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The value
160 mSv: chronic dose to lungs over one year smoking 1.5 packs of cigarettes per day, mostly due to inhalation of Polonium-210 and Lead-210[47][48]
is too large by three orders of magnitude. A more realistic value would be in the range of µSv instead of mSv. Do the math... or use a search engine of Your choice:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672370/
https://aip.scitation.org/doi/10.1063/1.4803637 — Preceding unsigned comment added by 185.68.78.221 ( talk) 21:04, 24 August 2019 (UTC)
This article is surprisngly unhelpful. After events such asChernobyl, Three Mile Island and more recently Fukushima the media have quoted units of radiation measurement in milisieverts and microsieverts. What readers want to know is what is the difference? And what is the scale of risk (eg compared to a chest x-ray, exposure from a transatlantic flight, living in Dartmoor England or in poarts of India where background radiation is far higher than the norm). Can someone please make this article accessible? —Preceding unsigned comment added by 93.97.55.97 ( talk) 21:13, 4 April 2011 (UTC)
I think better accessibility is happening and the article now covers the formal definition and examples of effects of dose in sieverts. I have made and added a graphic which may help to clarify the relationship between the dose types, which can be very confusing for the new reader switching between articles. Dougsim ( talk) 23:00, 9 December 2013 (UTC)
This is incorrect, but I don't know how to correct it. The gray (Gy) is correctly defined; and the sievert is defined from the gray by multiplying by a radiation weighting factor. The radiation weighting factor is defined as 1 for gamma radiation. Thus for gammas, 1 Sv = 1 Gy = 100 rad, which is approximately 87 roentgen (depending on the material.) If someone wants more info and can correct the entry, please email me at mcnaught@unm.edu .
I have made an attempt to construct a more accurate version. -- Sievert 18:17 Zeroidle ( talk) 10:59, 15 March 2011 (UTC), 7 Mar 2004 (UTC)
I have removed the list of alleged effects of different levels of sieverts, as they are not appropriate in this article. The unit "Sievert" can be applied to either equivalent dose or effective dose. Such effects as "nausea" and "death" are not appropriate if quoted in terms of the effective dose, since effective dose refers to stochastic effects only. These figures may be true in terms of equivalent dose, but you would have to say which part of the body has been irradiated.
If you want to put this back in, I would suggest at equivalent dose or effects of radiation or something.
-- Sievert 11:41, 2 Apr 2004 (UTC)
Equvalent dose vs. dose equivalent
The article at Equivalent dose states "The equivalent dose should not be mistaken for dose equivalent." Yet the Sievert article uses these terms interchangably in the same sentence. Someone who really understands the specifics should do some careful editing. Jedwards05 05:12, 17 July 2006 (UTC)
I have added a graphic showing the dose quantities with their correct names, and also given an explanation of how the nomenclature is used. Hopefully this will remove confusion. There is a coherent system, and careful use of terminology is important. Dougsim ( talk) 07:11, 27 April 2014 (UTC)
In the following, 50% or more lethality is alleged for more than 3 and more than 4 Sv. Which is it?
More than 3 Sv will lead to death in less than two months in more than 80% of cases, and much over 4 Sv is more likely than not to cause death.
-- Walter Siegmund (talk) 18:26, 21 October 2006 (UTC)
"Radiation produced by the granite of the United States Capitol building : 0.85 mSv/year"
If sievert is a measure of dosage received, it cannot also be a measure of radiation produced.
-- Fuhndhu ( talk) 22:32, 28 March 2011 (UTC)
The same comment applies to several of the entries in the examples list. It seems that the original author has not adequately separated in his thinking the concepts of effective dose (measured in Sv) and activity (measured in Bq). Either that or he or she is not sufficiently rigorous in the forms of expression used. For example, the granite question, and also the defective items in the examples list could be corrected by a change in the wording; e.g. "Effective dose received by a worker in the United States Capitol building due to the radioactivity of the granite in the building: 0.85 mSv/year", assuming that this is actually what is intended. The entire article is very carelessly written, and seriously needs revision by someone who is in the habit of thinking clearly about what they intend to write. 77.96.59.93 ( talk) —Preceding undated comment added 11:10, 2 February 2014 (UTC)
I've seen different tables of quality factors, and whatever values are used should be referenced. The best source I've found (not even an SI source!) is at [1]; a more authoritative version would be great. Note that this version has much more detail, disagrees on the QF for neutrons, and doesn't suggest a method for in-between values (that I noticed).
CRGreathouse ( t | c) 20:28, 20 August 2007 (UTC)
How do you work the quality factor(s?) into the equation? Can someone please give me an example how the Q values and N values work in an example equation, or maybe just put that into the article. I'm not particularly good at math, but I want to understand how it works, and I don't see any variables in the current example equation for Q or N. - Commandur ( talk) 05:34, 8 December 2009 (UTC)
How come the relative N values are ranged from high value to low value, e.g. 0.3 – 0.03? It just looks odd. Wouldn't 0.03–0.3 make more sense, or is that just a regional bias? / 85.228.39.223 11:22, 6 November 2007 (UTC)
I'm intrigued by the following statement: "There is some controversy that the Q or RBE for alpha radiation is underestimated due to mistaken assumptions in the original work in the 1950s that developed those values." Have you got a reference for that? —Preceding unsigned comment added by 74.45.14.168 ( talk) 02:54, 28 January 2009 (UTC)
How does this scheme handle differences between people? Does a postmenopausal woman still have an N of 0.20 applied to her gonads? Does a non-smoker still have the higher 0.12 value for the lungs? If a nuclear power company knows that a woman has had a hysterectomy and has no gonads, can they assign her to work longer because she doesn't take that dosage? (what if you're comparing two postmenopausal women...?) etc. Wnt ( talk) 22:55, 4 February 2009 (UTC)
Presumably the time period over which the dose is absorbed contributes somehow? Does 'acute' mean 'delivered over a short (to be qualified) time period'. 'acute'='sharp' suggests this. If so, article should say so, as this is a medical term or art. —Preceding unsigned comment added by 86.4.139.136 ( talk) 14:18, 16 May 2009 (UTC)
I have added a clarification about the time period. The definition of "short" is somewhat vage because it is related to the response time of the repair mechanisms in the body, which is not well known; it is larger than seconds and shorter than weeks. 213.4.112.58 ( talk) 14:32, 5 November 2009 (UTC)
This article needs serious work. It should be brought in line with the latest ICRP recommendations. Note that American literature on quality factors etc is not relevant (especially regulatory literature), as the US has not adopted the sievert. —Preceding unsigned comment added by 194.81.223.66 ( talk) 15:04, 25 August 2009 (UTC)
I am looking at this article trying to determine if sieverts are an instanteneous or cumulative amounts.
If the radiation source is emitting x sieverts and you are exposed to it for y hours, did you get a dose of xy sievert-hours ?
Or is the source emitting at x sieverts/hour and you are exposed for y hours, you get xy sieverts ?
It seems impossible that the rate of emission is measured in sieverts and the cumulative dose also in sieverts, thats what is being quoted and makes no sense. Eregli bob ( talk) 08:10, 15 March 2011 (UTC)
From the article, it is clear that the unit sievert refers to (absorbed) dose , multiplied by a biological factor, not to dose rate (intensity). —Preceding unsigned comment added by 217.162.65.50 ( talk) 09:56, 15 March 2011 (UTC)
From the examples I see, that a sievert is a commulative dose, because physiological effects depend on it e. g. 10 Sv cause death. An X-Ray gives you a certain dose, so a certain number of X-Rays would kill you.
The strength of radiation at a certain point in time is measured is Sv/time (e.g. Sv/hr or Sv/year). Spending a certain amount of time under this condition would collect an amount that could kill you. 8 mSv/hr would kill you in 1250 hours and would cause serious illness after around 125 hours.
Some of the examples are confusing and look wrong. (e.g.: Average dose to people living within 16 km of Three Mile Island accident: 0.08 mSv). Wouldn't that depend on how much time you have spent there.
Sconden ( talk) 06:38, 17 March 2011 (UTC)
I have found very quite different values: Chest radiography is 0.1 mSv Natural background radiation is between 1 and 3 mSv/year
check these links: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/R/Radiation.html http://www.radiologyinfo.org/en/info.cfm?pg=chestrad
Also I noticed that the various translations of the page show very different values. Zeroidle ( talk) 10:59, 15 March 2011 (UTC)
The sections on dose and symptom benchmarks are long and not essential to a page about sieverts, but are still useful. I suggest leaving a few benchmarks on this page to help people understand the relative scale of a sievert, while linking to a separate article for additional benchmarks. That page could simply be called "Radiation levels." That page could list all the benchmarks, perhaps with an explanation of different measures as well, such as sieverts, rems and grays. 98.246.191.164 ( talk) 12:53, 15 March 2011 (UTC)
Do we need them at all? We have a much more readable list in Orders of magnitude (radiation)..-- Pontificalibus ( talk) 17:01, 17 March 2011 (UTC)
As a scientist used to thinking about dpm, I would like to see some examples of Sv to dpm conversions, I understand that there are a lot of adjustment factors; but I think this would give a nice, concreteness to the idea of the Sv I also dont think the article should be split - it reads very nicely as it is; splitting would really reduce it to a stub - please leave it alone !! —Preceding unsigned comment added by 108.7.9.151 ( talk) 14:11, 15 March 2011 (UTC)
To reduce the risk of confusion, I think all examples should list the numbers in the same unit. Now it says
This could fool someone reading this quickly into thinking these are equivalent numbers. Better:
I'm sure we don't need to discuss why cunfusion in this matter is potentially very bad. (?) —Preceding unsigned comment added by 87.162.84.94 ( talk) 07:49, 17 March 2011 (UTC)
In my opinion, we should list here more hourly dose examples, since a lot of people use Wikipedia as a reference and come here to see how the recently published hourly doses at Fukushima and Tokyo relate to other accidents and to the normal background radiation. For this purpose, it would be better to use similar prefixes that are used in the news and in the reports of (for example) IAEA and JAIF. These reports (with rare exceptions) use microsieverts for values up to four digits and use millisieverts for higher quantities. It even makes sense to make lower hourly doses comparable to background radiation (microsieverts), and to make higher hourly doses to be comparable to yearly doses / yearly limits (millisieverts).
Giving hourly doses for background radiation is useful (even if redundant wrt. yearly doses) since most of us needs a pocket calculator for division by 8760. The (almost) four orders of magnitude difference between hourly and yearly doses justifies using different SI prefixes.
Yozi66 ( talk) 20:46, 20 March 2011 (UTC)
I agree. The unit mSv/h such as a unit that has two prefixes. It is not allowed in SI. Either Sv, or s instead of h (second and hour) but not both of them. +
The quoted source USA Today does not support the statement the Japanese Government uses censorship. Radiation measurements from the surrounding areas are in fact available (see these english translations). I am also not sure if such information is helpful in an article about a measurement unit. -- 132.234.227.1 ( talk) 01:34, 18 March 2011 (UTC)
Repaired example according to sources from 8K to 1K mSv/h —Preceding unsigned comment added by 193.40.10.222 ( talk) 20:36, 28 March 2011 (UTC)
What does the "Single dose example"
mean? Is it a lifetime dose - or should it be moved to the "Yearly dose examples", say? I've checked the reference (and Three Miles island accident). I think it may be an accumulated value for a person living in the region through the accident, which should include absorption the rest of that person's life if there are still elevated radiation levels. But I am not sure - can this be cleared up?-- Nø ( talk) 10:52, 18 March 2011 (UTC)
Replaced Fukushima example from 8K to 1K, according to linked sources.
...and I'd be delighted if the banana was used to show the relationship between these all.
Various news organizations quote "radioactivity" in their favourite expert's terms. And most of the wikipedia pages for these units seem to be devoted to explaining whether the unit is SI, or deprecated. This page thankfully explains Gys and rems, but bequerels are still a mystery. —Preceding unsigned comment added by 173.206.138.245 ( talk) 08:51, 19 March 2011 (UTC)
A graphical chart showing the scale of different radiation exposures would help in giving a better and more immediate overview of the subject.
Randall Munroe has made such a chart, elaborating on a more basic chart by a Reed Research Reactor employee. As his work xkcd is released under Creative Commons, it is likely he won't mind us copying the idea of the chart.
I suggest that someone with the appropriate skillz make a similar chart to conform with the sources (avoiding the wiki self-reference, of course). Or, someone could contact Randall and have him upload the chart to Wikimedia Commons so others can improve it. TGCP ( talk) 23:43, 19 March 2011 (UTC)
Edit: For people who asked about Japanese translations or other types of reprinting: you may republish this image anywhere without any sort of restriction; I place it in the public domain. I just suggest that you make sure to include a clear translation of the disclaimer that the author is not an expert, and that anyone potentially affected by Fukushima should always defer to the directives of regional health authorities.
There's already a radiation dose chart on this article: Orders of magnitude (radiation). It seems wiser to take radiation dose information here and move it there, than to start up another chart here. After all, this article is about "sieverts", which is a unit of radiation. I don't think you'd get a list of how tall things are in an article on "meters". (I could be wrong - I haven't checked.) 137.132.250.14 ( talk) 04:26, 22 March 2011 (UTC)
Radiation is measured in becquerels. The sievert is not a unit of radiation. It is a unit of radiation dose. Would you say the amount of energy emitted by a light bulb was the same thing as the number of lumens reaching an object that it illuminated ? Until contributors get this basic sorted, there is not much hope for a coherent article. Interestingly, you are right, the wikipedia article on "metre" does not give a list of how tall things are. Perhaps this is because everyone knows, roughly, what a metre looks like. Certainly, those who don't, once they are given the equivalent in inches, can visualise it. Many people have only learnt the word "sievert" since Fukoshima, and so they need to know what it means in everyday terms. Also, with a metre, you can mark two points on the ground, and say, "the distance between these two points is a metre". How do you do that with a sievert ? Fuhndhu ( talk) 23:06, 4 April 2011 (UTC)
Whilst visually it is an appealing way of getting a simple message across, there are several issues which others have pointed out. For me the most glaring error is the completely incorrect statement that the sievert is the unit of absorbed dose in the opening text. This is incorrect and going to give a really confusing message. Can the orignal author modify, or are we starting from scratch with a new one? I think this chart is great medium, but needs to be made credible. How to do this? Just blank out the opening text? Dougsim ( talk)
I have noticed that in the "single dose examples" section, there is a mix-up of using equivalent doses and effective doses: the dental x-ray dose and the mammogram dose are stated as equivalent doses (see the reference) whereas the CT doses and the radiation limits used effective dose (ie whole body doses). This may for example cause the reader to believe that having a mammogram is associated with the same cancer risk as (approximately) a brain CT. For the mammogram example, the breasts receive 3 mSv, but the effective dose is instead 3 x 0.05 mSv = 0.15 mSv and this should be the value that is used for comparisons (see also http://en.wikipedia.org/wiki/Effective_dose) Tobbel swe ( talk) 09:52, 22 March 2011 (UTC)
This article is about the sievert. We have numerous examples do draw from all supported by multiple reliable referenced sources. We do not need to include the latest reported measurements from the Fukushima I nuclear accidents, especially if those figures are only supported by a single source, or non-English sources, or if there is any uncertaintiy about their accuracy.-- Pontificalibus ( talk) 21:07, 24 March 2011 (UTC)
When I was young and carried my slide rule uphill through the snow both to and from school we measured radiation exposure in rems. The Fukushima incident is a opportunity to introduce this SI unit to us old hippies who have not kept up with nuclear medicine. So, when the article implies that radiation is measured in rems in the United States, there is an oppotunity to popularize the SI unit. I never edit an article unless I have an exceptionally high understanding of the topic. Obviously, this case does not meet that standard, but I do encourage those of you who know more than I do to do so. — Preceding unsigned comment added by Mikesartin ( talk • contribs) 04:33, 26 March 2011 (UTC)
W, Q and N - How are they related?
I know N has been deleted but does that mean W=Q? —Preceding
unsigned comment added by
88.207.179.198 (
talk) 15:46, 26 March 2011 (UTC)
A lot of people would like to learn more about the stochastic effects of exposure to various sievert levels. How much does your risk of fatal cancer rise from exposure to one sievert? What are the cumulative risks for the heroic workers at the Fukushima site? 98.246.90.0 ( talk) 13:45, 29 March 2011 (UTC)
It seems that there is a discrepancy of 100 times in the value of the dose received as a result of eating one banana, as quoted in this here article and as quoted in the article on Banana Equivalent Dose (BED). This here article states it is 0.0001 mSv, the article on Banana Equivalent Dose states it is 0.001 μSv.
Explanation: this here article states that
- Eating one banana: 0.0001 mSv
The article on Banana Equivalent Dose (BED) states that:
On average banana contains about half a gram of potassium. [1] Therefore if a typical person (70kg) is exposed to all of the radiation coming from one banana then the dose they will be absorbing is of order 10-13 watts per kg (or gray per second). Since 40K decay emits an electron or positron, the weighting factor of 1 is used to quantify the basic biological effect; the equivalent dose rate is of order 0.0001 μSv per hour.
A person's body maintains potassium under homeostasis, at a fairly constant level. [2] Therefore, eating an extra banana will not cause more potassium to be assimilate into the body than would otherwise have occurred. Instead it will cause the body to excrete potassium more quickly. Because the half-life of 40K is so long compared to biological time-scales and because the ratio in food is the same as that in the body, the isotopic ratio will stay the same. Therefore, eating a banana will only cause a temporary increase in the quantity of radioisotope enclosed by the body. Estimating that it takes an average of 8 hours to excrete excess potassium that was consumed from one banana, the total additional dose of radiation will around 0.001 μSv.
References
I propose that a competent editor checks again the facts and corrects one of the two articles (it most likely will be this article, since the article on Banana Equivalent Dose quotes the calculation method, which is unlikely to be incorrect, from what I can make of it.
The table "Equivalency Weighting Factors" in the "Definition" section is a duplication of the "Q values" and "N values" sections. Should one of them be removed? 217.33.231.34 ( talk) 11:58, 29 March 2011 (UTC)
Please see: BIPM SI brochure page No. 69. for name: dose equivalent, symbol: H, unit: sievert, its symbol: Sv
ZJ ( talk) 20:26, 2 April 2011 (UTC)
What is the background radiation for a marine organism (deep water/shallow water) or a human swimmer/diver? One source tells me granite or coffee is 1000 Bq/kg whereas seawater is 10,000 Bq/kg. Correcting for density, I'm guessing the marine background is x3 the terrestrial background, but you'd also need to correct for Q. Most organisms on the planet are marine, so marine background is a useful reference point. — MaxEnt 20:41, 3 April 2011 (UTC)
In recent days radioactive hazard has become a major topic of discussion world wide. The attention the subject gets is mainly due to the Fukushima nuclear situation, that triggered a global panic, overshadowing the natural disaster that caused it. The media have been very active in informing the population as best they could, but clearly not in respect to the actual hazard. Processed results of measurement were expessed in sievert value and presented to support the story.
What is not generally understood is the fact that a sievert is not at all meant to be used like that. A sievert result is primarily a policy instrument, meant to give decision makers something to guide and justify their decisions by. It is not in any way a conclusive measure of any actual radioactive hazard. There is no such thing as a 'sievert meter'. Presenting it as if it were a straight measure result is highly misleading. It is the result of a calculation on the basis of a number of subjective assumptions, adding together the presumed effect of many entirely different sources of various kinds of radiation. It's like adding apples to oranges to bananas to cherry pie in desperate need for a result. This is one of the reasons why the results seem so confusing at times.
Since Wikipedia's sievert article is one of the most frequently visited pages in search of understanding the unit, by many who can't read the value of the unit out of the article, this should actually be noted in the articles very first line. Futhermore the exact significance of the unit should be calculated statisticly, envolving more complex statistics than i can provide. What is known is that this significance is way lower than media presentation suggests, publicly spreading a sense of safety that is not justified by the calculated result.
Bchtd1parrot ( talk) 23:31, 6 April 2011 (UTC)
This article really needs at least a brief mention of cancer risks associated with different exposure levels. Shame that there is so much controversy (on wikipedia) about that. IDK112 ( talk) 05:44, 12 September 2011 (UTC)
The lead section should include a conversion factor to rem, just like the inch, kilogram, etc., include the conversion to other common units in their lead. I realize that there is already a section on conversions, but it is normal for the lead to summarize the most important points of the article. See MOS:LEAD-- Yannick ( talk) 18:39, 11 May 2012 (UTC)
I don't know what 2002 change you're talking about; I see a questionable mention of a 2002 change in the article, but that's an entirely separate issue that I've had nothing to do with. (Yannick)
I have looked at the lead conversion issue in more detail, and I found that infobox we've seen is actually a template specific to units of length. I'm not a programmer, and I'm not sure it would be worth the effort to make a template for radiation units anyway. For non-length measurements, the norm seems to be include conversions to common non-SI units in the text of the lead section, just as I'm proposing. See for example second, Candela per square metre, and kilogram. And finally, I would point you to this discussion, earlier on this talk page.-- Yannick ( talk) 17:47, 12 May 2012 (UTC)
As I look at this page, it really doesn't look like an article about a unit of measurement to me. It looks like haphazard notes written by someone researching radiation dosimetry. Most of the stuff about dose equivalent, effective dose, Q factors, etc., is really about those quantities, not the unit. Keeping it here helps promote confusion between quantity and unit which is already a common problem in radiation measurements. I propose moving most of this stuff out to pages like equivalent dose, effective dose (radiation), relative biological effectiveness, dosimetry etc. As to the examples, I can see why we need a few examples to get a sense of what the unit represents, and a sense of scale, but there are way too many here. Does anyone have concerns with this plan?-- Yannick ( talk) 01:00, 17 May 2012 (UTC)
I see you disregarded my remarks and made the article useless. I give up. − Woodstone ( talk) 16:21, 18 May 2012 (UTC)
Now the article is full of examples of quantities of sieverts received, but no one will have a clue how these are measured. Why not just re-add the factor tables? What is the harm? It would make the article so much more useful for the average reader. The mentioned Q and W in the history sections are completely hanging in the air. I had given the references for these long ago. − Woodstone ( talk) 10:20, 19 May 2012 (UTC)
Was somewhat surprised by this line in the dose example table
That is a massive dose, especially for a power source that's supposed to produce little to no long-lived radioactive waste. So I decided to read the cited source, but I can't really find any basis for this figure in the chapter being referenced. Was this deduced somehow?
Smocking ( talk) 14:57, 15 June 2012 (UTC)
According to Christopher Busby, at low doses, and dose rates, there is much less data, and much more controversy, regarding the possibility of cardiac and teratogenic effects, and the modelling of internal dose.[9] See the linear no-threshold hypothesis—however, this hypothesis was never based on true "low dose" studies[10] and Busby was discredited by the British Health Service for data falsifications and exploitation of Japanese parents after Fukushima emissions (2011).[11]
Yes, this seems incongruous in this article. Dougsim ( talk) 11:02, 8 November 2013 (UTC)
I went and added the U.S. regulations on maximum equivalent doses permitted... And by copying these regs I noticed that the regs are very specific on how they state the limits. They are in the habit of correctly stating, for example,
Notice that those four words all convey the proper meaning to the 0.05 Sv specific limit. We are not left wondering if the limit would pop up in grays or mR, etc. The limits had to be in Sv or rem. It's funny that the spec says "rems" but that is only slightly sloppy.
But browsing through the chart of the article, I notice that we say this sloppy sentence:
Well, that is not very specific. Do we mean their "dose" or their "total effective dose equivalent"? Dose to me means the Absorbed dose and is measured in grays or rads. So by not saying "equivalent" I fill in the "absorbed" part and the chart gets confusing. The U.S. wording especially shows me that the word dose by itself means something that needs to be modified... they put the "equivalent" adjective after the noun... "dose equivalent." I think the article would be better if the word "equivalent" was used adjacent to "dose." Why have a reference work like Wikipedia if it is going to use lazy or sloppy wording?
Furthermore, why did we quote an "average dose"? Shouldn't we care about individuals of the public, whereas averages work out to be dangerous when we are talking about people's health? I seem to think that the word "average" indicates to me that someone synthesized a stupid and worthless statistic. I want to know the highest dose equivalent received by a member of the public. Obviously if two people glued to the fence got 50,000 times the dose equivalent of the guy sleeping in his basement 10 miles away, I want to know about the men on the fence. I like to saw logs! ( talk) 04:24, 10 December 2013 (UTC)
Difference between gray and Sievert is that Sievert is not absorbed dose BUT effect of absorbed dose, that is why the tables have different conversion factors for different radiation type and organs.
I also note that there is no mention of that there is a massive difference in effect of doserates, I can understand that there is problem, I have not found any good source about that but it is quite different resultat wheather yu recive 1 Sv in 5 minutes or spread over 10 years. The first have a high death-risk, the second have good chance of not making any messaurable damage.
Seniorsag (
talk) 16:17, 22 July 2015 (UTC)
"If the equivalent dose is uniform throughout the organism, that is, if the radiation source equally impacts on the entire surface of the body, it will be equal to the body tissue specific effective dose."
It seems to me that there are several problems here.
1) The concept of uniformity. I do not think that uniformity over the surface of an organism is intended here. I suspect that this should read ".. that is, if the radiation source has delivered equal energy to equal increments of mass throughout the body...". I have changed the text to the latter quote.
2)As I understand this, to get "body tissue specific effective dose" from equivalent dose, you must multiply the former by a tissue weighting factor which is generally not unity, so, even if the dose is uniform throughout the body, the "body tissue specific effective dose" will not equal the effective dose. — Preceding unsigned comment added by 77.96.59.93 ( talk) 15:10, 30 January 2014 (UTC)
Thank you - I suspected that this is the answer, which is why I did not alter the original text. However, I feel the point should be explained. I have changed "organism" to "human body", which is the organism for which the usual weighting factors add to 1. However, I now find another problem. If what Woodstone has said reflects the thinking of the original author, should not "body tissue specific effective dose" be changed to "whole body effective dose". Am I correct in understanding the former phrase to relate to specific tissues, rather than the whole body ? If, on the other hand, we understand "body tissue specific effective dose" to mean what it says, then a weighting factor is needed. — Preceding unsigned comment added by 77.96.59.93 ( talk) 08:50, 31 January 2014 (UTC)
I am beginning to feel that this article is very defective, reflects extremely wooly thinking, and is in need of careful review in order to weed out careless errors of wording. I now question this: "...while the sievert is used to express the biological equivalent dose to human tissue". Surely, in view of the above, this should read "....the biological equivalent dose to the human body".
The sievert unfortunately seems to be one of the most poorly described units there is. I have made quite a few changes to the article based on ICRP 103 (which runs to over 300 pages) and other learned papers, and brought in a number of additional issues that need consideration when talking about the sievert, which has been in gestation for a while now. Hopefully these will have addressed your points. If not please put comments here. Dougsim ( talk) 14:04, 7 February 2014 (UTC)
The examples list includes dental X-rays, mammograms, and CT of the colon. In these cases only part of the body is irradiated. Do the quoted figures of dose relate to the mass of tissue irradiated (i.e in calculating J/kg, is the mass used that of the irradiated tissue only), or is the dose an average dose for the whole body, the mass used in the calculation being that of the whole body ? Clearly the former form of calculation will give a higher figure for dose than that obtained if the whole body mass is used. Unless this point is made clear, the figures given in these 3 cases are meaningless. To clarify this, could someone please explain how dose in Sv is calculated in the case of a single dental X-ray ? AJS
This is the expression of the effective dose, which is not wholly dependent on how much is irradiated. What is important is the irradiation received and its effect. All effects are summated to an overall expression of risk, which is the effective dose. This is shown in the graphic. It should be noted that the ICRP figures are averages taken over the world population based on decades of research, and are conservatively fixed.
Dougsim ( talk) 14:16, 7 February 2014 (UTC)
I have put operational and protection quantities and their relationship to physical quantities and instrument measurements into the article in order to tie up the many loose ends and to make the article coherent. Although the article may appear more complex, this is a true reflection of the complexity of use of the sievert.
I have added the CIPM definition and tied this in to the work of the ICRU and ICRP. I have devised a graphic for this based on the work of others leading back to ICRU report 57, as there are some difficult concepts. I have added in tissue effects for completeness but tried to avoid excessive duplication. Dougsim ( talk) 13:48, 7 February 2014 (UTC)
There is some confusion here! The conversion factor 1 Si = 100 REM is aproximately true, BUT since they have modivied the wheigt factors a little it is not compleatly true. For mormal use it is good enough, but not for precision use. Seniorsag ( talk) 15:21, 15 July 2014 (UTC)
I note that although there's a reference to the RadSafe mailing list, we have no article on it. We probably should have and soon will I hope. I've redlinked to it in anticipation. Andrewa ( talk) 21:29, 9 January 2015 (UTC)
We've got "ionising" and "ionizing" all over the place. As of January 2016, it was completely "z" except for one "s", but since then a bunch of "s" have crept in. There's no nationalistic component to the article's topic itself, so I assume we should go with original form and inertia. I plan to flip it all to "s" in a day or two unless someone disagrees (or beats me to making that edit:) DMacks ( talk) 08:06, 14 December 2016 (UTC)
Because someone reverted it for some reason: The "Dose examples" section is currently an entirely excessive listing of unexplained statistics: it is a collection of doses and dose rates that do absolutely nothing to further the understanding of the sievert as a unit. This is a unit that's intended to quantify stochastic risk - in other words, it isn't meant to represent deterministic effects. But that list is just item after item of deterministic (ARS, death) outcomes. You could list all the doses received by anyone ever, but it would not help anyone understand what the sievert is. Kolbasz ( talk) 01:27, 11 February 2017 (UTC)
Has there been any proposal to include the wisdom about nonlinear effects on the measurement of radiation effects? There are several works on low-dosage effects, like [4]. How about the amplitute form of the radiation applied - does it make no difference if the radiation occurs in several short higher-energy bursts or in one slight sinus-formed curve, as long as they have the same integral value? Any links to works on this subject are welcome. -- Bernd.Brincken ( talk) 10:44, 15 March 2017 (UTC)
I am going to revert the protection quantities graphic link back to the diagram I wrote a few years ago, which is a truer representation of what the ICRP/ICRU means. Effective dose does not exist at tissue or organ level for multiple organs. Effective dose is the summated value of the double-weighted quantities.
See the following explanation of this difficult area published in 2013; in this explanation the contributions to the effective dose are best described as equivalent organ or tissue doses in the most recent terminology.
From: "Radiological protection issues arising during and after the Fukushima nuclear reactor accident Abel J Gonzalez et al. Journal of Radiological Protection vol 33 (2013) 497–571
2.3.2. The changing names of the radiological protection quantities.
"The names used for the radiological protection quantities have evolved. ICRP Publication 26 (ICRP 1976) and
its amendment issued by the ICRP’s 1978 Stockholm statement introduced and defined the
quantities ‘organ or tissue dose equivalent’ and ‘effective dose equivalent’. ICRP Publication
60 (ICRP 1991) changed the terms to ‘equivalent dose in a tissue or organ’ and ‘effective dose’.
The reason for the change was that ‘the weighted dose equivalent (a doubly weighted absorbed
dose) has previously been called the effective dose equivalent but this name is unnecessarily
cumbersome, especially in more complex combinations such as collective committed effective
dose equivalent’. ICRP Publication 60 also states that ‘the Commission has decided to revert
to the earlier name of equivalent dose in a tissue or organ’. However, searching for the name
‘equivalent dose’ in previous ICRP reports failed to find clear evidence for this statement.
For example, in ICRP Publication 2 (ICRP 1959) the name ‘RBE dose’ was used and in
ICRP Publications 6 (ICRP 1962) and 9 (ICRP 1965) the name ‘dose equivalent’ was used.
Therefore, the coexistence of the names of equivalent dose and dose equivalent appears to be
due to changes introduced by the ICRP in Publication 60. The coexistence of the two different
names for the same quantity has added confusion and misunderstanding within an already
complex dosimetric system for radiological protection. Finally, ICRP Publication 103 (ICRP2007a)
uses equivalent dose without the specification ‘in a tissue or organ’ which can add
to misunderstanding with effective dose if the quantity is not clearly specified since the unit,
sievert (Sv), is the same."
Why the two are different ? I wrote "810 nSv/h avg Next to the Chernobyl Nuclear Power Plant sarcophagus ", as can be seen in the References. But when I watch this video, it tells another data ? Check [5] at 5:36 . The time different between the two pictures is five years, but I assume it's not causing the different in the data . Eliran t ( talk) 22:51, 24 June 2019 (UTC)
This template has been added, but no detail about why. What is the problem with the lead? Dougsim ( talk) 06:00, 23 August 2022 (UTC)
I notice the lead has been amended to wrongly describe the Sievert as being J/kg, which is actually absorbed dose not equivalent dose. Also there has been an unnecessary section added expanding on the Roentgen, which has now been removed. Dougsim ( talk) 06:29, 23 August 2022 (UTC)
ICRP report 103 says (para numbers)
(56) In Publication 60 (ICRP, 1991b) the Commission classified the radiation effects that result in tissue reactions as deterministic effects and used the term stochastic effects for radiation-induced cancer and heritable disease. Effects caused by injury in popula- tions of cells were called non-stochastic in Publication 41 (ICRP, 1984), and this was replaced by the term deterministic, meaning ‘causally determined by preceding events’ in Publication 60 (ICRP, 1991b). The generic terms, deterministic and stochastic ef- fects, are not always familiar to those outside the field of radiological protection. For this and other reasons (given in Annex A), Chapter 3 and Annex A also use the directly descriptive terms tissue reactions and cancer/heritable effects respectively. However, the Commission recognises that the generic terms, deterministic and sto- chastic effects, have a firmly embedded use in its system of protection and will use the generic and directly descriptive terms synonymously, according to context.
(57) In this respect the Commission notes that some radiation-associated health consequences, particularly some non-cancer effects (see Section 3.3), are not yet suf- ficiently well understood to assign to either of the generic categories. Since 1990, the Commission has reviewed many aspects of the biological effects of radiation. The views developed by the Commission are summarised in this Chapter with emphasis on effective doses of up to about 100 mSv (or absorbed doses of about 100 mGy of low-LET radiation) delivered as a single dose or accumulated annually
...................
(64) Although there are recognised exceptions, for the purposes of radiological protection the Commission judges that the weight of evidence on fundamental cellu- lar processes coupled with dose-response data supports the view that, in the low dose range, below about 100 mSv, it is scientifically plausible to assume that the incidence of cancer or heritable effects will rise in direct proportion to an increase in the equiv- alent dose in the relevant organs and tissues.
(65) Therefore, the practical system of radiological protection recommended by the Commission will continue to be based upon the assumption that at doses below about 100 mSv a given increment in dose will produce a directly proportionate incre- ment in the probability of incurring cancer or heritable effects attributable to radia- tion. This dose-response model is generally known as ‘linear-non-threshold’ or LNT."
The sievert for radiation protection is most reliably applied in this range. Dougsim ( talk) 12:24, 23 August 2022 (UTC)
In the article, it now says: Nonfatal dose to Anatoli Bugorski who was struck with a proton beam from a Particle Accelerator through the head while cleaning the U-70 synchrotron on the 13th of July 1978. He is still alive to this day.
Problems: Original measures this dose in röntgen, which is i believe just the measurement read using a gamma-ray capable geigermeter kindof? This seems to have been converted to rem, which is probably kindof accurate (probably actually).. but not really. There is also probably a conversion error, as 100 rem = 1 sievert, which makes his dose not 200-300 sievert, but 2000-3000 sievert (e.g. 200 000/100 = 2000, not 200.). Also maybe Bragg peak is a matter of life and death in his case, but not even mentioned. Finally the source is not the best, the original article reference an archived russian page. The source in Sievert article is malfunctioning.
I suggest we remove this entry. Its not good enough. Or someone fix it.
Google isn't properly giving me results on the difference between these two notations, so I was wondering what the differences was, as it isn't explained in the article either. Google keeps giving me results for the lowercase version no matter what I do, which is why I'm asking. 71.90.116.133 ( talk) 20:44, 27 September 2023 (UTC)
Cite error: There are <ref group=note>
tags on this page, but the references will not show without a {{reflist|group=note}}
template (see the
help page).
This
level-4 vital article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||
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The value
160 mSv: chronic dose to lungs over one year smoking 1.5 packs of cigarettes per day, mostly due to inhalation of Polonium-210 and Lead-210[47][48]
is too large by three orders of magnitude. A more realistic value would be in the range of µSv instead of mSv. Do the math... or use a search engine of Your choice:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672370/
https://aip.scitation.org/doi/10.1063/1.4803637 — Preceding unsigned comment added by 185.68.78.221 ( talk) 21:04, 24 August 2019 (UTC)
This article is surprisngly unhelpful. After events such asChernobyl, Three Mile Island and more recently Fukushima the media have quoted units of radiation measurement in milisieverts and microsieverts. What readers want to know is what is the difference? And what is the scale of risk (eg compared to a chest x-ray, exposure from a transatlantic flight, living in Dartmoor England or in poarts of India where background radiation is far higher than the norm). Can someone please make this article accessible? —Preceding unsigned comment added by 93.97.55.97 ( talk) 21:13, 4 April 2011 (UTC)
I think better accessibility is happening and the article now covers the formal definition and examples of effects of dose in sieverts. I have made and added a graphic which may help to clarify the relationship between the dose types, which can be very confusing for the new reader switching between articles. Dougsim ( talk) 23:00, 9 December 2013 (UTC)
This is incorrect, but I don't know how to correct it. The gray (Gy) is correctly defined; and the sievert is defined from the gray by multiplying by a radiation weighting factor. The radiation weighting factor is defined as 1 for gamma radiation. Thus for gammas, 1 Sv = 1 Gy = 100 rad, which is approximately 87 roentgen (depending on the material.) If someone wants more info and can correct the entry, please email me at mcnaught@unm.edu .
I have made an attempt to construct a more accurate version. -- Sievert 18:17 Zeroidle ( talk) 10:59, 15 March 2011 (UTC), 7 Mar 2004 (UTC)
I have removed the list of alleged effects of different levels of sieverts, as they are not appropriate in this article. The unit "Sievert" can be applied to either equivalent dose or effective dose. Such effects as "nausea" and "death" are not appropriate if quoted in terms of the effective dose, since effective dose refers to stochastic effects only. These figures may be true in terms of equivalent dose, but you would have to say which part of the body has been irradiated.
If you want to put this back in, I would suggest at equivalent dose or effects of radiation or something.
-- Sievert 11:41, 2 Apr 2004 (UTC)
Equvalent dose vs. dose equivalent
The article at Equivalent dose states "The equivalent dose should not be mistaken for dose equivalent." Yet the Sievert article uses these terms interchangably in the same sentence. Someone who really understands the specifics should do some careful editing. Jedwards05 05:12, 17 July 2006 (UTC)
I have added a graphic showing the dose quantities with their correct names, and also given an explanation of how the nomenclature is used. Hopefully this will remove confusion. There is a coherent system, and careful use of terminology is important. Dougsim ( talk) 07:11, 27 April 2014 (UTC)
In the following, 50% or more lethality is alleged for more than 3 and more than 4 Sv. Which is it?
More than 3 Sv will lead to death in less than two months in more than 80% of cases, and much over 4 Sv is more likely than not to cause death.
-- Walter Siegmund (talk) 18:26, 21 October 2006 (UTC)
"Radiation produced by the granite of the United States Capitol building : 0.85 mSv/year"
If sievert is a measure of dosage received, it cannot also be a measure of radiation produced.
-- Fuhndhu ( talk) 22:32, 28 March 2011 (UTC)
The same comment applies to several of the entries in the examples list. It seems that the original author has not adequately separated in his thinking the concepts of effective dose (measured in Sv) and activity (measured in Bq). Either that or he or she is not sufficiently rigorous in the forms of expression used. For example, the granite question, and also the defective items in the examples list could be corrected by a change in the wording; e.g. "Effective dose received by a worker in the United States Capitol building due to the radioactivity of the granite in the building: 0.85 mSv/year", assuming that this is actually what is intended. The entire article is very carelessly written, and seriously needs revision by someone who is in the habit of thinking clearly about what they intend to write. 77.96.59.93 ( talk) —Preceding undated comment added 11:10, 2 February 2014 (UTC)
I've seen different tables of quality factors, and whatever values are used should be referenced. The best source I've found (not even an SI source!) is at [1]; a more authoritative version would be great. Note that this version has much more detail, disagrees on the QF for neutrons, and doesn't suggest a method for in-between values (that I noticed).
CRGreathouse ( t | c) 20:28, 20 August 2007 (UTC)
How do you work the quality factor(s?) into the equation? Can someone please give me an example how the Q values and N values work in an example equation, or maybe just put that into the article. I'm not particularly good at math, but I want to understand how it works, and I don't see any variables in the current example equation for Q or N. - Commandur ( talk) 05:34, 8 December 2009 (UTC)
How come the relative N values are ranged from high value to low value, e.g. 0.3 – 0.03? It just looks odd. Wouldn't 0.03–0.3 make more sense, or is that just a regional bias? / 85.228.39.223 11:22, 6 November 2007 (UTC)
I'm intrigued by the following statement: "There is some controversy that the Q or RBE for alpha radiation is underestimated due to mistaken assumptions in the original work in the 1950s that developed those values." Have you got a reference for that? —Preceding unsigned comment added by 74.45.14.168 ( talk) 02:54, 28 January 2009 (UTC)
How does this scheme handle differences between people? Does a postmenopausal woman still have an N of 0.20 applied to her gonads? Does a non-smoker still have the higher 0.12 value for the lungs? If a nuclear power company knows that a woman has had a hysterectomy and has no gonads, can they assign her to work longer because she doesn't take that dosage? (what if you're comparing two postmenopausal women...?) etc. Wnt ( talk) 22:55, 4 February 2009 (UTC)
Presumably the time period over which the dose is absorbed contributes somehow? Does 'acute' mean 'delivered over a short (to be qualified) time period'. 'acute'='sharp' suggests this. If so, article should say so, as this is a medical term or art. —Preceding unsigned comment added by 86.4.139.136 ( talk) 14:18, 16 May 2009 (UTC)
I have added a clarification about the time period. The definition of "short" is somewhat vage because it is related to the response time of the repair mechanisms in the body, which is not well known; it is larger than seconds and shorter than weeks. 213.4.112.58 ( talk) 14:32, 5 November 2009 (UTC)
This article needs serious work. It should be brought in line with the latest ICRP recommendations. Note that American literature on quality factors etc is not relevant (especially regulatory literature), as the US has not adopted the sievert. —Preceding unsigned comment added by 194.81.223.66 ( talk) 15:04, 25 August 2009 (UTC)
I am looking at this article trying to determine if sieverts are an instanteneous or cumulative amounts.
If the radiation source is emitting x sieverts and you are exposed to it for y hours, did you get a dose of xy sievert-hours ?
Or is the source emitting at x sieverts/hour and you are exposed for y hours, you get xy sieverts ?
It seems impossible that the rate of emission is measured in sieverts and the cumulative dose also in sieverts, thats what is being quoted and makes no sense. Eregli bob ( talk) 08:10, 15 March 2011 (UTC)
From the article, it is clear that the unit sievert refers to (absorbed) dose , multiplied by a biological factor, not to dose rate (intensity). —Preceding unsigned comment added by 217.162.65.50 ( talk) 09:56, 15 March 2011 (UTC)
From the examples I see, that a sievert is a commulative dose, because physiological effects depend on it e. g. 10 Sv cause death. An X-Ray gives you a certain dose, so a certain number of X-Rays would kill you.
The strength of radiation at a certain point in time is measured is Sv/time (e.g. Sv/hr or Sv/year). Spending a certain amount of time under this condition would collect an amount that could kill you. 8 mSv/hr would kill you in 1250 hours and would cause serious illness after around 125 hours.
Some of the examples are confusing and look wrong. (e.g.: Average dose to people living within 16 km of Three Mile Island accident: 0.08 mSv). Wouldn't that depend on how much time you have spent there.
Sconden ( talk) 06:38, 17 March 2011 (UTC)
I have found very quite different values: Chest radiography is 0.1 mSv Natural background radiation is between 1 and 3 mSv/year
check these links: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/R/Radiation.html http://www.radiologyinfo.org/en/info.cfm?pg=chestrad
Also I noticed that the various translations of the page show very different values. Zeroidle ( talk) 10:59, 15 March 2011 (UTC)
The sections on dose and symptom benchmarks are long and not essential to a page about sieverts, but are still useful. I suggest leaving a few benchmarks on this page to help people understand the relative scale of a sievert, while linking to a separate article for additional benchmarks. That page could simply be called "Radiation levels." That page could list all the benchmarks, perhaps with an explanation of different measures as well, such as sieverts, rems and grays. 98.246.191.164 ( talk) 12:53, 15 March 2011 (UTC)
Do we need them at all? We have a much more readable list in Orders of magnitude (radiation)..-- Pontificalibus ( talk) 17:01, 17 March 2011 (UTC)
As a scientist used to thinking about dpm, I would like to see some examples of Sv to dpm conversions, I understand that there are a lot of adjustment factors; but I think this would give a nice, concreteness to the idea of the Sv I also dont think the article should be split - it reads very nicely as it is; splitting would really reduce it to a stub - please leave it alone !! —Preceding unsigned comment added by 108.7.9.151 ( talk) 14:11, 15 March 2011 (UTC)
To reduce the risk of confusion, I think all examples should list the numbers in the same unit. Now it says
This could fool someone reading this quickly into thinking these are equivalent numbers. Better:
I'm sure we don't need to discuss why cunfusion in this matter is potentially very bad. (?) —Preceding unsigned comment added by 87.162.84.94 ( talk) 07:49, 17 March 2011 (UTC)
In my opinion, we should list here more hourly dose examples, since a lot of people use Wikipedia as a reference and come here to see how the recently published hourly doses at Fukushima and Tokyo relate to other accidents and to the normal background radiation. For this purpose, it would be better to use similar prefixes that are used in the news and in the reports of (for example) IAEA and JAIF. These reports (with rare exceptions) use microsieverts for values up to four digits and use millisieverts for higher quantities. It even makes sense to make lower hourly doses comparable to background radiation (microsieverts), and to make higher hourly doses to be comparable to yearly doses / yearly limits (millisieverts).
Giving hourly doses for background radiation is useful (even if redundant wrt. yearly doses) since most of us needs a pocket calculator for division by 8760. The (almost) four orders of magnitude difference between hourly and yearly doses justifies using different SI prefixes.
Yozi66 ( talk) 20:46, 20 March 2011 (UTC)
I agree. The unit mSv/h such as a unit that has two prefixes. It is not allowed in SI. Either Sv, or s instead of h (second and hour) but not both of them. +
The quoted source USA Today does not support the statement the Japanese Government uses censorship. Radiation measurements from the surrounding areas are in fact available (see these english translations). I am also not sure if such information is helpful in an article about a measurement unit. -- 132.234.227.1 ( talk) 01:34, 18 March 2011 (UTC)
Repaired example according to sources from 8K to 1K mSv/h —Preceding unsigned comment added by 193.40.10.222 ( talk) 20:36, 28 March 2011 (UTC)
What does the "Single dose example"
mean? Is it a lifetime dose - or should it be moved to the "Yearly dose examples", say? I've checked the reference (and Three Miles island accident). I think it may be an accumulated value for a person living in the region through the accident, which should include absorption the rest of that person's life if there are still elevated radiation levels. But I am not sure - can this be cleared up?-- Nø ( talk) 10:52, 18 March 2011 (UTC)
Replaced Fukushima example from 8K to 1K, according to linked sources.
...and I'd be delighted if the banana was used to show the relationship between these all.
Various news organizations quote "radioactivity" in their favourite expert's terms. And most of the wikipedia pages for these units seem to be devoted to explaining whether the unit is SI, or deprecated. This page thankfully explains Gys and rems, but bequerels are still a mystery. —Preceding unsigned comment added by 173.206.138.245 ( talk) 08:51, 19 March 2011 (UTC)
A graphical chart showing the scale of different radiation exposures would help in giving a better and more immediate overview of the subject.
Randall Munroe has made such a chart, elaborating on a more basic chart by a Reed Research Reactor employee. As his work xkcd is released under Creative Commons, it is likely he won't mind us copying the idea of the chart.
I suggest that someone with the appropriate skillz make a similar chart to conform with the sources (avoiding the wiki self-reference, of course). Or, someone could contact Randall and have him upload the chart to Wikimedia Commons so others can improve it. TGCP ( talk) 23:43, 19 March 2011 (UTC)
Edit: For people who asked about Japanese translations or other types of reprinting: you may republish this image anywhere without any sort of restriction; I place it in the public domain. I just suggest that you make sure to include a clear translation of the disclaimer that the author is not an expert, and that anyone potentially affected by Fukushima should always defer to the directives of regional health authorities.
There's already a radiation dose chart on this article: Orders of magnitude (radiation). It seems wiser to take radiation dose information here and move it there, than to start up another chart here. After all, this article is about "sieverts", which is a unit of radiation. I don't think you'd get a list of how tall things are in an article on "meters". (I could be wrong - I haven't checked.) 137.132.250.14 ( talk) 04:26, 22 March 2011 (UTC)
Radiation is measured in becquerels. The sievert is not a unit of radiation. It is a unit of radiation dose. Would you say the amount of energy emitted by a light bulb was the same thing as the number of lumens reaching an object that it illuminated ? Until contributors get this basic sorted, there is not much hope for a coherent article. Interestingly, you are right, the wikipedia article on "metre" does not give a list of how tall things are. Perhaps this is because everyone knows, roughly, what a metre looks like. Certainly, those who don't, once they are given the equivalent in inches, can visualise it. Many people have only learnt the word "sievert" since Fukoshima, and so they need to know what it means in everyday terms. Also, with a metre, you can mark two points on the ground, and say, "the distance between these two points is a metre". How do you do that with a sievert ? Fuhndhu ( talk) 23:06, 4 April 2011 (UTC)
Whilst visually it is an appealing way of getting a simple message across, there are several issues which others have pointed out. For me the most glaring error is the completely incorrect statement that the sievert is the unit of absorbed dose in the opening text. This is incorrect and going to give a really confusing message. Can the orignal author modify, or are we starting from scratch with a new one? I think this chart is great medium, but needs to be made credible. How to do this? Just blank out the opening text? Dougsim ( talk)
I have noticed that in the "single dose examples" section, there is a mix-up of using equivalent doses and effective doses: the dental x-ray dose and the mammogram dose are stated as equivalent doses (see the reference) whereas the CT doses and the radiation limits used effective dose (ie whole body doses). This may for example cause the reader to believe that having a mammogram is associated with the same cancer risk as (approximately) a brain CT. For the mammogram example, the breasts receive 3 mSv, but the effective dose is instead 3 x 0.05 mSv = 0.15 mSv and this should be the value that is used for comparisons (see also http://en.wikipedia.org/wiki/Effective_dose) Tobbel swe ( talk) 09:52, 22 March 2011 (UTC)
This article is about the sievert. We have numerous examples do draw from all supported by multiple reliable referenced sources. We do not need to include the latest reported measurements from the Fukushima I nuclear accidents, especially if those figures are only supported by a single source, or non-English sources, or if there is any uncertaintiy about their accuracy.-- Pontificalibus ( talk) 21:07, 24 March 2011 (UTC)
When I was young and carried my slide rule uphill through the snow both to and from school we measured radiation exposure in rems. The Fukushima incident is a opportunity to introduce this SI unit to us old hippies who have not kept up with nuclear medicine. So, when the article implies that radiation is measured in rems in the United States, there is an oppotunity to popularize the SI unit. I never edit an article unless I have an exceptionally high understanding of the topic. Obviously, this case does not meet that standard, but I do encourage those of you who know more than I do to do so. — Preceding unsigned comment added by Mikesartin ( talk • contribs) 04:33, 26 March 2011 (UTC)
W, Q and N - How are they related?
I know N has been deleted but does that mean W=Q? —Preceding
unsigned comment added by
88.207.179.198 (
talk) 15:46, 26 March 2011 (UTC)
A lot of people would like to learn more about the stochastic effects of exposure to various sievert levels. How much does your risk of fatal cancer rise from exposure to one sievert? What are the cumulative risks for the heroic workers at the Fukushima site? 98.246.90.0 ( talk) 13:45, 29 March 2011 (UTC)
It seems that there is a discrepancy of 100 times in the value of the dose received as a result of eating one banana, as quoted in this here article and as quoted in the article on Banana Equivalent Dose (BED). This here article states it is 0.0001 mSv, the article on Banana Equivalent Dose states it is 0.001 μSv.
Explanation: this here article states that
- Eating one banana: 0.0001 mSv
The article on Banana Equivalent Dose (BED) states that:
On average banana contains about half a gram of potassium. [1] Therefore if a typical person (70kg) is exposed to all of the radiation coming from one banana then the dose they will be absorbing is of order 10-13 watts per kg (or gray per second). Since 40K decay emits an electron or positron, the weighting factor of 1 is used to quantify the basic biological effect; the equivalent dose rate is of order 0.0001 μSv per hour.
A person's body maintains potassium under homeostasis, at a fairly constant level. [2] Therefore, eating an extra banana will not cause more potassium to be assimilate into the body than would otherwise have occurred. Instead it will cause the body to excrete potassium more quickly. Because the half-life of 40K is so long compared to biological time-scales and because the ratio in food is the same as that in the body, the isotopic ratio will stay the same. Therefore, eating a banana will only cause a temporary increase in the quantity of radioisotope enclosed by the body. Estimating that it takes an average of 8 hours to excrete excess potassium that was consumed from one banana, the total additional dose of radiation will around 0.001 μSv.
References
I propose that a competent editor checks again the facts and corrects one of the two articles (it most likely will be this article, since the article on Banana Equivalent Dose quotes the calculation method, which is unlikely to be incorrect, from what I can make of it.
The table "Equivalency Weighting Factors" in the "Definition" section is a duplication of the "Q values" and "N values" sections. Should one of them be removed? 217.33.231.34 ( talk) 11:58, 29 March 2011 (UTC)
Please see: BIPM SI brochure page No. 69. for name: dose equivalent, symbol: H, unit: sievert, its symbol: Sv
ZJ ( talk) 20:26, 2 April 2011 (UTC)
What is the background radiation for a marine organism (deep water/shallow water) or a human swimmer/diver? One source tells me granite or coffee is 1000 Bq/kg whereas seawater is 10,000 Bq/kg. Correcting for density, I'm guessing the marine background is x3 the terrestrial background, but you'd also need to correct for Q. Most organisms on the planet are marine, so marine background is a useful reference point. — MaxEnt 20:41, 3 April 2011 (UTC)
In recent days radioactive hazard has become a major topic of discussion world wide. The attention the subject gets is mainly due to the Fukushima nuclear situation, that triggered a global panic, overshadowing the natural disaster that caused it. The media have been very active in informing the population as best they could, but clearly not in respect to the actual hazard. Processed results of measurement were expessed in sievert value and presented to support the story.
What is not generally understood is the fact that a sievert is not at all meant to be used like that. A sievert result is primarily a policy instrument, meant to give decision makers something to guide and justify their decisions by. It is not in any way a conclusive measure of any actual radioactive hazard. There is no such thing as a 'sievert meter'. Presenting it as if it were a straight measure result is highly misleading. It is the result of a calculation on the basis of a number of subjective assumptions, adding together the presumed effect of many entirely different sources of various kinds of radiation. It's like adding apples to oranges to bananas to cherry pie in desperate need for a result. This is one of the reasons why the results seem so confusing at times.
Since Wikipedia's sievert article is one of the most frequently visited pages in search of understanding the unit, by many who can't read the value of the unit out of the article, this should actually be noted in the articles very first line. Futhermore the exact significance of the unit should be calculated statisticly, envolving more complex statistics than i can provide. What is known is that this significance is way lower than media presentation suggests, publicly spreading a sense of safety that is not justified by the calculated result.
Bchtd1parrot ( talk) 23:31, 6 April 2011 (UTC)
This article really needs at least a brief mention of cancer risks associated with different exposure levels. Shame that there is so much controversy (on wikipedia) about that. IDK112 ( talk) 05:44, 12 September 2011 (UTC)
The lead section should include a conversion factor to rem, just like the inch, kilogram, etc., include the conversion to other common units in their lead. I realize that there is already a section on conversions, but it is normal for the lead to summarize the most important points of the article. See MOS:LEAD-- Yannick ( talk) 18:39, 11 May 2012 (UTC)
I don't know what 2002 change you're talking about; I see a questionable mention of a 2002 change in the article, but that's an entirely separate issue that I've had nothing to do with. (Yannick)
I have looked at the lead conversion issue in more detail, and I found that infobox we've seen is actually a template specific to units of length. I'm not a programmer, and I'm not sure it would be worth the effort to make a template for radiation units anyway. For non-length measurements, the norm seems to be include conversions to common non-SI units in the text of the lead section, just as I'm proposing. See for example second, Candela per square metre, and kilogram. And finally, I would point you to this discussion, earlier on this talk page.-- Yannick ( talk) 17:47, 12 May 2012 (UTC)
As I look at this page, it really doesn't look like an article about a unit of measurement to me. It looks like haphazard notes written by someone researching radiation dosimetry. Most of the stuff about dose equivalent, effective dose, Q factors, etc., is really about those quantities, not the unit. Keeping it here helps promote confusion between quantity and unit which is already a common problem in radiation measurements. I propose moving most of this stuff out to pages like equivalent dose, effective dose (radiation), relative biological effectiveness, dosimetry etc. As to the examples, I can see why we need a few examples to get a sense of what the unit represents, and a sense of scale, but there are way too many here. Does anyone have concerns with this plan?-- Yannick ( talk) 01:00, 17 May 2012 (UTC)
I see you disregarded my remarks and made the article useless. I give up. − Woodstone ( talk) 16:21, 18 May 2012 (UTC)
Now the article is full of examples of quantities of sieverts received, but no one will have a clue how these are measured. Why not just re-add the factor tables? What is the harm? It would make the article so much more useful for the average reader. The mentioned Q and W in the history sections are completely hanging in the air. I had given the references for these long ago. − Woodstone ( talk) 10:20, 19 May 2012 (UTC)
Was somewhat surprised by this line in the dose example table
That is a massive dose, especially for a power source that's supposed to produce little to no long-lived radioactive waste. So I decided to read the cited source, but I can't really find any basis for this figure in the chapter being referenced. Was this deduced somehow?
Smocking ( talk) 14:57, 15 June 2012 (UTC)
According to Christopher Busby, at low doses, and dose rates, there is much less data, and much more controversy, regarding the possibility of cardiac and teratogenic effects, and the modelling of internal dose.[9] See the linear no-threshold hypothesis—however, this hypothesis was never based on true "low dose" studies[10] and Busby was discredited by the British Health Service for data falsifications and exploitation of Japanese parents after Fukushima emissions (2011).[11]
Yes, this seems incongruous in this article. Dougsim ( talk) 11:02, 8 November 2013 (UTC)
I went and added the U.S. regulations on maximum equivalent doses permitted... And by copying these regs I noticed that the regs are very specific on how they state the limits. They are in the habit of correctly stating, for example,
Notice that those four words all convey the proper meaning to the 0.05 Sv specific limit. We are not left wondering if the limit would pop up in grays or mR, etc. The limits had to be in Sv or rem. It's funny that the spec says "rems" but that is only slightly sloppy.
But browsing through the chart of the article, I notice that we say this sloppy sentence:
Well, that is not very specific. Do we mean their "dose" or their "total effective dose equivalent"? Dose to me means the Absorbed dose and is measured in grays or rads. So by not saying "equivalent" I fill in the "absorbed" part and the chart gets confusing. The U.S. wording especially shows me that the word dose by itself means something that needs to be modified... they put the "equivalent" adjective after the noun... "dose equivalent." I think the article would be better if the word "equivalent" was used adjacent to "dose." Why have a reference work like Wikipedia if it is going to use lazy or sloppy wording?
Furthermore, why did we quote an "average dose"? Shouldn't we care about individuals of the public, whereas averages work out to be dangerous when we are talking about people's health? I seem to think that the word "average" indicates to me that someone synthesized a stupid and worthless statistic. I want to know the highest dose equivalent received by a member of the public. Obviously if two people glued to the fence got 50,000 times the dose equivalent of the guy sleeping in his basement 10 miles away, I want to know about the men on the fence. I like to saw logs! ( talk) 04:24, 10 December 2013 (UTC)
Difference between gray and Sievert is that Sievert is not absorbed dose BUT effect of absorbed dose, that is why the tables have different conversion factors for different radiation type and organs.
I also note that there is no mention of that there is a massive difference in effect of doserates, I can understand that there is problem, I have not found any good source about that but it is quite different resultat wheather yu recive 1 Sv in 5 minutes or spread over 10 years. The first have a high death-risk, the second have good chance of not making any messaurable damage.
Seniorsag (
talk) 16:17, 22 July 2015 (UTC)
"If the equivalent dose is uniform throughout the organism, that is, if the radiation source equally impacts on the entire surface of the body, it will be equal to the body tissue specific effective dose."
It seems to me that there are several problems here.
1) The concept of uniformity. I do not think that uniformity over the surface of an organism is intended here. I suspect that this should read ".. that is, if the radiation source has delivered equal energy to equal increments of mass throughout the body...". I have changed the text to the latter quote.
2)As I understand this, to get "body tissue specific effective dose" from equivalent dose, you must multiply the former by a tissue weighting factor which is generally not unity, so, even if the dose is uniform throughout the body, the "body tissue specific effective dose" will not equal the effective dose. — Preceding unsigned comment added by 77.96.59.93 ( talk) 15:10, 30 January 2014 (UTC)
Thank you - I suspected that this is the answer, which is why I did not alter the original text. However, I feel the point should be explained. I have changed "organism" to "human body", which is the organism for which the usual weighting factors add to 1. However, I now find another problem. If what Woodstone has said reflects the thinking of the original author, should not "body tissue specific effective dose" be changed to "whole body effective dose". Am I correct in understanding the former phrase to relate to specific tissues, rather than the whole body ? If, on the other hand, we understand "body tissue specific effective dose" to mean what it says, then a weighting factor is needed. — Preceding unsigned comment added by 77.96.59.93 ( talk) 08:50, 31 January 2014 (UTC)
I am beginning to feel that this article is very defective, reflects extremely wooly thinking, and is in need of careful review in order to weed out careless errors of wording. I now question this: "...while the sievert is used to express the biological equivalent dose to human tissue". Surely, in view of the above, this should read "....the biological equivalent dose to the human body".
The sievert unfortunately seems to be one of the most poorly described units there is. I have made quite a few changes to the article based on ICRP 103 (which runs to over 300 pages) and other learned papers, and brought in a number of additional issues that need consideration when talking about the sievert, which has been in gestation for a while now. Hopefully these will have addressed your points. If not please put comments here. Dougsim ( talk) 14:04, 7 February 2014 (UTC)
The examples list includes dental X-rays, mammograms, and CT of the colon. In these cases only part of the body is irradiated. Do the quoted figures of dose relate to the mass of tissue irradiated (i.e in calculating J/kg, is the mass used that of the irradiated tissue only), or is the dose an average dose for the whole body, the mass used in the calculation being that of the whole body ? Clearly the former form of calculation will give a higher figure for dose than that obtained if the whole body mass is used. Unless this point is made clear, the figures given in these 3 cases are meaningless. To clarify this, could someone please explain how dose in Sv is calculated in the case of a single dental X-ray ? AJS
This is the expression of the effective dose, which is not wholly dependent on how much is irradiated. What is important is the irradiation received and its effect. All effects are summated to an overall expression of risk, which is the effective dose. This is shown in the graphic. It should be noted that the ICRP figures are averages taken over the world population based on decades of research, and are conservatively fixed.
Dougsim ( talk) 14:16, 7 February 2014 (UTC)
I have put operational and protection quantities and their relationship to physical quantities and instrument measurements into the article in order to tie up the many loose ends and to make the article coherent. Although the article may appear more complex, this is a true reflection of the complexity of use of the sievert.
I have added the CIPM definition and tied this in to the work of the ICRU and ICRP. I have devised a graphic for this based on the work of others leading back to ICRU report 57, as there are some difficult concepts. I have added in tissue effects for completeness but tried to avoid excessive duplication. Dougsim ( talk) 13:48, 7 February 2014 (UTC)
There is some confusion here! The conversion factor 1 Si = 100 REM is aproximately true, BUT since they have modivied the wheigt factors a little it is not compleatly true. For mormal use it is good enough, but not for precision use. Seniorsag ( talk) 15:21, 15 July 2014 (UTC)
I note that although there's a reference to the RadSafe mailing list, we have no article on it. We probably should have and soon will I hope. I've redlinked to it in anticipation. Andrewa ( talk) 21:29, 9 January 2015 (UTC)
We've got "ionising" and "ionizing" all over the place. As of January 2016, it was completely "z" except for one "s", but since then a bunch of "s" have crept in. There's no nationalistic component to the article's topic itself, so I assume we should go with original form and inertia. I plan to flip it all to "s" in a day or two unless someone disagrees (or beats me to making that edit:) DMacks ( talk) 08:06, 14 December 2016 (UTC)
Because someone reverted it for some reason: The "Dose examples" section is currently an entirely excessive listing of unexplained statistics: it is a collection of doses and dose rates that do absolutely nothing to further the understanding of the sievert as a unit. This is a unit that's intended to quantify stochastic risk - in other words, it isn't meant to represent deterministic effects. But that list is just item after item of deterministic (ARS, death) outcomes. You could list all the doses received by anyone ever, but it would not help anyone understand what the sievert is. Kolbasz ( talk) 01:27, 11 February 2017 (UTC)
Has there been any proposal to include the wisdom about nonlinear effects on the measurement of radiation effects? There are several works on low-dosage effects, like [4]. How about the amplitute form of the radiation applied - does it make no difference if the radiation occurs in several short higher-energy bursts or in one slight sinus-formed curve, as long as they have the same integral value? Any links to works on this subject are welcome. -- Bernd.Brincken ( talk) 10:44, 15 March 2017 (UTC)
I am going to revert the protection quantities graphic link back to the diagram I wrote a few years ago, which is a truer representation of what the ICRP/ICRU means. Effective dose does not exist at tissue or organ level for multiple organs. Effective dose is the summated value of the double-weighted quantities.
See the following explanation of this difficult area published in 2013; in this explanation the contributions to the effective dose are best described as equivalent organ or tissue doses in the most recent terminology.
From: "Radiological protection issues arising during and after the Fukushima nuclear reactor accident Abel J Gonzalez et al. Journal of Radiological Protection vol 33 (2013) 497–571
2.3.2. The changing names of the radiological protection quantities.
"The names used for the radiological protection quantities have evolved. ICRP Publication 26 (ICRP 1976) and
its amendment issued by the ICRP’s 1978 Stockholm statement introduced and defined the
quantities ‘organ or tissue dose equivalent’ and ‘effective dose equivalent’. ICRP Publication
60 (ICRP 1991) changed the terms to ‘equivalent dose in a tissue or organ’ and ‘effective dose’.
The reason for the change was that ‘the weighted dose equivalent (a doubly weighted absorbed
dose) has previously been called the effective dose equivalent but this name is unnecessarily
cumbersome, especially in more complex combinations such as collective committed effective
dose equivalent’. ICRP Publication 60 also states that ‘the Commission has decided to revert
to the earlier name of equivalent dose in a tissue or organ’. However, searching for the name
‘equivalent dose’ in previous ICRP reports failed to find clear evidence for this statement.
For example, in ICRP Publication 2 (ICRP 1959) the name ‘RBE dose’ was used and in
ICRP Publications 6 (ICRP 1962) and 9 (ICRP 1965) the name ‘dose equivalent’ was used.
Therefore, the coexistence of the names of equivalent dose and dose equivalent appears to be
due to changes introduced by the ICRP in Publication 60. The coexistence of the two different
names for the same quantity has added confusion and misunderstanding within an already
complex dosimetric system for radiological protection. Finally, ICRP Publication 103 (ICRP2007a)
uses equivalent dose without the specification ‘in a tissue or organ’ which can add
to misunderstanding with effective dose if the quantity is not clearly specified since the unit,
sievert (Sv), is the same."
Why the two are different ? I wrote "810 nSv/h avg Next to the Chernobyl Nuclear Power Plant sarcophagus ", as can be seen in the References. But when I watch this video, it tells another data ? Check [5] at 5:36 . The time different between the two pictures is five years, but I assume it's not causing the different in the data . Eliran t ( talk) 22:51, 24 June 2019 (UTC)
This template has been added, but no detail about why. What is the problem with the lead? Dougsim ( talk) 06:00, 23 August 2022 (UTC)
I notice the lead has been amended to wrongly describe the Sievert as being J/kg, which is actually absorbed dose not equivalent dose. Also there has been an unnecessary section added expanding on the Roentgen, which has now been removed. Dougsim ( talk) 06:29, 23 August 2022 (UTC)
ICRP report 103 says (para numbers)
(56) In Publication 60 (ICRP, 1991b) the Commission classified the radiation effects that result in tissue reactions as deterministic effects and used the term stochastic effects for radiation-induced cancer and heritable disease. Effects caused by injury in popula- tions of cells were called non-stochastic in Publication 41 (ICRP, 1984), and this was replaced by the term deterministic, meaning ‘causally determined by preceding events’ in Publication 60 (ICRP, 1991b). The generic terms, deterministic and stochastic ef- fects, are not always familiar to those outside the field of radiological protection. For this and other reasons (given in Annex A), Chapter 3 and Annex A also use the directly descriptive terms tissue reactions and cancer/heritable effects respectively. However, the Commission recognises that the generic terms, deterministic and sto- chastic effects, have a firmly embedded use in its system of protection and will use the generic and directly descriptive terms synonymously, according to context.
(57) In this respect the Commission notes that some radiation-associated health consequences, particularly some non-cancer effects (see Section 3.3), are not yet suf- ficiently well understood to assign to either of the generic categories. Since 1990, the Commission has reviewed many aspects of the biological effects of radiation. The views developed by the Commission are summarised in this Chapter with emphasis on effective doses of up to about 100 mSv (or absorbed doses of about 100 mGy of low-LET radiation) delivered as a single dose or accumulated annually
...................
(64) Although there are recognised exceptions, for the purposes of radiological protection the Commission judges that the weight of evidence on fundamental cellu- lar processes coupled with dose-response data supports the view that, in the low dose range, below about 100 mSv, it is scientifically plausible to assume that the incidence of cancer or heritable effects will rise in direct proportion to an increase in the equiv- alent dose in the relevant organs and tissues.
(65) Therefore, the practical system of radiological protection recommended by the Commission will continue to be based upon the assumption that at doses below about 100 mSv a given increment in dose will produce a directly proportionate incre- ment in the probability of incurring cancer or heritable effects attributable to radia- tion. This dose-response model is generally known as ‘linear-non-threshold’ or LNT."
The sievert for radiation protection is most reliably applied in this range. Dougsim ( talk) 12:24, 23 August 2022 (UTC)
In the article, it now says: Nonfatal dose to Anatoli Bugorski who was struck with a proton beam from a Particle Accelerator through the head while cleaning the U-70 synchrotron on the 13th of July 1978. He is still alive to this day.
Problems: Original measures this dose in röntgen, which is i believe just the measurement read using a gamma-ray capable geigermeter kindof? This seems to have been converted to rem, which is probably kindof accurate (probably actually).. but not really. There is also probably a conversion error, as 100 rem = 1 sievert, which makes his dose not 200-300 sievert, but 2000-3000 sievert (e.g. 200 000/100 = 2000, not 200.). Also maybe Bragg peak is a matter of life and death in his case, but not even mentioned. Finally the source is not the best, the original article reference an archived russian page. The source in Sievert article is malfunctioning.
I suggest we remove this entry. Its not good enough. Or someone fix it.
Google isn't properly giving me results on the difference between these two notations, so I was wondering what the differences was, as it isn't explained in the article either. Google keeps giving me results for the lowercase version no matter what I do, which is why I'm asking. 71.90.116.133 ( talk) 20:44, 27 September 2023 (UTC)
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