The fluoridation war is alive in Portland, Ore.

The city is one of the few major American cities that does not fluoridate its water supply. It is now in the middle of a heated battle about whether to change that. While the Portland City Council voted last fall to reverse policy and begin fluoridating the city’s water, it drew the ire of anti-fluoride activists, who gathered the 20,000 signatures required to put the issue on the ballot. The fight has drawn comment from bands including the Dandy Warhols (anti-fluoridation) and the Decemberists (pro-fluoridation.)

In Portland, the fluoride vote will happen Tuesday and the most recent polls have the anti-fluoride camp up 50 percent to 43 percent. If Portland voters reject fluoridated water, it will follow in the path of many cities before it. Forty-four cities around the world – largely in the United States, Australia and Canada – have passed anti-fluoridation policies this year, according to the Fluoride Action Network.

The fluoride battle has a lengthy history. One article, published in 1985, described the fluoridation fight as “America’s Longest War.”fluoride

“A few things remain constant in America – death, taxes, baseball and, since the 1950s, widespread, often successful efforts by a passionate minority to keep fluoride out of drinking water,” Donald R. McNeil wrote in Wilson Quarterly.

McNeil has written one of the more complete histories of the fluoridation wars that I was able to find. It starts on Jan. 26, 1945 when the city of Grand Rapids, Mich. became the first city to fluoridate its water supply. It was meant to be a public health experiment, to test whether fluoridation could protect against tooth decay, especially among younger children.

It would take decades to have any results and, therefore, ”the pioneers of fluoridation were generally a cautious lot,” McNeil writes, noting that they thought “that communities should at first fluoridate only on a test-batch basis.”

Public health officials in nearby Wisconsin had other ideas; they began clamoring for statewide fluoridation as soon as possible. They began spreading the pro-fluoridation gospel–and that’s when the anti-fluoride advocates showed up. Their ranks were diverse including, in one fight over fluoridating Seattle’s water in 1951, “Christian Scientists, a few dentists, health food operators and fervent anti-Communists.” They won the Seattle vote, 84,000 to 44,000.

The medical establishment near universally supports fluoridation. The American Dental Association has endorsed the practice since 1950. The Surgeon General Regina Benjamin supports fluoridation and the Centers for Disease Control, which has described wide-spread water fluoridation as one of the 10 most important public health accomplishments of the 20th century.

Fluoridation opponents, meanwhile, have cited research finding that high levels of fluoride – about 4 milligrams per liter – can cause harmful health effects. The Department of Health and Human Services and the Environmental Protection Agency have recommended, since 2011, that cities maintain 0.7 milligrams per litter of fluoride in the water supply.

In Portland alone, this is now the fifth time the city has voted on the water fluoridation issue, according to the Oregonian newspaper. The last vote, Brad Schmidt reports, was in 1978, when voters overturned the city council’s decision to fluoridate the water.

Except, what we know about the fluoride wars suggests that the fight might actually be waning. Between 1950 and 1967 there were 1,009 fluoridation referendums, according to a Centers for Disease Control report. Forty-one percent of those fluoride proposals were adopted and 59 percent rejected.

Right around the same time, fluoridation became a plot line in the 1964 film Dr. Strangelove, where fluoridation is described as “the most monstrously conceived and dangerous Communist plot we’ve ever had to face,” with the Soviets accused of attempting to poison Americans’ “precious bodily fluids.”

From 1980 to 1988, there were fewer fluoridation votes, 150 in total, with a 36 percent success rate.

The early 90s were a bit of a golden age for fluoride advocates, who won 59 percent of the 32 referendums conducted. In the 2000 election cycle, there were 23 fluoridation ballot initiatives and those were bad news for fluoride advocates, who lost 14 of those fights. They did, however, win “in the largest cities or counties where it appeared on the ballot in San Antonio, Texas and Clark County, Nevada, which includes Las Vegas,” according to the CDC report.

Fluoridation rates, meanwhile, have creeped up in recent years. Americans living in areas with fluoridated water increased from 62 percent in 1992 to 69 percent in 2006, the most recent year for which data is available. fluoride2

The American Dental Association now estimates that 72.5 percent of Americans live in areas with fluoridated drinking water.