Scientists studied blood samples of 14 NASA astronauts who flew into space as part of the missions of the Space Shuttle program from 1998 to 2001, and found that all samples showed mutations in the cells’ DNA, reports Futurism. These mutations are quite low and do not pose a serious threat to human health. However, the study highlights the importance of regular medical examinations for astronauts, especially before long missions to the Moon and beyond.
Mutations were marked by a high proportion of blood cells originating from a single clone. This phenomenon is called clonal hematopoiesis. Such mutations can be caused by excessive amounts of ultraviolet radiation and other forms of radiation, including chemotherapy. Researchers suggest that in this case, the mutations could have been the result of cosmic radiation.
“Astronauts work in an extreme environment where many factors can result in somatic mutations, most importantly space radiation, which means there is a risk that these mutations could develop into clonal hematopoiesis,” David Goukassian, professor of medicine at the Icahn School of Medicine, said in a statement.
Last year, NASA proposed changing the radiation limits astronauts can be exposed to in order to protect their health. There, efforts are being made to allow younger astronauts to be exposed to relatively higher amounts of radiation than older ones, and the differences in limits between men and women are being eliminated.
For this study, blood samples were collected from 12 male and two female astronauts ten days before their flight and on the day of landing. The samples were then stored in cryogenic conditions at a temperature of -80 degrees Celsius for about two decades. The mutations seen in the blood samples resemble the type of somatic mutations we see in the elderly. However, on average, astronauts were 42 years old.
“Although the clonal hematopoiesis we observed was of a relatively small size, the fact that we observed these mutations was surprising given the relatively young age and health of these astronauts,” said Goukassian. “The presence of mutations does not necessarily mean that the astronauts will develop cardiovascular disease or cancer,” he added, “but there is the risk that, over time, this could happen through ongoing and prolonged exposure to the extreme environment of deep space”
Goukassian and his team recommend that NASA regularly check astronauts for such mutations. Scientists have long been thinking about the numerous risks to the health of astronauts, and the more we learn, the better we can ensure their safety.