It would have been preferable not to evacuate the people of Fukushima immediately

Research today questions the extent, suddenness, and duration of the evacuations around Fukushima, whose impact on the health of the populations concerned would ultimately be more severe than the effect of radioactive discharges if these people had remained at home or returned more quickly.

The immediate, forced, and prolonged evacuation around the Fukushima plant resulted in 2,200 deaths and had significant negative consequences on the mental health of the displaced. It affected about 160,000 people, and as of November 2025, around 23,000 of them were still officially evacuated. However, the Japanese authorities consider that only 20% actually returned to their homes of origin.

The study of the consequences of population evacuations carried out during the Chernobyl and Fukushima accidents showed that these effects could be greater than the radiation-induced health effects in the event of non-forced evacuation (especially among the elderly). 

For example, researchers have recently developed an indicator (the J value) to mathematically determine the effectiveness of a population protection measure based, in particular, on life expectancy. 

Applied to the effectiveness of the evacuation of populations during the Chernobyl accident, this evaluation method concludes that the authorities would have evacuated five to ten times too many people, three times too many during the first wave of departures (110,000 instead of 31,000) in 1986, with the second evacuation in 1990 being unjustified. 

Applied to the Fukushima accident, the same evaluation method establishes that no evacuation would have really been necessary given the low doses received. 

It would seem that a non-systematic, non-immediate, and time-limited evacuation would be preferable to what has been done up to now.