New ways need be found to communicate to the public the true risks of radiation from crisis like the one at Japan's Fukushima nuclear plant without fanning overblown fears of an "apocalypse", scientists say.
Communication has to convey statistics about risks and at the same time address people's fears, especially when they concern atomic power.
Many experts say the March 11 tsunami, which has so far left 28,000 people dead or missing, is likely to have a greater impact on public health in Japan than radiation leaking from the plant.
Part of the problem is that many scientists are giving both good news and bad news, and that can sound contradictory. They acknowledge they find it hard to express risks in a way that can guide both governments and individuals.
Jim Smith of the University of Portsmouth and an expert on the Chernobyl nuclear disaster, said: "On the one hand, scientists are saying, 'Yes, it is very severe.' On the other, I personally don't expect the health effects to be very severe from the radiation."
As an illustration of the problem between personal and public reactions, the risk of a person living in a developed nation getting cancer is about one in three over a lifetime. A dose of 170 millisieverts - a level found on two workers exposed to radiation at the plant and taken to hospital - might raise the risk of getting cancer by about 1 in 100.
Yet in coming decades, millions of people in Japan who develop cancer are bound to wonder if they might have prevented it by moving farther from Fukushima. So for peace of mind, getting away altogether may make sense even when risk levels are small.
On the other hand, the stress of uprooting a life and family to move elsewhere may have a greater health impact.
Studies of previous nuclear accidents have found the psychological impact of anxiety about radiation, and the rush to get away from it, is very real.
And scientists presenting a study on heart attack rates in the years after Hurricane Katrina in the United States say there may be lessons for Japan, where anxiety about radiation may add to psychiatric problems.
The UN scientific committee on the effects of atomic radiation reckons that the average dose from the Chernobyl disaster in contaminated areas of the former Soviet Union works out as equivalent to a CT scan in a hospital.
Those doses "should not lead to substantial health effects in the general population," it said.
It said there have been 6,000 thyroid cancers among people under 18 at the time - an unusually high number. Another UN report estimated that Chernobyl might eventually cause 4,000 to 9,000 deaths from cancer. Greenpeace, which opposes nuclear power, has estimated 93,000.
Little surprise then that people get confused and find reason to doubt almost all information.
In the case of Fukushima, many Japanese doubt the government; some scientists who say the health risks are slight have been denounced as stooges of the nuclear industry; and environmentalists may want to exaggerate risks as part of wider campaigns against nuclear power.
Nicholas Pidgeon, a professor of psychology at Cardiff University in Wales, said: "We worry about things where we don't trust the authorities. The nuclear industry has a long legacy of being fairly secretive since it grew out of the Cold War."
But experts should still try to get risk messages across.
"Don't be afraid to use statistics," said Mr Pidgeon, pointing out as an example that people fleeing Japan might be exposed on an intercontinental flight to doses of solar radiation higher than those they might have received by staying put.