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Cited by 455Spaceflight effects on biologyEffects of Radiation ExposureRadiation Therapy and Dosimetry

Space Radiation: The number one risk to astronaut health beyond low earth orbit

Open access
Chancellor, Jeffery, Scott, Graham, Sutton, Jeffrey·2014·Life
DOI 10.3390/life4030491PMC PMC4206856
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Abstract

Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS) decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO). Shielding is an effective countermeasure against solar particle events (SPEs), but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR) nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts.

AI snapshot

Written from the paper’s full text.

TL;DR

This review argues that space radiation is the number one health risk for astronauts beyond low Earth orbit, driven by galactic cosmic radiation (GCR) and solar particle events (SPEs). It summarizes NASA’s four radiation risk areas—carcinogenesis, degenerative tissue effects, CNS decrements, and acute radiation syndrome—and calls for combined proton/heavy-ion exposures and integrated omics in ground-based research.

Key findings

  • Space radiation beyond LEO combines GCR and SPEs; GCR is approximately 87% protons, 12% alpha particles, and 1%–2% HZE nuclei with charges from Z = 3 to about Z = 28. SPEs can produce fluences in excess of 10^9 protons/cm², with dose rates from zero to 100 mGy/h inside a space vehicle and zero to 500 mGy/h during EVA.
  • NASA identifies four primary biomedical risks: carcinogenesis, degenerative tissue effects, CNS decrements, and acute radiation syndrome. ISS mission doses were typically greater than 70 mSv; career effective dose limits vary by age and sex, e.g., 520 mSv for a 25-year-old male astronaut and 370 mSv for a 25-year-old female astronaut.
  • CNS studies report that 20 cGy of 1 GeV/u 56Fe particles impairs learning and memory in rodents, proton radiation causes neurocognitive deficits at doses as low as 25 cGy, and ferret emesis/retching occurs at doses as low as 50 cGy. SPE-like radiation suppressed immune system function at doses as low as 1.0 Gy in a mini-pig model.
  • Shielding is effective against SPEs but ineffective against the biological impacts of fast-moving GCR HZE nuclei; the paper recommends concatenating proton and heavy-ion exposures in low-dose regimens and using omics techniques correlated with phenotypic observations.

Methods

  • Narrative review synthesizing the space radiation environment, NCRP and National Research Council reports, NASA evidence reports, astronaut cytogenetic data, and animal studies including rodent, ferret, and mini-pig models.
  • No systematic search strategy, inclusion criteria, or meta-analysis is described; the text presents no primary data collection or formal statistical analysis methods.

Limitations

  • Stated: morbidity risk and unique toxicity profiles remain poorly understood, and uncertainties in dose toxicity plus complex SPE/GCR spectra limit dose projections.
  • Stated: animal models have limitations for translating results to humans, and mono-energetic acute heavy-ion or proton exposures do not accurately model low-dose-rate space radiation effects.
  • Stated/evident: no studies conclusively demonstrate increased cancer mortality versus the U.S. population, due to low LEO doses, variable time intervals, small sample size, individual variability, and insufficient statistical power; as a narrative review, it also provides no new experimental data or systematic synthesis.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.3390/life4030491

Cites

70 of 70 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 93 cited sources checked · 0 supported · 0 flagged

  • Findingcitation

    Five SPE events were recorded during the recent transit of the Mars Science Laboratory (MSL) spacecraft from Earth to Mars.

    “For example, five SPE events were recorded during the recent transit of the MSL spacecraft from Earth to Mars [11].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [11] Zeitlin, 2013, Measurements of energetic particle radiation in transit to mars on the mars science laboratory, Science source

      Not checked in the free run.

  • Findingnone given

    The yield of chromosomal aberrations decreases some years after a first flight, but without reaching the un-irradiated values.

    “This included the intriguing observation that the yield of chromosomal aberrations decreases some years after a first flight, but without reaching the un-irradiated values.”
    Quote in the paperNot a substantial claim
  • Findingcitation

    Hienz et al. demonstrated that proton radiation caused marked neurocognitive deficits at doses as low as 25 cGy.

    “Hienz et al. demonstrated that proton radiation caused marked neurocognitive deficits at doses as low as 25 cGy.”
    Quote in the paperNot a substantial claim
  • Findingcitation

    In 2008, using multi-color fluorescence in situ hybridization, Cucinotta et al. showed complex chromosomal aberrations in lymphocyte cells involving three or more chromosomes, observed post-mission in ISS astronauts.

    “In 2008, using multi-color fluorescence in situ hybridization, Cucinotta et al. vividly showed complex chromosomal aberrations in lymphocyte cells involving three or more chromosomes, observed post-mission in ISS astronauts [29], (Figure 5).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [29] Cucinotta, 2008, Physical and biological organ dosimetry analysis for international space station astronauts, Radiat. Res. source

      Not checked in the free run.

  • Findingcitation

    Britten et al. have shown that doses as low as 20 cGy of simulated GCR radiation (1 GeV/u 56Fe particles) can significantly impair learning and memory in a rodent model.

    “Britten et al. have shown that doses as low as 20 cGy of simulated GCR radiation (1 GeV/u 56Fe particles) can significantly impair learning and memory in a rodent model.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [55] Britten, 2012, Low (20 cGy) doses of 1 GeV/u 56Fe-particle radiation lead to a persistent reduction in the spatial learning ability of rats, Radiat. Res. source

      Not checked in the free run.

    • cites [56] Lonart, 2012, Executive function in rats is impaired by low (20 cGy) doses of 1 GeV/u 56Fe particles, Radiat. Res. source

      Not checked in the free run.

  • May combine two claims. 24
  • Classified as probably not a substantial claim. 26

  • May combine two claims.

    Findingnone given

    Chromosome breaks were two-fold more frequent in the Apollo astronauts compared to the Gemini astronauts, suggesting for the first time a link between dose and flight duration.

    “This work showed that chromosome breaks were two-fold more frequent in the Apollo astronauts compared to the Gemini astronauts, suggesting for the first time a link between dose and flight duration.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    In the mouse model, high dose rate proton exposure produced comparable effects on the number of circulating white blood cells, which subsequently returned to pre-irradiation levels within 30 days after exposure.

    “in the mouse model, high dose rate proton exposures resulted in comparable effects on the number of circulating white blood cells that subsequently returned to pre-irradiation levels within 30 days following exposure”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    In the mini-pig model, proton radiation exposure had a more detrimental effect on white blood cell counts than electron radiation, with counts not returning to normal at the 30-day time point.

    “The WBC counts did not return to normal levels at the 30-day time point, with proton radiation exposure having the more detrimental effect.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    In a mouse model, T-cells did not become activated following exposure to low doses of SPE-like proton radiation, and the animals were susceptible to a non-toxic bacterial challenge of organisms (Pseudomonas aeruginosa, Klebsiella pneumoniae) that are relatively innocuous and ubiquitous on Earth and have been detected aboard the ISS.

    “In a mouse model, T-cells did not become activated following exposure to low doses of SPE-like proton radiation, and the animals were susceptible to a non-toxic bacterial challenge of organisms (Pseudomonas aeruginosa, Klebsiella pneumoniae) that are relatively innocuous and ubiquitous on Earth and have been detected aboard the ISS [65,66].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [65] Sanzari, 2013, Leukocyte activity is altered in a ground based murine model of microgravity and proton radiation exposure, PLoS One source

      Not checked in the free run.

    • cites [66] Li, 2014, Hindlimb suspension and spe-like radiation impairs clearance of bacterial infections, PLoS One source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    High LET radiation found in the GCR spectrum can directly or indirectly damage biomolecules (e.g., proteins, DNA, lipids), as well as organelles and cellular structures.

    “With respect to the different qualities of space radiation that may be encountered, the high LET radiation found in the GCR spectrum can directly or indirectly damage biomolecules (e.g., proteins, DNA, lipids), as well as organelles and cellular structures.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The large ionization power of GCR ions makes them a major health threat to astronauts and constitutes one of the most important barriers impeding plans for interplanetary travel by crewed spacecraft.

    “The large ionization power of GCR ions makes them a major health threat to astronauts and constitutes one of the most important barriers impeding plans for interplanetary travel by crewed spacecraft.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    During transit outside LEO, every cell nucleus within an astronaut would be traversed, on average, by a hydrogen ion every few days and by heavier HZE nuclei every few months.

    “During transit outside of LEO, every cell nucleus within an astronaut would be traversed, on average, by a hydrogen ion every few days and by heavier HZE nuclei (e.g., 16O, 28Si, 56Fe) every few months [12].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [12] Cucinotta, 1998, The effects of delta rays on the number of particle-track traversals per cell in laboratory and space exposures, Radiat. Res. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events overlaid on a more predictable flux of GCR.

    “Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    The fluence of ionized nuclei that make up GCR is inversely proportional to the solar cycle and decreases by a factor of two during solar maximum.

    “The fluence of ionized nuclei that make up GCR is inversely proportional to the solar cycle and decreases by a factor of two during solar maximum [10].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [10] National Council on Radiation Protection and Measurements (NCRP) (2000). Radiation Protection Guidance for Activities in Low-Earth Orbit, NCRP.

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Exploration missions outside of LEO will include interplanetary transits, and shielding provided by the spacecraft may not be able to completely protect astronaut crews from the effects of an SPE.

    “Exploration missions outside of LEO will include interplanetary transits, and shielding provided by the spacecraft may not be able to completely protect astronaut crews from the effects of an SPE.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisereasoning

    Ionized transition metals, such as iron (Z = 26), are biologically harmful because no reasonable amount of spacecraft material can shield them.

    “Ionized transition metals, such as iron (Z = 26), are biologically harmful, as no reasonable amount of spacecraft material can shield them (Figure 2).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    The main radiation health risks to astronaut crews on exploration missions are degenerative vascular changes, genetic mutations and cancer.

    “The main radiation health risks to astronaut crews on exploration missions are degenerative vascular changes, genetic mutations and cancer [2].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [2] National Council on Radiation Protection and Measurements (NCRP) (2006). Information Needed to Make Radiation Protection Recommendations for Space Missions Beyond Low-Earth Orbit, NCRP.

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    SPE dose rates are variable over the course of an event and range from zero to 100 mGy/h inside a space vehicle and from zero to 500 mGy/h for an astronaut exposed during an extravehicular activity (EVA) on missions outside of LEO.

    “SPE dose rates are variable over the course of an event and range from zero to 100 mGy/h inside a space vehicle and from zero to 500 mGy/h for an astronaut exposed during an extravehicular activity (EVA) on missions outside of LEO [6].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [6] Wu, H., Huff, J.L., Casey, R., Kim, M.H., and Cucinotta, F.A. (2013). Evidence Report: Risk of Acute Radiation Syndromes Due to Solar Particle Events, National Aeronautical and Space Agency.

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Shielding is effective against solar particle events (SPEs) but ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR) nuclei.

    “Shielding is an effective countermeasure against solar particle events (SPEs), but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR) nuclei.”
    • Also stated in: § 2.1. Galactic Cosmic Radiation · plain
      “Shielding only partially reduces the doses experienced inside a spacecraft, given the penetrating ability of HZE ions [8].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [8] Cucinotta, 2006, Evaluating shielding effectiveness for reducing space radiation cancer risks, Radiat. Meas. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    GCR nuclei are high-LET relativistic particles with sufficient energies to penetrate any shielding technology used on current mission vehicles.

    “GCR nuclei originate from outside our solar system and are high-LET relativistic particles, possessing sufficient energies to penetrate any shielding technology used on current mission vehicles [8].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [8] Cucinotta, 2006, Evaluating shielding effectiveness for reducing space radiation cancer risks, Radiat. Meas. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationreasoning

    The morbidity risk and unique toxicity profiles of space radiation remain poorly understood.

    “However, the morbidity risk and unique toxicity profiles remain poorly understood.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    No studies to date have adequately assessed the possibility of synergism between high-LET radiation and the stresses of the space environment.

    “No studies to date have adequately assessed the possibility of synergism between high-LET radiation and the stresses of the space environment.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Lack of knowledge about the biological effects of, and responses to, space radiation is the single most important factor limiting the prediction of radiation risk associated with human space exploration.

    “lack of knowledge about the biological effects of, and responses to, space radiation is the single most important factor limiting the prediction of radiation risk associated with human space exploration”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [3] Committee on the Evaluation of Radiation Shielding for Space Exploration, Aeronautics and Space Engineering Board, Division on Engineering and Physical Sciences, and National Research Council (2008). Managing Space Radiation Risk in the New Era of Space Exploration, National Academies Press.

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    It remains unclear how moderate to large magnitude SPEs, when combined with continuous GCR exposure, will affect the health and performance of astronaut crews during interplanetary transits.

    “It remains unclear how moderate to large magnitude SPEs, when combined with continuous GCR exposure, will affect the health and performance of astronaut crews during interplanetary transits.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationreasoning

    Calculation of radiation exposures to astronauts in a detailed and realistic way is challenging because of the complexity of the radiation environment, the shielding effects of the vehicle and/or space suit and human anatomy and physiology.

    “Calculation of radiation exposures to astronauts in a detailed and realistic way is challenging because of the complexity of the radiation environment, the shielding effects of the vehicle and/or space suit and human anatomy and physiology.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationnone given

    Radiation outside LEO is composed of a toxic milieu of GCR and particles (predominantly protons) expelled from the Sun during SPEs; this mixture represents the most significant physical impediment to safe human space exploration.

    “Radiation outside of LEO is composed of a toxic milieu of GCR and particles (predominantly protons) expelled from the Sun during SPEs. This mixture of radiation modalities represents the most significant physical impediment to safe human space exploration.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    Exposure to space radiation affects multiple organs and physiological systems in complex ways.

    “Exposure to space radiation affects multiple organs and physiological systems in complex ways (Figure 4).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Exposure to space radiation increases astronauts' risks of developing cancer, central nervous system (CNS) decrements, degenerative tissue effects, or acute radiation syndrome.

    “Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS) decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome.”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [4] Cucinotta, F.A., and Durante, M. (2013). Evidence Report: Risk of Radiation Carcinogenesis, National Aeronautical and Space Agency.

      Not checked in the free run.

    • cites [5] Cucinotta, F.A., Wang, H., and Huff, J.L. (2013). Evidence Report: Risk of Acute or Late Central Nervous System Effects from Radiation Exposure, National Aeronautical and Space Agency.

      Not checked in the free run.

    • cites [6] Wu, H., Huff, J.L., Casey, R., Kim, M.H., and Cucinotta, F.A. (2013). Evidence Report: Risk of Acute Radiation Syndromes Due to Solar Particle Events, National Aeronautical and Space Agency.

      Not checked in the free run.

    • cites [7] Huff, J.L., and Cucinotta, F.A. (2013). Evidence Report: Risk of Degenerative Tissue or other Health Effects from Radiation Exposure, National Aeronautical and Space Agency.

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    SPE radiation and the synergistic effects of spaceflight can place the crew at significant risk for prodromal effects, skin injury, hematological changes and immune system dysfunction.

    “SPE radiation and the synergistic effects of spaceflight can place the crew at significant risk for prodromal effects (e.g., nausea and vomiting), skin injury, hematological changes and immune system dysfunction.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Current space radiation guidelines pertain only to missions in low Earth orbit (LEO) and are not considered relevant for missions beyond LEO; acceptable levels of risk for space exploration beyond LEO have not been defined.

    “Current space radiation guidelines pertain only to missions in LEO and are not considered relevant for missions beyond LEO. The acceptable levels of risk for space exploration beyond LEO have not been defined at this time and need to be dealt with before sending manned missions to colonize the moon or to deep space, such as a mission to Mars”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [2] National Council on Radiation Protection and Measurements (NCRP) (2006). Information Needed to Make Radiation Protection Recommendations for Space Missions Beyond Low-Earth Orbit, NCRP.

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    In spite of their low flux, HZE ions constitute a deleterious biological threat and contribute a significant amount to the cumulative GCR dose that astronauts will incur outside of LEO.

    “Therefore, in spite of their low flux, HZE ions constitute a deleterious biological threat and contribute a significant amount to the cumulative GCR dose that astronauts will incur outside of LEO.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Uncertainties with respect to dose toxicity and the complex variation in SPE and GCR spectra likely to be encountered in future exploration missions underscore the need for models that are capable of identifying particle energy and species on an event-by-event basis.

    “Uncertainties with respect to dose toxicity and the complex variation in SPE and GCR spectra likely to be encountered in future exploration missions underscore the need for models that are capable of identifying particle energy and species on an event-by-event basis.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    The resultant radiation-induced increase in oxidative stress levels has been shown to exacerbate some degenerative tissue changes that are normally associated with aging (e.g., cardiovascular disease and cataract formation).

    “The resultant radiation-induced increase in oxidative stress levels has been shown to exacerbate some degenerative tissue changes that are normally associated with aging (e.g., cardiovascular disease and cataract formation).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    GCR ions originate outside the solar system and consist mostly of highly energetic protons and alpha particles, with a small component of high charge and energy (HZE) nuclei moving at relativistic speeds and energies.

    “GCR ions originate from outside our solar system and contain mostly highly energetic protons and alpha particles, with a small component of high charge and energy (HZE) nuclei moving at relativistic speeds and energies [1].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [1] Simpson, 1983, Elemental and isotopic composition of the galactic cosmic rays, Ann. Rev. Nucl. Part. Sci. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    Unpredictable and intermittent solar particle events (SPEs) can produce large plasma clouds containing highly energetic protons and some heavy ions that may cause a rapid surge of radiation both outside and within a spacecraft.

    “In addition to GCR, unpredictable and intermittent solar particle events (SPEs) can produce large plasma clouds containing highly energetic protons and some heavy ions that may cause a rapid surge of radiation both outside and within a spacecraft (Figure 1).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationreasoning

    Created by passing through spacecraft shielding, fission products can deliver a significant fraction of the total mission dose and have the ability to damage critical cellular components when passing through the tissues of the body.

    “Created by passing through spacecraft shielding, these fission products can deliver a significant fraction of the total mission dose and have the ability to damage critical cellular components when passing through the tissues of the body.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    The interaction of energetic SPE protons and heavy-charged GCR particles with the spacecraft structure can produce an additional, secondary intravehicular radiation hazard.

    “The interaction of energetic SPE protons and heavy-charged GCR particles with the spacecraft structure can produce an additional, secondary intravehicular radiation hazard.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    The interpretation of animal-based CNS studies that model the space radiation environment is limited and confounds the development of mitigation strategies and countermeasures.

    “Furthermore, the interpretation of animal-based CNS studies that model the space radiation environment is limited and confounds the development of mitigation strategies and countermeasures.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    Interpretation of studies on chromosomal aberrations in astronauts and cosmonauts is limited by significant individual variability and insufficient statistical power.

    “However, interpretation of these studies is limited by significant individual variability and insufficient statistical power [37,38,39,40].”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [37] Durante, 2003, Chromosome aberration dosimetry in cosmonauts after single or multiple space flights, Cytogenet. Genome Res. source

      Not checked in the free run.

    • cites [38] George, 2001, Chromosome aberrations in the blood lymphocytes of astronauts after space flight, Radiat. Res. source

      Not checked in the free run.

    • cites [39] George, 2004, Chromosome aberrations of clonal origin are present in astronauts’ blood lymphocytes, Cytogenet. Genome Res. source

      Not checked in the free run.

    • cites [40] Horstman, 2005, Space radiation does not induce a significant increase of intrachromosomal exchanges in astronauts’ lymphocytes, Radiat. Environ. Biophys. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationcitation

    It still remains to be determined whether the higher doses of radiation incurred during future exploration class missions beyond LEO will increase the threat of cancer for astronaut crews.

    “It still remains to be determined whether the higher doses of radiation incurred during future exploration class missions beyond LEO will increase the threat of cancer for astronaut crews [4].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [4] Cucinotta, F.A., and Durante, M. (2013). Evidence Report: Risk of Radiation Carcinogenesis, National Aeronautical and Space Agency.

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    During long-duration exploration missions beyond LEO, it is anticipated that multiple SPEs will be encountered.

    “During long-duration exploration missions beyond LEO, it is anticipated that multiple SPEs will be encountered.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Ionizing radiation can damage the CNS, causing changes to cognitive function, inducing fatigue, and generating performance decrements.

    “Ionizing radiation can damage the CNS, causing changes to cognitive function, inducing fatigue, and generating performance decrements [2,30,42,43,44,45,46,47,48,49,50,51].”
    Quote in the paperSubstantial claim0 of 10 sources checked
    • cites [2] National Council on Radiation Protection and Measurements (NCRP) (2006). Information Needed to Make Radiation Protection Recommendations for Space Missions Beyond Low-Earth Orbit, NCRP.

      Not checked in the free run.

    • cites [30] National Research Council (1990). Health Effects of Exposure to Low Levels of Ionizing Radiation: Beir V, The National Academies Press.

      Not checked in the free run.

    • cites [42] Butler, 2006, Neurocognitive effects of treatment for childhood cancer, Ment. Retard. Dev. Disabil. Res. Rev. source

      Not checked in the free run.

    • cites [43] Castro, 1985, Current considerations in heavy charged-particle radiotherapy: A clinical research trial of the university of california lawrence berkeley laboratory, northern california oncology group, and radiation therapy oncology group, Radiat. Res. Suppl. source

      Not checked in the free run.

    • cites [44] Fabrikant, 1985, Heavy charged-particle bragg peak radiosurgery for intracranial vascular disorders, Radiat. Res. Suppl. source

      Not checked in the free run.

    • cites [45] Napolitano, 1998, Neurological complications of radiotherapy and chemotherapy, J. Neurol. source

      Not checked in the free run.

    • cites [46] Kjellberg, 1983, Bragg-peak proton-beam therapy for arteriovenous malformations of the brain, N. Engl. J. Med. source

      Not checked in the free run.

    • cites [47] Levy, 1989, Stereotactic heavy-charged-particle bragg peak radiosurgery for the treatment of intracranial arteriovenous malformations in childhood and adolescence, Neurosurgery source

      Not checked in the free run.

    • cites [48] Schultheiss, 1995, Radiation response of the central nervous system, Int. J. Radiat. Oncol. Biol. Phys. source

      Not checked in the free run.

    • cites [49] Steinberg, 1990, Stereotactic heavy-charged-particle bragg-peak radiation for intracranial arteriovenous malformations, N. Engl. J. Med. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    A second spaceflight apparently does not proportionately increase the yield of aberrations, suggesting a non-additive or even an infra-additive effect, raising the possibility of a radio-adaptive response in crewmembers (i.e., radiation hormesis).

    “Moreover, a second spaceflight apparently does not proportionately increase the yield of aberrations, suggesting a non-additive or even an infra-additive effect, raising the possibility of a radio-adaptive response in crewmembers (i.e., “radiation hormesis”).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    There is only a small probability that low-LET radiation from SPEs will reach high enough doses to cause degenerative tissue effects.

    “Furthermore, there is only a small probability that low-LET radiation from SPEs will reach high enough doses to cause degenerative tissue effects.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The linkage between DNA lesions (including point mutations, insertions and deletions, as well as intra- and inter-chromosomal rearrangements) and carcinogenesis is well-established.

    “The linkage between DNA lesions (including point mutations, insertions and deletions, as well as intra- and inter-chromosomal rearrangements) and carcinogenesis is well-established [27].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [27] National Council on Radiation Protection and Measurements (NCRP) (2010). Potential Impact of Individual Genetic Susceptibility and Previous Radiation Exposure on Radiation Risk for Astronauts, NCRP.

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    The veracity of data obtained and the reliability of conclusions drawn from ground-based studies using model organisms will benefit substantially from accurately simulating combined exposures to both proton and heavy ion sources.

    “The veracity of data obtained and the reliability of conclusions drawn from ground-based studies using model organisms will benefit substantially from accurately simulating combined exposures to both protons and heavy ions sources.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    Space radiation is the number one risk to astronaut health on extended space exploration missions beyond the Earth's magnetosphere.

    “Space radiation is the number one risk to astronaut health on extended space exploration missions beyond the Earth’s magnetosphere.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Animal experiments have contributed significantly to understanding the mechanisms of disease.

    “In general, animal experiments have contributed significantly to our understanding of the mechanisms of disease, but their value in predicting the effectiveness of treatment strategies has limitations [80,81,82].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [80] Hackam, 2006, Translation of research evidence from animals to humans, JAMA source

      Not checked in the free run.

    • cites [81] Perel, P., Roberts, I., Sena, E., Wheble, P., Briscoe, C., Sandercock, P., Macleod, M., Mignini, L.E., Jayaram, P., and Khan, K.S. (2007). Comparison of treatment effects between animal experiments and clinical trials: Systematic review. BMJ, 334. source

      Not checked in the free run.

    • cites [82] Hackam, D.G. (2007). Translating animal research into clinical benefit. BMJ, 334. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    The ability of humans to become a multi-planet species will hinge, to a large extent, on their ability to appropriately understand, manage, mitigate and overcome the significant dangers and health effects of space radiation.

    “The ability of humans to realize our potential by becoming a multi-planet species will hinge on, to a large extent, our ability to appropriately understand, manage, mitigate and overcome the significant dangers and health effects of space radiation.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationreasoning

    The selection of a single animal model for specific organ system studies may prove inadequate due to physiological interactions between organ systems that modify specific radiation toxicities.

    “the selection of a single animal model for specific organ system studies may prove inadequate due to physiological interactions between organ systems that modify specific radiation toxicities.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    In the ferret model, retching and vomiting occur at doses as low as 50 cGy and can be expected from SPE radiation exposure at doses up to 2 Gy.

    “Animal studies performed using a ferret model indicate that retching and vomiting occur at doses as low as 50 cGy and can be expected from SPE radiation exposure at doses up to 2 Gy [67,68].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [67] King, 1988, Characterization of radiation-induced emesis in the ferret, Radiat. Res. source

      Not checked in the free run.

    • cites [68] Sanzari, 2013, Effects of solar particle event proton radiation on parameters related to ferret emesis, Radiat. Res. source

      Not checked in the free run.

    • Rests on an assumption: Astronauts performing EVAs have compromised shielding that can leave them vulnerable to the effects of unpredictable SPEs.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Animal models are applicable to two stages of radiation research: mechanisms/discovery and validation.

    “The group concluded that animal models are applicable to the following two stages of radiation research: (1) mechanisms/discovery; and (2) validation.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [79] Augustine, 2005, Animal models for radiation injury, protection and therapy, Radiat. Res. source

      Not checked in the free run.

47 of 47

  • The paper relies on this without support.

    The biological effects of space radiation observed in animal models can be extrapolated to human astronauts.

    “These research data demonstrate that important changes to the CNS can be expected to occur at mission-relevant dose and dose rate levels.”

  • The paper relies on this without support.

    Ground-based research studies employing model organisms can accurately mimic the biological effects of the space radiation environment if they concatenate exposures to both proton and heavy ion sources.

    “ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources.”

  • The paper relies on this without support.

    Astronauts performing EVAs have compromised shielding that can leave them vulnerable to the effects of unpredictable SPEs.

    “Astronauts performing EVAs have compromised shielding that can leave them vulnerable to the effects of unpredictable SPEs.”

  • The paper relies on this without support.

    Fatigue has been observed in radiotherapy patients receiving therapeutic radiation doses as low as 2 Gy.

    “it has been observed in radiotherapy patients receiving therapeutic radiation doses as low as 2 Gy.”

  • The paper relies on this without support.

    Individual differences in responses to radiation exist at all levels of biological organization (molecular, cellular and tissue).

    “Previous radiobiology research has shown individual differences in responses to radiation at all levels (i.e., molecular, cellular and tissue) of biological organization.”

  • The paper relies on this without support.

    Only limited testing has occurred to study the efficacy of medical countermeasures and pharmaceuticals when radiation exposure is a concomitant and aggravating factor.

    “only limited testing has occurred to study the efficacy of these measures and pharmaceuticals when radiation exposure is a concomitant and aggravating factor.”

  • The paper relies on this without support.

    Space radiation exposures at the dose rates expected for a mission to Mars may not induce significant acute or sub-acute biological responses.

    “This is tempered by evidence that space radiation exposures at the dose rates expected for a mission to Mars may not induce significant acute or sub-acute biological responses.”

  • The paper relies on this without support.

    Some commonly-used animal models do not accurately reflect the pathologies and pathologic response (outcomes and endpoints) seen in humans.

    “Some commonly-used animal models do not accurately reflect the pathologies and pathologic response (i.e., outcomes and endpoints) seen in humans”
8 of 8

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Exposure to ionizing radiation of cosmic rays during transit and on the Martian surface can result in carcinogenesis, tissue degeneration, and potentially acute radiation syndrome.

    “Exposure to the ionizing radiation of cosmic rays during transit as well as while on the Martian surface is also of great concern as it can result in carcinogenesis, tissue degeneration, and potentially acute radiation syndrome (Chancellor et al., 2014; Pavleti ´ c et al., 2022).”

    From Cyanobacteria and microalgae in supporting human habitation on Mars (2022) · cites this paper as Chancellor et al., 2014

    Section 3.1 links galactic cosmic radiation to degenerative tissue effects, and Section 3.2 discusses space-radiation-induced carcinogenesis. But Section 3.4 associates acute radiation syndromes with large solar particle events, not ordinary cosmic-ray exposure; Section 5.1 says the dose rates expected for a Mars mission may not induce significant acute responses. The claim therefore blurs an important distinction between radiation sources. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

  • Research on radio-susceptibility of cyanobacterium species is complicated because ionizing radiation in space is complex, temporal, and comes in many wavelengths and particle sizes.

    “Research related to the radio-susceptibility of cyanobacterium species is complicated by the fact that ionizing radiation (IR) in space is complex, temporal, and comes in many wavelengths and particle sizes [103].”

    From Biologically-Based and Physiochemical Life Support and In Situ Resource Utilization for Exploration of the Solar System—Reviewing the Current State and Defining Future Development Needs (2021) · cites this paper as [103]

    The Introduction and §5.1 describe space radiation as a changing mixture of particle types and energies that is difficult to simulate in radiobiology research. The paper does not address cyanobacteria or their radio-susceptibility, and it does not describe this variation in terms of wavelengths or particle sizes. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

  • The shielding provided by Earth's atmosphere and magnetic field is not available beyond low Earth orbit (LEO), and astronauts will have to contend with exposure to the compositionally complex, spatially and temporally variable space radiation environment, introducing critical risks to crew health and the completion of mission objectives.

    “Although this program represents a major step forward in human space exploration, the fact remains that the shielding provided by Earth’s atmosphere and magnetic field is not available beyond low Earth orbit (LEO) and astronauts will have to contend with exposure to the compositionally complex, spatially and temporally variable space radiation environment, introducing critical risks to crew health”

    From First evaluation of wearable radiation protection for human deep space exploration, as flown on Artemis I (2026) · cites this paper as [2]

    Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

    Experimental — accuracy not yet measured

  • The secondary spectrum reaching the Martian surface includes high LET low energy protons, neutrons and α-particles as well as penetrating high energy γ-rays.

    “The secondary spectrum reaching the Martian surface includes high LET low energy protons, neutrons and α-particles as well as penetrating high energy γ-rays (Chancellor et al., 2014).”

    From Medical countermeasures for the hematopoietic-subsyndrome of acute radiation syndrome in space (2022) · cites this paper as Chancellor et al., 2014

    Section 2.3 (Intravehicular Radiation; page unavailable) lists protons, alpha particles, neutrons and gamma rays among secondary particles produced when radiation passes through spacecraft shielding. It does not describe the spectrum reaching the Martian surface or assign the claimed LET and energy characteristics to those particles. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

  • The Martian atmosphere is thick enough to generate secondary particles from nuclear interactions of energetic protons from solar events and heavy-charged GCR particles with atmospheric atoms and molecules.

    “On the other hand, the atmosphere layer is thick enough to generate secondary particles from nuclear interactions of energetic protons from solar events and heavy-charged GCR particles with atmospheric atoms and molecules.”

    From Medical countermeasures for the hematopoietic-subsyndrome of acute radiation syndrome in space (2022) · cites this paper as Chancellor et al., 2014

    Section 2.3 (page not available) says energetic solar-event protons and heavy-charged GCR particles can generate secondary particles through interactions with spacecraft structures. It does not say that the Martian atmosphere is thick enough to generate them through interactions with atmospheric atoms and molecules. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

Cites

Flagged first, then by citations

Research works printed but not linked: 5

  1. Committee on the Evaluation of Radiation Shielding for Space Exploration, Aeronautics and Space Engineering Board, Division on Engineering and Physical Sciences, and National Research Council (2008). Managing Space Radiation Risk in the New Era of Space Exploration, National Academies Press.
  2. National Research Council (1973). Hze-Particle Effects in Manned Spaceflight, The National Academies Press.
  3. National Research Council (1996). Radiation Hazards to Crews of Interplanetary Missions:Biological Issues and Research Strategies, The National Academies Press.
  4. Davis, C.M., Roma, P.G., Brady, J.V., and Hienz, R.D. (2011, January 11–15). Neurobehavioral effects of space radiation on choice impulsivity. Proceedings of the 18th Biannual Meeting of the International Academy of Astronautics’ Humans in Space Symposium, Houston, TX, USA.
  5. Hienz, R.D., Davis, C.M., Weed, M.R., Guida, P.M., Gooden, V.L., Brady, J.V., and Roma, P.G. (2011, January 11–15). Neurobehavioral effects of space radiation on psychomotor vigilance and reaction time tests. Proceedings of the 18th Biannual Meeting of the International Academy of Astronautics’ Humans in Space Symposium, Houston, TX, USA.

Cited by

Sorted by citations

Related

Authors
Chancellor, J., Scott, G., & Sutton, J.
Affiliations
National Space Biomedical Research Institute (US)
Corresponding author
Sutton, Jeffrey
ORCID
Venue
Life
Publisher
MDPI AG
Published
2014-09-11
Volume
4
Issue
3
Pages
491-510
ISSN
2075-1729 (ISSN-L)
DOI
10.3390/life4030491
PMC
PMC4206856
OpenAlex
W2017290871
Semantic Scholar
0dae08815aba61fd12b71ab76d84c5815b55323d
Cited by
455
References
69
Citations by year
2026: 42 · 2025: 64 · 2024: 65 · 2023: 37 · 2022: 49 · 2021: 64 · 2020: 36 · 2019: 25 · 2018: 34 · 2017: 20 · 2016: 14 · 2015: 5
FWCI
1.53
Type
journal article
Language
en
Open access
Licence
Locations
  • Life (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Civil War Book Review (submittedVersion, cc-by)
  • Civil War Book Review (submittedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
  • National Space Biomedical Research Institute (NCC 9-58)
  • Baylor College of Medicine (Friedkin Chair for Research in Sensory System Integration and Space Medicine)
Topics
  • Health Sciences › Medicine › Physiology › Spaceflight effects on biology
  • Health Sciences › Medicine › Radiology, Nuclear Medicine and Imaging › Effects of Radiation Exposure
  • Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Radiation Therapy and Dosimetry
Keywords
space radiation, astronaut health, galactic cosmic rays, solar energetic particle events, radiation-induced cancer, radiation sickness, radiation shielding, Mars missions, model organisms, omics, long-duration spaceflight

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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