Interviewer: If there's a way to tell that you know X amount of fluoride causes x amount of x amount of cancer and it's linear would it be safe to assume that there's no safe level then of water for fluoridation?
Dr. David Kennedy: I think that's correct. As Dr. Marcus explains in the movie that as a scientist how do you develop a safe level of exposure? And he said he doesn't know how he would attack it but he thinks it would probably end up like lead. Where zero is the amount that you should be exposed to. Because the reason he brings up lead is, one, Dr Marcus was the guy that got lead out of the water in the first place and, two, Fluoride is more toxic than lead. So if everybody's worried about lead today, well, why don't we have our children brush with something that's worse than lead? That's insane! It's a hairless toxic and arsenic if I invented an arsenic toothpaste we'd say "You're protected because you'll spit it out." Well, you can't spit stuff out of your mouth. If you measure blood level of fluoride and give a child a dab of toothpaste or do a topical treatment in a dental office, their blood level of fluoride goes up. Even if you supervise them and make them spit out, their blood level of fluoride goes up because your mouth absorbs whatever goes in. So the moral of that story is you should not put anything in the child's mouth that you also couldn't put in the dinner. So if it's not a food, if it's not a nutrient, it doesn't belong in the child's mouth.