Few issues at Portland City Hall have been as polarizing as a pending decision to add fluoride to the local water supply.

On one side, there’s a well-organized campaign in support that features dentists, health care providers and a host of community organizations. On the other is a group of volunteers launching an initiative to hold a public vote on fluoride in 2014, in hopes of banning it.

Both sides claim science and common sense are on their side.

Portland is the largest city in the country that hasn’t taken steps to add fluoride to its drinking water, which serves about 900,000 people in Portland, Gresham, Tigard, Tualatin and beyond.

The Portland City Council will hold a public hearing on the issue Sept. 6 before voting Sept. 12. The outcome has been established: Three of the five City Council members — Mayor Sam Adams and Commissioners Randy Leonard and Nick Fish — support fluoride.

Here’s a review of some of the arguments on both sides:

IN SUPPORT:

Fluoride helps prevent tooth decay. The national average for untreated decay among third-graders was 29 percent in 2007, according to a state study. In Oregon, the rate was 35 percent, fifth-worst in the nation. The rate in the Portland area was 21 percent, but the rate outside the metro area was 44 percent. The state’s newest report, issued every five years, won’t be available until February.

Fluoridation is widely accepted in the United States. Nearly 277 million people receive water from community water systems and, of those, 74 percent — or more than 204 million — drink fluoridated water. Among all Americans, 66 percent drink fluoridated water.

Reputable organizations say fluoridation is safe. The Centers for Disease Control and Prevention named “fluoridation of drinking water” one of the “10 great public health achievements” of the 20th century. The American Dental Association reports that studies throughout the past 60 years show that fluoridation is “safe and effective” in preventing dental decay in kids and adults.

Water fluoridation helps level the playing field between the privileged and the poor. Low-income Oregon children have tooth decay rates twice as high as those with high incomes, according to Oregon’s 2007 study. The report found that 42 percent of low-income students had untreated tooth decay compared with 20 percent for high-income students. The study did not track specific incomes but instead used free or reduced lunch programs at participating schools as a gauge.

Fluoridation saves money. Based on the estimates from the Portland Water Bureau, a fluoridation facility would cost $5 million, with maintenance and operations of $575,000 per year. But proponents point to a study that found investing $1 in fluoride saves $38 in annual dental costs. Asked for a rough estimate, Water Bureau officials said the average customer would probably pay about $1 more a year for the fluoride facility and a yet-to-be-determined amount for annual expenses. As for return on investment, a 2001 study cited by the CDC estimated that, on average, communities larger than 20,000 could spend 50 cents on fluoride per person and receive an estimated net savings of $18.62 on community dental expenses.

IN OPPOSITION:

There are other options for fighting tooth decay. Opponents call for better education on diet and dental hygiene and greater access to dental care instead of forcing everyone to live with fluoridated drinking water.

In high concentrations, fluoride can damage teeth. The federal government in 2011 lowered the recommended dosage to 0.7 milligrams of fluoride per liter, down from a range of 0.7 to 1.2 milligrams. After reviewing studies, officials with the U.S. Department of Health & Human Services concluded that the percentage of children with dental fluorosis — spotting, staining or pitting of teeth — increased when exposed to higher fluoride concentration in water.

Some fear that fluoride lowers IQ. A National Institute of Environmental Health Sciences study that included a research scientist from Harvard found that “children who lived in areas with high fluoride exposure had lower IQ scores than those who lived in low exposure or control areas.” The report reviewed 27 studies on fluoride in China and Iran, finding that children had access to water with fluoride levels up to 11.5 milligrams per liter. In the U.S., the Environmental Protection Agency sets maximum levels at 4 milligrams per liter.

Fluoridation carries too many unknown risks, critics say. For one thing, fluorosilicic acid is a “co-product” of phosphorite associated with the fertilizer industry. Adding an industrial “co-product” to drinking water makes some people nervous. A liquid, it is preferred over dry fluoride options and is used by most fluoride programs in the United States, according to the CDC.

Portlanders aren’t getting a say on this latest plan. The City Council is set to pass a plan, despite three public votes over the years against fluoridation. The political climate has something to do with that: Only one of the five council members faces voters in November: Commissioner Amanda Fritz, who has expressed support for a citywide vote.

Print PDF