# What's the straight dope on fluoride? **URL:** \ **Category:** Factual Questions\ **Created:** [October 31, 2004, 8:23pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191 "2004-10-31T20:23:57Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![jacknewton423](https://avatars.discourse-cdn.com/v4/letter/j/df788c/32.png) [@jacknewton423](https://boards.straightdope.com/u/jacknewton423)\ **Post date:** [October 31, 2004, 8:23pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/1 "2004-10-31T20:23:57Z")
What’s the straight dope on fluoride? Several of my friends have told me, with straight faces, that the fluoride in our water supply is toxic, a by-product of industrial cleaning agents. Searching the Internet, I find myriad pages devoted to this belief, or, at least, to the idea that fluoride is harmful. If this were true, however, given the litigious nature of our society, and given this mountain of “evidence”, wouldn’t the folks behind flouridation have been sued into oblivion ages ago? I understand that ANYTHING, in sufficient amounts, can be lethal, but is fluoride especially nefarious? Are my friends certifiable? Help me, my whole world is in turmoil! ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [October 31, 2004, 8:32pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/2 "2004-10-31T20:32:50Z")
This rumor got started in the 50’s, from ultra-anti-government types. They objected to the “compulary medication” aspect of getting dental treatments in your tapwater, & spun these dumbo tales. Of course, in 5 minutes somebody will[list=a] [li]Post an obscure study done in Ulan Bator about a link between fluoride & Lethal Atomic Nostril Warts.[/li] OR [li]Post a link to a tinfoil hat community.[/li][/list] But think–with all the concern about environmentally-caused diseases, wouldn’t there be a jillion lawsuits going on to stop this? ---
**Author:** ![RandomLetters](https://avatars.discourse-cdn.com/v4/letter/r/8edcca/32.png) [@RandomLetters](https://boards.straightdope.com/u/RandomLetters)\ **Post date:** [October 31, 2004, 8:56pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/3 "2004-10-31T20:56:14Z")
You forgot ``` c. Mention how Flouride contaminates our precious bodily fluids. ``` ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 31, 2004, 9:00pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/4 "2004-10-31T21:00:20Z")
No, no no, it doesn’t merely contaminate them, it _saps and impurifies_ our precious bodily fluids. Fortunately those of us in the know can preserve our bodily fluids by denying women our essense. Drives them nuts, but now we’re OK. ---
**Author:** ![danceswithcats](https://avatars.discourse-cdn.com/v4/letter/d/9e8a1a/32.png) [@danceswithcats](https://boards.straightdope.com/u/danceswithcats)\ **Post date:** [October 31, 2004, 9:09pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/5 "2004-10-31T21:09:19Z")
Sadly, Cecil has yet to weigh in on the issue. [This article from Snopes](http://www.snopes.com/toxins/toothpaste.asp) discusses high levels of fluoride in dollar store toothpaste. I guess fluoride, like good booze, should be administered in moderation. 😉 ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [October 31, 2004, 9:27pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/6 "2004-10-31T21:27:48Z")
[Quackwatch](http://www.quackwatch.org/03HealthPromotion/fluoride.html) ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [October 31, 2004, 9:59pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/7 "2004-10-31T21:59:52Z")
Yes, fluoride is toxic. So are most vitamins. It’s all a question of quantity. The minuscule amounts in tapwater will not do you any harm. As for “a by-product of industrial cleaning agents”, what the hell is that supposed to mean? Fluoride is fluoride. F[sup]–[/sup]. There’s a lot of bunk on the Internet which talks about hydrofluoric acid (HF) which can **etch glass** (OMG!!!1111 :rolleyes: ) as if that is the same thing as the 1 part per million of fluoride ion in your water. If you drink a middling amount of tap water you probably swallow more fluoride from your toothpaste (typically as much as 1000ppm F[sup]–[/sup]) than you do in tap water. ---
**Author:** ![Pushkin](https://avatars.discourse-cdn.com/v4/letter/p/ee59a6/32.png) [@Pushkin](https://boards.straightdope.com/u/Pushkin)\ **Post date:** [October 31, 2004, 10:10pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/8 "2004-10-31T22:10:41Z")
Is the Flouride in tap water supposed to be ingested by the body to strengthen our teeth or remain on the teeth as the water we drink flows past? 😕 ---
**Author:** ![jacknewton423](https://avatars.discourse-cdn.com/v4/letter/j/df788c/32.png) [@jacknewton423](https://boards.straightdope.com/u/jacknewton423)\ **Post date:** [October 31, 2004, 10:13pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/9 "2004-10-31T22:13:44Z")
> [@Colophon](#): > > As for “a by-product of industrial cleaning agents”, what the hell is that supposed to mean? Fluoride is fluoride. My anti-fluoride friends constantly claim that the fluoride in American water supplies comes from industrial corporations, whose smokestacks become clogged with fluoride compounds, which are then disposed of, with govt approval, into our water. Understand me…_I_ don’t believe this, but I would love to be able to refute this specific claim, which is ubiquitous on the net, and which is always accompanied by quotes from EPA spokespeople. Sample: [Cargill fertilizer plant - where fluoride is made](http://www.nofluoride.com/phosphate_plant.htm) ---
**Author:** ![Shrinking\_Violet](https://avatars.discourse-cdn.com/v4/letter/s/df705f/32.png) [@Shrinking\_Violet](https://boards.straightdope.com/u/Shrinking_Violet)\ **Post date:** [October 31, 2004, 10:18pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/10 "2004-10-31T22:18:59Z")
Water is fluoridated in some parts of the UK, and not in others. I saw a TV documentary some time ago which claimed that children in the Birmingham (?) area - at that time one of the few fluoridated areas - had a higher incidence of discolouration in their “second” teeth as they came in. Anyone got the gen on this? ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [October 31, 2004, 10:39pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/11 "2004-10-31T22:39:17Z")
> [@jacknewton423](#): > > My anti-fluoride friends constantly claim that the fluoride in American water supplies comes from industrial corporations, whose smokestacks become clogged with fluoride compounds, which are then disposed of, with govt approval, into our water. > > Understand me…_I_ don’t believe this, but I would love to be able to refute this specific claim, which is ubiquitous on the net, and which is always accompanied by quotes from EPA spokespeople. > > Sample: [Cargill fertilizer plant - where fluoride is made](http://www.nofluoride.com/phosphate_plant.htm) Why do you feel the need to refute it? As I said, fluoride is fluoride. Why does it matter where it comes from? Same with vinegar - acetic acid is acetic acid so why does it matter whether it is made by bacterial action on ethanol or by a purely synthetic industrial process? Surely if these compounds can be taken out of the chimneys and recycled into something useful, this is a _good_ thing, not a bad thing? Here’s a [page](http://64.233.183.104/search?q=cache:ooDv1lQ5erwJ:pmeiers.bei.t-online.de/chemicals.htm+%22sodium+fluoride%22+water&hl=en) that discusses where the compounds may or may not come from. I say again - why does it matter? Sodium fluoride as a byproduct of aluminium smelting is still sodium fluoride. Surely it is better to use the stuff you already have rather than throw it away and synthesise some more especially to go in the water. Note that I do not know for certain that this \*is/i] what is going on, but it would seem logical. What I don’t understand is why that is picked up on as being a bad thing. Think of it as recycling 🙂 ---
**Author:** ![Tapioca\_Dextrin](https://avatars.discourse-cdn.com/v4/letter/t/3d9bf3/32.png) [@Tapioca\_Dextrin](https://boards.straightdope.com/u/Tapioca_Dextrin)\ **Post date:** [October 31, 2004, 10:51pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/12 "2004-10-31T22:51:47Z")
> [@danceswithcats](#): > > Sadly, Cecil has yet to weigh in on the issue. Except for [this](http://www.straightdope.com/columns/020208.html) > [@](#): > > _You’re worried about fluoride being taken out? You should worry about fluoride being put in! Fluoride is dangerous! Fluoride causes cancer! Fluoride can . . ._ Whatever. Long a target of fringe groups, fluoridation is widely considered one of the great public-health achievements of the last century, having reduced cavities on the order of 50 percent and saved billions in dental care costs ($39 billion from 1979 to 1989, according to one study). That said, fluoride is only one of thousands of chemicals that have been introduced into the environment, and it’d be foolish to claim we understand the physiological effects of all of them. If you want to take a stab at filtering chemicals out of your water and doing so doesn’t cost very much, why not? ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [November 1, 2004, 3:12am UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/13 "2004-11-01T03:12:38Z")
> [@Shrinking Violet](#): > > Water is fluoridated in some parts of the UK, and not in others. I saw a TV documentary some time ago which claimed that children in the Birmingham (?) area - at that time one of the few fluoridated areas - had a higher incidence of discolouration in their “second” teeth as they came in. > > Anyone got the gen on this? Excessive fluoridation does discolour teeth somewhat, and I’d be surprised if that was so for very long, presumably they would reduce the concentration pretty soon after this was discovered. Better than having them rot though. ---
**Author:** ![Leonard](https://avatars.discourse-cdn.com/v4/letter/l/a6a055/32.png) [@Leonard](https://boards.straightdope.com/u/Leonard)\ **Post date:** [November 1, 2004, 4:45am UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/14 "2004-11-01T04:45:49Z")
Just an anecdote–When I was young, my dentist had me use a toothpaste that had a high enough level of fluoride to make it a presciption drug. I’m 30 years old, alive, and have never had a cavity. :shrug: ---
**Author:** ![Roches](https://avatars.discourse-cdn.com/v4/letter/r/bc8723/32.png) [@Roches](https://boards.straightdope.com/u/Roches)\ **Post date:** [November 1, 2004, 5:23am UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/15 "2004-11-01T05:23:11Z")
Puskin: Fluoride, IIRC, works by reacting with tooth enamel directly. Tooth enamel is mostly calcium hydroxyapatite (Ca[sub]5[/sub][(PO[sub]4[/sub])[sub]3[/sub] **OH** ]), a mineral-like material which can be dissolved by acids below about pH 5.5. Fluoride reacts with the enamel by replacing OH groups with F groups, producing calcium fluoroapatite, Ca[sub]5[/sub][(PO[sub]4[/sub])[sub]3[/sub] **F** ], which is more resistant to attack by acid and dissolves at pH below about 4.5. This is why fluoride treatments at a dentist’s office involve treating the teeth with fluoride (at a much higher concentration than in tap water) directly, rather than with an ingested dose. (Presumably fluoride in tap water only acts on the teeth when it’s actually in contact with them.) Most of the fluoride in tap water doesn’t end up reacting with calcium hydroxyapatite in the teeth. It is absorbed in the digestive system and excreted in the urine with a half life measured in hours (i.e. not days). A very small amount reacts with bone in a manner similarly to the reaction with teeth. ---
**Author:** ![Bob55](https://avatars.discourse-cdn.com/v4/letter/b/e9c0ed/32.png) [@Bob55](https://boards.straightdope.com/u/Bob55)\ **Post date:** [November 1, 2004, 6:17am UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/16 "2004-11-01T06:17:55Z")
I thought the fluoride was put there to prevent tooth decay by strengthening the enamel’s resistance to streptococcus mutans and their acids, the bacteria responsible for plaques and cavities. ---
**Author:** ![Roches](https://avatars.discourse-cdn.com/v4/letter/r/bc8723/32.png) [@Roches](https://boards.straightdope.com/u/Roches)\ **Post date:** [November 1, 2004, 7:00am UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/17 "2004-11-01T07:00:46Z")
Yes, that’s what it does. The acid secreted by _Streptococcus mutans_ is lactic acid (pK[sub]a[/sub] 3.86); without knowing a typical concentration of lactic acid in a person’s mouth I can’t figure out what the pH would be. I would suspect that the average acidity caused by S. mutans is fairly close to the level needed to damage unprotected enamel but not sufficient to damage enamel protected with fluoride. I don’t think the fluoridation of enamel would do much to protect the teeth from the bacteria themselves (unless they need the hydroxyl groups to adhere to teeth or something); it just makes the enamel less vulnerable to acidity. BTW, the reaction with fluoride is quite permanent, but I would think it only occurs on the surface of the exposed enamel. Regular treatments (and fluoridated tap water) may be necessary only to protect enamel that has been exposed by the wearing-away of fluoridated enamel since the last treatment. ---
**Author:** ![TheLoadedDog](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheLoadedDog](https://boards.straightdope.com/u/TheLoadedDog)\ **Post date:** [November 1, 2004, 7:08am UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/18 "2004-11-01T07:08:21Z")
> [@Bosda Di'Chi of Tricor](#): > > Lethal Atomic Nostril Warts. BWAHA! We don’t do the "band name! thing anymore, do we? ---
**Author:** ![Excalibre](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@Excalibre](https://boards.straightdope.com/u/Excalibre)\ **Post date:** [November 1, 2004, 12:39pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/19 "2004-11-01T12:39:01Z")
> [@LSLGuy](#): > > No, no no, it doesn’t merely contaminate them, it _saps and impurifies_ our precious bodily fluids. > > Fortunately those of us in the know can preserve our bodily fluids by denying women our essense. Drives them nuts, but now we’re OK. Yeah, women are _always_ trying to steal away our _jerungdu_ with the evil power of their menstrual fluids. ---
**Author:** ![moriah](https://avatars.discourse-cdn.com/v4/letter/m/b2d939/32.png) [@moriah](https://boards.straightdope.com/u/moriah)\ **Post date:** [November 1, 2004, 2:06pm UTC](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191/20 "2004-11-01T14:06:53Z")
> [@Roches](#): > > A very small amount [of fluoride] reacts with bone in a manner similarly to the reaction with teeth. Cool! Am I going to have a hardened flouride skeletal structure like Wolverine’s titanium bones? [Next page](https://boards.straightdope.com/t/whats-the-straight-dope-on-fluoride/272191.md?page=2)