"This was an innocent mistake by an obviously inexperienced traveler," said Paul Haney, deputy executive director of airports and security for the city's airport agency.
"This is only the second time in nearly 20 years that anyone can recall a traveler mistakenly putting an infant through an airport X-ray machine. Since then LAX has served more than 1 billion travelers without an incident of this type," he said.
In 1988, an infant in a car seat went through an X-ray machine at LAX Terminal 4. Also that year, officials at Winnipeg International Airport in Canada accidentally sent a 2-month-old wrapped in blankets through an X-ray machine.
The TSA said it is continuing to review Saturday's incident at LAX.
"We're trying to figure out what changes we can make, short of putting up signs saying, 'Don't put your baby through the X-ray machine,' " Melendez said. "We're trying to determine how we can make this not happen again."
The baby that went through the airport luggage machine was exposed to less radiation than a passenger on a cross-country flight. Typical radiation exposures*:
Luggage screener: 1
Cross-country flight: 5
Chest X-ray: 10
* Measured in millirems, which takes into account both the amount of exposure and the biological effect of the type of radiation in question.
The machines cost about $125,000 each and will allow the 2,200 security screeners at LAX to zoom in on specific items that catch their attention.
LAX and JFK to get 'backscatter' machines
The TSA opened its first "PreCheck" lane at Mineta for passengers who had been approved beforehand by their airlines and cleared by the federal agency.
X-ray devices show carry-ons in 3-D