Do you think the city you live in should add fluoride to the drinking water?
The book tells you to do your own research on this topic, so totally do it! And to help you, here is a summary of the research I found:
If you feed a rat LARGE amounts of fluoride (~4ppm in water), bone density increases, but fracture rates also increase indicating that the bones are heavier, but weaker. Some older studies found that bone mass decreased with a large fluoride intake. Many cities in the US have high naturally occurring fluoride concentrations in their water.
If you feed a human child SMALL amounts of fluoride (~1ppm in water) tooth decay is reduced dramatically. The mechanism (how it works) is entirely topical – the fluoride gets into the persons saliva and then absorbs into the teeth. Exposure to these small amounts has been shown to reduce bone fractures or to have no affect on bone strength.
Fluoride pills/rinses are very effective ways to get kids the fluoride they need, but many families (especially low income families) often do not get their kids these forms of fluoride. Thus, fluoride is added to drinking water in many cities.
The largest study on humans found that when the concentration of fluoride in water was below 1ppm people had more bone fractures, and above 1 ppm people also had more bone fractures. While the authors state that a much larger study is needed to be sure of their results, this indicates that there there is a small threshold between beneficial amounts of fluoride and detrimental amounts of fluoride.
Different people drink different amounts of tap water each day. How much tap water does a kid in your town drink? Calculate their fluoride intake if the water has 1ppm fluoride
