Solar and Space Physics and the Vision for Space Exploration Understanding and Mitigating the Radiation Hazards of Space Travel: Progress and Future Needs Richard B. Setlow Senior Biophysicist Brookhaven National Laboratory

Some References 1. E.L. Alpen, (1998) RADIATION BIOPHYSICS, second edition, Academic Press, NY. 2. E.L. Alpen, et al. (1993) Tumorigenic Potential of High-Z, High-LET Charged-Particle Radiations. Radiat. Res. 136, M.J. Bissel, panel chair (1997) “Modeling Human Risk: Cell and Molecular Biology in Context” Laurence Berkley National Laboratory F. Cucinotta, et al., (2002) “Space Radiation Cancer Risk Projections for Exploratory Missions: Uncertainly Reduction and Mitigation”. NASA/ Technical Publication R.B. Setlow (1999) The U.S. National Research Council’s views of the radiation hazards in space. Mutat.Res. 430, R.B. Setlow (2003) The hazards of space travel. EMBO reports 4,

Values of LET for a Range of HZE Nuclei (From Reference 4, page 8) ________________________________________________________________ _ Particle Type LET (keV/µm) ____________________________________________ 60 Co 0.23

Modeling Human Risk: Cell & Molecular Biology in Context Report Number : LBNL June 1997 Mina J Bissel, Panel Chair Calculated Value Experimental Value

J.RADIAT.RES., 43: SUPPL.,S1-S6 (2002) How Do We Get from Cell and Animal Data to Risks for Humans from Space Radiations? J.F.DICELLO

Reference 2, p.385, 386, 388

Ion Energy LET (MeV/A) (keV/um) 60 Co-gam 0.23 Protons Helium Neon Iron Iron Niobium

LET (keV/µm) Cross Section for Tumor Induction in Hardarian Gland in Mice Versus LET Reference 2, p.386 Cross Section ( µm 2 ) Cobalt-60 ProtonsHelium Neon Iron-350 Iron-600 Niobium

Figure 3. Cumulative excess lifetime incidence of mammary tumours as a function of dose for the photon, proton and iron irradiated rats. At the higher doses, the likelihood of an animal surviving without at least one tumour, when the natural background rate is included, is approaching zero. Although the primary regions of interest for risk analysis are the lower dose regions, background rates and the shape of the response function at high doses was not known.

Induction of Apoptosis by Iron Nuclei or Gamma Rays RADIATION RESEARCH 164, in press (2005) Cytotoxic Effects of Low- and High-LET Radiation on Human Neuronal Progenitor Cells P. Guida, M. E. Vazquez and S. Otto

Features Beams of heavy ions extracted from the booster accelerator with masses and energies similar to the cosmic rays encountered in space: 1 billion electron volt (GeV)/nucleon iron GeV/nucleon gold GeV/nucleon silicon-28 1-GeV/nucleon protons 1-GeV/nucleon titanium 0.29-GeV/nucleon carbon a new 100-meter transport tunnel and beam line to deliver the beam to a 400 square-foot shielded target hall for NASA-funded space-effects experiments

SHIELDING

Figure 6. Effects of diets A, B, D and E on the total antioxidant levels in Sprague-Dawley rats irradiated with 1 GeV/n iron ions.

1g ~0g

AN EXAMPLE OF A RECENT DETERMINATION OF RBEs THE EFFECTS OF HZEs ON THE INDUCTION OF GERM-CELL MUTATIONS

Proceedings of the National Academy of Sciences (2005) vol. 102, Germ cell mutagenesis in medaka fish following exposures to high energy cosmic ray nuclei: a human model Atsuko Shimada*, Akihiro Shima †║, Kumie Nojima ‡, Yo Seino † and Richard Setlow §¶ *Department of Biological Sciences, School of Sciences, † University of Tokyo, Department of Integrated Biosciences 102, Graduate School of Frontier Sciences, University of Tokyo, ‡ International Space Radiation Laboratory, National Institute of Radiological Sciences, Chiba, § Biology Department, Brookhaven National Laboratory, Upton, NY Contributed by Richard Setlow ¶ To whom correspondence should be addressed. Classification: Biological Sciences, Genetics

Dose Response Data sperm tids gonia

Table 3. Relative Biological Effectiveness (± SD) of HZE Nuclei Induction of Mutations in Sperm, Spermatids (tids) and Spermatogonia (gonia) 3.5 GeV 12 C 56 GeV 56 Fe sperm DL 1.32 ± ±.020 TM 1.69 ± ± 0.20 tids DL 1.54 ± ± 0.23 TM 2.1 ± ± 0.47 gonia DL 5.4 ± ± 8 TM 1.0 ± ± 1.2