Is fluoride in drinking water safe?

Question

"The recommended fluoride concentration in drinking water is 0.7 milligrams of fluoride per liter of water, which is about equal to 3 drops in a 55-gallon barrel, according to the CDC. 

In 2015, officials lowered the recommendation for drinking water fluoride levels to address fluorosis, a condition that can cause discoloration on teeth."

Answer 1

Regarding fluoride's effectiveness at strengthening enamel and preventing tooth decay, the article cites reliable sources like the World Health Organization. The hyperlink it provides redirects to a page that specifically states fluoride's use in tooth disease prevention.

https://www.who.int/news-room/fact-sheets/detail/sugars-and-dental-caries#:~:text=Severe%20dental%20caries%20can%20impair%20quality%20of,chronic%20systemic%20infection%20or%20adverse%20growth%20patterns.&text=Early%20stages%20are%20often%20without%20symptoms%2C%20but,pain%2C%20infections%20and%20abscesses%2C%20or%20even%20sepsis.

The article's mention the concern with fluoride is also correct. The article states that the NIH report states that " 'with moderate confidence' that there is a link between higher levels of fluoride exposure and lower IQ in kids", when it is double the US standard. The NIH report states that "there were insufficient data to determine if the low fluoride level of 0.7 mg/L currently recommended for U.S. community water supplies has a negative effect on children’s IQ", and the "higher levels of fluoride" mentioned in this article is “ higher than 1.5 mg fluoride/L of drinking water”, which is double the US fluoride level. The NIH report's ground for determining higher levels of fluoride is that studies in non-US countires find drinking  higher than 1.5 mg fluoride/L has some effect on IQ.

https://ntp.niehs.nih.gov/whatwestudy/assessments/noncancer/completed/fluoride

Answer 2

Fluoride is a mineral that strengthens teeth and reduces cavities by repairing and preventing damage caused by bacteria that produce acid, which can dissolve tooth minerals and lead to tooth loss, according to the U.S. Centers for Disease Control and Prevention. One of the biggest points of controversy about fluoride arose from a 1990 study by the US National Toxicology Program, which found "equivocal" evidence showing that drinking fluoridated water caused increased incidence of bone cancer in male rats. However, it should be noted that this phenomenon was not observed in female rats or in mice. Research by various other health organizations have also concluded that as long as fluoride levels in drinking water are within optimal range (0.7 milligrams per liter of water), the chemical is not considered a cancer risk. 

Comments

I appreciate this comment in response to the claim, "Is fluoride in drinking water safe?” Helpful because it gave an example of how studies can be blown out of proportion and not apply to other species, via the 1990 study mentioned by American Cancer Society that studied the effects of fluoride on male rats which then led people to apply this specific research with only male mice, a much higher fluoride to body ratio, to humans and fluoride in drinking water. This helped me understand not only the claim but making me keep in mind studies can be taken out of proportion and should be thoroughly evaluated before accepting.

Answer 3

When discussing whether fluoride is safe in drinking water, the most important factor to consider is the concentration. Since 1945, fluoride has been added to drinking water, preventing tooth decay. Now, fluoride is present in at least 75% of drinking water at the current recommended fluoride concentration in drinking water is 0.7 mg per liter of water. However, RFK and others have concerns that fluoride is not safe for the general public.

These concerns are not entirely baseless. The EPA has found that greater than 2.0mg/L may cause dental fluorosis in younger children, and greater than 4.0mg/L in adults and children for a long period of time may cause skeletal fluorosis. With this knowledge, one may conclude that a certain concentration of fluoride may be harmful. However, the standard of 0.7mg/L is under both these guidelines, meaning the fluoride present in drinking water is safe. Even with additional fluoride intake from other sources, such as dental hygiene products, it would be difficult to intake more than 2.0mg/L daily.

https://www.cancer.org/cancer/risk-prevention/chemicals/water-fluoridation-and-cancer-risk.html

Others note concerns about osteosarcoma, a type of bone cancer. These concerns come from a study of lab animals by the NTP in 1990, which found uncertain evidence of fluoride drinking water causing osteosarcoma in male rats. However, this was not found in female rats or male and female mice, and because osteosarcoma is so rare in the general populace, it is difficult to do more research on its association with fluoride intake. Thus, the European Scientific Committee on Health and Environmental Risks concluded in 2010 that the evidence linking fluoride in water to osteosarcoma was not significant enough to classify fluoride as a carcinogen. 

The article also references an NIH study from 2024 which concluded with moderate conference that there is a link between higher levels of fluoride exposure and lower IQ. However, this study was conducted at fluoride levels about twice the recommended limit, meaning it does not deem the level of fluoride in drinking water as harmful.

https://www.cbsnews.com/news/fluoride-in-water-health/

Thus, the industry standard of fluoride concentrations at 0.7mg/L of drinking water is not harmful.