Lightning-Produced X-rays and Gamma Rays a Potential Health Concern for Air Travelers

[steven johnson]

Ten REM is considered the maximum safe radiation exposure over a person's lifetime and is equal to 400 chest X-rays, three CAT scans or 7,500 hours of flight time in normal conditions. A new study extimating the potential ionizing radiation generated by lightning is that a single lightning flash at close proximity to an airline could produce this amount of ratiation exposure. On the average, commercial planes are struck once or twice a year by lightning so this is not just a theoretical concern.

Now you know why you are afraid to fly.

ScienceDaily (Dec. 12, 2009) — New information about lightning-emitted X-rays, gamma rays and high-energy electrons during thunderstorms is prompting scientists to raise concerns about the potential for airline passengers and crews to be exposed to harmful levels of radiation.

Scientists at the Florida Institute of Technology, University of California, Santa Cruz and the University of Florida have estimated that airplane passengers could be exposed to a radiation dose equal to that from 400 chest X-rays if their airplane happens to be near the start of a lightning discharge or related phenomena known as a terrestrial gamma ray flash.

"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."

Instead, they estimated radiation based on satellite and ground-based observations of X-rays and gamma rays. ..The scientists concluded the radiation in a football field-sized space around these lightning events could reach "biologically significant levels," up to 10 rem, according to their paper.


Lightning-Produced Radiation a Potential Health Concern for Air Travelers

[Silent3]

1. Being in a plane in JUST THE RIGHT place...

...(or just the wrong place, depending on how you look at it) seems pretty damned unlikely. A "football field-size space" is a pretty small thing up in the big three-dimensional space a plane is moving through.

Interesting phenomena if it turns out to be true, and something to take note of as being possible if and when it happens, but not anything to lose sleep over, any more than worrying greatly about being directly struck by lightning.

[TheWraith]

2. There is absolutely no reason to be frightened of this.

"Ten REM is considered the maximum safe radiation exposure over a person's lifetime"

Umm, no. You can safely absorb up to 50 REM before you even notice any symptoms. A single 10 REM dose might give you a slightly increased risk of cancer, but so does going outdoors in the summer. For that matter, the occupational safety limit for people working with radioactive material is 10 REM over the course of 5 years.

[salvorhardin]

4. Yeah, the risks here are rather low

For instance, the Skylab crew was exposed to about 18 REM. http://www.astronomycafe.net/qadir/q2906.html

10 REM is biologically significant, but not that high of a dose. And out of the thousands of airline flights in the U.S. a year, if only two are struck by lightning that might cause a 10 REM exposure, then any individual's risk of exposure is really small. Even for airline crews, the risk is low.

[Orrex]

3. "Flight attendant give Hulk another bag of peanuts..."

"Or Hulk will SMASH!!!!!"