Senior project researcher and associate professor of regenerative medicine Dr. Christopher Porada said that radiation exposure could up the risk of leukemia in space travelers in two ways.
Now, another team of scientists from the Wake Forest Institute for Regenerative Medicine, funded by Nasa, have conducted more basic research with human stem cells to measure the effects of deep space radiation.
A new study over travelling to Mars has claimed that humans going to space have higher leukaemia risk as their bodies encounter with risky radiations during the deep space travel.
NASA's Human Research Program, which involves this recent study, catalogues the effects of human spaceflight on the body, especially as it has not evolved to deal with conditions such as weightlessness. In turn, by being able to simulate these scenarios in a laboratory setting, the researchers have been able to reportedly assess their direct effects on mice with the help from human hematopoietic stem cells (HSCs) obtained from healthy donors.
Radiation practically shut the HSCs down, impeding their ability to produce blood cells by up to 80 percent. That duration is considered a stepping stone to a three-year Mars journey.
The participants were all between 30 and 55 years old, among the typical ages for being an astronaut. This means that astronauts will have to cope with a weakened immune system and a high risk of developing blood cancer and infections during prolonged journeys.
Although there are very few of these stem cells in the human body - they make up less than 0.1% of adults' bone marrow - they are important because they give rise to all other blood cells that play a role in transporting oxygen, fighting off infections, but also targeting malignant cells that can appear.
"Radiation exposure at these levels was highly deleterious to HSC function, reducing their ability to produce nearly all types of blood cells, often by 60-80%", said lead author Christopher Porada. Exposed mice developed what researchers deemed to be T-cell acute lymphoblastic leukemia. First, the genetic damage to HSCs leads to leukemia. The team describe this as the first demonstration that deep space radiation may increase the leukemia risk in humans.
Porada believes these latest findings offer serious concerns for future astronauts as previous research into the body's reaction to weightlessness and microgravity also showed significant changes in an astronaut's immune function during even the shortest mission.
Exposure to rays affected the ability to create key infection-fighting cells that actively target infections and tumours. "This may reduce the ability of the astronaut's immune system to eliminate malignant cells that arise as a result of radiation-induced mutations".