Noah Smith: Clean up lead before it wrecks more American lives

When I was a kid, my dad half-joked that the Roman Empire fell because the Romans used lead to make their pipes, thus poisoning their drinking water supply. Even at age 7, I found that one hard to believe.But maybe, in some crucial ways, my dad was on to something. Strong evidence shows that lead is a uniquely toxic substance that can wreak permanent and devastating changes on both the human brain and a human life. Leads is also still ubiquitous in the U.S.Like the Romans, the U.S. uses lead to