New research indicates that amidst protests over US airport security procedures, what's often overlooked is that flying itself dwarfs the radiation doses delivered by the new body scanners.
The radiation you get from body scanners is the same as what you get in two minutes in an airplane at 30,000 feet.
Of bigger concern is whether pilots, flight attendants, and extreme frequent travelers are getting too much radiation from flying itself.
"Most people are unaware about the fact that there is significant radiation exposure associated with air travel because they are well above the Earth's atmosphere," Discovery News quoted Robert J. Barish, a radiological and health physicist in New York City, as saying.
"You'd get as much radiation in a whole-body scanner as you'd get in two minutes at 30,000 feet," he said.
For casual flyers, there probably isn't much to worry about, said Barish.
But flying raises real risks for pilots, flight attendants, and the half a million business travellers who spend much of their time in the air.
Barish argued that airplane personnel should be classified as "radiation workers." And with that designation, they should be educated and monitored appropriately, much like doctors who routinely deliver X-rays and cancer treatments.
"If you are a business frequent flyer who travels more than 85,000 miles a year on typical cross-country, international-type routes, your exposure goes above the limits that you would be allowed if those exposures came from any kind of medical, industrial, nuclear or other sources here on the planet," said Barish.
"It takes only seven trips from New York to Tokyo to exceed the general public limits," he said.
Cosmic radiation comes from our sun and other stars in the form of particles, such as protons, and electromagnetic waves, such as X-rays. These energetic rays stream through our bodies all the time, though Earth's atmosphere deflects most of them before they reach us.
The higher you go in altitude, the less atmosphere there is to protect you, and the more radiation hits you.
As our sun enters a new phase of activity in its 11-year-or-so cycle, the risks of flying may be rising.
Solar storms throw out as much as 20 percent more cosmic radiation than a less active sun does, Barish said, meaning that travelers on a poorly timed flight could get exposed to far more radiation than they banked on.
"During a solar flare event, one flight can give you as much exposure as several flights," said Barish, adding that solar storms have previously caused flights to be diverted from the poles, where the Earth's magnetic field diverts most of the sun's radiation.
"There are not that many every year, but if you're just unlucky, you can end up in them," he said.
The findings were published in the Employee Responsibilities and Rights Journal.