By LiveScience Staff
posted: 09 December 2009 09:29 am ET
Airline passengers flying through storms might have more to worry about than a little turbulence. A new study suggests that if jets pass near lightning discharges or related phenomena known as terrestrial gamma-ray flashes, passengers and crew members could be exposed to harmful levels of radiation, a dose equal to that of 400 chest X-rays.
However, the likelihood of encountering these lightning events is very small, the researchers say. In addition, airline passengers are always exposed to slightly elevated radiation levels due to cosmic rays, which bombard Earth's upper atmosphere constantly but typically don't make it to the surface.
Airplane passengers would only be exposed to this high radiation dose if their airplane happens to be near the point of origin of a lightning discharge or a gamma-ray flash, and scientists aren't sure how often, if ever, such exposure occurs. The radiation bursts are extremely brief and extend over just a few hundred feet in the clouds.
"We know that commercial airplanes are typically struck by lightning once or twice a year," said Joe Dwyer, professor of physics and space sciences at Florida Tech. "What we don't know is how often planes happen to be in just the right place or right time to receive a high radiation dose. We believe it is very rare, but more research is needed to answer the question definitively."
more:
http://www.livescience.com/strangenews/091208-airplane-lightning-radiation.html