Hillsboro residents opposed adding fluoride to the water supply in a non-binding vote Tuesday.

As of 12 a.m. Wednesday, partial returns showed 42% supporting the measure and 58% against, with 54% turnout thus far.

Though the vote on Measure 34-338 is advisory only, the Hillsboro Water Department committed beforehand to following voters’ recommendation, unless the regulations on fluoride or the costs of adding the mineral change dramatically.

Throughout much of the U.S., fluoride is put in public drinking water at a concentration of 0.7 milligrams per liter to strengthen tooth enamel. Portland is the largest city in the country not to do so.

“I think the results say that the people of Hillsboro do prefer having choice on whether they ingest fluoride or not,” Matthew Sztelle, director of anti-fluoridation political action committee Clean Water Hillsboro, said Tuesday night.

Healthy Teeth Hillsboro, which supported the measure, expressed disappointment and said the group would continue advocating for community health in a social media post.

In Hillsboro, implementing fluoridation would have taken at least four to five years, Hillsboro Water Department Director Niki Iverson told The Oregonian/OregonLive in September. The project would cost about $4 million, but spreading it out and delaying other, non-urgent projects would have allowed the department to avoid raising water rates, Iverson said.

The Hillsboro Water Department currently supplies fluoride-free water to Gaston, Cornelius and the parts of Hillsboro that are west of Cornelius Pass Road and south of U.S. 26. The Tualatin Valley Water District, which already puts fluoride in the water, supplies about 15,000 Hillsboro residents.

Within Washington County, Beaverton and Forest Grove also fluoridate the water.

Supporters of Measure 34-338 pointed to the mineral’s dental benefits as the key reason to add it to Hillsboro’s water supply. The Centers for Disease Control and Prevention hails water fluoridation as one of the greatest public health achievements of the 20th century, and the American Dental Association “unreservedly endorses” the practice.

But opponents pointed to a growing body of research that fluoride can hurt children’s neurological development.

A report from the federal National Toxicology Program found an association between fluoride at concentrations of at least 1.5 milligrams per liter and lower IQ — though the scientists didn’t draw conclusions about the impact of fluoride at lower concentrations. In September, a federal judge in San Francisco ruled that the Environmental Protection Agency must increase its regulation of fluoride out of concerns for the impact on the development of children’s brains.

Experts also dispute the efficacy of putting fluoride in the water. Ashley Malin, who studies the effect of fluoride exposure on neurodevelopmental outcomes at the University of Florida, said in September that fluoride works best when applied topically, as via a mouthwash or toothpaste.

However, the American Dental Association supports both topically applied and ingested fluoride. Some research, including a 2018 federal government-funded study, has found fluoridated water to be associated with lower cavity rates.

In the Portland area, this issue is particularly controversial. Hillsboro hadn’t voted on fluoridation in about 70 years, when it approved adding fluoride before rejecting it in a second vote a year later. In 2013, meanwhile, Portland debated a measure similar to Hillsboro’s that voters ultimately rejected 61% to 39%.

Healthy Teeth Hillsboro had raised about $35,000 to support the measure, campaign finance records showed Tuesday. Clean Water Hillsboro raised $20,000.

Original article online at: https://www.oregonlive.com/politics/2024/11/hillsboro-voters-appear-to-oppose-adding-fluoride-to-water.html