As countries rush to the Moon, with plans for future manned exploration of Mars and beyond, one of the biggest threats to astronauts is exposure to radiation in space. Researchers at the International Space Station (ISS) have now detected and measured the damage caused by radiation exposure to astronauts during space flights.
Astronauts aboard the Flying Outpost are constantly studying ways to reduce the risk of spaceflight and develop capabilities to predict space radiation exposure for future exploration missions.
In a study published in the journal Nature-Scientific Reports, scientists demonstrate how the sensitivity of an individual astronaut’s DNA to radiation exposure on Earth can predict the response of their DNA during space flight, as measured by changes in its chromosomes.
Radiation exposure for astronauts
As part of the research, scientists studied blood samples from 43 crew missions taken before and after the flight. While pre-flight blood samples were exposed to varying doses of gamma rays, post-flight blood samples were taken shortly and several months after landing.
Japan Aerospace Exploration Agency astronaut Akihiko Hoshide poses for a photo after undergoing a generic blood test at the European Laboratory / Columbus Orbital Facility (COF). (Photo: Nasa)
“We wanted to know if it is possible to detect and measure the damage caused by radiation exposure in the body of astronauts, and if there are differences based on age, sex and other factors. that could be measured before they go into space, âthe senior scientist said. Honglu Wu of NASA’s Johnson Space Center. The researchers studied the impact of this radiation on the chromosomes of astronauts. Chromosomes contain the building blocks of our body’s DNA, and changing them can increase the risk of developing cancer and other diseases.
During the experiment, scientists measured the levels of chromosome alterations due to radiation and other factors before and after a mission. These chromosome alterations are seen in a very small percentage of individual cells in a person’s blood.
This is what they found
As part of the study, the scientists performed three measurements, first, they analyzed blood samples from astronauts before their flight to the ISS, to assess their basic chromosomal status, and then these blood samples. were intentionally exposed to gamma radiation on Earth to measure how easily cells accumulate changes, and third, after the astronauts returned from their missions, the study team again took blood samples from the individuals to assess their level of chromosomal alterations.
Blood samples taken by former NASA astronaut Chris Cassidy before boarding the International Space Station. (Photo: Nasa)
Following in-depth analysis of the samples, the scientists found:
- Older crew members had higher levels of basic chromosomal irregularities
- Blood cells of older astronauts were more susceptible to developing chromosome alterations
- Crew members with higher inherent sensitivity, as determined by gamma radiation on the ground, were more likely to see higher levels of their chromosome changes in their blood samples after the flight than those with higher sensitivity. weak.
- People who had higher baseline chromosome alterations in their pre-flight blood samples also tended to be more susceptible to the development of additional chromosome changes.
- “The results suggest that if older astronauts do indeed have a higher sensitivity to radiation, they may be at greater risk for chromosomal damage,” Wu said.
What is space radiation?
The ISS is constantly exposed to several forms of radiation emerging from the vastness of the cosmos, including a continuous bombardment of particles from the Sun. Space radiation comes from the Earth’s magnetic field, particles thrown into space during solar flares, and galactic cosmic rays, which originate outside our solar system.
The older crew members exhibited higher levels of basic chromosomal irregularities. (Photo: Nasa)
Continued exposure to this radiation can lead to cancerous damage to the central nervous system, cardiovascular disease and other adverse health effects. While astronauts are shielded from major radiation in low Earth orbit, due to the Earth’s magnetic field, spacecraft armor, and limited time in space, these factors would change dramatically for long duration missions.
Therefore, studying these changes is essential so that new pathways and medical treatments can be devised.