Astronauts remain at higher risk of catching cancer, a new study warns. Blood taken from astronauts was stored and studied for 20 years to assess their risk to DNA mutations in blood that can lead to the development of cancer.

First things first, space is an extremely unforgiving place for humans. Exposure to space radiation can increase the risk of astronauts developing cancer, undermine the central nervous system, and cause premature death of tissues, and even develop acute radiation syndrome.

For the study’s purpose, fourteen astronauts from NASA’s space shuttle programme took part. The study, published in Nature Communications Biology on August 31 concluded that all astronauts had DNA mutations in blood-forming stem cells.

The mutations were high given the astronauts’ age, but it still remained below a key signifier of concern. A higher frequency of somatic mutations was found in the genes of 12 astronauts who took part in the study. These astronauts went to space between 1998 and 2001 on shuttle missions that lasted for 12 days on average. 85% of this group was male, and six of these astronauts were on their first mission.