The daily upper limits (UL) for fluoride are listed below, according to the National Institutes of Health Office of Dietary Supplements (Taking more than the UL can be harmful and not recommended)
Life Stage | Upper Limit |
---|---|
Birth to 6 months | 0.7 mg |
Infants 7–12 months | 0.9 mg |
Children 1–3 years | 1.3 mg |
The US Department of Health and Human Services (1991) estimated that total fluoride exposure in fluoridated communities ranges from 1.6 to 6.6 mg/day
According to "Fluoride contamination, consequences and removal techniques in water: a review," in the journal Environmental Science: Advances (Issue 5, 2022),
"The sources of fluoride in the environment include industrial plants, aluminum smelters producing glass brick, hydrofluoric acid, tile works and phosphate fertilizer plastic factories, textile dyeing, and industries that consume high sulfur non-coking coal for thermal power.
Currently, high-tech companies developing semiconductors and integrated circuits produce significant fluoride-containing industrial wastewater.
Cigarettes, which contain an average of 236 ppm fluoride, play a significant role in human fluoride consumption.
Teflon-coated cookware may potentially increase the fluoride absorption in humans. The fluoride concentrations in Teflon-coated cookware is as high as almost 3 ppm, whereas it is lower in aluminum cookware.
Also, the fluoride concentrations are high in stainless steel and Pyrex ware, although to a lower extent. In normal and high quantities, fluoride in water may cause aluminum to leach from cooking utensils and copper from pipework."