PLANS for a radical overhaul of the world鈥檚 radiation safety regime have been abandoned because of widespread opposition from scientists, regulatory agencies and the nuclear industry. The International Commission on Radiological Protection now says that the way in which people are protected from radiation should stay much the same.
The ICRP, a group of 13 experts who advise countries on radiation safety limits, had wanted to make wholesale changes to their recommendations. One of their most controversial proposals was to do away with assessments of the 鈥渃ollective dose鈥� of radiation received by large populations over long periods of time.
This method estimates the total number of cancers that might be caused by the release of radioactive isotopes, by considering the radiation they will emit over thousands or even millions of years. ICRP chairman Roger Clarke was concerned that, taken to extremes, this could vastly overestimate the likely number of deaths caused. But scientists warned that dropping the collective-dose assessments would give the nuclear industry a licence to pollute the seas and air (快猫短视频, 9 June 2001, p 5).
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The ICRP has now agreed to retain the collective dose, as long as the figures are presented as a matrix showing the radiation doses to which people will be exposed over different time periods (Journal of Radiological Protection, vol 23, p 129). 鈥淭his will avoid the misinterpretation of collective dose that has led to seriously misleading predictions of deaths,鈥� says Clarke.
The commission had also planned to replace the overall safety limit of 1 millisievert per year for members of the public with a series of 鈥渃onstraints鈥� for different sources of radiation. But this was opposed by both nuclear regulators and operators, who argued that the change was unnecessary and costly. As a result, the ICRP has decided to keep the safety limit as part of its recommendations, due to be published in 2005. 鈥淲idespread consultation has produced a consensus that much of the basic system is sound and should remain unchanged,鈥� ICRP scientific secretary Jack Valentin told 快猫短视频.
The ICRP鈥檚 change of heart has been welcomed by radiation scientists. 鈥淧lanning for evolution not revolution dispels the greatest concern many of us had,鈥� says Geoffrey Webb, president of the International Radiation Protection Association.