Scientific Jigsaw Puzzle: Fitting the Pieces of the Low-Level Radiation Debate 140
New submitter Lasrick writes "Skip past the dry abstract to Jan Beyea's main article for a thorough exploration of what's wrong with current 'safe' levels of low-level radiation exposure. The Bulletin is just releasing its 'Radiation Issue,' which is available for free for two weeks. It explores how the NRC may be changing recommended safe dosages, and how the studies for prolonged exposure have, until recently, been based on one-time exposures (Hiroshima, etc.). New epidemiological studies on prolonged exposure (medical exposures, worker exposures, etc.) are more accurate and tell a different tale. This is a long article, but reads well." Here's the free, downloadable PDF version, too.
Low level radiation (Score:3, Insightful)
There is no threshold below which radiation is 'safe'. There is a threshold below which is become statistically indistinguishable from random events, but that is not the same thing. We've known even "low" levels of radiation can be dangerous -- look at the cancer clusters showing up in TSA screeners. The scanners were declared 'absolutely safe' and had a 'low' level of radiation. There is a long history in the medical field of radiology where equipment, engineering, or our understanding of underlying principles failed and led to death or serious injury. The fact is, there is no such thing as "safe". That doesn't mean don't use the equipment -- it's often the only way to get the information needed (note: full body scanners NOT included, there are alternatives which provide the same information). But it does mean use the least amount of radiation necessary, only use it when necessary, and carefully track a person's exposure -- time, dosage, etc., to identify trends.
Radiation is a daily reality in our lives. Go outside, look up. There it is; the biggest source of radiation in your life (most likely). We can't avoid it... but we can limit it.
Re:Low level radiation (Score:5, Insightful)
There is no threshold below which radiation is 'safe'. There is a threshold below which is become statistically indistinguishable from random events, but that is not the same thing. We've known even "low" levels of radiation can be dangerous -- look at the cancer clusters showing up in TSA screeners.
Unfortunately, what you say is at best inconclusive, but at worst wrong. Google "hormesis".
Studies "including for example the respected "Iowa Radon Lung Cancer Study" of Field et al. (2000), which also used sophisticated radon exposure dosimetry....argue that radon exposure is negatively correlated with the tendency to smoke and environmental studies need to accurately control for this; people living in urban areas where smoking rates are higher usually have lower levels of radon exposure due the increased prevalence of multi-story dwellings".
http://en.wikipedia.org/wiki/Radiation_hormesis [wikipedia.org]
I know that hormesis sounds like a crackpot theory along with holistic super-diluted medicinal honey therapy, but some of the greatest minds in Medical Physics believe it exists. It is basically the hypothesis that low levels of additional radiation can actually make you healthier than no additional radiation at all (including daily dosage of cosmic rays). Hence the quote about high background radon studies and inverse correlations with health outcomes.
One of the main mechanisms that is thought to possibly explain it is that while the additional radiation exposure is not enough to cause significant DNA damage, it still activates certain dormant mechanisms for DNA repair, resulting in a healthier-than-average individual.
So in short, there is at least very suggestive evidence for a "safe" (and even moreso than safe) level of radiation.
Re:Short summary (Score:5, Insightful)
Re:Low level radiation (Score:3, Insightful)
Linked paper talks about hormesis, specifically about how it's a largely debunked theory that isn't taken seriously by anyone in the field any more. In fact, there's research that shows low level radiation being more harmful (in a relative, risk vs Sv exposed way) than less.
Re:Short summary (Score:4, Insightful)
Ah I'm not talking about cancer being like evolution, talking about evolution if you live in a niche of really high radioactive potassium consumption from eating bananas all the time, after a bazillion generations you'd expect the survivors to be better than the average human about excreting radioactive or otherwise K and/or getting by with as little of that nasty stuff inside them as possible, despite it being a big part of their diet.
Bad article, little information [Re:Short summary] (Score:5, Insightful)
Ionizing radiation causes cancer. More ionizing radiation causes more cancer.
Of course. The question is, how much more cancer is caused by a given dose of radiation?
Unfortunately, this is a question that the paper in question does not answer, because it completely neglects to mention actual numbers. (The pretty colored graphs have units of "excess relative risk." How do you convert that to deaths? You can't. What are the units-- per year? Per lifetime? they don't say. Relative to what? They don't say.) I'd like to see a number, like "excess cancers per year per sievert of exposure," but they don't give one. They compare different studies, but never discuss whether the differences are statistically significant.
There is no "safe dose", though there is a certain unavoidable dose.
That is a question. That is what is known as the "linear no threshold" model-- but although these authors assert the validity of that model, you can't tell it from the data they show. Figure 1 shows too much scatter below 0.3 Sv to give much information about thresholds, and Figure 2 sure looks like it would be well fit by a threshold model.
In short, I'd like to have seen an article with real information.
Re:Anti-nuclear publication (Score:5, Insightful)
Do note that the "Bulletin of the Atomic Scientists" is a generally an anti-nuclear, scare-mongering publication. These are the people whose count-down to nuclear disaster has been just a few minutes before midnight for decades. Whatever they publish should be viewed with this in mind.
As a strong supporter of nuclear power I feel this attitude is exactly what makes it so easy to scare up opposition to nuclear power. That article was extremely well written and researched. IMO it presented a fairly balanced view of the existing studies and the overall challenges to new research and regulation. Yes their are concerns about low and protracted doses, and yes the industry has tried to downplay and bury that research. Just like the "green power" industry doesn't want anyone to look at the lifecycle costs on those PV cells and LiPo batteries.
The only way to stop fear mongering and get new power plants is with open and honest research - not making attacks on an article that tries to present the facts.