Radiation and Health
17 Aug 1995 16:51
Lots of radiation is bad for you, of course, but how much is lots, and what about a little? A professor of medical physics will soon (21 April) be giving a talk on this, claiming there is evidence low-level radiation doses can make cancer less likely. (I append a copy of his abstract.) If true, the implications are staggering. For instance, could you sue your landlord for negligently failing to provide you with low-level radiation? [13 April 1995]
Prof. Cameron made a strong case that linear dose-response curves without thresholds are empircally wrong, and that the dose-response cruves for different sources vary dramatically. His case for high thresholds was weaker, though the matter deserves to be looked into. He speculated that low-level doses of radiation might improve health by stimulating cell division, but he presented no good evidence that this is so. To take, e.g., the case of the nuclear shipyard workers, these were workers who were (a) self-selected for nuclear work, (b) carefully screen by the Navy and (c) following safety regulations of almost obsessional elaboration: it's not surprising they're in good health. He had some genuinely disturbing stories about regulatory authorities insisting on ``linear, no-threshold'' theories sans evidence, which were rather undermined by his repeating the ``safe for children to eat dirt every day'' story, which I've heard so often in so many versions, and never with any citation, that I think it's an urban legend. In short: it's probably safe to move to Denver, it's probable even that radon is not a cause for panic, but I'm wouldn't move to Chernobyl, or even Hanford, any time soon.
Title and abstract of the talk given at the UW-Madison physics colloquium, 21 April 1995
Is Radiation as Dangerous as They Say? John R. Cameron
Medical Physics, UW-Madison
Ionizing radiation is often describe as being able to induce cancer in the smallest amounts. This no-threshold assumption of radiation risk is not based on fact. Many human and animal data indicate that low level radiation is not a health risk. It often appears to reduce the incidence of cancer. The talk will describe the apparent threshold for radiation-induced cancer in A-bomb survivors equivalent to about 150 years of background radiation. A-bomb survivors are now living longer on the average than Japanese who were not exposed to the bomb. Several thousand radium dial painters received huge doses of alpha radiation to their skeletons over several decades. There was no increased bone cancer until their skeletal doses exceeded 1,000 rads or 20,000 rem. The 70% who exceeded this threshold still did not have bone cancer and on the average lived longer than their age-matched controls. The talk will discuss the good news from the Nuclear Shipyard Workers Study and the reduced lung cancer in areas with high radon levels. Despite these data billions of dollars are being wasted each year to protect the public from low-level radiation which may be good for their health. Adequate time will be allowed for questions and comments.
