Do you know where fluoride comes from? It turns out that so-called "fluoride" is really fluorosilicic acid, a toxic waste byproduct of the phosphate mining industry. If it wasn't being dumped into the water supplies of major cities, it would have to be disposed as a hazardous toxic waste chemical under EPA rules.
When the phosphate mining industry used to release fluoride byproducts directly into the atmosphere (from the fumes of the acidic slurry used to process phosphate rock), it caused the widespread death of cattle and crops. In order to protect local livestock from fluoride poisoning, wet scrubbers were installed at the phosphate mining processing sites in order to collect the toxic fluoride and prevent it from being released into the atmosphere.