I’d like to think that fluoridation opponents are merely wrong or mistaken, but here is an example of the reverse logic and obviously irrelevant claims that they use to support an argument (and they apparently consider this to be one of their better ones). It seems unlikely that someone would see the math behind these claims and make the backwards interpretation they do. Yet this article is being copied around various places, with strongly worded conclusions, but which have nothing to do with the results of the study they cite.
It describes an experiment in which rats were given fluoride, in an attempt to cause a measurable physiological or biochemical change, and then see if lycopene (available in “health food stores”!) could be used to reduce the change. The argument depends on assuming that rats are a fair model for humans, g per g, so let’s accept that and read on. They gave rats 10.3 mg of sodium fluoride per kg body weight per day for five weeks. That means 45% of 10.3, or 4.64 mg of fluoride per kg body weight per day. Did the mice suffer fatal illness, deformity, etc.? No, but there was some detectable change in response, labelled “oxidative stress”.
How much fluoridated city water would this mean for me, as a 70 kg person? At this rate of 4.64 mg, I would get 324.45 mg fluoride per day. Our water fluoridation target is 0.7 mg fluoride per liter. I would have to drink 463.5 liters per day, every day. Anything over 15 liters of even the purest spring water per day will kill you. So, I would have to drink enough water to kill over 30 men, and do it each day for 5 weeks (obviously I would be gone after one or two days). So, in other words, they see data that shows you could get a measurable change in blood chemistry, but to obtain it from fluoridated water you would have to drink a hundred times your normal amount, and keep it up for 5 weeks, if you want to match this study, and they think that is evidence of danger.
The study was obviously directed at extreme levels of fluoride, perhaps related to industrial exposures, accidents, or extreme geological sources. But the anti-fluoride people interpret these results to mean that 0.7 mg/L is dangerous. Even if the water treatment managers completely flubbed the mix and double-dosed the whole city, it would still not be anywhere near a toxic effect.
Multiply the exposure to car exhaust, table salt, cigarette smoke, hot peppers, vitamin supplements, or many other things by 50 to 100 or more times the normal daily dose, and see what happens: more than just a measurable oxidative change!
At the end of the article, they make the most significant point:
Lycopene is available as a dietary supplement and interested food consumers may find it on the Internet and local health stores. In addition to lycopene, early research suggests that taking vitamin C supplements can reduce the toxicity of fluoride. Fluoride in water can only be removed using reverse osmosis water filters which are available on the Internet and local stores.