When fictional General Jack D. Ripper locks himself and RAF Group Captain Lionel Mandrake in Ripper’s office in Dr. Strangelove, Ripper is well on his way to launching an unofficial nuclear attack on the Soviet Union. In the course of explaining his actions to Mandrake, General Ripper says he has uncovered a communist plot to pollute the “precious bodily fluids” of American citizens by adding fluoride to the water supply.

That conspiracy theory in the 1964 film lights up the suspicion many Americans have held in the debate over the efficacy of fluoridation. People more rational than General Ripper may not charge a communist plot, but they remain skeptical that adding fluoride to public drinking supplies is providing the health benefit that government officials, as well as mainstream health experts, attest.

The conspiracy about conspiracy theories even has seeped into criticism of the John Birch Society, the ultra-right-wing organization that wielded its greatest influence during the “commie scare” days after World War II. It’s virtually axiomatic that the John Birch Society sided with General Ripper in believing that fluoridation was a communist plot.

Most John Birch followers actually never claimed a communist conspiracy, but they did have a conspiracy theory of their own, one they felt was just as pernicious as the one General Ripper thought he detected.

Although some of its more off-the-wall members may have believed fluoridation was a Communist plot to throw a mind-control blanket over Americans (paranoia ran rampant in the days of the “Pinko” scare), the official position of the John Birch objection to fluoridation rested on the organization’s belief that it was forced medicine, a violation of citizens’ individual right to choose what medications they use. According to a current John Birch website, “If citizens want to add fluoride to their diet or daily routine, there are plentiful opportunities for them to do so. It’s a choice they should make, not their local government.”

The fluoridation debate has travelled a far distance from the satiric conspiracy Stanley Kubrick hung on “Dr. Strangelove” and the equally satiric days of the Pinko scare and the House Un-American Activities Committee. The debate has moved from an irrational paranoia of Communism to a rational inquiry about the science behind fluoridation and whether it’s helpful or harmful to human health.

As with virtually all scientific debates, studies exist on both sides of the fence. A group of Marin residents who oppose fluoridation want the county to follow most European countries that don’t add fluoride to their water supply. The group is circulating a petition calling for the Marin Municipal Water District (MMWD) to stop fluoridating the water it supplies to about 190,000 people from Sausalito to San Rafael. (The North Marin Water District, which serves Novato and parts of West Marin, doesn’t fluoridate its supply.)

Jacob Barnett, who is circulating the petition, says it has 1,940 names attached to it at last count. He dismisses the thought that fluoridation added to MMWD water is a Communist plot, but he doesn’t dismiss the possibility that pharma may be playing a hand in flaking chemicals to water districts in general. He says he has no knowledge of that taking place in Marin, but he says he has questions about why so many people are “vehemently into” promoting fluoridation.

Barnett and other anti-fluoridationists say the science foundation that fluoridation reduces cavities among children is built on intellectual rubble. The facts don’t hold the theory, according to those opposed to fluoridating public water supplies. They also say dosages of fluoride cannot be adequately controlled when added to drinking water. Spending a day in the summer sun means more intake of water, which contains fluoride.

“I believe everyone should have a choice about the chemical substances in the water they drink,” says Barnett. “Hydrofluorosilicic acid has never been approved by the FDA [federal Food and Drug Administration] for human consumption.” Fluoridation critics often say that the substances used to fluoridate water supplies are medical chemicals and should be treated as such, which is what Barnett believes.

But the FDA isn’t the government agency that oversees the efficacy and safety of fluoride chemicals used at MMWD. The NSF International/American National Standards Institute does that job. “The California Department of Public Health says that you must use a chemical approved by the NSF,” says Paul Sellier, water quality engineer at MMWD. The NSF puts its approval stamp on three chemicals: sodium fluoride, sodium fluorosilicate and hydrofluorosilicic acid.

MMWD didn’t initiate the program to fluoridate water. The district began fluoridating in December 1973, after a voter-initiated ballot measure passed with a 56.8-percent margin in November 1972. The move didn’t go over without some rustling among district residents who raised objections. But a 1978 ballot measure that passed with a 52.6 margin reaffirmed the approbation among the majority of district residents. That belies the charge that district residents have no say in whether they receive fluoridated water.

Nevertheless, almost 2,000 signatures on a petition indicate at least some residual discomfort with the policy. What a petition can accomplish, however, remains an open question. According to the district, to overturn a ballot measure like the ones that approved fluoridation, a similar ballot measure would have to go to the ballot for a vote of district residents.

To complicate matters, at least for anti-fluoridationists, legislation passed in 1995 mandates that water districts like MMWD must fluoridate their water supplies. AB 733 “Directs the [state] Department of Health Services to adopt regulations that require the fluoridation of all public water systems that have at least 10,000 service connections.” The bill stipulates that water districts cannot use ratepayer money to pay for fluoridation. The MMWD program costs about $140,000. According to a staff report, the district “receives about one million dollars in rental income from its antenna site and property leases.” It uses part of the money to cover the $140,000 annual fluoridation cost.

The district maintains that AB 733 requires it to fluoridate district water. And it does. The language is explicit. But opponents of fluoridation say 21 communities have given the boot to fluoridation programs without any consequences. One of the latest is Crescent City. In November 2012, residents voted to end a fluoridation program. But other districts are joining the fluoridation movement, even with the controversy that continues to surround the programs. The Santa Clara Valley Water District currently is moving toward fluoridation. And because it is a water wholesaler and not a community water district, it doesn’t have to abide by AB 733. Officials there obviously believe the science that says adding fluoride to water supplies is beneficial.

The question of whether fluoride compounds are beneficial or harmful has swirled since the 1940s, when fluoridation programs first began in this country. The story goes back to the turn of the 20th century, when in 1901, a dental school graduate opened a practice in Colorado Springs. He noticed that people there had remarkable brown stains on their teeth–but they also had fewer cavities than people elsewhere in the country.

That connection between fluoride and fewer cavities is being challenged now, but dental societies and other health professionals are mostly in favor of continued fluoride treatment. The problem, say opponents of adding fluoride to water supplies, is that the most effective delivery system is topical rather than one that’s ingested. Adding fluoride to toothpaste, for instance, makes more sense than adding it to water. That’s the debate point. It’s one that echoes the John Birch Society argument about individual responsibility versus collective action.

John Purdue’s biggest beef is the “forced medication” aspect of a water-based fluoride program. Purdue, a resident in the MMWD district, says he also objects to the chemical compound that MMWD uses. He and other anti-fluoridationists point out that the chemical compound MMWD and other districts use is essentially a waste byproduct of the fertilizer industry and is inherently unsafe. Some opponents of water-based fluoridation say that at the least water districts should use a fluoride compound that’s more closely related to a pharmaceutical product.

But MMWD maintains that the chemical it uses is safe and falls under state regulation. That contretemps gets played out over and over again whenever the science of fluoridation is on the table. Opponents, for instance, say definitive study proves that fluoride decreases the IQ of children. Proponents of fluoridation say the studies are inexact and the amount of IQ reduction essentially falls within a margin of error, proving nothing. The list of organizations that endorse fluoridating water includes the American Medical Association and the National Institutes of Health. In opposition are critics such as a scientist from the National Academy of Sciences Fluoride Committee and Ralph Nader.

Mary Larkin, an opponent of fluoridating MMWD water, says the Centers for Disease Control and Prevention (CDC) in 2010 said fluoride is causing dental fluorosis in children. The condition is marked by streaks or spots on the teeth caused by fluoride. But whether that condition is cosmetic or medical is a contested debate point. The CDC found that two of five adolescents have fluorosis. The finding led the U.S. Department of Health and Human Services to join the Environmental Protection Agency (EPA) in proposing to drop the recommended level of fluoride in drinking water.

According to an MMWD staff report, the EPA threshold for fluoride is 5 milligrams per liter of water. The California threshold is 2 milligrams per liter. Sellier, the MMWD water quality engineer, says the district adds fluoride that would amount to about one drop per 13 gallons of water.

That doesn’t comfort Larkin. “We know the benefit from fluoride is not from ingestion. We know this. Water fluoridation is outdated and ineffective.” She goes further: “It’s unethical. Once you put a drug into the water, you can no longer control the dosage. It makes no scientific sense.”

But a statement from the CDC sees much sense in fluoride. The agency states that it “recommends community water fluoridation as a safe, effective and inexpensive way to prevent tooth decay among populations living in areas with adequate community water supply systems. Similar to many vitamins and minerals we consume for our health, fluoride should be taken in the proper amount. Past comprehensive reviews of the safety and effectiveness of fluoride in water have concluded that water fluoridation is safe and effective.”

Even some previous supporters of adding fluoride to the water are expressing at least a modicum of uncertainty now. Diet Stroeh, who left his tenure with MMWD in 1980 as general manager, was an MMWD engineer in the 1970s. There was support for fluoride then, he says, although “at the time we didn’t know much about fluoridation.” The support that district residents displayed led MMWD officials to think “it must be good.”

But continued scientific inquiry into fluoridating water supplies has raised doubts that have persisted ever since the district responded to the voter-approval ballot measure, which Stroeh says the local dental association supported.

He disagrees with Larkin on at least one point: Stroeh says fluoride isn’t a drug; it isn’t a medicine. If it were, it would be better, he adds because the FDA would get involved in regulating it. “Now we don’t have that level of control.”

Stroeh says the water district should “take another hard look at the stuff” because there is more (although conflicting) scientific investigation today about fluoride and water supplies and cavities in children. He goes a step further in suggesting that MMWD might be wise in putting the fluoride issue to another vote.

The CDC reiterated its approval in a statement regarding its review of a National Research Council report. “Water fluoridation should be continued in communities currently fluoridating and extended to those without fluoridation.”

About 2,000 MMWD district residents (so far) would beg to differ.