Just how dirty is the air you breathe? The American Lung Association's annual report of the most polluted cities in the U.S. rates communities on levels of ozone, sulfur dioxide, air-borne particulates and tainted tap water. Here are the 20 cities most polluted by year-round particle pollution:
Secret Service Director Julia Pierson, who has faced intense scrutiny over the Sept. 19 White House security breach, has resigned, according to the U.S. Department of Homeland Security. Here's what you should know about the highly secretive agency.