New studies show high fluoride levels can lead to behavioral issues and lower IQ’s in children.
SAN DIEGO — The federal government is scaling back its dependence on fluoride in drinking water after new studies found a link between high fluoride exposure to behavioral issues and lower intelligence in children.
Despite this, data obtained by CBS 8 shows that over the past five years, San Diego residents have seen higher levels of fluoride than before and fluctuating levels from one testing station to the next.
According to the data obtained through a public records request, the highest fluoride reading in more than five years was taken in San Carlos in August 2024. The reading registered 1.1 milligrams of fluoride per liter, just .01 milligrams less than the state threshold allows. Meanwhile, the lowest reading also occurred in 2024 but less than 10 miles away in Kensington, where in April 2024, city water testers found just .22 milligrams of fluoride per liter.
Despite the U.S. Health Department’s recommendation to lower fluoride levels to a uniform .7 milligrams per liter, California has stuck with the acceptable range of .7 to 1.2 milligrams per liter.
When looking strictly at drinking water in San Diego, the city has barely managed to stay within that range. In fact, the data shows that fluoride levels have increased on average since 2019.
Rethinking fluoride
In 1945, federal health professionals in Grand Rapids, Michigan, began adding fluoride to drinking water and launched a pilot program to address tooth decay and the many health problems associated with poor dental health. During the pilot program, health experts recommended fluoride levels stay at or under 1.0 milligrams per liter.
The pilot program grew; by 2012, approximately 235 million Americans had access to fluoridated water in the U.S.
Yet, as the number of Americans who drank fluoridated water increased, the recommended level of fluoride dropped. By 2011, the Health and Human Services Department lowered the acceptable fluoride range from .7 to -1.2 milligrams per liter to .7 milligrams.
Then, in 2015, the Health and Human Services Department ditched the range and recommended dropping the level to a uniform .7 milligrams per liter.
Since dropping the recommended level, little additional research has been conducted in the U.S., that is, until recently.
This year, federal health researchers found a connection between high fluoride exposure – above 1.5 milligrams per liter – and a lower IQ rate in children.
Young children can also develop dental fluorosis, a condition that can leave a child’s tooth enamel with white flecks, spots or lines. While this impact is typically cosmetic, it can become moderate or severe and cause extensive enamel changes.
Other researchers have found additional negative impacts.
Professor Ashley Malin is a scientist at the University of Florida. Malin, along with researchers at U.C.L.A and USC, found that pregnant mothers with high fluoride levels have a better chance their kids will exhibit neurobehavioral problems by the time they are three years old.
“Of course, three-year-olds can have temper tantrums and experience some anxiety, maybe have somatic complaints like headaches or stomach aches, but in our study, we found them to be over and above what would be considered the realm of normal or typical for these behaviors,” Dr. Malin told CBS 8 in an October 2024 interview.
Malin said the findings are now leading to additional studies about fluoride’s impact, not just in drinking water but in toothpaste and other sources, on a child’s behavior and for pregnant mothers.
“The latest studies and the National Toxicology Program report highlight the importance of both pregnant women and mothers of young children and babies to be cognizant of their fluoride intake, ideally to reduce their fluoride intake and continue to monitor their child’s fluoride intake,” said Malin.
Malin said she and her colleagues are also not ruling out fluoride’s effects on adults and older people.
“Concerning the average person, the issue is that we really don’t know what some of the health effects for adults’ brains might be or for effects on other bodily systems because much of that research at population-relevant levels has not been conducted,” added Malin.
“We don’t know if that is a potential risk factor for Alzheimer’s disease or dementia in the U.S.,” said Malin. “If the general population is concerned about all that we don’t know about the potential health impacts of fluoride exposure, then it makes sense for them to take steps to reduce their fluoride intake.”
Fluoride in the city of San Diego
CBS 8 analyzed city fluoride readings from January 2019 through September 2024 and found the average yearly fluoride reading has increased year over year. In addition, the data shows numerous testing stations reporting just below the 1.2-milligram threshold.
The highest reading over the course of five years occurred in San Carlos, where in September 2024, water crews found the fluoride level to be at 1.11 milligrams per liter.
Numerous other locations throughout the city had read just below that level but not at or exceeding it.
“The fact that it reaches a level of over one milligram per liter is quite concerning, especially for pregnant women or children living in those areas,” said Dr. Malin.
Another issue, said Dr. Malin, is the high fluctuation rate found in San Diego’s drinking water.
The data shows that many stations have seen large spikes over the course of a few months.
Search the table below to see the fluoride levels in your neighborhood for 2024:
For instance, water testers in San Carlos, where the highest reading occurred in the past five years, measured the fluoride level at .42 milligrams in April 2024, just five months before the 1.11 milligram reading was taken.
On Adams and Marlborough in Kensington, water crews reported a .22 reading in April 2024; three months later, in July, the level measured 1.09 milligrams per liter.
City of San Diego Response
CBS 8 contacted the city of San Diego for comment on the high levels seen in neighborhoods throughout the city.
A spokesperson said the city’s fluoride reading complies with state and federal guidelines.
“The State of California has adopted regulations establishing standards for adding fluoride to drinking water. The City’s drinking water meets all state and federal drinking water health standards, which are the primary standards for treating and monitoring water,” wrote the city spokesperson.
The spokesperson added, “The City has a robust water quality monitoring plan, including daily fluoride monitoring to ensure we meet all state and federal drinking water standards. Since fluoridation began in San Diego, the City’s fluoride levels have remained within the control range. The State of California reviews all of the City’s water quality data for compliance.”
Original article online at: https://www.cbs8.com/article/news/investigations/fluoride-in-drinking-water-san-diegos-levels-rise/509-57fa9250-d877-4ee8-a677-6fcf26e2560b