Fluoride exposure may come from various sources including public water fluoridation, fluoridated toothpaste and mouth rinse, untested bottled waters, and certain foods. Vitamins, dietary supplements, and insecticides are also known sources of fluoride exposure. Natural water also appeared to be a common source of excessive fluoride exposure. According to the World Health Organization (WHO), millions of people worldwide are exposed to this neurotoxin through drinking water that is taken from natural geological sources.
WHO data also revealed that high fluoride concentrations occurred in various parts of the world such as southern Asia, the eastern Mediterranean, and Africa. High fluoride concentration is also noted in areas stretching from Turkey to China, encompassing several countries including Iraq, Iran, and Afghanistan as well as India and northern Thailand.
The neurotoxin is known to have several mechanisms of toxicity. According to an article published in Medscape, fluoride poisoning either by ingestion or other forms of exposure primarily affects the gastrointestinal tract. According to the article, ingested fluoride can form hydrofluoric acid in the stomach. This may lead to GI irritation or corrosive effects. Once absorbed in the body, the neurotoxin binds calcium ions and in turn raise the odds of hypocalcemia. The toxic chemical is also found to spur direct cytotoxic effects and inhibit oxidative phosphorylation, glycolysis, coagulation, and neurotransmission. The article also noted that severe fluoride toxicity may lead to multi-organ failure, central vasomotor, and even death.
Symptoms of excessive fluoride exposure include the following:
Some people may exhibit more alarming symptoms that may include:
In 2016, The Lancet classified fluoride as a neurotoxin. According to the research team, neurotoxins such as fluoride raise the odds of neurodevelopmental disabilities including attention-deficit hyperactivity disorder (ADHD), dyslexia, and other cognitive impairments. These conditions have now greatly affected hundreds of thousands of children worldwide.
In line with this, the research team proposed a global prevention initiative, writing that "untested chemicals should not be presumed to be safe to brain development, and chemicals in existing use and all new chemicals must therefore be tested for developmental neurotoxicity. To coordinate these efforts and to accelerate translation of science into prevention, we propose the urgent formation of a new international clearinghouse."
A 2014 study conducted by the Harvard School of Public Health (HSPH) and Icahn School of Medicine at Mount Sinai also demonstrated that exposure to neurotoxins such as fluoride may lead to the onset of neurodevelopmental conditions in children such as autism, ADHD, and dyslexia.
"The greatest concern is the large numbers of children who are affected by toxic damage to brain development in the absence of a formal diagnosis. They suffer reduced attention span, delayed development, and poor school performance. Industrial chemicals are now emerging as likely causes...The problem is international in scope, and the solution must therefore also be international. We have the methods in place to test industrial chemicals for harmful effects on children’s brain development — now is the time to make that testing mandatory," said Philippe Grandjean, adjunct professor of environmental health at HSPH.