Scientific Jigsaw Puzzle: Fitting the Pieces of the Low-Level Radiation Debate

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.

Comments

Short summary

[Anonymous Coward]

Ionizing radiation causes cancer. More ionizing radiation causes more cancer. There is no "safe dose", though there is a certain unavoidable dose. So we're all at risk of cancer if we live long enough.

Re:Short summary

[MozeeToby]

Exposure is always expressed in amounts over the background rate. So "Lower than background level" effectively means exposure to up to 2x the background level (background level + artificial); there's nothing illogical about being worried about it (though I wouldn't personally be concerned about a ~.0025 Sv per year exposure rate).

As for the rest of your comment, if you read the paper the summary links to, you'll see that all the evidence is pointing toward all exposure (presumably below radiation poisoning levels) carrying approximately the same relative risk. It doesn't matter high or low energy, it doesn't matter if you're exposed in 10 minutes or 10 years. Your total exposure level linearly maps to your risk of cancer (and, new information to me at least, heart attack and stroke).

Re:Short summary

[History's Coming To]

Your best bet is to read a high-school level introduction. Concisely, there are three types of radiation from radioactive atoms, alpha, beta and gamma. Alpha is a He nucleus, two protons and two neutrons - it can do a huge amount of damage to living cells, but is easily stopped by, eg, a sheet of paper. Beta is a high speed electron, less damaging but will penetrate clothing etc. Gamma is nasty - it can travel through a reasonable thickness of lead and still do harm.

If we look at the Uranium example, it gives off alpha, so you'd probably be quite safe with it on the other side of the room. Handling it, on the other hand, is an easy way to accidentally ingest some, which would probably be more harmful because it's then inside the body (this goes for any ionizing radiation source). When you see people being showered off after radiation exposure it doesn't stop any harm thats already been done, just reduces the chances that they are still in contact with a source.

This all ignores the fact that Uranium decays into several other isotopes which give off their own idiosyncratic radiation in turn, and a bunch of other things.

Re:Low level radiation

[InterGuru]

There might be a level at which radiation is beneficial. This is called hormesis

From Wikipedia

Hormesis (from Greek hórmsis ...) is the term for generally favorable biological responses to low exposures to toxins and other stressors. A pollutant or toxin showing hormesis thus has the opposite effect in small doses as in large doses

The concept is vigorously debated, but has been shown to work in some animal experiments. In humans, small doses of alcohol, a toxin, seems to improve heart health.

Humans, as all life, have evolved under low level background radiation. We may be adapted to it.

Re:Extended exposure is riskier, and no superpower

[vlm]

The standard /. car analogy breaks down in that running my car engine up to 80% of redline RPM for a half hour a day is a pretty stupid idea that will only wear it out faster. Yet daily aerobic exercise seems to be a brilliant idea for long term cardiovascular health.

You can also have hilarious fun making vaccine analogies. "You mean, you'd intentionally inject small amounts of possibly fatal microbes into a healthy body? Madness I tell you! Madness!" Sadly there are highly educated actresses and pr0n models who pretty much use this argument when providing their valuable medical advice, along with the usual folks doing the FUD-for-profit thing.