The costs of evacuating residents from near the Fukushima No. 1 plant and the dislocation the people experienced were greater than their expected gain in longevity, a British study has found.

The researchers found that at best evacuees could expect to live eight months longer, but that some might gain only one extra day of life. They said this does not warrant ripping people from their homes and communities.

The team of experts from four British universities developed a series of tests to examine the relocations after the Fukushima crisis and earlier Chernobyl disaster in 1986.

After a three-year study, the academics have concluded that Japan “overreacted” by relocating 160,000 residents of Fukushima Prefecture, even though radioactive material fell on more than 30,000 sq. km of territory.

“We judged that no one should have been relocated in Fukushima, and it could be argued this was a knee-jerk reaction,” said Philip Thomas, a professor of risk management at Bristol University. “It did more harm than good. An awful lot of disruption has been caused However, this is with hindsight and we are not blaming the authorities.”

The team used a wide range of economic and actuarial data, as well as information from the United Nations and the Japanese government.

In one test, an assessment of judgment value, the researchers calculated how many days of life expectancy were saved by relocating residents away from areas affected by radiation.

They compared this with the cost of relocation and how much this expenditure would impact the quality of people’s lives in the future.

From this information, they were able to work out the optimal or rational level of spending and make a judgment on the best measures to mitigate the effects of a nuclear accident.

Depending on how close people were to the radiation, the team calculated that the relocations added a period of between one day to 21 days to the evacuees’ lives.

But when this was compared with the vast amounts of money spent, the academics came to the conclusion that it was unjustified in all cases.

In some areas, they calculated that 150 times more money was being spent than was judged rational.

Thomas adds, the tests do not take into account the physical and psychological effects of relocating, which have been shown to have led to more than 1,000 deaths among elderly evacuees.

Other studies have also found that once people have lived away for a certain period of time it can become increasingly difficult to persuade them to return.

After Chernobyl, the world’s worst nuclear disaster, around 116,000 people were initially relocated away from the disaster zone.

Looking back on the incident, the team judged it was only worthwhile to relocate 31,000 people because they would have lost in excess of 8.7 months in life expectancy had they remained.

However, for the rest of the 116,000 people, it would have been a more rational decision to keep them where they were, given that their average loss of life was put at three months.

Four years later, a further 220,000 people were relocated from areas close to Chernobyl. Researchers found this unjustified.

Thomas says the loss in life expectancy following a nuclear accident has to be put into context alongside other threats all people face.

For example, it has been claimed that the average Londoner will lose about 4½ months in life expectancy due to high pollution levels.

Thomas concludes governments should carry out a more careful assessment before mounting a relocation operation of at least a year. A temporary evacuation could be a good idea while authorities work out the risk from radiation, he said.

In the future, Thomas would like to see more real-time information made available to the public on radiation levels in order to avoid hysteria and bad planning.

On a plus note, the team found that other remedial measures — decontaminating homes, deep ploughing of soil and bans on the sales of certain food products — were far more effective.

Thomas has already discussed his findings with colleagues at the University of Tokyo and he is keen that his findings can help better quantify the risks from radioactive leaks.

The project was sponsored by the Engineering and Physical Sciences Research Council, Britain’s main agency for funding research in engineering and the physical sciences. It was intended to give advice for nuclear planners both in Britain and India.

The research team comprised specialists from City University in London, Manchester University, the Open University and Warwick University.