Thursday, August 26, 2010

Nu-unclear

I remember seeing once a Horizon documentary (also on youtube) which raised the topic of how dangerous radiation (and by extension) nuclear power) really and how the risks might well be much less than is commonly assumed. Given the whole climate change debate and the potential role nuclear power might play, for me the significance of this was huge, so it surprised me that I never saw the same facts or issues discussed anywhere else. The basic premise seemed so solid - that the model of how dangerous radiation really is at low levels is an unverified extrapolation - that I was astonished this wasn't something being actively commented upon and hopefully studied. Surely this was something that should be clarified once and for all, given that the one real downside of nuclear power, is the dangers of either an accident or the semi-eternal problem of the waste. My own personal views were wholly based on the assumption that it was a major health risk, and since most countries and even some countrysides rarely remain stable for even hundreds of years, the chances of finding a safe place for a half life of thousands are virtually nil.

At last however I have seen an article about this topic (in Scientific American, ), and the author seems just as bowled over as I was. Which at least confirms both that it is information that makes an impression, and it really must not be on the general radar since I'm not the only one to not hear much about it, and wonder why.

some of the points (and here I quote) which the Sciam article list are :

—There is no clear-cut evidence of adverse health effects from radiation at levels below 100,000 millirem a year. The health effects of radiation have been calculated from people who received extremely high doses, including survivors of the atomic attacks on Hiroshima and Nagasaki, the Chernobyl accident, and "radium girls" who painted radium on watches and other instruments in the early 20th century. The cancer epidemiologist Charles Key told Cravens that "compared to tobacco, gasoline, drunk drivers or being a couch potato, radiation is of very little risk to most of the public."

—Claims about adverse effects from low levels of radiation are often based on a so-called linear non-threshold model. The model assumes, for example, that if an exposure of n millirem kills 50 percent of a population, then 0.1 n will kill 5 percent, 0.01 will kill 0.5 percent and so on. There is no evidence for this model. Background radiation from natural sources varies around the world from an annual dosage of less than 100 to over 10,000 millirem. (Residents of Ramsar, Iran, receive up to 26,000 millirem a year!) Studies have not found increased cancer or other illnesses in areas with naturally high radiation.

—Fifty plant and emergency workers died of acute radiation exposure in the 1986 Chernobyl disaster in the U.S.S.R., the worst nuclear accident in history. The explosion contaminated more than 200,000 square kilometers with radioactive fallout, but radiation in parts of this zone is now lower than in Finland and other regions of the world with naturally high radiation. The International Agency for Research on Cancer estimates that radiation releases from Chernobyl caused a slight increase in thyroid cancer but adds that "smoking will cause several thousand times more cancers in the same population." So far, there have been no excess deaths among the 200,000 "liquidators" who helped clean up the mess from Chernobyl compared with controls.

—The worst nuclear accident in U.S. history was the 1979 partial meltdown at Three Mile Island in Pennsylvania, which led to venting of radioactive gas. The highest dose received by plant workers was 4,000 millirem, 1,000 less than the annual dose permitted for U.S. nuclear workers. The highest dose for people living near the plant was 100 millirem. There is no credible evidence of increased cancer or birth defects among plant workers or residents near Three Mile Island.

—According to the U.S. Centers for Disease Control, so-called depleted uranium, which consists primarily of the isotope U 238 and not the more fissionable U 235, "has never caused a case of cancer in animals or humans." The dense metal is used to make tank armor, armor-piercing projectiles, shielding for x-ray machines, boat keels and other applications.

Surely even just the fact that radiation in Finland is higher than in the Chernobyl fallout zone raises major questions about the safety levels?

Of course statements like 'no clear cut evidence' (rarely is any evidence 100%) and the irrelevance of bringing mentioning how more harmful smoking is (that doesn't mean radiation isn't still harmful) have to be treated carefully. But some solid questions are still raised, and in my view ones that need urgent answer.

I wouldn't mind, but nuclear is big business, with probably much more lobbying power and cash on it's side than against, which makes the lack of further study into an area which seems to be in its favour even more puzzling. Hmm,...then again, maybe there has been, and the evidence wasn't good, and said lobby is just sitting on it. Alwayos a possibility, but not a likely one given the size of the studies which would need to be involved.

Actually maybe I should just start combing the net myself for some info...stay tuned!


Copies of referenced Articles are (a) nuclear fall in and (b) Nuclear Nightmares