Flying and Radiation Risk
Physicists say many travelers and airline crews are at higher risk of radiation exposure during flights that fly high over the poles.
Aug 24, 2009
By DBIS
Inside Science News Service
Science Insider
BACKGROUND: Airline pilots and flight crews may be exposed to higher radiation levels and therefore greater risk of developing cancer. They and frequent fliers can be subjected to a considerable amount of radiation in flight. The type of radiation is generally classified as cosmic radiation and can include subatomic particles and gamma and X-rays, from the sun and other sources in space. The atmosphere around equatorial regions tends to be thick and acts as a radiation shield. This layer is thinner near the poles, and therefore courses that carry planes over polar regions are the most susceptible to cosmic radiation. Higher cruising altitudes reduce atmospheric protection and people experience more exposure to radiation.
HOW RADIATION AFFECTS CELLS: Most of us are aware that the sun's ultraviolet (UV) radiation can damage surface skin cells, even leading to skin cancers, but at high energies it can become ionizing radiation. Ions are electrically charged atoms, a byproduct of a high-energy light ray (X-rays or gamma rays) knocking electrons off of atoms. The resulting free electrons then collide with other atoms to create even more ions. This is dangerous because an ion's electrical charge can lead to unnatural chemical reactions inside cells. It can break DNA chains, causing the cell to either die or develop a mutation and become cancerous, which can then spread. And if the mutation occurs in a sperm or egg, the result can be birth defects, which is why pregnant women should never be subjected to X-rays.
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Some careers have occupational hazards, but airline crews and frequent fliers may be exposed to hidden flight risks and not even know it.
Joseph Tremper is happy to be home working on his garden, but as a frequent flier, time at home is rare. Much of his days are spent in the sky.
"I travel about three out of four weeks a month," Tremper told Ivanhoe.
Flying a lot can have regular risks, but space physicists say many travelers and airline crews are at higher risk of radiation exposure during flights that fly high over the poles.
"The frequent flyer is susceptible to more radiation in particularly high latitudes," Chris Mertens, Ph.D., a space physicist at the NASA Langley Research Center in Hampton, Va., said.
We're all exposed to some radiation every day, but the earth's atmosphere shields us from most of it. At higher latitudes, near the poles, and altitudes above 30,000 feet, the earth's protection is weaker, putting flight crews and passengers at risk.
Now researchers have a new model that predicts the amount of radiation in space and how much radiation reaches earth during solar storm activity.
"The model shows the real time radiation exposure levels that is received from the surface of the earth," Dr. Mertens explained.
During a solar storm, radiation levels increase. This model shows high levels of radiation in red near the earth's poles. The new model helps alert crews of radiation risk in flight, so pilots can take measures to avoid it.
"If you descend one or two kilometers in altitude, then you can significantly reduce the radiation exposure," said Dr. Mertens.
Scientists hope to make radiation prediction forecasts similar to local weather forecasts. Right now, Joseph hopes his travels will keep him safe and focused on fun.
"My favorite part of traveling is that I get to see lots of interesting places," Tremper said.
The most susceptible person to radiation on high altitude and latitude flights is an unborn baby in the first trimester. In Europe, it's mandatory that flight crews are educated about radiation. There are no regulations in the U.S.
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