Abstract

This issue of Fluoride contains three new reports on fluoride (F) and neurotoxicity. A study of neurotoxic effects of F in aluminum potroom workers in Iran shows the importance of neurobehavioral testing for the early detection of cognitive impairment in workers occupationally exposed to airborne F. Two studies, from Iran and India, examined the IQ of children drinking high F water (2.38 and 2.45 mg F/L [ppm], respectively), but only one of the two studies showed what was considered a statistically significant result. Attention is thus drawn to the importance of examining confounding and effect-modifying factors. For example, the reported protective effects of magnesium against F toxicity in certain drinking waters, especially when they are soft, need to be considered. Whether there is a threshold at which neurotoxicity from F begins to occur is examined by considering nine other studies showing a significant association between lower IQ or neonatal neurobehavioral impairment and higher oral F intake. If the accumulated evidence of human neurotoxicity from F is viewed dispassionately, two conclusions can be drawn. Airborne F in industrial situations may pose a health risk to workers and may be detected by neurobehavioral testing. The studies currently available on the development of IQ all have their limitations, and although cases can be made, based on a pool of eight reports and a paper by Xiang et al., respectively, for levels of F in drinking water of 0.1 and 0.185 mg F/L being safe for all children, other evidence, from Ding et al., suggests that even a level as low as 0.081 mg F/L is not safe. Thus there is no threshold for F neurotoxicity in drinking water, and the only assuredly safe level
is zero.

• Related Studies :

  • Effects of fluoride on psychomotor performance and memory of aluminum potroom workers

    In this cross-sectional study, the psychomotor performance and memory skills of a fluoride-exposed group (FEG) of 64 male workers in an aluminum potroom were compared with those of 60 male workers in a nonfluoride-exposed group (NFEG). The FEG had a mean age of 37.59±4.82 yr and had been employed for

  • Is Fluoride Potentially Neurotoxic?

    An Editorial by David C. Bellinger, PhD, MSc Environmental epidemiology is a field replete with controversies, but the intensity of the debate inspired by the fluoridation of municipal water supplies to reduce dental caries is perhaps unrivaled. Governments, as well as individuals, differ in their assessments of water fluoridation as public policy.

  • Fluoride exposure and hypothyroidism in a Canadian pregnancy cohort.

    Highlights • Fluoride may disrupt thyroid function. • Thyroid dysfunction in pregnancy can adversely impact offspring development. • Fluoride in water increased risk of hypothyroidism in pregnant women. • Boys had lower IQ scores if their mothers were hypothyroid in pregnancy. • Thyroid disruption may contribute to developmental neurotoxicity of

  • The importance of timing in fluoride-induced developmental neurotoxicity.

    Exposure to the fluoride ion can, in sufficient dose, induce neurotoxicity at any age, in both adults and children, but for fluoride-induced neurotoxicity to occur, in response to exposure to low doses of fluoride in the developing brain, the timing of the exposure is of importance. The evidence to date

  • Threshold effects of moderately excessive fluoride exposure on children's health: A potential association between dental fluorosis and loss of excellent intelligence.

    Highlights Childhood fluoride exposure was inversely associated with dental health and IQ. Threshold and saturation effects for aforementioned associations existed. Moderate fluoride exposure was mainly related to excellent intelligence loss. Dental fluorosis may be useful to reflect excellent intelligence loss. BACKGROUND: Excessive fluoride exposure is associated with adverse health outcomes, but

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    The NRC's analysis on fluoride and the brain.

  • Fluoride's Effect on Fetal Brain

    The human placenta does not prevent the passage of fluoride from a pregnant mother's bloodstream to the fetus. As a result, a fetus can be harmed by fluoride ingested pregnancy. Based on research from China, the fetal brain is one of the organs susceptible to fluoride poisoning. As highlighted by the excerpts

  • Fluoride & IQ: 76 Studies

    Note: See the Updated list of fluoride IQ studies at https://fluoridealert.org/researchers/fluoride-iq-studies/the-fluoride-iq-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

  • Fluoride: Developmental Neurotoxicity.

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