We've known for a long time that lead can do some horrible things to the human body.
And so the government took steps to curtail the ways in which lead is used... it is no longer an ingredient in paint or gasoline, for example.
But critics point out that the government has been slow to take further steps that might have protected people, but also would have caused some business impacts.
The critics include science historians Gerald Markowitz and David Rosner, the authors of the book Lead Wars.
We revisit our interviewfrom 2013 with the authors.