We report on the contributions of model factors that appear in projection models to the overall uncertainty in cancer risks predictions for exposures to galactic cosmic ray (GCR) in deep space, including comparisons with revised low LET risks coefficients. Annual GCR exposures to astronauts at solar minimum are considered. Uncertainties in low LET risk coefficients, dose and dose-rate modifiers, quality factors (QFs), space radiation organ doses, non-targeted effects (NTE) and increased tumor lethality at high LET compared to low LET radiation are considered. For the low LET reference radiation parameters we use a revised assessment of excess relative risk (ERR) and excess additive risk (EAR) for radiation induced cancers in the Life-Span Study (LSS) of the Atomic bomb survivors that was recently reported, and also consider ERR estimates for males from the International Study of Nuclear Workers (INWORKS). For 45-y old females at mission age the risk of exposure induced death (REID) per year and 95% confidence intervals is predicted as 1.6% [0.71, 1.63] without QF uncertainties and 1.64% [0.69, 4.06] with QF uncertainties. However, fatal risk predictions increase to 5.83% [2.56, 9.7] based on a sensitivity study of the inclusion of non-targeted effects on risk predictions. For males a comparison using LSS or INWORKS lead to predictions of 1.24% [0.58, 3.14] and 2.45% [1.23, 5.9], respectively without NTEs. The major conclusion of our report is that high LET risk prediction uncertainties due to QFs parameters, NTEs, and possible increase lethality at high LET are dominant contributions to GCR uncertainties and should be the focus of space radiation research.

我们报告了投影模型中出现的模型因素对在深空暴露于银河宇宙射线 (GCR) 的癌症风险预测的整体不确定性的贡献，包括与修订后的低 LET 风险系数的比较。考虑了宇航员在太阳最低时的年度 GCR 暴露。与低 LET 辐射相比，低 LET 风险系数、剂量和剂量率调节剂、质量因子 (QF)、空间辐射器官剂量、非靶向效应 (NTE) 以及高 LET 下肿瘤致死率增加的不确定性被考虑在内。对于低 LET 参考辐射参数，我们在最近报道的原子弹幸存者寿命研究 (LSS) 中使用辐射诱发癌症的超额相对风险 (ERR) 和超额附加风险 (EAR) 的修订评估，并考虑国际核工人研究 (INWORKS) 中男性的 ERR 估计值。对于处于任务年龄的 45 岁女性，每年暴露导致死亡 (REID) 的风险和 95% 的置信区间预计为 1.6% [0.71, 1.63]（无 QF 不确定性）和 1.64% [0.69, 4.06]（有 QF 不确定性）。然而，基于对风险预测的非靶向影响纳入的敏感性研究，致命风险预测增加到 5.83% [2.56, 9.7]。对于男性，使用 LSS 或 INWORKS 的比较导致预测分别为 1.24% [0.58, 3.14] 和 2.45% [1.23, 5.9]，没有 NTE。我们报告的主要结论是，由于 QF 参数、NTE、