#1 – New study on fluoride and IQ just published in an NIH-funded scientific journal.
The study examined a cohort of mothers and children living in Bangladesh who were exposed to fluoride levels similar to people living in fluoridated areas of the U.S. This is the 8th high-quality study finding lowered IQ at exposures below 1.5 mg/L, contradicting fluoridation defenders’ claims there are no such studies.
The study used a prospective cohort study design to assess the impact of prenatal fluoride exposure and controlled for many factors that can influence IQ besides fluoride.
The results? Fluoride exposure during pregnancy was associated with a significant reduction in the IQ of children. The drop in IQ was observed in children at both 5 and 10 years of age. The median urine fluoride concentration in the mothers was 0.63 mg/L while the median water fluoride concentration was just 0.20 mg/L and the maximum was 0.74 mg/L.
“Our results support the hypothesis that even relatively low fluoride concentrations can impact children’s early development.” – Maria Kippler, associate professor at the Institute of Environmental Medicine, Karolinska Institutet.
This study is the latest in a long series of studies finding neurological harm from fluoride exposures at the same doses as people get from water fluoridated to 0.7 mg/L. It reinforces the recent federal court decision that concluded fluoridation has no safety margin whatsoever. Claims by fluoridation defenders that there are no studies finding IQ loss at exposure levels of people living in places with artificial fluoridation are simply false. Equally false is the claim that only low-quality studies have found IQ loss.
This latest study meets highest-quality standards with its prospective cohort design, large sample size, individualized measurement of exposure, and control for many potential confounders. Its senior author, Maria Kippler, of Sweden’s Karolinska Institute, has published over 90 studies of the effects of toxic chemicals like lead, cadmium, mercury, and arsenic. Some of the other high-quality studies linking fluoride to IQ loss come from Canada where fluoridated water averages 0.6 mg/L and from Mexico where fluoridated salt gives the same doses as water fluoridation.
Fluoridation defenders are wrong when they say there are no high-quality studies at exposure levels commonly found in fluoridated areas. They are wrong when they claim there is a safe threshold at 1.5 mg/L. They are wrong when they claim studies finding harm at 1.5 mg/L and above are so high that they are irrelevant to exposures from fluoridated water at 0.7 mg/L. About 10% of people drink twice as much water as average, so they will get the same dose from 0.7 mg/L water as an average water consumer from 1.5 mg/L water. But even more importantly, humans vary widely in their sensitivity to any toxic chemical with the most susceptible few percent typically being 10x more sensitive than average persons. These most sensitive individuals will likely experience IQ loss at fluoride levels ten times lower than the average.
#2 – Another just-published study confirms pregnant women in the US have equal or greater fluoride levels as in eight studies finding IQ loss.
Another study published in the same journal found urine fluoride levels in pregnant women living in fluoridated areas of the United States were the same or greater than in the eight high-quality studies finding IQ loss. The study found women in fluoridated areas had an average urine fluoride of 1.0 mg/L. The authors noted that the majority (over 75%) of women exceeded a benchmark urine fluoride concentration associated with child IQ loss in Grandjean et al. (2024), and stated “[Maternal urine fluoride] in this population of midwestern US women exceeds the safety benchmark for pregnancy.”