Of Linear Non-Threshold, Airplanes and Overreactions
August 7th, 2009
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Ionizing radiation is something that we all are exposed to every day. Trying to avoid enviornmental radiation is an exercise in futility. Radiation comes from cosmic rays, naturally occurring minerals and a variety of natural isotopes found all around us. Soil, gypsum, cement, many rocks and minerals and even food are mildly radioactive and so are people, with a portion of the exposure coming from internal radioisotopes like potassium 40 and carbon 14, both found in the human body.
There certainly is some variation in the amount of radiation exposure a person will get in a given year. All things being equal, higher elevations have slightly more cosmic rays, areas where uranium and thorium occur in abundance have higher geological radiation. Cooking with gas or working in a granite or marble building can increase exposure as well. The good news is that there’s no evidence at all that such trivial levels of radiation are at all harmful and there is even mounting evidence that some radiation exposure may have a net health benefit.
Still, many organizations still officially support the Linear Non-Threshold hypothysis for radiation health effects. This model was created as a means of estimating the health concequences of exposure to low doses of radiation by considering the general health impacts to be directly proportional to dose. Thus, observation of high dose levels health effects could be applied to all doses simply by adjusting to the dose directly. So if 500 rems causes an increase of cancer rates of X percent, then one rem is expected to cause a total increase of X/500 percent.
While LNT was created as a kind of “precautionary” approach, given the lack of data and the difficulty in isolating small effects against statistical noise, it is still a widely accepted standard for safety evaluations. The result of this is that policy has been to make radiation dose “As low as reasonably possible.” The problem is some people’s definition of “reasonable” seems a little, well, unreasonable. Even if you use LNT as the method of evaluating dose risk, you’ll still find out that the amount of radiation you get from living near a nuclear power plant or taking a few airline flights turns out to reduce your life expectancy by a level comparable to spending a few minutes in a smokey bar or eating a large order of french fries.
Flying on a plane is one example of an activity that can increase radiation exposure. This is even more the case when the plane is flying near the poles. The increase is small, even minuscule, but that does not seem to have stopped some (who really ought to know better) from becoming very concerned about the matter.
Now here’s a plan to take radiation exposure concerns to a new level of “unreasonable!” In addition to the millions that would be spent on the “radiation warning” system, there are other consequences that one should consider. Diverting flights and changing routes can make the job of air traffic controllers and pilots all the more complex, and if radiation is the fear then it may end up putting aircraft into less favorable regions of weather or turbulence. Furthermore, flight times could be extended. Anyone who has even had a connecting flight is aware of how a single late aircraft can cause a cascading series of delays. At lower altitudes aircraft burn more fuel, increasing operating expenses and possibly resulting in ticket prices increases. Aircraft tend to go slower at lower altitudes and weather becomes more of an issue, possibly even reducing safety.
This entry was posted on Friday, August 7th, 2009 at 3:41 pm and is filed under Bad Science, Misc, Obfuscation, Quackery, media. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
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August 7th, 2009 at 4:47 pm
This goes beyond ridiculous. It would seem that some airlines are now offering lead blankets to their frequent fliers.
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August 7th, 2009 at 5:43 pm
Oh yeah that sounds like a GREAT idea. Airlines don’t fly at high altitudes for the hell of it. Dropping 2 km is 2000 meters in altitude, ~6500 feet. The jet engines don’t preform as well at lower altitudes. There is more drag. Result= worse performance and speed and the plane drinks more fuel. Another reason for flying at high altitude is you fly ABOVE the weather. An airliner can fly above major storms and if it’s up above them it’s no sweat. Go down and you’re in the thick of it and that’s going to result in more turbulence and discomfort as well as possible increase in danger.
This is insanity. All for the tiny dose of radiation?
And there are space scientists etc on there. These people should know better!
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August 7th, 2009 at 6:42 pm
Seems to me that the levels of radiation from a plane trip couldn’t be that bad even if there were some high radiation. If that were then how long are you going to be in it? I think not very long. This sounds like it is not necessary and might create a new set of problems. I’d be questioning before thinking it needs to be used.,
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August 7th, 2009 at 7:56 pm
Nuclear pioneer Ted Rockwell made some pretty scathing remarks on Rod Adams’ podcast regarding those whose living is provided by the extra conservatism imposed by LNT. Something along the lines of; “That money doesn’t just disappear, it doesn’t go down a rat-hole. It goes into some rat’s pocket.”
Listen to it here:
http://atomic.thepodcastnetwork.com/2008/04/03/the-atomic-show-088-the-lnt-controversy-with-ted-rockwell-michael-stuart-robert-margolis-and-rod-adams/
This is yet another case of someone trying to make a buck off the fear of “deadly radiation.”
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August 7th, 2009 at 9:35 pm
I never really understood why LNT would lead to the ridiculous measures it has. Even if you accept the hypothesis as true, and you consider it the valid way to determine the dose risk of exposure to radiation, it still does not support taking extreme steps to avoid radiation.
If you consider LNT to be factually true as a measure of radiation risk then the following would be true:
- The extensive building of nuclear reactors would have the effect of increasing the total cancer risk to the surrounding population, although this risk would be signifficantly less than that presented by the use of granite as a building material, cooking with natural gas, radon (even at what is considered acceptable levels) and numerous consumer products. Thus if we are looking for ways to reduce cancer risk, getting rid of nuclear energy will fall far down on our list and far bellow the level of elimination of all granite and marble buildings.
- Flying on an airplane will raise the average cancer risk to passengers, but this risk can be negated even to the point of producing a reduction in risk if airlines simply hand out a small bottle of complimentary sunblock.
- It wouldn’t really make much sense to worry about nuclear energy compared to coal. The coal plants should rank number one in terms of radiation sources to the public that need to be shut down as soon as possible.
- The reduction in cancer rates which would be expected from reducing nuclear fuel cycle exposure to zero would be far less than the reduction expected by spending a few million dollars nationally on providing support programs and counciling to encourage people to stop smoking.
- If the risk from nuclear energy to the surrounding population is deemed to be unacceptably high then we must necessarily declare most of Colorado and many other areas to be completely unfit for human habitation and evacuate them all. Similarly, the US Capital Building and Grand Central Station must be condemned and nobody allowed to enter them due to the risk.
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August 7th, 2009 at 9:54 pm
drbuzz0 said:
The evidence against the linear model and for radiation hormesis has been solid as a rock for 40 years. Yet the LNT model prevails. Why? Follow the money and the politics. The health-physics community is divided, roughly along the lines of who puts money before principles. There have been some amazingly bitter fights within the Health Physics Society.
The fact is that there is no money to be made ‘protecting’ people from the radiation from granite as a building material or cooking with natural gas or burning coal. Also these industries would not take these sorts of accusations lying down, and could very well raise enough questions about LNT to have the concept dismissed as a basis for regulation, spoiling the party for everyone.
I suspect that it is thus a case of letting sleeping bears lie.
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August 7th, 2009 at 10:12 pm
DV8,
We can only hope that piling additional requirements on barely solvent airline might provoke just the sort of reaction you suggest and bring the whole shaky LNT house of cards down. The anti-nukes would then find themselves deprived of one of their favorite arguments.
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August 8th, 2009 at 2:01 am
LNT came into being, from what I can tell, due to the lack of data available. It was a sort of “worst case” which, in a situation relating to safety is a valid way of going about things. (The sane version of Precautionary Principle, before it became a buzzword for overreaction)
Unfortunately, there are still regulatory groups and various organizations that use it as a matter of policy.
But I still don’t see how the hell it could be a valid argument against nuclear power.
If LNT is an argument against nuclear power, then it’s also an argument of equal validity against kitty litter. If you are going to oppose nuclear energy and use LNT as your reasoning, then that’s fine with me, as long as you oppose granite and gypsum, bananas and many varieties of cement with equal energy and oppose coal power with several times the tenacity.
I’ve never heard of anyone who spends one day at a nuclear energy protest and another day at a kitty litter protest. If they did, at least they’d be consistent.
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August 8th, 2009 at 4:02 am
There is being cautious and then there is just being silly. I almost fell out of my chair when I saw this one. They even have a NASA research scientist on this one.
I like how they keep saying “in greater danger of radiation exposure” or “in greater risk of radiation” or something. It is as if the radiation itself is the concern and not the concequences. Sure, they may be at slightly “greater risk” of radiation (slightly) but does that actually mean anything? The best evidence as of now says no.
I like one thing that Buzz said especially
drbuzz0 said:
I will use that!
I probably should fact check that, but with these tiny levels of exposure I’d tend to think it probably would have a reduced risk if you gave out sunblock, even if we start off with the assumption that LNT is the best model for radiation long term effects (which it is not).
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August 8th, 2009 at 5:08 am
After World War II, the details were released of the A-bombing of Japan. Studies of atomic bomb survivors from Hiroshima and Nagasaki, seemed to show a linear relationship between cancer mortality and estimated doses of radiation. As a result fallout hysteria became one of the themes of the times. The situation was not helped by lurid stories of a few high dose incidents reported in the press. Health Physics and Genetics were supported lavishly by radiation fears, and Radiation Biology became the most intensely researched science in history. Health physicists soon learned that their livelihood depended upon scaring funds out of governments and science became irrelevant if the paymasters wanted to mislead the public about the hazards of radiation. If a particular study failed to find evidence of radiation’s ill effects, the data was simply forced into the LNT model. Yet some of these studies are among the best evidence for radiation hormesis because the authors were not looking for it, and effectively denied that it existed.
The LNT model was first considered in the 1940s purely on the theoretical grounds that a single hit by ionizing radiation on a single cell could cause chromosome damage that could cause a mutation or cancer without any hard evidence to support that contention. The justification for using the LNT model was that too many test animals or too much time would be needed to evaluate chronic dose rates. If the LNT model is correct, there is no “no observed adverse effect level” (NOAEL) for regulators to observe, thus officials responsible for public health can claim justification in calling for minimization of exposures to ionizing radiation. Note that this is tantamount to saying that avoiding sunlight is justified on the grounds that nobody will get sunburns in the dark. Added to this, during the Cold War a number of people promoted the LNT model in an attempt to discourage nearly all uses of nuclear weapons and nuclear power, and used it as leverage in their campaigns
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August 8th, 2009 at 11:27 am
DV82XL said:
Indeed. Nobody will deny that there are very adverse effects of radiation if you get a high enough dose.
While I understand the theory from which LNT was born, it’s interesting to note that if it were true and the human body had no tolerance for raidation at any level it would be quite unique in physiology. With just about any toxin or stress on the human body, there is a level at which the dose is low enough that no adverse reactions are observed.
I might add that right now I have several micrograms of mercury in my body (among other things that would be very damaging at higher levels) There’s no evidence that a person who has a bit less mercury or lead in their body than the average (which is very low) has any advantage at all. Sure, at higher levels they’ll cause all kinds of problems and nervous system damage, but the fact that at a given level they’ll cause problems does not mean that you’re less likely to have problems when you have a few less picograms.
(I’m talking about levels that are extremely low and bellow recognized safety standards)
It would be a little weird of radiation, as a human stressor was entirely different than all the others.
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August 8th, 2009 at 11:41 am
But in the end it is as you said above: there is total hypocrisy in the way the rule is applied. If the authorities really did believe the LNT hypothesis, it would have to hold for every low level radiator and it demonstrably does not. This to me is proof positive that it is a political tool and nothing else.
Where the pronuclear community better organized and funded this discrepancy could be the foundation of enough legal action to make things very uncomfortable for a wide spectrum of our enemies.
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August 8th, 2009 at 1:37 pm
The worry is not so much the passengers but the pilots and flight attendants (who are classified as radiation workers) who fly a lot more often than all but a very small number of passengers.
Having Geiger counters in the aircraft like Concorde had probably is a good idea though, just to know how much they have been exposed to (they do get exposed to more than those who work at nuclear facilities, so unless you can justify not having radiation monitoring equipment at nuclear or coal power plants, or in grand central station…).
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August 9th, 2009 at 1:45 am
Anonymous said:
They are only considered radiation workers because of the ridiculously low total exposure limits that have been set by the LNT hypothesis.
Anonymous said:
Geiger counters don’t measure dosage – dosimeters measure total dosage and for this purpose the sealed filmbadge type would be more than sufficient.
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August 9th, 2009 at 4:40 am
Anonymous said:
The reason dosimeters are worn at nuclear facilities is not just to measure the low exposure levels a worker normally encounters. Stuff like spent fuel is pretty radioactive and if it were grossly misshandled or if somehow someone got too close to something they shouldn’t like a discharge of radioactive gas then they could get a really high dose. This almost never happens, but it’s a precaution to catch it if some kind of situation happens that causes it.
When it comes to safety I doubt it really matters that much to count the milirems exactly for each and every worker, under normal circumstances that is. If nothing goes wrong and nobody makes a mistake or does something they shouldn’t, then it would always be well bellow the levelsof anything dangerous.
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August 9th, 2009 at 10:06 am
You can calculate dosage from Geiger counter readings though (just integrate the count over the time you want to know the dose for, of course that would assume that everyone on the plane got about the same dose as the counter, but I think it highly unlikely that they wouldn’t).
As for the exposure limits, what is a safe dose and how does it compare with the worst case of what airliner crews get?
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August 10th, 2009 at 12:02 am
This is just one more reason to limit flying. We already fly too much and it is one of the luxuries that is killing the enviornment. Flying is going to be only for when it is completely necessary and that is almost never. Most flying is for people taking holiday for their own pleasure at the planet’s expense. Some people take a holiday by plane every year and this is inexcusable and criminal to the world. Radiation adds one more reason to curtail this.
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August 10th, 2009 at 5:46 am
1974Jacob said:
Well then we better limit some other things that expose people to radiation too:
Better limit living in Colorado.
Better limit granite coutertops.
Better limit heating & cooking with natural gas.
Better limit eating bananas.
Better limit using electricity generated by radiation spewing natural gas and coal plants…
…quick, 1074Jacob, turn your computer off right now!
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August 10th, 2009 at 6:43 am
If those who are plane stupid would use the radiation argument maybe they will actually manage to do something useful (even if it isn’t what they want to do).
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August 10th, 2009 at 11:21 am
Sorry I’m late to this discussion, but this is certainly high on my list of passions. Buzz0, DVX, et al have nailed this issue, so I’m going to second their comments. I like the comment, “…who puts money before principles”. I am a health physicist and I am appalled by so many of my peers and their adherence to the LNT. I blame my peers for much of the radiation ignorance and fear in our society. There is this constant waffling and subtle fear mongering going on with many health physicists. This issue is just like the global warming issue – professionals sell out to fear mongering, then policians and the media eat it up and exponentially propogate the fear. Then there are the anti-groups who exploit the ignorance and fear. If more of my peers would get out there and honestly educate the public, we would not have stupid articles, like the Geophysics article and stupid “solutions” like the video.
Anonymous: there are instruments that directly tell us what the dose is, notably an ion chamber (real time) or dosimetry such as film badges. A Geiger counter is worthless for determining dose unless it has been calibrated to the energies of the radiation which it is seeing.
1074Jacob: to add one more fact to your list of worries, you should know that there is an average of 2 pCi of Uranium per GRAM of soil in all soil, some of which gets taken up into the plants we eat. All the soil you walk on is teeming with radiation! Absolutely teeming, I say! Given your propensity to take extremely small risk and apply it to your utopian idealism, you should extrapolate this fact and urge a ban on all farming and food ingestion. Please be the first to adopt this ban.
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August 10th, 2009 at 5:17 pm
If you want another twist to this, some folks are now suggesting that the South Atlantic Anomaly could have been involved in the recent tragic Air France crash, when all evidence currently points strongly towards iced-over airspeed indicators (a known issue with A330s that now has some pilots refusing to fly them). It’s highly unlikely, but I imagine the radiation fearmongers will pick up on that. The SAA does tend to have higher rates of cosmic rays due to decreased field strength in the Earth’s magnetic field, though not *that* much, at the altitudes at which airliners fly.
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August 10th, 2009 at 6:23 pm
leg,
Your post is spot on. In the Atomic Show episode I linked up-thread, Ted Rockwell discusses having read the riot act to a group of (I believe) health physicists with words along the lines of “When this all come to light [meaning the unreasonable application of LNT] do you want to holding the flashlight or be one of the roaches scurrying for cover?”
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August 10th, 2009 at 8:33 pm
Calli Arcale said:
It had actually occurred to me, shortly after the crash, that the location put it flying through the heart of the South Atlantic Anomaly. I really doubt this had anything to do with it, and the data thus far seems to indicate that is unrelated. However, the South Atlantic Anomaly does not only have the effect of producing increased exposure to cosmic radiation at very high altitudes. The area is well known for experiencing unusual geomagnetic activity, of course the classic one is having compasses reverse, but it also has field fluctuation and very unusual radio propagation effects.
There’s of course nothing that mysterious about this. The area is known to be an anomaly in the earth’s magnetic field and it is therefore prone to greater ionospheric activity and magnetic variation. The same thing happens at the poles, especially during a geomagnetic storm or a solar flare or something.
Even on an aircraft that is as “wired” as the A330, it would take more than some local fluctuation to really mess with the systems enough to bring it down. Also, at the time of the crash there was nothing unusual going on in that respect. The data from SOHO, various space weather observatories and world propigation reports have all indicated nominally low activity and it would be pretty unlikely to get a major geomagnetic event now anyway, given that we’re still in a fairly low activity period of the solar cycle.
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March 12th, 2010 at 11:55 am
[...] Needless to say, many have pointed out that there’s a flaw in this logic and as knowledge of r…. Unfortunately for the promoters of LNT, examination of the cancer rates in populations living in high radiation background areas shows no increase in cancer and in fact, has produced some evidence of a decreased risk of cancer. [...]
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