Scientists have found a new potential hazard to space travel: Exposure to radiation in space could cause brain damage and may cause astronauts to develop early-onset Alzheimer's disease, according to a new study released Monday.
Animals exposed to iron radiation particles that are similar to those caused by exploding stars in space showed neurodegeneration much earlier than would be expected, and the animals' brains showed plaque associated with Alzheimer's disease. The radiation levels were similar to levels an astronaut would experience while traveling on a mission to Mars.
Unlike many types of space radiation, the particles associated with iron are able to penetrate a spacecraft's walls.
"It is extremely difficult from an engineering perspective to effectively shield against [iron particles]," Kerry O'Banion, a researcher at the University of Rochester Medical Center and lead author of the study, said in a released statement. "One would have to essentially wrap a spacecraft in a six-foot block of lead or concrete."
The finding is the latest to suggest that space may not be as habitable as scientists had once hoped. A study of 27 astronauts published in March found that nearly all of them had eye and brain abnormalities after returning from space. The abnormalities are believed to be caused by increased pressure on the brain caused by space's lack of gravity. Previous studies have also suggested that radiation in space could cause cancer.
"Galactic cosmic radiation poses a significant threat to future astronauts," O'Banion said. "This is yet another factor that NASA, which is clearly concerned about the health risks to its astronauts, will need to take into account as it plans future missions."