Low-level radiation from nuclear plants may be up to ten times more hazardous than has been previously estimated, a panel of experts said today.
A committee set up to examine radiation safety said that action was needed after new information about the risks from radioactive particles that can be swallowed or inhaled.
But the report from the Committee Examining Radiation Risks of Internal Emitters (CERRIE) fell well short of the controversial claims published by two of its members in a minority report last month, saying that radiation doses to child leukaemia victims across Europe could have been a 100 times higher than experts believe.
Instead it said that the level of risk from exposure to radioactive particles was uncertain, and could range from ten times the previous estimate to almost zero.
CERRIE was established by Michael Meacher, the then Environment Minister, in 2001 after concerns about radiation risks, including reports of increased incidents of cancer near nuclear sites and in the wake of the Chernobyl disaster.
Last month Mr Meacher provoked a row by accusing the committee of gagging the two dissenting experts.
He made his attack at the launch of the minority report by the experts, Richard Bramhall and Chris Busby, who argued that the risk of cancer from low level radiation was much higher than officials estimated.
According to their theory, inhaled radioactive particles could lodge in the body of a foetus and damage cells in a confined area.
Unborn children were said to be especially at risk. The hazard could explain clusters of leukaemia cases near nuclear installations in North Wales and Essex, and the Sellafield Reprocessing plant in Cumbria, it was claimed.
Mr Meacher alleged that attempts had been made to keep a lid on the evidence. He told the Guardian: "The idea was to examine all the questions, and where there was disagreement to recommend further research.
"It is criminally irresponsible not to allow all the evidence to come out so there can be a properly organised, informed public debate."
The row over reports followed deep divisions among members of the committee. One nuclear scientist, Marian Hill, who was part of the committee’s secretariat, resigned alleging establishment bias.
Launching today’s report, CERRIE chairman Professor Dudley Goodhead acknowledged that there had been disagreements but said that the report had tried to reflect the diversity of opinion.
He said: "The main findings of the committee’s report is that we have to be particularly careful in judging the risks of radioactive sources inside the body.
"The uncertainties in these internal radiation risks can be large and these need to be taken properly into account in policy and regulatory decisions.
"There is much public debate about the risks to health from ionising radiation, with widely differing views being held. This is particularly so with radiation from radioactive materials taken into the body, whether from nuclear discharges, or natural sources of radioactivity in air and food."
Speaking of the divisions in the committee, he went on: "The CERRIE committee was set up to reflect these differing views. The report examines the views of all members, including hypothesis for very large risks put forward by two members, who finally dissented from the report.
"The committee concluded that the available scientific evidence did not support these hypothesis and, in many cases, substantially contradicted them."
The report gave warning that newly discovered affects of radiation, including long-term damage to DNA within cells, and inherited DNA changes, were "real biological events that need further research".
However the report concluded there was no "no clear evidence" that current radiation risk assessments were "substantially wrong".
The Government radiation watchdog, COMARE (Committee On Medical Aspects of Radiation in the Environment) said it agreed with CERRIE that available data did not support a "speculative hypothesis" that the risks were radically underestimated.
It also agreed with the majority view of CERRIE that present evidence did not indicate a need for a fundamental change in radiological protection standards.
But COMARE added that it had reservations about the way CERRIE was set up and in particular how it's composition "was influenced by environmental politics rather than science".