Talk:Ionizing radiation/Archive 2013

Biological effects, recent changes

The recent changes to the Biological effects section place too much importance is given to an odd mix of details: double-strand breaks, the Cedars-Sinai Medical Center scandal, Chernobyl mortality, etc. Some of this information is correct, but it belongs in other more specific articles. This section should just give an overview of the biological effects of radiation, with links to more specific articles. I'll see if some of this material can be moved to more appropriate pages, but either way I'm going to delete a lot of it from here.--Yannick (talk) 20:22, 22 June 2012 (UTC)

Most of the first paragraph is duplicating the second paragraph.— Preceding unsigned comment added by Nenpog (talk • contribs) 00:19, 23 June 2012 (UTC)

I don't see the first two paragraphs as repetitive. Three of the links are repeated, which is poor style, but if you ignore the links, they look like very different paragraphs to me. The first gives an overview of the major effects of radiation for someone who's completely new to this, and the second paragraph divides up the effects between stochastic and deterministic.--Yannick (talk) 03:09, 23 June 2012 (UTC)

The current accepted model is the LNT according to which radiation is bad at any dose, no matter how small. This first paragraph would give an impression, that is completely against what most scientists think. Additionally, these pro radiation statements are not backed by any source. Even the hormesis article that was provided doesn't support the text of the wikipeida article, because that scientist just proposed a theory, and the testing of that theory. --Nenpog (talk) 07:59, 23 June 2012 (UTC)

Well I agree with you about LNT, and I agree that the hormesis article has serious problems with it. Like many parts of Wikipedia it's a work in progress. I certainly don't want to give the wrong impressions to readers, and I'm willing to work with you to come up with better phrasing. But it's also true that radiotherapy can cure cancer, that hormetic effects have been observed at the cellular level, that internal contamination doesn't seem to follow LNT at all, that high doses deviate from linearity substantially, etc., and we have to be careful not to over-generalize.--Yannick (talk) 12:08, 23 June 2012 (UTC)

It have the unsourced statement "Controlled doses are used for medical imaging and radiotherapy to improve health", which I think is not true, because the ionizing radiation component there damages the health. The ways to image (MRI) or treat cancer (chemotherapy), that don't use radiation are preferred in terms of health.— Preceding unsigned comment added by Nenpog (talk • contribs) 00:19, 23 June 2012 (UTC)

Really, you disagree that radiotherapy improves health? Sure, it has side-effects that are damaging to health, but so does chemotherapy, and some people think MRI's might too.--Yannick (talk) 03:09, 23 June 2012 (UTC)

First you ignored the complaint about not sourced matter.Nenpog (talk) 07:59, 23 June 2012 (UTC)

No I didn't! I said I could get a cite from the introductory chapter of an oncology textbook, but don't really want to because uncontroversial statements need not be cited.--Yannick (talk) 12:08, 23 June 2012 (UTC)

If you would feel sick, would you go to do a radiotherapy session to improve your health, like you go to a spa?Nenpog (talk) 07:59, 23 June 2012 (UTC)

If you feel sick from cancer, would you go to a spa? Neither spas nor radiotherapy are universal treatments.--Yannick (talk) 12:08, 23 June 2012 (UTC)

I read a lot about cognitive decline, and so far I got the impression that radiation cause it much more than chemotherapy.Nenpog (talk) 07:59, 23 June 2012 (UTC)

Probably true, but besides the point. Chemotherapy does cause cancer, so according to your logic it does not improve health. Which is nonsense.--Yannick (talk) 12:08, 23 June 2012 (UTC)

I never seen an article that stated that MRI is damaging (except if you have implants that interact with the magnet).Nenpog (talk) 07:59, 23 June 2012 (UTC)

Your parenthesis seems to support my point. I would add that electromagnetic radiation at any frequency are now considered a possible carcinogen by the World Health Organization.--Yannick (talk) 12:08, 23 June 2012 (UTC)

"Possible" is not "probable." RF frequency experiments with animals have been more or less null. Radiant heat is composed of electromagnetic radiation. Why don't all animals immediately get skin cancer from it? SBHarris 18:34, 23 June 2012 (UTC)

Agreed. I think that's consistent with my earlier statement that "some people think MRI's might" be harmful, and I'm not proposing that we go over to the MRI page to put up hazard warnings.--Yannick (talk) 19:50, 23 June 2012 (UTC)

What do you mean by the "ionizing radiation component"? What other component is there to radiotherapy? If you really want me to, I'm sure I can cite an introductory chapter from an oncology textbook, but is that really necessary?--Yannick (talk) 03:09, 23 June 2012 (UTC)

By the ionizing radiation component, I meant that if it is possible to kill the tumor, or image the body without that component, then it is better for the health to do it without that component. The other component is the result, the killing of the tumor, or the imaging of the body. Nenpog (talk) 07:59, 23 June 2012 (UTC)

Almost any treatment has side effects. Chemotherapy causes cancer, just like radiotherapy does. Echography is not currently known to cause cancer, but who knows? When x-rays got started, we grossly underestimated their potential harm. I would hope that my doctor balances the benefits against the risks and the unknowns and offers me the best treatment overall. And in many cases, it will be radiotherapy or nuclear imaging or CT scans that provide the best health benefit.--Yannick (talk) 12:08, 23 June 2012 (UTC)

The statement "Sometimes the presence of a radiation hazard can be a boon to wildlife by reducing human interference in their habitat.[23]" is not a biological effect of ionizing radiation but an effect of humans staying out of a zone. I am puzzled that this statement of Chernobyl replaced the statement that the overall disease rate in the exposed population rose.— Preceding unsigned comment added by Nenpog (talk • contribs) 00:19, 23 June 2012 (UTC)

OK, I know I'm on shaky ground on this one. But it's not just Chernobyl; this applies to exclusion zones around any reactor or radioactive waste dump or uranium mine. The public has a perception of a radioactive wasteland as looking like the Nevada desert because that's where the early tests were. Therefore it would seem useful for the article to correct that impression with the facts - radioactive wastelands are usually greener than their surroundings! Is there a better way that we can say that and cite it?--Yannick (talk) 03:09, 23 June 2012 (UTC)

Well, as you said, that is true for any exclusion zone, so it is not a biological effect of ionizing radiation. What you are trying to say, is that for certain small doses, that exist in some parts of the exclusion zones, life seem to flourish, although neither of us know what is the radiation dose there, if the animals there are sick or uncomfortable, or mutated, and how similar small doses would affect humans. I think that maybe with more data, this could be interesting, but I also think that hazards of ionizing radiation deserve priority. Additionally we do know that the people exposed before the evacuation got a higher disease rate, so it is odd to chose this over that. --Nenpog (talk) 07:59, 23 June 2012 (UTC)

Oh, we know for a fact that the animals and plants there are sick and mutated from the radiation. And they're flourishing. Do you see how I'm trying to address popular misconceptions about radioactive wastelands? I agree that the hazards deserve priority, and I thought I had given them priority. But if there's a better way to present this, I'm all for it.--Yannick (talk) 12:08, 23 June 2012 (UTC)

I think that this section should concentrate and summarize many biological effects of ionizing radiation, so that people who read this article will not have to read the in depth articles. Additionally, the removed information included material where effects of absorption of certain levels of ionizing radiation was studied, and the insertion of that subject matter is objected to by some editors of other articles, because of not mentioning the topic of the article (e.g. CT), or because of other bureaucratic reasons. — Preceding unsigned comment added by Nenpog (talk • contribs) 00:19, 23 June 2012 (UTC)

I think we need to consider the overall length of the article, and the place of this section in context. If we were to take all the material from radiation-induced cancer and acute radiation syndrome and radiation burn and put it here, the article would be unhelpfully long. And then on top of that, there are a lot of other interesting things to say about ionizing radiation other than its effects on human health. --Yannick (talk) 03:09, 23 June 2012 (UTC)

I think that it is possible to summarize all the effects, in a way that is as short as the current section, or not much longer.--Nenpog (talk) 07:59, 23 June 2012 (UTC)

Well then that would be good and I'm in favor. The removed material didn't seem to approach that ideal.--Yannick (talk) 12:08, 23 June 2012 (UTC)

I've been thinking for a while that we need to spin off a whole page on the biological effects or health effects of ionizing radiation, and that might be a place to put more detail. But even there, CT scans should be given less importance than radon, and DSB's should be given much less weight than the BEIR VII linear no-threshold risk model. --Yannick (talk) 03:09, 23 June 2012 (UTC)

That's a good idea to start a page about biological effects of ionizing radiation. I think that it should present the information about the molecular damage as well as the symptoms of that damage, like cancer.--Nenpog (talk) 07:59, 23 June 2012 (UTC)

Sounds good to me, so long as it also talks about ARS and burns and heart enlargement, etc.--Yannick (talk) 12:08, 23 June 2012 (UTC)

What you seem to be most interested in is radiation-induced cancer and radiation induced cognitive decline caused by X-ray computed tomography, so maybe you should be working on those, even if it means raising your standards to match those of the other editors there. Or maybe you want to start a page on the hazards of X-ray computed tomography.--Yannick (talk) 03:09, 23 June 2012 (UTC)

The thing is, that these editors are not able to understand that the damage is caused by the ionizing radiation of the CT, and thus they disqualify every study that study the effects of ionizing radiation of the same magnitude of a CT, if the study don't mention a CT. For some reason they think that a CT has a special ionizing radiation, that have a different effect on the body, and that all the research about ionizing radiation is not relevant for CTs, that produce just as much ionizing radiation. On the other hand researches about some effects of ionizing radiation in humans are scares, and thus finding a review (they only accept reviews), that handle a certain effects of a CT ionizing radiation is something that I was not able to accomplish yet. --Nenpog (talk) 07:59, 23 June 2012 (UTC)

That's a dispute you need to have with them. You can't use this article for your material just because you've been chased out of the main article where it belongs. I will say that biology and radiation are very complicated and their interactions even more so. It does not seem so outlandish to me to suspect that a sievert of CT dose might have a different effect than a sievert of radiotherapy or a sievert of nuclear blast. I've recently been trying to make sense of why a 50 Gy radiotherapy dose to the breasts seem to cause much less secondary cancers than the LNT model would predict. So why couldn't a similar kind of thing be happening with CT scans?--Yannick (talk) 12:08, 23 June 2012 (UTC)

Very large local doses of radiation don't have the secondary carcinogenis predicted by the naive linear model, simply because they kill a lot of cells that would otherwise become cancer. The same thing is seen in the thyroid, where thyroid ablation by radiation (I-131) doesn't cause nearly as much cancer as lower doses of I-131. The other thing to keep in mind is that every tissue has a weighting factor in terms of carcingenic risk, and CT's to the head involve a lot of brain, which is relatively resistant to radiation carcinogenesis, due to having all those neurons. It can get astrocyctomas and gliomas, but adult neurons are not going to mutate and cause tumors-- they'll simply die. So you have to subtract the risk from all those cells. SBHarris 18:28, 23 June 2012 (UTC)

I'm aware of those effects, but they don't really help explain why atomic bomb results (LSS cohort) would not be applicable to CT scans. The low dose group of the LSS cohort received an average dose of 40-odd mSv, which is in the ballpark of CT scans, and the relative radioresistance of the brain is supposed to be taken into account by its low tissue weighting factor of 0.01. But there might be other effects, not yet understood, that make CT scans different even for whole-body work.--Yannick (talk) 19:50, 23 June 2012 (UTC)

You're going to have to cite sources. This source [1] found that "The median life expectancy for

all survivors combined who had estimated doses of at least 0-.005 Gy (mean dose 0.27 Gy) was 80 years 265 days, about 4-months shorter than the zero-dose individuals." That's not very much for 270 mGy, and could well be in the noise for people who lived to 80, on average. The study extrapolated a loss of life from of 13 years at 1.0 Gy (quite a lot!) to .012 years at 0.01 Gy (10 mGy). For 50 mGy that would extrapolate to 0.060 years = 22 days or 3 weeks of life lost. This is too small to see in any study. It generally confirms my belief that no study of human beings is going to be of enough power to detect any carinogenic effects of ionizing radiation doses in the 50 to 100 mSv or mGy range. All that stuff comes from believing in extrapolation of the linear "no zero risk" model. The correctness of which we don't really know. You can't use your theoretical expectations to argue for the correctness of your theory. We don't KNOW that happens to people who get a 50 mSv or mGy radiology test. In any case, the Japanese cohort included a lot of children who were exposed to I-131, and they are not going to look like adults who are CT scanned. You won't find too many cohort studies of whole body CT scanning of children till they get to 50 mSv, either! Children who get that much radiation from medical imaging already HAVE cancer, by and large, so it's not something you can look at very well, against the gigantic cancer mortality background they have already. SBHarris 21:35, 24 June 2012 (UTC)

I'm going to assume that SBharris is not just trolling, and try to guess at the argument he is trying to bring forward: I believe SBharris wants to make sure the biological effects section maintains the mention of hormesis which was briefly deleted. Did I get that right? In the future, it would be helpful if you could make your central point explicit, preferably at the start or end of your argument. Assuming I got that right, then I agree that a mention would be kept, even though most of what SBharris says above is incorrect. I suggest you read Brenner DJ, Hall EJ (2007). "Computed tomography--an increasing source of radiation exposure" (PDF). N. Engl. J. Med. 357 (22): 2277–84. doi:10.1056/NEJMra072149. PMID 18046031. {{cite journal}}: Unknown parameter |month= ignored (help).--Yannick (talk) 22:20, 24 June 2012 (UTC)

"There was a significant increase in the overall risk of cancer in the subgroup of atomic-bomb survivors who received low doses of radiation, ranging from 5 to 150 mSv; the mean dose in this subgroup was about 40 mSv, which approximates the relevant organ dose from a typical CT study involving two or three scans in an adult."

Hormesis should go in, because it's a valid view with evidence behind it. As for your quote, it needs a cited source and critique of that. Brenner, the author, didn't find it out by ESP, but by some study of this group of bomb survivors. If they had more cancer, it didn't affect their life span. And if they had more cancer, what was the control group they were being compared to? These are valid questions. Survivors need to be compared to the same population in the same area, who happened to be a little farther from the bomb, but otherwise in no way differ. I did my own search and found the cite above (which did just that), which is a direct study of this group, not somebody discussing CT exposure and pulling some statistic out of his hat from some other study, to prove a point. If this is where YOU got it, it's not good enough for the purposes you're using it for, and you need to review those sources yourself (and perhaps you'll find the answer to your "problem." Ah, this is full text article, so we see the survival studies upon which Bremmer et al are relying for their statement. If you will hold for a bit, I will review them to see if the community generally agrees with the conclusions.

• Preston DL, Shimizu Y, Pierce DA, Suyama A, Mabuchi K. Studies of mortality of atomic bomb survivors. Report 13: Solid cancer and noncancer disease mortality: 1950-1997. Radiat Res 2003;160:381-407.

• Pierce DA, Preston DL. Radiation related cancer risks at low doses among atomic bomb survivors. Radiat Res 2000; 154:178-86.

• Preston DL, Ron E, Tokuoka S, et al. Solid cancer incidence in atomic bomb survivors: 1958-1998. Radiat Res 2007;168: 1-64.

SBHarris 23:05, 24 June 2012 (UTC)

Okay, here's the data: [2] Look at slides 13 and 14.

Slide 13 looks like a nice line, but it's quite high radation doses. Slide 14 is where the low dose body is burried. See those blue dots bouncing around from zero relative risk, up to 0.1-0.12 relative risk, then back down to zero, again? Till you get to about 0.2 Gy? That's what we call "noise." You can draw a line through it, of course, but if you connected the blue data dots with a line, you'd get a giant squiggle that people would laugh at. If you use the data below 0.1 Gy, you get no statistical difference. If you use all the dots to 0.15 Gy, you get a significant "trend" but the trend comes from data that bounce up and down like a game of pong. This is "how to lie with statistics." Looking at the data, I see no trend, I see "crap."

Which is just what I expected. SBHarris 23:35, 24 June 2012 (UTC)

Now you're definitely just trolling. Stop it. We agree that hormesis deserves mention.--Yannick (talk) 01:48, 25 June 2012 (UTC)

The troll is yours. After all, you're the one complaining: "I've recently been trying to make sense of why a 50 Gy radiotherapy dose to the breasts seem to cause much less secondary cancers than the LNT model would predict. So why couldn't a similar kind of thing be happening with CT scans?". I provided the simplest and most likely answer: The LNT model is wrong. The cite you provided uses data (which I thoughtfully provided a cite to) that do not break free of the signal-threshhold noise until a dose of between 100 to 150 mGy. Below that, the signal (here, the colon tumor risk ratio) bounces around randomly between nothing (RR = 1.00), and what RR is (still) at 200 mGy (about 1.10). Even though it is supposed to be 1.01 at 160 mGy, and the same at 70 mGy, but 1.00 at 110 mGy...?! Hmmm. Sometimes, in between those points, it goes up to 1.12 or 1.15. I assumed you had seen data from a sensor, or done some signal processing (in other words, I assumed more education than you evidently have-- not all engineers ever see raw data). Clearly, my message is not penetrating. My fault.

You write: I'm aware of those effects, but they don't really help explain why atomic bomb results (LSS cohort) would not be applicable to CT scans. The low dose group of the LSS cohort received an average dose of 40-odd mSv, which is in the ballpark of CT scans... Sorry, but this 40 mGy is an average over a large group of very low dose atomic bomb radiation people, which it is statistically impermissible to do, given that you cannot prove an effect from the direct data, in people who have a dose below 100-150 mGy. Therefore, you cannot fold these people who have lower doses in, in a comparison between them and people who have only background dose. Doing an average for everybody below that figure, assumes that you know what the form of the dose-response curve IS, for the people below that figure. IOW, doing a non-weighted average presumes already that it is linear risk-dose relationship, and this is exactly what you do NOT know, in this region. So this is one of those situations where you presume a priori something that you don't know, then ask why you don't get the answers you expect from that assumption. (Hmmmm). Of course, the NEJM authors have done the same, finding the threshhold that exists in the data, then presuming there's no theshhold below it, so one can fairly lump everybody below it who has gotten ANY radiation at all over background, into one large group like hamburger, then average over them. When we take the mean of THAT mean dose, goodness, it's really low! The upshot of such a method, however, is that if there indeed exists any low-dose threshhold for increased cancer risk in reality, you won't ever find it. You can't find it, since in this method you lump all the very-low dose people in with the higher-dose group that shows the minimum effect. You can't ever see what you don't look for. However, it's bound to cause you misery, when trying to figure out why everybody who has gotten 40 mSv or mGy of CT radiation does not show this same 10% increase in lifetime tumor incidence that Japanese LSS survivors show at 200 mGy. Gosh, maybe something odd about CT radiation? You've created a medical mystery. Can't help you there, though. SBHarris 23:27, 25 June 2012 (UTC)

This is now at Wikipedia:Administrators' noticeboard/Incidents#User:Nenpog. --Guy Macon (talk) 01:39, 10 July 2012 (UTC)

Immediately following the 'mention' of hormesis, I added "but the National Academy of Sciences Biological Effects of Ionizing Radiation Committee 'has concluded that there is no compelling evidence to indicate a dose threshold below which the risk of tumor induction is zero'" with a citation. It seemed sloppy to mention "some scientists" while ignoring the National Academy of Sciences. Nonukes (talk) 00:46, 12 November 2013 (UTC)

It's even sloppier to pretend that there is no controversy. Especially when the people on the other side of this issue are equally as prestigious as the NAS, and in addition, are even more specialized. And some have only lately changed their opinions after years of promoting the LNT model. [3] You do realize that the no threshold model is literally evidence-proof, since any time you get evidence of no effect, it can always be claimed that there is an effect, but too small to see. At some point, however, the evidence for no effect threshold has to become the responsibility of those who hold the "pro" position, just as is the case with non-ionizing radiation. There is already good evidence that effects of ionizing radiation become (at least) non-linear at low doses. So that part is already on the way out. SBHarris 02:21, 12 November 2013 (UTC)

Dr. Ari Brynjolfsson

Dr. Ari Brynjolfsson has been referenced as a noted figure in this field and more information is needed to improve an article about him. Orrerysky (talk) 18:19, 30 November 2013 (UTC)