Dose dependence of prenatal fluoride exposure associations with cognitive performance at school age in three prospective studies

Philippe Grandjean, Alessandra Meddis, Flemming Nielsen, Iben H Beck, Niels Bilenberg, Carly V Goodman, Howard Hu, Christine Till, Esben Budtz-Jørgensen

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

11 Citationer (Scopus)

Abstract

Background
Fluoride may be a developmental neurotoxicant at elevated exposures. We merged new data from a prospective Odense Child Cohort (OCC) with results from two previous birth cohort studies from Mexico and Canada to characterize the dose–effect relationship in greater detail.

Methods
The OCC contributed 837 mother–child pairs to the total of >1500. We measured creatinine-adjusted urine-fluoride concentrations in maternal urine samples obtained during late pregnancy. Child IQ was determined at age 7 years using an abbreviated version of the Wechsler Intelligence Scales for Children. Findings from the three cohorts were used to calculate the joint benchmark concentration (BMC) and the lower confidence limit (BMCL) after adjustment for covariables.

Results
In the OCC, urine-fluoride concentrations varied between 0.08 and 3.04 mg/l (median 0.52 mg/l) but were not significantly associated with full-scale IQ at age 7 years (β = 0.08; 95% confidence interval −1.14 to 1.30 for a doubling in exposure). No difference was apparent between boys and girls. In the OCC, the BMC was 0.92 mg/l, with a BMCL of 0.30 mg/l. The joint analysis of all three cohorts showed a statistically significant association between urine-fluoride and IQ, with a BMC of 0.45 mg/l (BMCL, 0.28 mg/l), slightly higher than the BMC previously reported for the two North American cohorts alone.

Conclusions
As the BMCL reflects an approximate threshold for developmental neurotoxicity, the results suggest that pregnant women and children may need protection against fluoride toxicity.
OriginalsprogEngelsk
TidsskriftEuropean Journal of Public Health
Vol/bind34
Udgave nummer1
Sider (fra-til)143–149
Antal sider7
ISSN1101-1262
DOI
StatusUdgivet - 2024

Bibliografisk note

Published by Oxford University Press on behalf of the European Public Health Association 2023.

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