It is very important to determine the precise internal thyroid doses of Fukushima residents involved in the 2011 Fukushima nuclear disaster, particularly for small children. This has been challenging due to the lack of direct human measurements to identify 131I, the biggest contributor to the thyroid doses. We previously used a dataset of late whole-body counter (WBC) measurements targeting 134Cs and 137Cs for the thyroid dose estimation in comparison with the intake ratios of 131I to 137Cs (or 134Cs) derived from thyroid and whole-body doses individually obtained from different subject groups, assuming simultaneous acute intake via inhalation. Herein, we applied the same method to the doses of residents in Iwaki city (located south of the Fukushima Daiichi Nuclear Power Plant) with a relatively high activity ratio (131I/137Cs) for the ground deposition density. Our analyses revealed that the intake ratio (131I/137Cs) for the Iwaki residents was 4.2-4.3, which is relatively consistent with the values obtained in other studies (average 3.0-5.0). No regional difference in the intake ratios from other areas was observed, but further studies are required to determine the accurate intake ratio in the early phase of the accident, in particular focusing on the reasonable interpretation of results of the late WBC measurements to evaluate the actual Cs intake.
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机译:是非常重要的来确定精确的内部甲状腺剂量的福岛居民参与2011年的福岛核灾难,特别是对于小孩子。由于缺少直接的人类发起挑战131年测量来确定我,最大的贡献者甲状腺剂量。使用一个数据集的全身计数器(WBC)测量目标134 cs - 137 c甲状腺剂量评估与比较摄入比例131我137 cs(或134 cs)分别从甲状腺和全身剂量从不同的学科组,假设同时通过吸入急性摄入。我们应用的剂量相同的方法磐城市的居民(位于南部福岛第一核电站)活动比率相对较高(131 i / 137 cs)地面沉积密度。显示,摄入比例(131 i / 137 cs)磐居民4.2 - -4.3,这是相对与中获得的值一致其他研究(平均3.0 - -5.0)。从其他地区不同摄入率观察,但还需要进一步的研究来吗确定准确的早期摄取率阶段的事故,尤其关注结果的合理的解释晚WBC测量来评估实际的Cs的摄入量。
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