Psychological fall-out of nuclear accidents 'most serious public health issue'
Nuclear accidents can have a "devastating" impact on people's lives that has nothing to do with the effects of radiation, say experts.
More needs to be done to plan for the psychological fall-out of events such as the Chernobyl and Fukushima disasters, according to a major report.
One of the most vital lessons from the past is the importance of preventing needless fear and panic after a radiation leak, it concluded.
A key task of health services is to communicate the fact that in most nuclear accidents very few people are exposed to a life-threatening dose of radiation.
Physicians should receive specialist training in handling a nuclear disaster response, and evacuations managed carefully in a "stepwise" manner taking into account local levels of radiation exposure, the experts concluded.
Another study, one of a series of three published in The Lancet medical journal, looked at the evidence of long-term damage to health caused by radiation from a nuclear bomb blast or power plant accident.
It found that cancer risk increased significantly after exposure to moderate and high doses of radiation, but the lasting effects of lower doses remain unclear. Children are more at risk of radiation-triggered cancer than adults.
Researchers cited a UN report that found psychological damage to be the "most serious public health issue" in the aftermath of the 1986 Chernobyl disaster in Russia.
Rates of depression and post-traumatic stress disorder remained elevated 20 years after the event.
Similar problems were seen after the Fukushima disaster in Japan in 2011. A survey found that among evacuees, the proportion of psychologically distressed adults was almost five times higher than it was in the general population.
Dr Koichi Tanigawa, from Fukushima Medical University, said: "Although the radiation dose to the public from Fukushima was relatively low, and no discernible physical health effects are expected, psychological and social problems, largely stemming from the differences in risk perceptions, have had a devastating impact on people's lives."
The disaster, caused by a massive earthquake that damaged the core of the Fukushima Daiichi nuclear power station, led to the evacuation of 170,000 residents living within a 18.6-mile radius of the plant.
Three years later, a survey revealed that 49% of responding evacuees remained separated from their loved ones, 68% reported mental or physical health problems affecting their families, 57% experienced disturbed sleep and 47% suffered from depression.
The authors wrote: "These results suggest that substantial issues are unresolved as the affected population recovers from the accident and aftermath."
Relocation after a disaster could also disrupt health care systems leading to disease outbreaks and higher death rates, they pointed out.
Commenting on the findings, Sir Simon Wessely, president of the Royal College of Psychiatrists and Professor of Psychological Medicine at King's College London's Institute of Psychiatry, Psychology and Neuroscience, said: "This shows that the psychological and social consequences of nuclear accidents are more profound, long-lasting, divisive and difficult to manage than the more direct consequences of radiation leaks.
"In future, far more attention needs to be given to community engagement and choice, and less to the extreme risk-aversion which currently dominates thinking.
"Over-precaution and over-reaction can have just as serious long-term reactions as under-reaction... We have known for a long time that radiation is associated in the minds of the public with particular fear and dread, but that is no excuse for policy makers and emergency planners to react in similar fashion."
Professor Geraldine Thomas, from Imperial College London, said uncertainty about the long-term effects of low-dose radiation exposure had led to the assumption that people should be protected against even the smallest doses.
She added: " These papers however suggest that the measures that we put in place (long term evacuation etc) to protect ourselves from what may be a health risk, which is not definable at low doses, may be creating a greater health risk, unrelated to the dose of radiation, but related to our human responses to the situation.
"Perhaps the biggest lesson we need to learn from past releases of radiation is how to communicate the real potential risks in the case of any future accidents. The major effect on health of the general population from both Chernobyl and Fukushima is not related to the actual effects of radiation, but the fear of radiation."