I once read something and I don't remember if it was from a good source. It said that one of the ways they can identify bones from the last 100 year is that ol

I once read something and I don't remember if it was from a good source. It said that one of the ways they can identify bones from the last 100 year is that older bones have something like 400x less lead traces in them. Basically everyone alive has a degree of lead poisoning thanks to leaded gasoline.