What factor is affected by high radiation levels in outer space?

High radiation levels in outer space primarily affect DNA integrity and cancer risk. In the space environment, cosmic rays and other types of radiation can cause direct damage to the DNA molecules in cells. This damage can lead to mutations, which are alterations in the DNA sequence. If these mutations occur in genes that control cell growth and division, they can increase the likelihood of cancer development.

Research has shown that astronauts exposed to higher levels of ionizing radiation are at an increased risk of developing cancer compared to those on Earth. This risk emphasizes the importance of protective measures for space missions, as well as ongoing monitoring of astronauts' health. While mental acuity, bone density, and physical stamina can also be impacted by the space environment, the direct and significant threat of high radiation levels is most clearly linked to the potential for DNA damage and the subsequent increase in cancer risk.