The number of weapons confiscated at American airports is increasing, according to the Transportation Security Administration (TSA), which detected more than 1,500 firearms in 2012, up from about 1,300 in 2011. Nearly 85 percent of the weapons, or about 1,260, were loaded—which is illegal. Under TSA rules, passengers with proper permits may fly with unloaded guns stored in hard-sided checked baggage, but not in carry-on items or on a passenger.

Atop the list sits the world’s busiest airport, Hartsfield-Jackson Atlanta International Airport, which confiscated more than 100 guns in 2012, followed by 78 at Dallas/Ft. Worth International Airport, 53 at Phoenix, and 49 at Houston.

But if one accounts for airport size by measuring gun confiscations per passenger enplaned, Atlanta falls nearly to the bottom with a rate of 2.03 guns seized per million enplanements, far behind list leader Provo, Utah, Municipal Airport, with its rate of 134.6 guns per million. Provo is followed by Roswell, Arizona, at 80.51; Dickinson, North Dakota, at 52.6; Elko, Nevada, at 42.48; Joplin, Missouri, at 36.5; Ft. Smith, Arkansas, at 35.6; and Lafayette, Louisiana, at 34.42.

Counting only the 31 large airports with at least 500,000 enplanements, Portland International in Portland, Oregon, led with 3.82 guns per million, followed by Ft. Lauderdale/Hollywood, Florida, at 3.62, Tampa, Florida, at 3.55, and St. Louis, Missouri, at 3.25.

The most common type of gun confiscated was the .380 semiautomatic pistol, although TSA also seized stun guns, grenades, spear guns, and rocket launchers.

From December 14 to 21, the week after the school massacre in Newtown, Conn., TSA noted a small increase in weapons seized, with screeners detecting 11 passengers with stun guns, 3 with grenades and 34 with guns. “It does concern us that this number is rising,” said Lisa Farbstein, an agency spokeswoman. “But we will not speculate on the causes.”

-Matt Bewig

To Learn More:

Rise in Guns Confiscated at Airports (by Robbie Brown, New York Times)

Guns Seized by TSA at US airports (TSA)

Firearms and Ammunition: Traveling with Special Items (TSA)