According to U.S. Substance Abuse and Mental Health Services Administration, roughly 3.1 million Americans entered military service between 2001 and 2011, and nearly 2 million were deployed to Afghanistan or Iraq. More than 6,000 American troops have been killed, and roughly 44,000 wounded.
The budgets of the Coast Guard, Transportation Security Administration and Border Patrol have all more than doubled since 2001.
And it was only in December 2011 that we pulled our remaining troops out of Iraq
Passengers are selected at random for more intense screenings.
Over the decade, airport security has tried different types of searches and screenings, introducing new equipment.
A study of nearly 13,000 rescue workers published in the April 2010 New England Journal of Medicine found that 30%-40% of the workers who suffered impaired lung functions still show little or no improvement in symptoms.