Abstract

The Intelligence Quotient (IQ) was measured in 118 children, aged 10-12 years, who were life-long residents in two villages of similar population size and social, educational and economic background but differing in the level of fluoride in drinking water. The children in the high-fluoride area (drinking water fluoride 3.15 ± 0.61 mg/L [ppm]) (mean ± S.D.) had higher urinary fluoride levels (4.99 ± 2.57 mg/L) than the children in the low-fluoride area (drinking water fluoride 0.37 ± 0.04 mg/L) (urinary fluoride 1.43 ± 0.64 mg/L). The IQ of the 60 children in the high-fluoride area was significantly lower, mean 92.27 ± 20.45, than that of the 58 children in the low-fluoride area, mean 103.05 ± 13.86. More children in the high-fluoride area, 21.6%, were in the retardation (<70) or borderline (70-79) categories of IQ than children in the low fluoride area, 3.4%. An inverse relationship was also present between IQ and the urinary fluoride level. Exposure of children to high levels of fluoride may therefore carry the risk of impaired development of intelligence.

• Related Studies :

  • The relationships between thyroid-stimulating hormone and/or dopamine levels in peripheral blood and IQ in children with different urinary iodine concentrations.

    Highlights TSH is not related IQ in children with different urinary iodine concentrations. Dopamine in plasma is unrelated to IQ in children with adequate or excessive iodine. Dopamine has positive correlation with intelligence in iodine deficiency group. The interaction between dopamine in plasma and TSH is not related to

  • Prenatal exposure to fluoride and neuropsychological development in early childhood: 1-to 4 years old children.

    Highlights Maternal fluoride levels were associated with better cognitive scores in childhood. The neuropsychological association is gender dependent; only seen in boys. Positive associations do not disappear after adjustment by different covariates. A potential positive neuropsychological association at low fluoride levels cannot be excluded. Background Cross-sectional and prospective studies have provided

  • Decreased intelligence in children and exposure to fluoride and arsenic in drinking water.

    Recent evidence suggests that fluoride (F) and arsenic (As) may adversely affect intelligence quotient (IQ) scores. We explore the association between exposure to F and As in drinking water and intelligence in children. Three rural communities in Mexico with contrasting levels of F and As in drinking water were studied:

  • Dose-response analyses of the 27 human developmental neurotoxicity studies ranked highest quality by National Toxicology Program (NTP) systematic review.

    BACKGROUND AND AIM: The National Toxicology Program (NTP) has been conducting a systematic review of the evidence for fluoride’s neurotoxicity. Drafts of the NTP report conclude fluoride is a presumed hazard for developmental neurotoxicity, but have not included rigorous dose-response analyses to estimate a safe dose. This is of great

  • Community water fluoridation and intelligence: prospective study in New Zealand

    OBJECTIVES:  This study aimed to clarify the relationship between community water fluoridation (CWF) and IQ. METHODS: We conducted a prospective study of a general population sample of those born in Dunedin, New Zealand, between April 1, 1972, and March 30, 1973 (95.4% retention of cohort after 38 years of prospective follow-up).

• Related FAN Content :

  • Fluoride Affects Learning & Memory in Animals

    An association between elevated fluoride exposure and reduced intelligence has now been observed in 65 IQ studies. Although a link between fluoride and intelligence might initially seem surprising or random, it is actually consistent with a large body of animal research. This animal research includes the following 45 studies (out

  • Fluoride & IQ: 76 Studies

    • As of July 18, 2022, a total of 85 human studies have investigated the relationship between fluoride and human intelligence. • Of these investigations, 76 studies have reported that elevated fluoride exposure is associated with reduced IQ in humans. • The studies which reported an association of reduced IQ with exposure

  • Fluoride: Developmental Neurotoxicity.

    Developmental Neurotoxicity There has been a tremendous amount of research done on the association of exposure to fluoride with developmental neurotoxicity. There are over 60 studies reporting reduced IQ in children and several on the impaired learning/memory in animals. And there are studies which link fluoride to Attention Deficit Hyperactivity Disorder. Teaching

  • NRC (2006): Fluoride's Neurotoxicity and Neurobehavioral Effects

    The NRC's analysis on fluoride and the brain.

  • Fluoride's Direct Effects on Brain: Animal Studies

    The possibility that fluoride ingestion may impair intelligence and other indices of neurological function is supported by a vast body of animal research, including over 40 studies that have investigated fluoride's effects on brain quality in animals. As discussed by the National Research Council, the studies have consistently demonstrated that fluoride, at widely varying concentrations, is toxic to the brain.