John Maddox explains an important, but scarcely noticed, EU-inspired change to radiation exposure rulesby John Maddox / March 20, 1997 / Leave a comment
A crucial change is on the way in the management of radiation hazards throughout the EU. Hitherto legislation on the subject has been based on the notion that there is some degree of exposure to radiation, or some “dose” of radiation below which no damage will be done. No longer. The essence of a European directive promulgated by the European commission on 13th May last year is that even small doses of radiation can increase the chance that a person exposed to it will at some stage develop cancer. European governments have four years in which to amend their legislation accordingly.
It is strange that this development has caused so little excitement. Forty years ago, when nuclear power stations were being built for the first time in several countries, the issue of whether there is a “threshold” quantity of radiation that can damage a person was one of the most contentious in the field. At the UN conference on nuclear energy in 1955, Admiral Lewis Strauss (pronounced “straws”), then chairman of the US Atomic Energy Commission, effectively created the concept of a “maximum permissible dose” of radiation, which has been the yardstick in most national legislation ever since. The “permissible” has now been dropped.
Plainly, the authorities have never been wholly wedded to the notion of a threshold. British legislation has always, for example, dealt separately with people registered as “radiation workers” and members of the “general public.” The permissible dose for the former has always been greater than that for the latter. That would be inconsistent with a belief that radiation doses less than some fixed amount are incapable of damaging a person’s health.
Accumulating evidence seems now to have thoroughly undermined the threshold notion, at least so far as the causation of cancer is concerned. Molecular biology has helped to make the case by confirming what had been suspected, that quite simple mutations of the DNA in body cells can become foci for the development of tumours. The clinching evidence seems to be the rate at which cancers have occurred among the survivors of the Hiroshima and Nagasaki bombs.
All this has been plain since 1991, when the body known as the International Commission on Radiological Protection (ICRP) issued its most recent recommendations. ICRP, which goes back 70 years, is a remarkable organisation. It is a self-perpetuating body of independent scientists, which is now registered as a…