Blood data trends of children in Fukushima after the Great East Japan Earthquake: Fukushima health management survey

Background After the Great East Japan Earthquake on March 11, 2011 and the subsequent accident at the Tokyo Electric Power Company-operated Daiichi Nuclear Power Plant, the Fukushima Prefecture government initiated the Fukushima Health Management Survey (FHMS) to assess the long-term health effects of the disaster on Fukushima residents. The blood tests of children aged <= 15 years between 2011 and 2012 did not reveal any changes regarding peripheral blood data; however, long-term monitoring is still necessary. Therefore, this study aimed to investigate the long-term health status of children aged <= 15 years who had evacuated the Fukushima Prefecture.Methods From 2011 to 2018, 71,250 evacuees aged 15 years or younger participated in the FMHS and were subjected to blood tests. By analyzing the data of the comprehensive health check survey managed by the FHMS, we examined the changes in hemoglobin (Hb) levels, white blood cell (WBC) counts, including fractions, and platelet (PLT) counts among children from 2011 to 2018.Results Minor fluctuations in Hb levels, PLT counts, and WBC counts were observed during the study period, but the central 95% intervals of distribution of the laboratory values were generally within previously reported reference intervals. In particular, there was no increase in the proportions of patients with anemia, polycythemia, or deviating WBC counts.Conclusion From 2011 to 2018, there was no increase in the percentages of children with anemia, polycythemia, or deviating WBC counts among the Fukushima Prefecture evacuees.