With plans underway to revisit the moon and explore other distant locations, a team of scientists headed up by M. Kerry O’Banion, M.D., Ph.D., a professor in the University of Rochester Medical Center (URMC) Department of Neurobiology and Anatomy, have found evidence that cosmic radiation from deep space travel could lead to cognitive problems and even speed up the processes that lead to Alzheimer’s disease.
When astronauts go into deep space, they are exposed to various types of radiation because they are no longer under the protection of the ozone layer and magnetic field provided by the Earth. While engineers have developed protective shielding for astronauts’ safety, it is almost impossible to prevent exposure to constant low level Galactic Cosmic Radiation (GCR). The Earth’s magnetic field is able to keep exposure to GCR at a minimum during low-orbit shuttle missions, but the amount of radiation received from a trip between Earth and Mars could be enough to expose the brain to a higher risk of degeneration.
While other studies indicate that space travelers could be at a higher risk of cancer of the cardiovascular and musculoskeletal systems, this new piece of research is the first to focus on neurodegeneration, as part of their study of space travel and the effects on the central nervous system.
Exploding stars emit high-mass, high-charged (HZE) particles at very high speeds and are almost feasibly impossible to shield, unlike hydrogen protons (emitted from solar flares) which are lighter in mass. “One would have to essentially wrap a spacecraft in a six-foot block of lead or concrete,” said O’Banion.
Extensive testing was carried out on lab mice to see what kind of effects long term radiation had on their brains. The mice underwent a series of experiments during which they had to recall objects or specific locations. The researchers observed that mice exposed to radiation were far more likely to fail these tasks, suggesting neurological impairment earlier than these symptoms would typically appear.
The brains of the mice also showed signs of vascular alterations and a greater than normal accumulation of beta amyloid, the protein “plaque” that accumulates in the brain and is one of the hallmarks of the disease.
The findings strongly suggested that long term exposure to GCR could significantly speed up the development of Alzheimer’s disease.
These findings add yet another blow to NASA’s planned missions to a distant asteroid in 2021 and Mars in 2035. O’Banion said that “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.”
You can view the entire research paper here.