2023 study on fluoride & IQ contradicts so-called 'safe' levels in drinking water.

Professor Philippe Grandjean is a professor of environmental medicine at the University of Southern Denmark and a research professor at the University of Rhode Island.

‘We have to do everything we can to remove toxic exposures to support brain development.’

This study lead by Grandjean brought together 3 cohort studies, from Mexico (ELEMENT study), Canada (MIREC) and Denmark (OCC) of mothers and infants. With over 1500 mother child pairs participating, this study was highly powered. The dose levels overlapped.

REFERENCE LIST: https://psgr.org.nz/component/jdownloads/send/1-root/111-23-pg

• Maternal urine-fluoride concentrations were measured, and child IQ was determined at age 7 years

• Higher-level fluoride exposures in North America and lower-level exposures in Denmark gave the researchers a broad basis to arrive at a joint benchmark dose level, where at that level one IQ point would be lost. This was 0.45 mg/l fluoride in urine.

• Regulators need to know the lowest level at which harm (a lowered IQ as a result of exposure) might commence, the approximate threshold for fluoride neurotoxicity, benchmark dose confidence level. In this study it was found to be at 0.33 mg/l fluoride in urine.

• The WHO's guideline value in drinking water is 1.5 mg/l (1500 µg/l). This was set in 1984.

• Background levels are found low level in nature. Fluoride is not a nutrient, rather it is a toxicant. Humans might have evolved a degree of tolerance at lower levels.

• This study contributes to 20 years of research into developmental neurotoxicity and fluoride.

• Developmental exposures which alter intelligence impact the capacity of that child to progress in life.

• The 'optimal level' for addition to drinking water has been in place since the 1950's 'In areas with a hot climate, the "optimal" fluoride concentration is below 1 mg/litre while in cold climates it may be up to 1.2 mg/litre (Galagan & Vermillion, 1957). See 1984 WHO EHC 36: https://iris.who.int/bitstream/handle/10665/37288/9241540966-eng.pdf?sequence=1

• Philippe Grandjean and Jodie Bruning discussed a 40-year history of stacking scientific committees considering fluoride and health, with oral and dental experts. Oral and dental experts may be more likely to support fluoridation of water, and thus have a bias, or weight their decision-making to support fluoridation.

FOR MORE INFORMATION:
Grandjean P, Meddis A, Nielsen F, Beck IH, Bilenberg N, Goodman CV, Hu H, Till C, Budtz-Jørgensen E. (2023) Dose dependence of prenatal
fluoride exposure associations with cognitive performance at school age in three prospective studies. Eur J Public Health. 2023 Oct
5:ckad170. doi: 10.1093/eurpub/ckad170. Epub ahead of print. PMID: 37798092

University of Southern Denmark press release: https://www.sdu.dk/en/om_sdu/fakulteterne/sundhedsvidenskab/nyheder/fluor-paavirker-intelligensen (in English)

PSGR.org.nz for a PDF copy of the references cited at the end of the interview.