The latest research suggests that exposure to lead may diminish the functioning of the aging brain decades later.

The good news is that Americans’ exposure to lead has decreased markedly since lead was removed from paint and gasoline, beginning in the 1970s.

The bad news is that too many children who live in older buildings are still exposed to lead. We already know that lead poisoning can cause mental retardation. Now it appears that even children who appear to be unaffected could suffer adverse consequences from the exposure as they age.

Republicans, remember that next time you feel like mocking a Democratic proposal to test children for lead exposure.