More security precautions in the wake of the failed Christmas Day 'terrorist' attack could have health implications too. Full-body scanning and the possibility of having to remain seated for a full hour before landing are both causes for concern.
The US Transportation Security Administration plans to deploy about 450 new full-body imaging units at airports throughout the country. The units use low-level X-rays to develop what look like naked images of the passengers passing through. Another, similar device used at 19 airports around the nation -- including Los Angeles International Airport -- uses low-level radio waves to produce its images.
The American College of Radiology and the National Council on Radiation Protection and Measurements have both concluded that exposure to new screening devices creates no significant danger to passengers.
TSA officials say the amount of energy or radiation emitted by the screeners is much lower than what passengers are exposed to by simply flying on an airplane or using a cellphone.
Some say the discretion given to airlines crew to bar passengers on international flights to the U.S. from getting out of their seats for one hour before the planes land is even more problematic than the radiation danger.
Passengers who are overweight, have a history of blood clotting or are recovering from surgery face a greater risk of deep-vein thrombosis when they sit in a cramped airline seat for too long, which can hamper blood flow to the legs, said Peter Lawrence, chief of vascular surgery at the Ronald Reagan UCLA Medical Center.
A thrombosis occurs when a clot forms in a vein, leading to pain and swelling. If the clot breaks loose, it can travel to the lungs and cause a pulmonary embolism, he said.
If passengers are confined to their seats for long hours, Lawrence said they should try to flex their feet and calves to get blood flowing.
"The longer you are inactive the more risk," he said. "One hour by itself is probably not a great risk, but nobody knows for sure."
Although the one-hour confinement may not be a serious health risk for the 25 million Americans who suffer from incontinence, it could be a matter of serious embarrassment, said Steve Goelman, chief executive of Unique Wellness, a New York company that makes absorbent adult briefs.
He said the number of people with bladder control problems is growing as baby boomers age.
"This is a growing concern," Goelman said.
"The security measures could put a heavy burden on those traveling."
However, a spokesman for the country's largest airlines said flight crews would use their discretion when imposing the new security measures on passengers with medical problems, Hugo Martín wrote in Los Angeles Times.