Still worrying about fluoride?@ C_B......
You can't reason with folks that are sick. They have been mentally toxicated and lamed by design. No Joke.
So, put a spin on this and drive the point home. Fix the lame with a dose of punch.
"For optimal dental health, the World Health Organization recommends a level of fluoride from 0.5 to 1.0 mg/L (milligrams per litre), depending on climate.* Adverse effects are possible at fluoride levels far above this recommended dosage. The U.S. Health and Human Services Department recommends 0.7 milligrams of fluoride per liter of water – the lower limit of the current recommended range of 0.7 to 1.2 milligrams."
* WHO Expert Committee on Oral Health Status and Fluoride Use. See report "Fluorides and oral health," 1994.