Airport restaurants packed with holiday travelers have been cited in the past year for hundreds of food safety violations, local health department reports show.

A USA TODAY review of inspection records for nearly 800 restaurants at 10 airports found items such as tuna salad and turkey sandwiches stored at dangerously warm temperatures, raw meat contaminating ready-to-eat foods, rat droppings and kitchens lacking soap for workers to wash hands.

Serious violations are common. On the most recent inspections available online, 42% of 57 restaurants reviewed at Seattle-Tacoma International Airport had at least one "critical" violation. So did 77% of 35 restaurants reviewed at Reagan National Airport.

Grab-and-go coolers often don't keep sandwiches and salads cold enough to stop dangerous pathogens, reports show.

"The grab-and-go sandwich problem, it's a constant battle," said David Jefferson, of the Tarrant County, Texas, health department, which inspects Dallas-Fort Worth International Airport.

There are 76 million cases of food-borne illnesses annually in the U.S., the Centers for Disease Control and Prevention estimates. Most aren't traced to the source and doing so is even harder with airport restaurants because customers scatter, the Food and Drug Administration's Dean Davidson said.