That nutjob senator from Oklahoma had it wrong: It's not climate change that's the biggest hoax ever perpetrated on the American People.

It's bottled water. Way back at the Bioneers conference in 2005, when I traded my Nalgene bottle for a stainless steel Klean Kanteen, which I fill with filtered tap water, I had reservations about drinking bottled water that had been transported from Australia/Fiji/England/France/Venus in plastic. I was only concerned about my health back then, not so much the planet.

But after reading about plastic in the oceans, plastic in the landfills, the environmental cost of manufacturing and disposing of plastic bottles and this:

[I]n Fiji, a state-of-the-art factory spins out more than a million bottles a day of the hippest bottled water on the U.S. market today, while more than half the people in Fiji do not have safe, reliable drinking water. Which means it is easier for the typical American in Beverly Hills or Baltimore to get a drink of safe, pure, refreshing Fiji water than it is for most people in Fiji.

(From a fine bottled-water exposé on Fast Company ) I've become a tap-water fascist.

I gently lecture everybody who insists that bottled water is the only healthy way to live. I recite statistics about the relative safety and health of municipal water supplies. I remind them that, as a New York Times editorial pointed out last week, if we don't drink our tap water we won't invest in our clean water infrastructure, and we'll all be like Fiji: The only people with clean water are the ones who can pay for it. "The last thing America needs," said the NYT, "is two water streams - one for the rich and another for the rest of us."

But just as this movement was gaining steam, along comes the Metropolitan Water District, hell bent on going through with its four-year plan to fluoridate Southern California's tap water. As of October 29, the MWD will begin adding 0.8 parts per million fluoride to the water of 18 million customers in Los Angeles, Orange, San Diego, and parts of San Bernardino, Riverside and Ventura counties. Whether you like it or not. (They call it "adjusting" the fluoride levels in water, because Southern California water already has naturally occurring fluoride concentrations of 0.1 to 0.4 parts per million.)

Why? Because the American Dental Association says so. Fluoride kills decay-causing microbes on contact, and the ADA believes fluoride is a public health necessity, especially for children. Does it matter if those children also get little white spots on their enamel, an undisputed side-effect of preventing tooth decay with fluoride called "enamel fluorosis"? Or if several studies have strongly suggested that fluoridated drinking water may disrupt thyroid function, lower IQs and cause an increase in a rare form of bone cancer, osteosarcoma, in children?

The Environmental Working Group has been arguing for months now that several studies have been released in the last four years that cast doubt on the public-health value of fluoridated drinking water. Even the American Dental Association, in its "Interim Guidance on Fluoride Intake for Infants and Young Children," recommends that infant formula should be mixed with non-fluoridated bottled water to avoid exposing babies to dangerously high levels of fluoride.

This is crazy. The more I read about it, the crazier it gets. Even if it's true that the ingestion of fluoride (as opposed to its topical application) prevents tooth decay, why do we have to have industrial-waste silicofluoride chemicals -- chemicals that have never been FDA-approved for human ingestion -- forced on us in our drinking water? Why can't we choose it in our toothpaste, for example (I, personally, don't)?

Simply because a certain percentage of lower-income families may not choose that toothpaste. "[Fluoridation] is a powerful strategy to reduce disparities in tooth decay among different populations and is more cost-effective than other forms of fluoride treatments or applications," says the ADA.

In other words, it saves money. Intriguingly, even though the URL "fluoridealert.org" belongs to the anti-fluoridation Fluoride Action Network, "fluoridealert.com" will redirect you to an ADA-controlled Web site, where you'll learn that "The average cost for a community to fluoridate its water is estimated to range from approximately $0.50 a year per person in large communities to approximately $3 a year per person in small communities. For most cities, every $1 invested in water fluoridation saves $38 in dental treatment costs."

Given that 108 million Americans have no dental insurance, that dentists often have to fill cavities below cost in rural and low-income urban communities, this represents a cost-savings bonanza for the dental profession. Better that adults should come in to have their teeth capped, bonded and whitened due to enamel fluorosis than that a dentist should have to fill another child's cavity on an Indian reservation in Alaska.

I don't buy the conspiracy theory that municipal water fluoridation is just a cheap way for industry to dump its fluoride. But I do believe the ADA, which has been known to suppress the opinions of dentists opposed to fluoridation, has something at stake in the fluoride issue. And it isn't an altrustic concern for public health.