Conspiracy theories have an origin somewhere. Maybe there is a morsel of fact that starts them, or maybe it's just an individual person someplace. How do they take hold? It's safe to suspect that most of them never get any traction and just fade away.
The following dialog is from one of my favorite movies, Dr. Strangelove (directed by Stanley Kubrick in 1964). The troubled General Ripper (played by Sterling Hayden) is talking to Captain Mandrake (Peter Sellers) .
Ripper: Mandrake. Mandrake, have you never wondered why I drink only distilled water, or rain water, and only pure-grain alcohol?
Mandrake: Well, it did occur to me, Jack, yes.
Ripper: Have you ever heard of a thing called fluoridation. Fluoridation of water?
Mandrake: Uh? Yes, I-I have heard of that, Jack, yes. Yes.
Ripper: Well, do you know what it is?
Mandrake: No, no I don’t know what it is, no.
Ripper: Do you realize that fluoridation is the most monstrously conceived and dangerous Communist plot we have ever had to face?
Fluoride does, by the way, prevent cavities. Generally, municipalities aim for a level of fluoride in the drinking water of about 1mg per liter. In some areas, often mountain or volcanic areas (like much of the western U.S.), well water can contain many times this amount, even 50mg/L. (The makers of bottled water are under no obligation to report if the water contains any fluoride or too much.) It's hard to imagine that communists, wherever they may be, are conspiring to bring to some areas of the country what other areas have had naturally for generations.
Fluoride helps to form really tough tooth enamel that is resistant to bacterial attack, resulting in less tooth decay and fewer cavities. It's very effective, and reduces cavities by somewhere between 20% and 60%.
You can get too much, however. If too much is consumed all at once, fluoride can cause nausea, diarrhea, and vomiting. This happened in a village in Alaska in 1993, when water levels were 150mg/L.
In many areas of China, natural fluoridation of the water, from rock in the ground, keeps water levels about what we usually get in our tap water. It's often in coal, and in the city of Sichuan, there's enough coal pollution in the air so that just by breathing, people there get many times our usual daily dose of fluoride.
When children between 1 and 4 have too much fluoride, they can develop teeth with brownish stains. Children over 8 are not at risk for this.
Since we are not meant to swallow toothpaste, it has a fluoride concentration much higher than our drinking water. It's not toxic as long as we don't eat the whole tube.
At some point, a now-wealthy entrepreneur invented delicious, candy-flavored toothpaste for kids. They willingly brushed their teeth. Then, when their parents weren't looking, they snuck into the bathroom and ate the whole tube. So fluoride is no longer in children's toothpaste. But they still want to eat the whole tube. So I think the right idea is for you to dispense the toothpaste for them, and keep the tube with your medications, in a secure place.
Babies, especially as their teeth start coming in, don't need any kind of toothpaste. Clean their teeth with a clean cloth moistened with water.
And every child should go to the dentist. I strongly encourage parents to take them to the dentist when they are well, so the child can see what the place is like and what the exam is about. After that, there's a better chance that if they need dental work, it won't be too scary.
The mineral crystals pictured at top are Calcium Fluorite. The glowing thing on the left, below it, is also Fluorite but viewed under untraviolet light. This is the origin of the word fluorescent.