before that concentration was reached. And again, once the maximum solubility is reached, ie. the solution becomes saturated, any excess solute is simply held in aqueous suspension and is easily excreted.

So the problem with sodium fluoride is that there is virtually NO limit as to the number of fluoride ions available in the solution, where death will occur WELL before the solution reaches saturation.

Next, you have the solubility problem wrong. If you have a substance like CaF that isn't very soluble in water, you need to have MORE of the compound in the water to give you a high steady state ion level. That is opposed to a substance that is easily soluble. In that case you don't need to add as much.

It is the IONS that pose a problem, not so much the compound itself. If there are n number of ions available, as you say, a fluoride ion is a fluoride ion. Until maximum solubility is reached, ALL sodium fluoride molecules (formula units) are dissolved in the solution. So yes, there IS more calcium fluoride compound present in a solution with the same ion level as sodium fluoride, as it stops dissolving at a MUCH lower concentration.

As the fluoride ions remain bound to the calcium however, they are NOT available and pose no risk.

I'm sorry, but you MUST give at least a link to these calculations.

SOLUBILITY AS A FUNCTION OF TEMPERATURE

In a endothermic reaction such as the disassociation of sodium fluoride, energy is absorbed by the system.

The rule for solutions in relation to temperature is, if the solution process absorbs energy then the solubility will be INCREASED as the temperature is increased. If the solution process releases energy then the solubility will DECREASE with increasing temperature.

Some common salts are shown in the graph below;

I can't seem to find a chart depicting the solubility in relation to temperature for the various fluorides, but I'll see what I can find if you're interested..

So your boiled water example is backwards. Although I don't think it is valid anyway.

Nope, I didn't have it backwards, and it IS valid.

Now that we have established that tap water with natural and adjusted fluoride are identical

And BTW Tom, we have NOT established that, we have established just the opposite. The tap water IS different obviously, as the tap water from a fluoridated water system is a solution of sodium fluoride, whereas the tap water from a naturally occuring source is a solution of calcium fluoride.

Nice try.

Let me restate something, as I should have qualified the following statement;

So yes, there IS more calcium fluoride compound present in a solution with the same ion level as sodium fluoride, as it stops dissolving at a MUCH lower concentration.

I should have said,

After the solution exceeds a concentration of 16 ppm, there IS more calcium fluoride compound present in a solution with the same ion level as one containing sodium fluoride, as calcium fluoride stops dissolving at that concentration, whereas sodium fluoride does not.

Now that is more accurate.

For those of you still around and keeping score, we can now see that FL has backtracked from:

Fluoride is a toxin, so ANY amount is too much. Those areas that DO have naturally occuring fluoride in their water supply DO also have children with statistically significant lower IQ and develop skeletal fluorsis.

To, well, calcium fluoride is, admittedly present in most water supplies, but it is OK because.....

While sodium silicofluoride is added to water supplies and that is bad.

Once again you try to throw a bunch of crap against the wall and hope at least some of it sticks. But your theory is based on a flawed premise, so all that comes after it is wrong. You say:

Since a solution of calcium fluoride will be limited to a maximum solubility of 16 ppm, there will ONLY be 16 ppm of fluoride ions available in blood if the solute is calcium fluoride. With a maximum solubility of 42,200 ppm for sodium fluoride, the concentration of fluoride ions available could increase to 42,200 ppm,

That, once again, clouds the issue that the level (ppm) is ALREADY ESTABLISHED in the water itself. The solubility information is great if you are trying to determine how much compound you want to add to a water supply to get the proper flouride level, but since we are dealing with supplies that the fluoride is already present and measured, your information is useless.

In addition, could you explain how you can get water with a fluoride concentration of 1 ppm and have it increase to 42,000 ppm? That makes no sense.