Wealthy people are more likely to have good childcare (nannies, after school activities) where kids spend less time unsupervised and able to, for example, eat paint chips. For that matter, stuff like chipped paint is less likely to be left in a deteriorating state by more affluent owners.
Just as a matter of common sense and gut-check plausibility, what are we talking about when we talk about "eating paint chips?" Does eating a couple flakes lower your IQ in a measurable way? Seems very unlikely. What are we talking about, then? Do we imagine kids to be shoveling paint chips into their mouth day after day? Surely that's a pretty small number of children (if it's any), nowhere near enough to suggest generational, cohort-level effects. So what is it that we really think is happening here?
My personal experience as a landlord: kids putting their mouths on rails and banisters that are at the level of their mouths. Vivid memories of kids standing around just hanging out on the deck (pre-Internet obviously) with their mouth on the rail.
"Does eating a couple flakes lower your IQ in a measurable way? Seems very unlikely."
Like asking about the effect of a little second-hand smoke. Probably not a measurable effect, but many people would not be consoled by the inability of the data to register an effect.
The study in the OP also specifically calls it out:
>Our estimates, based on leaded gasoline consumption, may also have underpredicted high-lead exposures owing to leaded paints and pipes, which tend to aggregate within particular communities (e.g., those with high rates of homes with lead service lines and lead paint in disrepair).
It's from dust on surfaces, toys, and hand to mouth. All toddlers should be tested. There is no surety! Any soils or dust could be contaminated from the heyday of leaded gasoline and paint.
Unemployed people don't need nannies, and they're the poorest. I think you're deliberately avoiding saying that poor people abuse their children, which is true. It's not much about affording anything.
