The people in charge have long said that fluoridating drinking water, which the CDC called “one of the top health achievements of the past century,” is safe and effective. They also say this is true even though high levels of exposure have been linked to a number of bad health effects in humans, such as osteoporosis, endocrine dysfunction, calcification of tendons, and bone deformities.
People who tried to say that the government’s plan to stop tooth decay could lead to problems like mental retardation were often called names. It looks like the people who were thought to be crazy or conspiracy theorists were right again.
A study released Wednesday by the National Toxicology Program, part of the U.S. Dept. of Health and Human Services, says that kids whose water is treated may have lower IQs.
The Office of Dietary Supplements at the National Institutes of Health said that about 60% of fluoride intake in the U.S. comes from fluoridated public drinking water, and that by 2020, 62.9% of the population would have access to a fluoridated water system.
The NTP report said that children with lower IQs are more likely to be exposed to higher levels of fluoride. For example, drinking water fluoride levels that are higher than 1.5 mg/L of fluoride are an example of this.
The NTP uses four levels of trust to look at the scientific evidence that links a certain health result to an exposure: high, moderate, very low, and very low.
In Canada, China, India, and Mexico, there was proof that some pregnant females, babies, and kids were taking water with more fluoride than 1.5 milligrams per liter. The NTP “came to the conclusion that there is moderate confidence in the data that showed a link between children having higher amounts of fluoride and lower IQs.”
The researchers were interested in a lot of studies, but it looks like they mostly looked at 19 high-quality studies with low risks of bias. In 18 of these studies that looked at kids’ IQ, there was “consistent evidence of a negative relationship between predicted fluoride exposure and IQ results.”
There are different safety limits for fluoride according to different groups. The World Health Organization says 1.5 mg/L is safe, but the HHS says 0.7 mg/L is safe because “this is the amount that prevents tooth decay and supports good oral health.” But different cities and towns in the United States may have a little more or a little less water in their sources.
For example, NY City adds a fluoride substance that gives the water supply a concentration of about 0.8 mg/L.
