Fluoride is the ionic form of fluorine, which is one of the most abundant elements on Earth, constituting 0.08 percent of the crust. It exists in rocks, soil, air and water across the globe. Lewiston Public Works Director Chris Davies said the city has had fluoride in the water supply since 1945. Depending on where it’s measured, fluoride is found at 0.64 to 1.12 parts per million in the water, well below the federal limit of 4 ppm.

Davies said, on average, the water supply is at about 0.96 ppm, which equates to something like 0.96 milligrams per liter of water.

Fluoride is naturally occuring in the Lewiston area. Though it could also be discharge from fertilizer.

Much of the research into fluoridation has shown it has limited beneficial effects on bone density, but does not correlate to fewer bone fractures. It mainly has some benefits in preventing dental caries, which is an infectious lesion developed in the tooth enamel causing tooth decay. Fluoride is one piece of overall oral hygiene that helps prevent and regress tooth decay, according to a 2018 National Institutes of Health study.

Fluoride has a very low retention rate. Only about one-quarter to one-third of absorbed fluoride winds up calcified into the bones. It is recommended that infants receive 0.7 milligrams of fluoride daily with 3 mg for adult women and 4 mg for adult men.

But it’s true that the chemical can have adverse effects.

Another NIH study found that fluoride can have health risks, with only modest benefits for preventing tooth decay. The 2014 paper concluded the adverse effects do not justify the limited health benefits.

“Given the questionable evidence of benefit and increasing evidence of harm, the policy of water fluoridation for the prevention of dental caries should be abandoned in favor of more effective interventions,” the study states.

But the Centers for Disease Prevention and Control lauds the introduction of fluoride to drinking water as one of the greatest public health benefits of the century. Still other studies point toward its contributions to bone density and enamel protection in youth. So which studies are to be believed? The NIH conducted an overview of the benefits and hazards of fluoride, publishing several studies. Depending on which research you consider more thorough, you could be swayed either way. What several studies conclude, however, is that fluoride is better applied topically than through a water supply, since amounts can fluctuate in the water as can the amount people drink.

Adverse effects largely stem from unmoderated amounts in drinking water above the recommended dosages. A meta-analysis of 27 studies, largely China-based, found “strong indications” that fluoride may disrupt cognitive development in children. All but one of the studies in the meta-analysis found that cognitive development was adversely affected. The effects, however, were very small, amounting to a negative difference of seven points on Intelligence Quotient scores, or a 0.45 percent reduction.

Water with fluoride in it isn’t making you dumber.

Fluoride’s efficacy in preventing tooth decay hovers around 15 percent in reducing the enamel disease, according to the 2014 study. But the 2018 study that looked at 113 other research papers found its effectiveness was between 40 percent to 50 percent.

The harm caused by ingesting too much fluoride can be minor to crippling in prolonged, excessive dosages. Extended exposure to fluoride can cause skeletal fluorosis, which leads to joint pain, numbing of the extremities and back pain. Fluoride toxicity can cause nausea, vomiting, diarrhea and even death. It is usually found in children younger than 6 and is rare for adults. Toxicity is usually a result of fluoridated water consumption paired with improper use of other heavily fluoride-infused products such as mouthwash and toothpaste.

Another debate that has arisen online regards the ethics of removing the public’s choice by adding fluoride to water systems. The other side of the debate advocates for free preventative care through water consumption to benefit low-income people with inadequate access to dental care.

Both NIH studies suggest fluoride be introduced topically instead of ingested through the water supply. The 2014 study advocates for an ideological reverse from public health organizations that promote the benefits of fluoridation but neglect to highlight the risks.

While going online to find answers about whether fluoride is dangerous can be a dubious task, some research suggests it can be beneficial if appropriately applied.