Ok, I see the comment now. Yes, you seem to provide a source, but you claim that the source shows that humans are affected by prolonged exposure. Obviously that's true, but comes with the obvious caveat that our exposure is nowhere near dangerous levels. I'm no expert, but I have some experiencing in parsing papers and trying to determine legitimacy so I'll take a stab at what it's saying.

In this review, it mentions that all the animals studied, problems arose when calculating the amount of fluoride measured against the body weight of the animal. Developmental toxicity occurs at ~13.2 mg/kg of body weight. A litre of water is advised to have .7 mg of flouride in the US. While some states have more or less, they're all around there. Now, you tell how many litres of water you'd have to drink to actually reach that level of concentration in your body. I'll give you a hint, it's at least several times your body weight.

This review also mentions that most flouride is excreted through urine or feces, and 99% of what is preserved is found in the teeth. I didn't read the studies on what the percentages that are excreted are, but since this review concludes that flouridated water is a non-issue, I'm gonna assume that it's substantial enough to not be an issue when it comes to flouride buildup.

Here's the thing though, this study is a review of other studies, why that's relevant is because of some of the epidemiological data that's brought up could still show that flouride is bad. However, All studies comparing populations that this review looks at have significant flaws, flaws that the review goes into. The review essentially concludes that all the epidemiological data from other studies are garbage. And rightly so, since a study trying to determine IQ between very different populations is next to impossible to make accurate.

Anyway, the short of it is that this review does not help your case. I'd say if anything, it makes it pretty clear that flouride is not an issue, and that if you're looking for data to say otherwise, this study recommends much more substantial epidemiological research to be carried out, unlike the epidemiological data they reference in the review.

To get more on topic, I don't believe most people would have looked more in depth at the article so perhaps they moved the goalposts when they were talking to you. That's fair to criticize them, but then again, what you're saying is also not entirely honest. Perhaps you didn't mean to be dishonest, but still, that just falls under the category of "speak within your limitations". Acknowledge that you don't understand or can't interpret the data. Maybe just ask for help clarifying points. Because what you had said was much too broad for the discussion you were having, and wasn't remotely helpful, and was, for a lack of a better term, misinformation.

Honestly, the best tactic for catching yourself doing this is to assess others' goals before attempting to comment on them. For example, don't start with assuming that governments across the world are proactively poisoning their population. Assume the obvious and go from there. Like considering that governments want healthy populations that are good workforces and produce high quality goods in order for them to compete at the world stage for power, clout, and money. This means producing educated adults, not mindless labour drones. Thus, if there existed credible studies (because not all studies are credible, as this review and many others point out) to increase intellectual output and reduce costs of infrastructure by removing flouride from water (as you wouldn't bother putting flouride in the water), you can bet that the government would be recommending or even forcing the elemination of flouridated water. There's just nothing substantial to gain otherwise. Clean teeth or only so much of a positive, and governments, again, do not want a mindless population. We're in the information age, manual labour is worth a fraction of the GDP output as high quality, educated work is.