Around one-in-three children globally suffer from lead poisoning
I can't give a cite for the following I read it in either a newspaper or magazine probably 30+ years ago.There was a school district in a small town that for the first time gave IQ tests to all of the children in some younger age group, I think around 7 or 8. The results showed a several point difference between the white kids and the Black kids. The district wrote this off as due to cultural bias in the tests.One teacher decided to look deeper to see if there could be some other factor that could explain the difference. What that teacher found was that in this district all of the white kids lived in suburban single family homes that had been recently built, and all of the Black kids lives in decades old apartment buildings.In particular, the white kids' homes at all been built after we stopped using lead point, and the Black kids' homes were all built before that.The kids were tested for lead exposure, and it turned out all the Black kids and none of the white kids had high lead levels. That lead to (no pun intended) cleaning up the environments in the old apartments and treating the Black kids for their high lead levels.This was caught early enough for these kids to prevent permanent damage, and when tested a few years later the IQ gap had largely disappeared, and the Black kids were doing as well as the white kids in school which they had not been before being treated for their lead exposure.