The aptly named Mercury News reports this bad news about lead poisoning:
Now, however, findings published in April in the New England Journal of Medicine strongly suggest not only that any amount of lead is harmful to a child’s brain but also that greater damage seems to occur at levels below 10 micrograms than above that.
In other words, there is no threshold for lead’s effects on the brain, and just small amounts seem to have relatively large effects.
Lead based paint is still an issue:
One-quarter of American homes with children younger than 6 contain lead-based paint.
This 1999 report suggests that blood lead levels are declining but also notes that mean blood levels are 1.7-2.3 micrograms for 1-5 years olds which makes the new study even more ominous.
Eliminating lead poisoning would probably do more to improve eductional performance in our schools than all the batteries of tests being engendeer by the all children left behind act. (and, no, I don’t know the marginal cost of eliminating the last vestiges of lead poisoning).
A cursory search did not turn up any studies on lead poisoning as a factor in political party selection.