Mothersill Carmel, Seymour Colin
1Medical Physics and Applied Radiation Sciences Department, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
Medical Physics and Applied Radiation Sciences Department, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
Health Phys. 2018 Jul;115(1):170-178. doi: 10.1097/HP.0000000000000876.
To address the following key question, what are the consequences of nontargeted and delayed effects for linear nonthreshold models of radiation risk? This paper considers low-dose "indirect" or nontargeted effects and how they might impact radiation protection, particularly at the level of the environment. Nontargeted effects refer to effects in cells, tissues, or organisms that were not targeted by irradiation and that did not receive direct energy deposition. They include genomic instability and lethal mutations in progeny of irradiated cells and bystander effects in neighboring cells, tissues, or organisms. Low-dose hypersensitivity and adaptive responses are sometimes included under the nontargeted effects umbrella, but these are not considered in this paper. Some concepts emerging in the nontargeted effects field that could be important include historic dose. This suggests that the initial exposure to radiation initiates the instability phenotype which is passed to progeny leading to a transgenerational radiation-response phenotype, which suggests that the system response rather than the individual response is critical in determining outcome.
Nontargeted effects need to be considered, and modeling, experimental, and epidemiological approaches could all be used to determine the impact of nontargeted effects on the currently used linear nonthreshold model in radiation protection.
解决以下关键问题，即非靶向和延迟效应对于辐射风险的线性无阈模型有何影响？本文探讨低剂量“间接”或非靶向效应，以及它们如何可能影响辐射防护，特别是在环境层面。非靶向效应是指在未受照射且未接受直接能量沉积的细胞、组织或生物体中产生的效应。它们包括受照射细胞后代中的基因组不稳定性和致死性突变，以及邻近细胞、组织或生物体中的旁观者效应。低剂量超敏反应和适应性反应有时也被纳入非靶向效应范畴，但本文对此不予考虑。非靶向效应领域中一些可能重要的新兴概念包括历史剂量。这表明最初的辐射暴露引发了不稳定表型，该表型传递给后代，导致跨代辐射反应表型，这意味着系统反应而非个体反应对于确定结果至关重要。
需要考虑非靶向效应，建模、实验和流行病学方法均可用于确定非靶向效应对辐射防护中当前使用的线性无阈模型的影响。
