External exposure doses were estimated from activity records over four months following the nuclear accident for 2,055,238residents in the prefecture as of 11 Mar. 2011.
Out of the 467,484people (as of the end of March 2024) who responded to the survey excluding those with experience in radiation work and those whose estimated exposure period was less than four months, 99.8% were exposed to less than 5 mSv (millisieverts), with the maximum value being 25 mSv.
*Total number of respondents: 569,691 (response rate: 27.7%)
The dose estimates obtained in this survey (external effective dose for the first 4 months after the accident: 99.8% less than 5mSv, etc.) have been evaluated as being below the level of statistically significant differences in verifiable health effects in the light of current scientific knowledge.
Ultrasound examinations were conducted to Fukushima residents who were around 18 years old or younger at the time of the disaster.
The Thyroid Ultrasound Examination Evaluation Subcommittee summarised its view on the results from the Preliminary Baseline Survey to the Full-Scale
Survey (4th round), concluding that "no association between thyroid cancer and radiation exposure was found".
Meanwhile, the necessity of monitoring the generation of infants at the time of the nuclear accident, who had relatively high thyroid equivalent doses and are highly sensitive to radiation, was suggested for future examinations due to the possibility of delayed effects from low-dose radiation exposure.
The survey was conducted to understand the mental and physical health of pregnant and postpartum women, reduce anxiety, and provide necessary care.
The survey consists of a "Main Survey" conducted about one year after a pregnancy notification has been submitted and "Follow-up Surveys" conducted four and eight years after childbirth.
The Main Survey ended in FY2022 because the rates of premature birth, low birth weight, and congenital anomalies were found to be almost no different from government statistics and generally reported data.
For more detailed results of the survey, please see the link below.
The examination measures the radioactive cesium absorbed into the body from the atmosphere, food and other sources using a whole-body counter, and estimates the radiation dose expected to be received over a lifetime.
Fukushima Health Management Survey Investigative Committee
For Fukushima Health Management Survey, an investigative committee consisting of experts has been established for professional insight.
For the latest survey status of the Fukushima Health Management Survey, please refer to the materials of Investigative Commitee at the links below. Fukushima Health Management Survey Investigative Committee (Japanese Only)