SOME of the evidence was from way more than what humans get. Also, let’s not get all gloaty and dismiss all questions about flouride’s safety just yet. Science is a process.

Based on the body surface area of humans and animals, and considering the metabolism and absorption of fluoride in rats, according to calculations, the WHO’s safety threshold for fluoride intake from drinking water (1.5 mg/L) corresponds to a fluoride concentration of 10 mg/L in the drinking water of rats. After 1 week of acclimatization, the 150 rats were randomly assigned to 5 groups (n = 30) and provided with drinking water containing 0, 10, 25, 50, or 100 mg/L of fluoride. Although 50 and 100 mg/L are not equivalent to the doses humans are exposed to in natural environments, they are commonly used in animal models of fluorosis and have been widely demonstrated to be robust in rat models of fluorosis [35,36,37]. According to the exposure mode and time of fluoride, it can be divided into three modes: fluoride treatment for 12 weeks (12 w), fluoride treatment for 24 weeks (24 w), and fluoride treatment for 12 weeks and 12 weeks of improve water(12 w12 wi) (Table S1). Rats were euthanized with isoflurane anesthesia at the end of the breeding period.