Time to look again at radiation safety

Five years after the nuclear accident at Fukushima Daiichi, the scientific community is ready to assess what the real health consequences have been and put them into perspective with other risks in our lives, Gerry Thomas says.

Speaking on the Today program on the fifth anniversary of the accident, Thomas, who is head of the Chernobyl Tissue Bank at Imperial College London, said, "It's a common misconception that nuclear accidents from power stations cause high doses of radiation to individuals but in actual fact they are a lot lower than people think. And people tend to equate nuclear power plants with the atomic bomb and the two are very different things."

"We were brought up to believe that the next atomic weapon that went off would probably finish our species on the planet," she continued, "and we seem to have confused the two in our minds and therefore find it very difficult to move on from there."

"And I think also we didn't really know the effects of nuclear power accidents until we've had sufficient time after they've happened to really look at the results and we're there now with Chernobyl, we're 30 years past the accident, it's the 30th anniversary this year. And so we've got adequate amounts of data to look at and say, 'it's not that same as an atomic weapon and we can now prove that.'"

The key difference, she said, is that nuclear weapons produce huge amounts of penetrating gamma radiation, whereas a reactor accident produces isotopic radiation from caesium-137 and iodine-131 that can only cause harm if taken into the body. So despite the large release of the Fukushima accident and the wide area it affected, said Thomas, "in actual fact the doses that were around Fukushima have been calculated to be around 1 milliSievert to 95% of the population - that's a tenth of a CT scan, that's all."

With hindsight, she said, we can look back and say the risk to local residents was overestimated, "and actually it would have been far better to treat this as if it was like a chemical toxin. And what are we told then: Stay indoors, your windows and doors shut, and we'll come and get you when it's safe - if we need to evacuate you. And it gives you time to appraise what the doses would be, what the releases would be, and time to put a proper plan in place."

"You can't reduce risk to nothing, it's just impossible to do that," said Thomas, calling for society to balance the risk of a nuclear accident against the risks of other forms of generation, particularly fossil fuels that damage health and the environment. Regarding nuclear power, she proposed the question, "Are we trying to be too safe?"

"I think that the balance of scientific opinion," she said, is looking to "assess what the real health consequences have been of these accidents and put things into perspective with other risks in our lives. Most of the scientific community is saying, we have to take notice of what's happened, we have to re-appraise because in two or three generations they might look back and say we are completely mad because we've been over-cautious."

Geraldine Thomas was speaking in an interview with the BBC.

Geraldine Thomas of Imperial College London specialises in molecular pathology of cancer and is head of the Chernobyl Tissue Bank.