Review of NASA's Biomedical Research Program (2000) / Chapter Skim
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8 Radiation Biology
8 Radiation Biology
Pages 51-57
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From page 51... ...
Hence quantitative designs of appropriate countermeasures, such as shielding, and biochemical or biological schemes to reduce the damage from HZE particles or augment repair following radiation exposure, are very rudimentary. The Strategy report recommended a comprehensive research program to determine the risks from different types and energies of HZE particles and from 51
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From page 52... ...
The higher-priority recommendations were aimed at determining the carcinogenic risk and effects on the CNS of exposure to energetic protons and HZE particles; how the composition of the shielding would quantitatively ameliorate the biological effect of HZE particles; and whether there are studies on radiation-induced genetic changes that could increase confidence in extrapolating from rodents to humans and might enhance a similar extrapolation for cancer. Other high-priority recommendations were to determine if there were better analyses that could decrease the present uncertainties in the risks of HZE effects, to determine how the design of the space vehicle could affect the internal radiation levels, and to determine whether SPEs could be predicted with sufficient advance warning for astronauts to return to a shielded shelter.
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From page 53... ...
NASA's Strategic Program Plan (NASA, 1998) is very clear in pointing out that "current knowledge of radiation effects in space is not adequate for the design of long-duration missions without incurring either unacceptable risks or excessive costs." In 1998 and 1999, the total program in radiation biology and dosimetry included 35 NASA Research Announcements (NRAs)
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From page 54... ...
of HZE particles for cancer induction. These molecular and cell biology experiments were proposed in the Strategy report as a way to validate the general biological effects of radiation fields behind shielding, but no such shielding experiments have yet been carried out.
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From page 55... ...
The flux rate of HZE particles in space is low, and although the particles, if not appropriately shielded, could over a long period of time produce deleterious effects in humans, the use of such radiation for radiobiological experiments on small vertebrates in space is impractical because it is not possible to transport an HZE accelerator into space. Some radiation experiments In space, using sparsely ionizing radiation, have been carried out on human lymphocytes, microorganisms, and the small roundworm Caenorhabditis elegans.
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From page 56... ...
Data on translocations and on the methods used to calculate dose equivalents from these translocations should be available to compare with the subsequent monitored health of astronauts, as emphasized in the discussion of human flight in the Strategy report. SUPPORT OF ADVANCED TECHNOLOGIES NASA is a strong supporter of advanced and innovative technologies in radiation dosimetry, biodosimetry, and molecular and cellular biology as applied to radiation effects, as indicated by
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From page 57... ...
NASA understands this problem and, to address it, has allocated initial funds to begin construction of a dedicated accelerator facility (the Booster Application Facility (BAF)
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