Astronauts exposed to low dose radiation on the journey to Mars risk suffering brain disorders, memory loss and anxiety. A study published today (August 5) in the open-access journal eNeuro, has highlighted the need for better protection in space. NASA is currently in the development stage of Mars 2020 – an unmanned mission to send a robotic rover to the Red Planet. But the space agency is also looking at sending manned missions on the seven-month-long trip to Mars.
Because of this, Professor Charles Limoli of the University of California and his colleagues, have looked at the effects of space radiation on mice.
The neurobiologists reported disrupted brain activity and behaviour in the test subjects, alongside “severe impairments in learning and memory”.
Exposure to low dose neutron radiation also contributed to “distress behaviours”, which the experts believe will also affect human astronauts.
As a result, the researchers predict one-in-five astronauts on deep space missions will suffer anxiety.
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One-in-three astronauts are also likely to suffer memory loss and the astronauts may also struggle with decision making.
What sets this study apart from similar radiation exposure tests, is the research focused on long-term low dose radiation.
The researchers wrote in their study: “As NASA prepares for a mission to Mars, concerns regarding health risks associated with deep space radiation exposure have emerged.
“Until now, the impacts of such exposures have only been studied in animals after acute exposures, suing dose rates approximately 1.5×10^5 higher than those actually encountered in space.
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“Using a new, low dose rate neutron irradiation facility, we have uncovered that realistic, low dose rate exposures produce serious neurocognitive complications associated with impaired neurotransmission.”
The study exposed lab mice to low doses of neutron and photon radiation over a period of six months.
After the sixth month period, the mice were anaesthetised and decapitated to examine their brains.
The prolonged space radiation exposure resulted in “serious neurocognitive complications” and “impaired neurotransmission”.
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Before death, the rodents also exhibited increased “anxiety behaviours”, suggesting impairments in the amygdala.
With NASA’s goal to send humans to Mars by the end of the 2030s, scientists are concerned about the long-term health effects this will have on astronauts.
The researchers concluded: “Currently, NASA, other governments and multiple commercial enterprises are racing to develop the capabilities necessary to send humans to Mars by the 2030s.
“However, a number of health concerns related to prolonged radiation exposure ins space have compelled increased research into how ionising radiation affects the brain.”