Fluorida-what?

Fluoride to again be added to west Cumbria’s water supply” says the headline on the website of the News and Star (09/09/13) bringing to the fore the issue both the specific issue of water fluoridation and the wider issue of widespread public medication. I’m not going to go into the issue of putting additives into our food or water supply for our own good because that’s an ethical issue and not the point I’m trying to make. What I want to discuss here is the science behind fluoridation, why it’s a good idea and why the anti-fluoridation brigade has it wrong and what they’re really opposed to and why.

Fair enough. What is fluoridation though?

Water fluoridation is the addition of fluoride containing compounds into the public water supply so that those who drink it will be exposed to increased fluoride levels.

Woah, woah! Isn’t that dangerous? I’ve heard fluorine is a nasty chemical.

It is. Elemental fluorine is one of the nastiest, most reactive and gosh-darn dangerous chemicals you’ll ever have the misfortune to hear about. It reacts with almost anything, in a manner that would put the buffet rush at a wedding to shame. However, this isn’t about fluorine, the element, this is about its much less excitable ion, fluoride. Fluoride is stable and happy to partner up with other elements in a more genteel manner. If you’re still not convinced, look at oxygen. Left to its own devices, oxygen burns, corrodes and generally makes life a nuisance for anything it comes into contact with. However, stick it with hydrogen, another substance happy to down airships and explode on cue, and you get water, something spectacularly unimpressive on the whole scale of reactions.

So what’s so good about it?

Increased levels of fluoride are proven to reduce dental decay, particularly in children, and reduce costs for the treatment of cavities and other dental problems by a significant factor. Food, especially sugar, is converted by the bacteria on your teeth (plaque) into organic acids. If these acids build up and lower the pH of the environment around them to less than 5.5, then the material that makes up your teeth (called hydroxyapatite) starts to dissolve. Your own body can fight this by remineralising hydroxyapapite back onto your teeth from saliva once the sugars are scrubbed off and the pH is back to normal. Tooth decay kicks in when this rate of remineralisation exceeds the rate of dissolution.

When enough fluoride is ingested, it’s present in your saliva and during periods of remineralisation, joins with the hydroxyapapite to form a layer that not only forms faster than the usual material, but it’s also more resistant to dissolution; the pH required to dissolve it is now 4.5.

This is a well proven method and has been known for decades; areas of the world with higher natural flouride concentrations typically had much less instances of tooth decay than those without.

So if it’s so good, why don’t people like it?

Excess amounts of fluoride in your diet can cause something called fluorosis, which causes dark streaks to appear on your teeth and is, essentially, an aesthetic concern. Typical levels of fluoridation in public water supplies are around 0.4 mg/L, levels where fluorosis occurs is much higher, at 1 mg/L.

Opponents of fluoridation will assert that fluoride can cause cancer, increase the risks of bone fractures and other such claims. This is a blatant lie. Fluorine is a scary substance and, yes, it’ll strip the calcium from your bones quite happily, but the fluorides used, and especially fluoride present in the concentrations given, has no adverse health effects. Parts of the world have concentrations of fluoride much higher than that put into public water and people there suffer little or no effects. The same people who will insist water fluoridation is dangerous and unhealthy are still quite happy to use toothpaste with concentrations of fluorides thousands of times higher. Yes, you don’t eat the toothpaste, but even accidental ingestion of a tiny amount of toothpaste will result in more fluoride than a whole litre of water.

It can’t be just that, if the science is so good, surely?

You’re right, it’s not. Water fluoridation is often seen by its opponents as a method of mass medication of the public by governmental forces for nefarious purposes, usually along the lines of population control, mood alteration or to ‘soften us up’ for the introduction of other, more potent, additives in the future. Objectors to fluoridation are often also critics of mass vaccinations, fortification of cereals with vitamins and other such public heath schemes. Some simply oppose the introduction of any additional substance into our food and drink, purely on principle. Of course, these same people would probably complain if dirty river water was piped directly to their homes and their food bought at the supermarket was riddled with parasites and of poor quality.

So they’re just cranks and moonbats?

Some objectors to fluoridation have genuine concerns, usually brought about through ignorance of the science or misinformed concepts as to the reasons why it’s performed. A small minority have real and substantive ethical concerns, who view no ‘greater good’ as sufficient for authority intervention over personal choice of medication. However, the majority of objectors tie in fluoridation with a host of other conspiracy theories and crack-pot ideas. Don’t assume all objectors are like this however, take the time to discuss why somebody objects to it. Nine times out of ten, it’s because they misunderstand or are ignorant of the science.

 

 

The CDC in the USA says that water fluoridation is one of the most successful public health initiatives ever attempted and the science behind it is robust and well proven. For less than 10 pence a day, it’d be criminal not to fluoridate the water.

 

Links/references

http://www.bfsweb.org/

http://en.wikipedia.org/wiki/Water_fluoridation

http://www.skepdic.com/fluoridation

http://rationalwiki.org/wiki/Water_fluoridation

http://www.bmj.com/content/321/7265/855