That's mostly likely a factor but 100% of the story. The decrease of lead in soil is another. http://www.motherjones.com/environment/2013/01/lead-crime-link-gas

That's mostly likely a factor but 100% of the story. The decrease of lead in soil is another. http://www.motherjones.com/environment/2013/01/lead-crime-link-gasoline http://www.motherjones.com/environment/2013/01/lead-crime-li...