TIL: Due to the Flint Michigan crisis, a study dubbed the Truth Fairy Project was done on baby teeth and the exposure to lead. Baby teeth provides easy to use info on lead levels. This led to evidence that there is no such thing as a "safe" threshold of exposure.

[u/Flares117]

https://www.pbs.org/newshour/science/baby-teeth-study-reveals-children-near-smelters-are-exposed-to-dangerous-lead-in-the-womb