The article was about the lack of utility of testing for it in individual psychiatric cases. When you have a correlated problem like an entire school underperforming for no apparent reason (that is, even by the standards of a poor school, it is exceptionally poor), the math changes a lot. You have a rational reason to suspect some sort of correlated cause.

I know. Lead testing is a soap box for me. Palatka has a high crime rate. I would love to know how much of it might be solved with cops testing.