You're closer to the sun on a plane, but not in danger of overexposure to radiation.
Not much. Yes, it’s true that the sky is constantly bathed in radiation from cosmic rays and from the sun, says David Hoel, a professor and radiation expert at the Medical University of South Carolina.
It’s also true that the higher you fly, the stronger the radiation. A typical plane flight from Portland or Boise to Hawaii might expose you to about 15 microsieverts—less than 1 percent of what you’d normally get during a year on the ground.
Yet even when the sun is sending off massive flares—its habit lately—radiation poses practically zero risk to fliers, says Hoel. The dose could be many times higher than normal during a major solar flare, but Hoel says it still isn’t enough to threaten health.
Tellingly, studies have so far found no conclusive evidence that airplane radiation causes cancer in full-time international pilots, the ultimate frequent fliers. “Pilots may be slightly more likely to get skin cancer, but that could be because they spend their vacations on the beach,” Hoel says.
Illustration by Ron Chan
This article was first published in March 2013. Some facts may have aged gracelessly. Please call ahead to verify information.