Medical Radiation Physics, Department of Translational Medicine, Lund University, Malmö, Sweden.
Department of Radiation physics, Institute of Clinical Sciences, Sahlgrenska Academy University of Gothenburg, Gothenburg, Sweden.
PLoS One. 2020 Feb 5;15(2):e0228549. doi: 10.1371/journal.pone.0228549. eCollection 2020.
The effect of age and gender in risk estimates related to long-term residence in areas contaminated by nuclear power plant fallout was evaluated by applying the lifetime attributable risk (LAR) concept to an existing exposure model that was previously used for cumulative effective dose estimates. In this study, we investigated the influence of age distribution on the number of cancer cases by applying five different age distributions from nuclear power-producing countries (India, Japan, South Korea, and the United States), and Egypt because of intentions to develop nuclear power. The model was also used to estimate the effective dose and gender-specific LAR as a function of time after fallout for the offspring of the population living in 137Cs fallout areas. The principal findings of this study are that the LAR of cancer incidence (excluding non-fatal skin cancers) over 70 y is about 4.5 times higher for newborn females (5.4% per MBq m-2 of initial 137Cs ground deposition) than the corresponding values for 30 y old women (1.2% per MBq m-2 137Cs deposition). The cumulative LAR for newborn males is more than 3 times higher (3.2% versus 1.0% per MBq m-2 137Cs deposition). The model predicts a generally higher LAR for women until 50 y of age, after which the gender difference converges. Furthermore, the detriment for newborns in the fallout areas initially decreases rapidly (about threefold during the first decade) and then decreases gradually with an approximate half-time of 10-12 y after the first decade. The age distribution of the exposed cohort has a decisive impact on the average risk estimates, and in our model, these are up to about 65% higher in countries with high birth rates compared to low birth rates. This trend implies larger average lifetime attributable risks in countries with a highly proportional younger population. In conclusion, the large dispersion (up to a factor of 4 between newborns and 30 y olds) in the lifetime detriment per unit ground deposition of 137Cs over gender and age in connection with accidental nuclear releases justifies the effort in developing risk models that account for the higher radiation sensitivity in younger populations.
研究应用终生归因风险（LAR）概念，对先前用于估算累积有效剂量的暴露模型进行评估，以考察年龄和性别因素对与长期居住在核电厂放射性沉降物污染区相关的风险估计的影响。在本研究中，我们通过应用来自核生产国（印度、日本、韩国和美国）和计划发展核能的埃及的 5 种不同年龄分布情况，调查了年龄分布对癌症病例数量的影响。该模型还用于估算生活在 137Cs 沉降区的人口的后代在放射性沉降物之后随时间推移的有效剂量和特定性别 LAR。本研究的主要发现是，对于新生儿女性（每 137Cs 初始地面沉积 5.4%，每兆贝克/平方米），70 岁以上癌症发病率（不包括非致命性皮肤癌）的 LAR 比 30 岁女性高约 4.5 倍（每 137Cs 沉积 1.2%，每兆贝克/平方米）。新生儿男性的累积 LAR 高 3 倍以上（每 137Cs 沉积 3.2%，每兆贝克/平方米）。该模型预测，女性的 LAR 普遍在 50 岁之前较高，之后性别差异逐渐收敛。此外，最初在放射性沉降物区内新生儿的危害迅速下降（第一个十年内下降约三倍），然后在第一个十年后以约 10-12 年的近似半衰期逐渐下降。暴露队列的年龄分布对平均风险估计有决定性影响，在我们的模型中，与低出生率国家相比，高出生率国家的平均风险估计值高达 65%。这一趋势意味着在人口年轻化比例较高的国家，平均终生归因风险更大。总之，在与意外核泄漏相关的性别和年龄每单位 137Cs 地面沉积的终生危害方面，存在很大的分散性（新生儿与 30 岁人群之间的差异高达 4 倍），因此有必要努力开发考虑到年轻人群中更高辐射敏感性的风险模型。
