>I wonder how long it takes fluoride to clear from a person’s system and clarity to return?
Years, based on my own personal experience after I "overdosed".
But removing fluoride from your diet is difficult.
Cities share water, so even if your city doesn't fluoride, some others in your supply chain might. Tap water is never safe.
Also buying drinks any where, even alcohol can subject you to fluoride. Soda, bottled water, coffee, etc. Any food product that contains water or uses water in the process may be contaminated. Many health products contain fluoride.
Reverse osmosis is the only way to remove fluoride. Oh, there are drip filters that will do the job, but filters are slow and not always 100% effective. Plus they need to be replaced often.
Being fluoride free takes hard work and discipline. Not sure this had any positive effect on Chicago.