Space radiation cancer risks and uncertainties for Mars missions

Citation
Fa. Cucinotta et al., Space radiation cancer risks and uncertainties for Mars missions, RADIAT RES, 156(5), 2001, pp. 682-688
Citations number
37
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Experimental Biology
Journal title
RADIATION RESEARCH
ISSN journal
0033-7587 → ACNP
Volume
156
Issue
5
Year of publication
2001
Part
2
Pages
682 - 688
Database
ISI
SICI code
0033-7587(200111)156:5<682:SRCRAU>2.0.ZU;2-2
Abstract
Projecting cancer risks from exposure to space radiation is highly uncertai n because of the absence of data for humans and because of the limited radi obiology data available for estimating late effects from the high-energy an d charge (HZE) ions present in the galactic cosmic rays (GCR). Cancer risk projections involve many biological and physical factors, each of which has a differential range of uncertainty due to the lack of data and knowledge. We discuss an uncertainty assessment within the linear-additivity model us ing the approach of Monte Carlo sampling from subjective error distribution s that represent the lack of knowledge in each factor to quantify the overa ll uncertainty in risk projections. Calculations are performed using the sp ace radiation environment and transport codes for several Mars mission scen arios. This approach leads to estimates of the uncertainties in cancer risk projections of 400-600% for a Mars mission. The uncertainties in the quali ty factors are dominant. Using safety standards developed for low-Earth orb it, long-term space missions (> 90 days) outside the Earth's magnetic field are currently unacceptable if the confidence levels in risk projections ar e considered. Because GCR exposures involve multiple particle or delta -ray tracks per cellular array, our results suggest that the shape of the dose response at low dose rates may be an additional uncertainty for estimating space radiation risks. (C) 2001 by Radiation Research Society.