Summaries of Expert Opinions on the Neurotoxicity of Fluoride Presented as Evidence to the US District Court for the Northern District of California at San Francisco in May 2020.
(FOOD AND WATER WATCH, et al. v. U.S. EPA)
What was being assessed is the potential neurotoxic risk of fluoridated water on the basis of a scientific approach which identifies and characterizes the best available science from the most up-to-date scientific databases that have examined neurotoxicity as an effect of fluoride exposure.
The four key experts who declared before the court were:
A.
Professor Philippe Grandjean, MD, DMSc who is a Danish scientist working in environmental medicine. He is the head of the Environmental Medicine Research Unit at the University of Southern Denmark and adjunct professor of environmental health at the Harvard School of Public Health. He is known for his research into the developmental toxicity and adverse effects of certain environmental chemicals to which children are commonly exposed. Grandjean’s study on the neurodevelopmental effects of prenatal mercury exposure in a birth cohort
from Faroe Islands was relied upon by the EPA as the critical study for the Agency’s derivation of a Reference Dose for methylmercury.
A summary of his declared opinions on fluoride reads:
“The weight of epidemiological evidence leaves no reasonable doubt that developmental neurotoxicity is a serious human health risk associated with elevated fluoride exposure, including those occurring at the levels added to drinking water in fluoridated areas.
The IQ losses associated with community water fluoridation are substantial and of significant public health concern.
Application of the Benchmark Dose (BMD) methodology to the recent prospective birth cohort data shows that the level of fluoride added to water in fluoridation programs greatly exceeds the science-based limit needed to protect against developmental neurotoxicity.”
See full Expert Declaration.
B.
A summary of his declared opinions on fluoride reads:
“The ELEMENT prospective cohort studies of fluoride‘s neurodevelopmental effects are methodologically rigorous studies that provide scientifically reliable and robust results.
The results of the ELEMENT prospective cohort studies are consistent with and support the conclusion that fluoride is a developmental neurotoxicant at levels of exposure seen in the general population in water-fluoridated communities.”
C.
Professor Bruce Lanphear, MD, MPH who is a clinical investigator at the British Columbia Children’s Hospital Research Institute and professor in the faculty of health sciences at Simon Fraser University in Vancouver. He is also the co-principal investigator of an ongoing study to examine the impact of early-life fluoride exposures on intellectual abilities in a cohort of mothers and offspring from Canada known as the MIREC Study. Early childhood health, environmental neurotoxins, lead poisoning and the epidemiology of asthma are other key research interests. Lanphear’s research has been extensively relied upon by environmental and public health agencies, including the EPA. His pooled analysis of blood lead and IQ (Lanphear 2005) was cited by the EPA as the critical study upon which the Agency based the current national air standard for lead.
A summary of his declared opinions on fluoride reads:
“Our study of prenatal fluoride and IQ in the MIREC cohort (Green 2019) further enhances the quality of data related to the neurotoxicity of fluoride. As with the ELEMENT cohort, we employed a prospective cohort design, had extensive control for potential confounders, and had multiple measures of fluoride exposure during pregnancy, including three types of urinary fluoride measurements for each trimester of pregnancy.
The maternal urinary fluoride levels in the MIREC cohort were significantly associated with lower intellectual abilities in 3-4-year-old children. These associations remain large and significant when controlling for relevant covariates.
Converging results from the MIREC and ELEMENT cohorts indicate that exposure to “optimal” levels of fluoride during fetal development is associated with diminished intelligence in childhood.
In the MIREC cohort, exposure to fluoridated water in infancy, particularly among formula-fed infants, was also associated with diminished intelligence (Till 2020). This association remains significant after controlling for fetal fluoride exposure and other relevant covariates, suggesting that susceptibility to fluoride’s adverse neurological effects may extend into infancy.”
D.
Kathleen M. Thiessen, Ph.D who is a risk assessment scientist at Oak Ridge Center for Risk Analysis in Oak Ridge, Tennessee. For more than 30 years, she been involved in the evaluation of exposures, doses, and risks to human health from trace levels of contaminants in the environment, including fluoride, and in the use of uncertainty analysis for environmental and health risk assessment. She was asked to apply risk assessment frameworks used by the Environmental Protection Agency (EPA) to the current scientific literature on fluoride neurotoxicity to determine whether neurotoxicity is a hazard of fluoride exposure, and whether this hazard is a risk at the levels of fluoride added to drinking water for fluoridation (0.7 mg/L).
A summary of his declared opinions on fluoride reads:
“Under EPA’s Guidelines for Neurotoxicity Risk Assessment, there is sufficient evidence to conclude that neurotoxicity is a hazard of fluoride exposure.
The animal data on fluoride neurotoxicity are consistent with the epidemiological data in showing a risk of cognitive deficits at doses of fluoride ingested from fluoridated water.
Fluoridation chemicals present an “unreasonable risk” of neurotoxic effects, including IQ loss, if assessed under the same risk characterization and risk determination framework that EPA uses in its evaluations of other chemicals under TSCA.”