Dobney William, Mols Louise, Mistry Dhruti, Tabury Kevin, Baselet Bjorn, Baatout Sarah
Radiobiology Unit, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium.
School of Aeronautical, Automotive, Chemical and Materials Engineering, Loughborough University, Loughborough, United Kingdom.
Front Nucl Med. 2023 Sep 21;3:1225034. doi: 10.3389/fnume.2023.1225034. eCollection 2023.
Ionizing radiation and microgravity are two considerable health risks encountered during deep space exploration. Both have deleterious effects on the human body. On one hand, weightlessness is known to induce a weakening of the immune system, delayed wound healing and musculoskeletal, cardiovascular, and sensorimotor deconditioning. On the other hand, radiation exposure can lead to long-term health effects such as cancer and cataracts as well as have an adverse effect on the central nervous and cardiovascular systems. Ionizing radiation originates from three main sources in space: galactic cosmic radiation, solar particle events and solar winds. Furthermore, inside the spacecraft and inside certain space habitats on Lunar and Martian surfaces, the crew is exposed to intravehicular radiation, which arises from nuclear reactions between space radiation and matter. Besides the approaches already in use, such as radiation shielding materials (such as aluminium, water or polyethylene), alternative shielding materials (including boron nanotubes, complex hybrids, composite hybrid materials, and regolith) and active shielding (using fields to deflect radiation particles) are being investigated for their abilities to mitigate the effects of ionizing radiation. From a biological point of view, it can be predicted that exposure to ionizing radiation during missions beyond Low Earth Orbit (LEO) will affect the human body in undesirable ways, e.g., increasing the risks of cataracts, cardiovascular and central nervous system diseases, carcinogenesis, as well as accelerated ageing. Therefore, it is necessary to assess the risks related to deep space exploration and to develop mitigation strategies to reduce these risks to a tolerable level. By using biomarkers for radiation sensitivity, space agencies are developing extensive personalised medical examination programmes to determine an astronaut's vulnerability to radiation. Moreover, researchers are developing pharmacological solutions (e.g., radioprotectors and radiomitigators) to proactively or reactively protect astronauts during deep space exploration. Finally, research is necessary to develop more effective countermeasures for use in future human space missions, which can also lead to improvements to medical care on Earth. This review will discuss the risks space travel beyond LEO poses to astronauts, methods to monitor astronauts' health, and possible approaches to mitigate these risks.
电离辐射和微重力是深空探索过程中面临的两大重大健康风险。二者都会对人体产生有害影响。一方面，失重会导致免疫系统减弱、伤口愈合延迟以及肌肉骨骼、心血管和感觉运动功能失调。另一方面，辐射暴露会导致癌症和白内障等长期健康问题，还会对中枢神经和心血管系统产生不利影响。电离辐射主要源于太空中的三个来源：银河宇宙辐射、太阳粒子事件和太阳风。此外，在航天器内部以及月球和火星表面的某些太空栖息地内，宇航员会受到舱内辐射，这种辐射是由太空辐射与物质之间的核反应产生的。除了已在使用的方法，如辐射屏蔽材料（如铝、水或聚乙烯），人们正在研究替代屏蔽材料（包括硼纳米管、复合混合物、复合混合材料和风化层）以及主动屏蔽（利用场来偏转辐射粒子）减轻电离辐射影响的能力。从生物学角度来看，可以预测在近地轨道（LEO）以外的任务中暴露于电离辐射会以不良方式影响人体，例如增加患白内障、心血管和中枢神经系统疾病、致癌以及加速衰老的风险。因此，有必要评估与深空探索相关的风险，并制定缓解策略将这些风险降低到可容忍的水平。通过使用辐射敏感性生物标志物，航天机构正在制定广泛的个性化医学检查计划，以确定宇航员对辐射的易感性。此外，研究人员正在开发药理学解决方案（如辐射防护剂和辐射缓解剂），以便在深空探索期间主动或被动地保护宇航员。最后，有必要开展研究以开发更有效的对策用于未来的载人航天任务，这也可能会改善地球上的医疗保健。本综述将讨论近地轨道以外的太空旅行给宇航员带来的风险、监测宇航员健康的方法以及减轻这些风险的可能途径。
