Shuryak Igor, Brenner David J
Center for Radiological Research, Columbia University Medical Center, New York, USA.
Radiat Prot Dosimetry. 2019 May 1;183(1-2):203-212. doi: 10.1093/rpd/ncy223.
Heavy ion-induced carcinogenesis is a challenge for human space exploration, and mechanistically-motivated mathematical models are needed to predict space-relevant low dose-rate risks, which are difficult to measure experimentally, based on data at higher dose rates. We present such a model, which quantifies targeted and non-targeted radiation effects. We fitted it to lung carcinogenesis data in radon-exposed miners and rats, which provide valuable information on carcinogenesis from protracted exposure to densely-ionizing radiation. We generated model-based estimates for the dose-rate-effect, relative to acute exposures, on heavy ion-induced carcinogenesis at doses/dose rates expected during a Mars mission. A small and not statistically-significant dose-rate effect was predicted: 1.00 (95% CI: 0.54, 1.40) for human data and for combined human and rat data 0.93 (0.06, 1.49). Consequently, heavy ion carcinogenesis estimates from moderate/high dose-rate experimental data may be applicable to doses/dose rates relevant for space exploration.
重离子诱导致癌是人类太空探索面临的一项挑战，需要基于高剂量率数据建立有机制依据的数学模型，以预测与太空相关的低剂量率风险，而这种风险很难通过实验测量。我们提出了这样一个模型，该模型对靶向和非靶向辐射效应进行了量化。我们将其与氡暴露矿工和大鼠的肺癌发生数据进行拟合，这些数据提供了长期暴露于密集电离辐射下致癌作用的宝贵信息。我们针对火星任务期间预期的剂量/剂量率，生成了基于模型的重离子诱导致癌作用相对于急性暴露的剂量率效应估计值。预测的剂量率效应较小且无统计学意义：人类数据为1.00（95%置信区间：0.54，1.40），人类和大鼠综合数据为0.93（0.06，1.49）。因此，来自中/高剂量率实验数据的重离子致癌作用估计值可能适用于与太空探索相关的剂量/剂量率。
