Abstract：
The accident at Fukushima Daiichi Nuclear Power Plant (FDNPP) in 2011 resulted in the dispersion of radioactive materials throughout the surrounding area and an increase in the air dose rate was even confirmed in Fukushima City, which is located approximately 60 km northeast of FDNPP. A Tokyo Electric Power Company (TEPCO) Holdings employee, who has lived and worked in Fukushima City since the FDNPP accident, measured individual external doses, GPS data, and his activities in Fukushima Prefecture over a 9 year period beginning in 2014. This data provides valuable information about the area. The data show the following results. (i) Comparison of the air dose rate at the home location to the individual external dose per hour at the home shows that the average conversion factor has increased over the 9 years and exceeded 0.3 since 2019, indicating an overall relatively good correlation. (ii) Individual external doses measured in the office on the fourth floor of a concrete structure in Fukushima City have not changed significantly from 2014 to 2022, when air dose rates showed a decrease. (iii) Outdoor individual external doses, such as those measured when commuting on foot, have a relatively strong correlation with air dose rates from airborne monitoring with the conversion factor of about 0.6. The conversion factor do not differ significantly from 2014 to 2022.In this study, the individual external dose data is applicable to the TEPCO measurer and is not necessarily representative of all residents of Fukushima City. However individual external dose data for 9 consecutive years will be useful for estimating individual external doses from air dose rates, and estimating annual additional exposure doses, if even some of them are applicable to similar life patterns and lifestyles.
摘要：
2011年福岛第一核电站（FDNPP）事故导致放射性物质在整个周边地区扩散，甚至在福岛市证实了空气剂量率的增加，位于FDNPP东北约60公里处。东京电力公司(TEPCO)控股公司的一名员工，自FDNPP事故以来一直在福岛市生活和工作，测量个体外部剂量，GPS数据,以及他从2014年开始的9年期间在福岛县的活动。这些数据提供了有关该地区的宝贵信息。数据显示以下结果。＆＃xD;④2014年至2022年，在福岛市一座混凝土结构的四楼办公室测得的个人外部剂量没有显着变化，当时空气剂量率显示下降。＆＃xD;户外个人外部剂量，比如步行上下班时测量的，与机载监测的空气剂量率具有相对较强的相关性，转换因子约为0.6。从2014年到2022年，转换系数没有显着差异。
在这项研究中,个人外部剂量数据适用于东京电力公司测量员，不一定代表福岛市的所有居民。然而，连续9年的个人外部剂量数据将有助于根据空气剂量率估算个人外部剂量。估计每年的额外暴露剂量，即使其中一些适用于类似的生活模式和生活方式。
