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Online Comics => Escape From Terra => Topic started by: paddyfool on July 01, 2012, 06:15:36 am

Title: Radiation hormesis?
Post by: paddyfool on July 01, 2012, 06:15:36 am
Pretty out there, so far as theories go.  And is anyone seriously suggesting a benefit to annual doses of 300 mSv? (100 times earth normal).

Also, I'd recommend this article as a summary of some of the best available study data, although it's a bit old: http://bjr.birjournals.org/content/76/901/1.full

Put simply: Before 1960, when radiologists were exposed to relatively high doses of occupational radiation (>5 mSv), they died earlier than other doctors on account of increased cancer mortality.  After that, not so much, and the data for British physicians at least seems to show a decreased rate of death from non-cancer mortality among radiologists more recently.  However, it seems unlikely that this would be down to radiation exposure, as you're talking about exposures to pretty tiny levels of radiation (<1 mSv), and there may well be differences in lifestyle between radiologists and other doctors.
Title: Re: Radiation hormesis?
Post by: SandySandfort on July 01, 2012, 07:39:02 am
Pretty out there, so far as theories go.  And is anyone seriously suggesting a benefit to annual doses of 300 mSv? (100 times earth normal).

No study has ever been conducted that showed that low levels of radiation are dangerous. None. All the dire warnings are derived from the  assumption that radiation's biological damage is linear.

However, numerous studies have shown that low levels of radiation reduce the incidence of cancer and other illnesses. In fact, it would appear that most people are gamma deficient.

Mellyrn may jump in  on this, or you can google radiation hormesis.
Title: Re: Radiation hormesis?
Post by: Tucci78 on July 01, 2012, 08:31:03 am
Before 1960, when radiologists were exposed to relatively high doses of occupational radiation (>5 mSv), they died earlier than other doctors on account of increased cancer mortality.  After that, not so much, and the data for British physicians at least seems to show a decreased rate of death from non-cancer mortality among radiologists more recently.  However, it seems unlikely that this would be down to radiation exposure, as you're talking about exposures to pretty tiny levels of radiation (<1 mSv), and there may well be differences in lifestyle between radiologists and other doctors.

Having known radiologists both personally and professionally for decades, I always figured that their higher death rates were due to the fact that most of 'em smoked like chimneys. 

Until the "Smoke-Free Hospital" doctrine took hold, I'd never once entered a Radiology Department's reading rooms without encountering the stench of tobacco smoke and the sight of overflowing ashtrays, many of them improvised from hospital cafeteria crockery. 

Hey, you spend most of your life in darkened little subterranean chambers getting pestered by people like me wanting to know whether those stat studies from the Emergency Department show anything significant. 

I consider it something of a miracle that the only stuff they were smoking was tobacco.

Title: Re: Radiation hormesis?
Post by: paddyfool on July 01, 2012, 09:53:12 am
Pretty out there, so far as theories go.  And is anyone seriously suggesting a benefit to annual doses of 300 mSv? (100 times earth normal).

No study has ever been conducted that showed that low levels of radiation are dangerous. None. All the dire warnings are derived from the  assumption that radiation's biological damage is linear.

However, numerous studies have shown that low levels of radiation reduce the incidence of cancer and other illnesses. In fact, it would appear that most people are gamma deficient.

Mellyrn may jump in  on this, or you can google radiation hormesis.

I didn't just leap into this without doing some Pubmed reading first.  But the key to what the advocates of radiation hormesis are talking about lies in the findings from really low doses of radiation, and specifically from cancer excess not being seen at levels <100 mSv.  On the contrary, there's good evidence that doses about 100 mSv (never mind 300 mSv, or "a hundred times Terra background") genuinely are harmful; it's below this level that things get ambivalent.  

See this article for more: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2663584/?tool=pubmed
Title: Re: Radiation hormesis?
Post by: customdesigned on July 01, 2012, 06:53:20 pm

No study has ever been conducted that showed that low levels of radiation are dangerous. None. All the dire warnings are derived from the  assumption that radiation's biological damage is linear.

However, numerous studies have shown that low levels of radiation reduce the incidence of cancer and other illnesses. In fact, it would appear that most people are gamma deficient.

When my dentist got a new digital xray sensor, one of the touted benefits was a much lower xray dose for the same picture quality.  When I read up on it, however, I discovered that radiation levels substantially *lower* than earth background have been shown to be harmful.  It seems that the really low levels do so little damage, it fails to trigger DNA repair mechanisms - like the old malicious viruses that would flip one random bit somewhere on your harddrive every hour or so.  You would not notice anything wrong until much too late... 

The digital xray dose was low enough, that there was some concern it might be hitting that leg of the curve.  Fortunately, it is an easy problem to fix once there is enough hard data to quantify the optimum dose.  :-)
Title: Re: Radiation hormesis?
Post by: sam on July 01, 2012, 07:29:23 pm
Pretty out there, so far as theories go.  And is anyone seriously suggesting a benefit to annual doses of 300 mSv? (100 times earth normal).

The fallout from Chernobyl was extremely patchy.  So if Chernobyl level fallout caused harm, we would expect some cancer clusters highly localized in the high radiation patches.

Allegedly there is thyroid cancer cluster, which has killed a grand total of nine, yes nine, people.

However, it is plausible that this is an artifact of increased diagnosis, rather than increased cancer - lots of people die of old age with lumps in their thyroid that cannot be distinguished from cancer, other than that nothing much happened in consequence.

If Chernobyl killed millions, or thousands, or hundreds, the patchiness of the fallout should have caused patchiness in the deaths, which should result in detectable clusters.

There are no detectable Chernobyle clusters, with the arguable exception of the thyroid cluster.
Title: Re: Radiation hormesis?
Post by: sam on July 01, 2012, 07:36:49 pm
I didn't just leap into this without doing some Pubmed reading first.  But the key to what the advocates of radiation hormesis are talking about lies in the findings from really low doses of radiation, and specifically from cancer excess not being seen at levels <100 mSv.  On the contrary, there's good evidence that doses about 100 mSv (never mind 300 mSv, or "a hundred times Terra background") genuinely are harmful; it's below this level that things get ambivalent.  

See this article for more: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2663584/?tool=pubmed

Which article tells us:
Quote
Contrary to previous claims, there was no increase in leukemia or other cancers (except thyroid cancer) in regions contaminated after the Chernobyl accident where thyroid doses ranged up to 1 Sv (123). The increase in thyroid cancer among young children is correlated with dose (124), and a threshold at 200 mSv is compatible with data (125).

The evidence for an increase in thyroid cancer is equivocal, because with thyroid cancer, the more you test, the more "cancers" you find.  There is no evidence of an increase in deaths from thyroid cancer.

So all up, Chernobyl event indicates that with the possible exception of thyroid cancer, there is no low dose effect below 1Sv (1000 mSv)

Chernobyl was the largest natural experiment in low dose radiation effects, randomly plonking patches of radioactivity all over the place according to the accidents of wind and weather.
Title: Re: Radiation hormesis?
Post by: Helian on July 01, 2012, 10:24:31 pm
Why does everyone seem to think cancer will be an issue in the future?  I they've already cured it.  I hope they're up to primates, but I know I've heard of lab rats being cured.

This one is from 6 months ago, only did a quick search on kanzius machine.
http://www.theblaze.com/stories/could-an-idea-started-with-pie-tins-and-hotdogs-lead-to-symptom-free-cancer-treatment/

Basically they extract some cancer cells, make a gold fleck (nanite) that self attaches to that type of cancer, and inject the nanites into a patient.  After enough time for it to spread through the whole blood stream/body they zap the patient with radio waves, frying whatever the nanites were attached to.  The way it attaches to the cancer cells is related to how the cancer grows & spreads, so it gets all of it regardless of what organ it is in, stage 4 shouldn't matter.  Surrounding tissue is completely unharmed, no side effects.  That article states up to 3 years till human trials, so 2.5 from now.  Millions of dollars and outsourcing are being used to speed up the process.

The argument for AnCap, or at least WAYYYY less government intervention, how many will die while this goes through FDA approval.
P.S. I hear the Israelis came up with a very promising cancer vaccine.
Title: Re: Radiation hormesis?
Post by: paddyfool on July 02, 2012, 07:36:08 am
Why does everyone seem to think cancer will be an issue in the future?  I they've already cured it.  I hope they're up to primates, but I know I've heard of lab rats being cured.

Two problems with this:
- One is that the number of things which show promising results in lab rats is much larger than the number of things which actually work when tested in humans.  So take everything you hear about revolutionary results from something tried in animal testing with a very large pinch of salt - any such finding is still in the very early stages.
- The other is that cancer is not a disease, but a category of diseases.  It's basically what happens when the regenerative capacity of your body goes wrong, and things start growing where they shouldn't, or not dying where they should.  The characteristics of different cancers and their appropriate treatment vary massively by the organ of origin and on exactly how the cancer cells have turned cancerous.  I very much doubt there will ever be any single cure for cancer, any more than there will ever be any single cure for "infection".

Also, people think that cancer will be a leading cause of death in the future because it's a straightforward extrapolation both from the past century or so, and from current demographic trends.  Currently, cancer is the second leading cause of death in the USA today, and on course to overtake the leading cause (heart disease), although back in 1900 it was back in 8th place (largely because most people died of something else first): http://www.nejm.org/doi/full/10.1056/NEJMp1113569.  The risk of getting most cancers, meanwhile, strongly increases with age; so as the population gets older, we're going to see more and more cancer.

See this article for more: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2663584/?tool=pubmed

Which article tells us:
Quote
Contrary to previous claims, there was no increase in leukemia or other cancers (except thyroid cancer) in regions contaminated after the Chernobyl accident where thyroid doses ranged up to 1 Sv (123). The increase in thyroid cancer among young children is correlated with dose (124), and a threshold at 200 mSv is compatible with data (125).

The evidence for an increase in thyroid cancer is equivocal, because with thyroid cancer, the more you test, the more "cancers" you find.  There is no evidence of an increase in deaths from thyroid cancer.

So all up, Chernobyl event indicates that with the possible exception of thyroid cancer, there is no low dose effect below 1Sv (1000 mSv)

Chernobyl was the largest natural experiment in low dose radiation effects, randomly plonking patches of radioactivity all over the place according to the accidents of wind and weather.

The problem here is that you're selectively quoting from an article advocating for a threshold relationship for the little bit of the data it provides which vaguely supports a higher (safe or beneficial) threshold than the authors of the article itself propose (they sum up all the data they consider by saying: "there is no convincing evidence of a carcinogenic effect in humans or experimental animals for doses of less than 100 mGy of low linear energy transfer radiation". 

Also, this particular evidence offers only vague support, partly because you can't prove a negative, and partly because there might well be vested influences in downplaying the impact of Chernobyl.

I should, at this point, however, admit to being less than complete in my linking to the evidence myself, in only linking to the article positing this alternative point of view, and not its twin article, which puts the case instead for the linear risk model. This article presents the evidence for that point of view here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2663578/

To sum up, then: the jury's out on whether there's a higher safe threshold around 100 mSv, never mind any hormetic (better than safe) effects.  Partly because whatever effects there are below 100 mSv in either direction look to be really very small, and small effects (harmful or beneficial) are hard to measure.  And while it's interesting to posit that solid evidence of some small net benefit of low dose radiation might yet be found, >300 mSv is not low dose.
Title: Re: Radiation hormesis?
Post by: sam on July 02, 2012, 08:12:49 pm
The problem here is that you're selectively quoting from an article advocating for a threshold relationship for the little bit of the data it provides which vaguely supports a higher (safe or beneficial) threshold than the authors of the article itself propose (they sum up all the data they consider by saying: "there is no convincing evidence of a carcinogenic effect in humans or experimental animals for doses of less than 100 mGy of low linear energy transfer radiation".  

The only evidence they have for harmful effects at doses of less than 200 mSv is the Chernobyl thyroid cancer clusters - which evidence is unconvincing, because the cluster of thyroid cancers may well reflect a cluster of testing for thyroid cancer.  We don't have a persuasive cluster of Chernobyl related deaths from thyroid cancer.

there might well be vested influences in downplaying the impact of Chernobyl.

Oh come on.  Compare the big drama about anthropogenic global warming and chernobyl and all the rest, with any actually observed effects.  It is pretty obvious which side the vested interests on.

Ask any random person in the street, chances are he thinks that Chernobyl killed a billion people and polar bears are dying of heatstroke.  Al Gore has made billions out of the Anthropogenic Global Warming scare, selling carbon indulgences, which pay for his private jet, and his gigantic mansion, with all the lights and air conditioning he leaves on all night.

Ask any random person in the street about species extinction, and he will tell you that every year ten thousand species go extinct, or ten million species go extinct, despite the fact that no one can name any species that have gone extinct in the last year or two.  People make billions out of supposed endangered species, by threatening to take away people's land.  "Pay me ten thousand dollars in consultation fees, or I will discover that your land is vital to endangered species."

Come to think of it, my land actually is vital to supposedly endangered species, since supposedly endangered species steal my bananas and smash my fences - though I rather think that if they were actually endangered, I would not have to watch my bananas so closely.

Radioactivity is like witchcraft.  The same vested interests that promoted belief in witchcraft, promote belief in radioactivity, for much the same reasons.

its twin article, which puts the case instead for the linear risk model. This article presents the evidence for that point of view here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2663578/

Anyone claiming linear is refuted by Chernobyl, an unintended experiment carried out on a gigantic scale.  If the effect was linear, then we would see enormous patches of excess deaths, because Chernobyl fallout was patchy.

We only see excess deaths in regions exposed to significantly more than 1000 mSv.  Either people are dying like flies, or the most careful examination only finds questionable effects at the very edge of statistical significance, with nothing in between.  It is an obvious threshold effect, with the threshold setting in somewhere around 1000 mSv or so, with the possible exception of thyroid cancer, which, if it is an exception, killed around nine people.
Title: Re: Radiation hormesis?
Post by: Andreas on July 03, 2012, 03:43:59 pm
Radiation is one thing.
But it has to come from somewhere. Some isotopes are such that I would strongly advise against tolerating their presence, even if the radiation output is low.
Radioactive isotopes of cesium for instance, have the unfortunate property, that the sodium pump can mistake them for Potassium, pumping them into the cells of the body... but the cell membrane port that lets potassium back out aren't so easily fooled. This means that radioactive cesium has a much higher probability of degrading (and producing radiation) close to the nucleus of biological cells.
Title: Re: Radiation hormesis?
Post by: paddyfool on July 04, 2012, 08:09:32 am
Oh come on.  Compare the big drama about anthropogenic global warming and chernobyl and all the rest, with any actually observed effects.  It is pretty obvious which side the vested interests on.

Let's leave AGW (and species extinction) out of this.  With Chernobyl, certainly, environmentalists might overhype it, but those responsible also have a major incentive for a cover-up.

More relevantly, though, to the doses in question, you're talking small effects and limited scope to observe them without close observation.  Which there seems to have been to a better extent with the Japanese Survivor Survey (from those exposed to another very large natural experiment, which is what the linear model is based on).

Quote
Anyone claiming linear is refuted by Chernobyl, an unintended experiment carried out on a gigantic scale.  If the effect was linear, then we would see enormous patches of excess deaths, because Chernobyl fallout was patchy.

We only see excess deaths in regions exposed to significantly more than 1000 mSv.  Either people are dying like flies, or the most careful examination only finds questionable effects at the very edge of statistical significance, with nothing in between.  It is an obvious threshold effect, with the threshold setting in somewhere around 1000 mSv or so, with the possible exception of thyroid cancer, which, if it is an exception, killed around nine people.

Do you have a source on that 1000 mSv figure?  It would seem to contradict this data (where they saw a significant increase in leukaemia among those with 150-300 mSv of exposure) http://www.bmj.com/rapid-response/2011/10/29/elevated-leukemia-rates-chernobyl-accident-liquidators
Title: Re: Radiation hormesis?
Post by: sam on July 04, 2012, 07:12:03 pm
Oh come on.  Compare the big drama about anthropogenic global warming and chernobyl and all the rest, with any actually observed effects.  It is pretty obvious which side the vested interests on.

Let's leave AGW (and species extinction) out of this.  With Chernobyl, certainly, environmentalists might overhype it, but those responsible also have a major incentive for a cover-up.

Those responsible are the government of the Soviet Union, which no longer exists.  Most of their successors seem perfectly happy to blame anything and everything on them.

Further, the successor regime is still hyping the bejesus out of Chernobyl, rather than covering up.  People are still forbidden to go into areas that once upon a time used to be radioactive, even though there is no evidence that people suffered detectable harm even back when they actually were radioactive.

More relevantly, though, to the doses in question, you're talking small effects and limited scope to observe them without close observation.

That is a criticism of all studies before Chernobyl.  Chernobyl was an experiment on a gigantic scale.  If there were low dose effects, they would show up.

If low dose effects, should have killed about four thousand people, a large proportion of them in a few small towns near Chernobyl.  That would be statistically detectable.

The Chernobyl results are:  No indication of a low dose effect below 200 mSv.  Questionable evidence of a low dose effect for thyroid cancer from 200 mSv up - which thyroid cancer cluster, supposing it to be real rather than a result of over diagnosis, killed nine people.

Above 1000 mSv, people start dying all over the place.  There is no doubt whatever that 1000 mSv or more is really seriously bad for you.   If the effect was linear between 200 mSv and 1000 msV, we would see plenty of excess deaths in the 200 mSv - 1000 mSv range, which is roughly what most of the evacuees got.  We don't.

Which there seems to have been to a better extent with the Japanese Survivor Survey (from those exposed to another very large natural experiment, which is what the linear model is based on).

But the Japanese survivor survey does not support the linear model:  From the survivor survey, looks like radiation protects against cancer and improves general health in doses of 50 - 100 mSv, begins to have harmful effects on one's chances of cancer at around 100 - 200 mSv, and increases linearly thereafter.  It supports the linear model above 100 mSv, with a threshold around 100 mSv.

However, in the Japanese survivor survey, radiation shows no linear effect on total deaths, with an increase of total deaths setting in at about 1000 mSv, consistent with the conjecture that doses of radiation above 100 mSv result in a small increased risk of being diagnosed with cancer and having one's death blamed on cancer, and a decreased risk of having one's death blamed on something else.

Quote
Anyone claiming linear is refuted by Chernobyl, an unintended experiment carried out on a gigantic scale.  If the effect was linear, then we would see enormous patches of excess deaths

It would seem to contradict this data (where they saw a significant increase in leukaemia among those with 150-300 mSv of exposure) http://www.bmj.com/rapid-response/2011/10/29/elevated-leukemia-rates-chernobyl-accident-liquidators

There is no liquidator subpopulation that is known to have been exposed to only 150-300 mSv.  The radiation exposure was guesswork.  Radiation exposure of liquidators is uncertain and unreliable.

The liquidator study gives "bordering level of significance" - in other words not really significant.  Further, the significance assumes that "dose reconstruction" is precise, but the dose reconstruction was guesswork, and guesswork made by people who knew the outcome.  If someone is suffering from leukemia, people will be more apt to recall higher dose events, and more apt to interpret events as high dose events.  If someone is in fine health, people will be less apt to recall higher dose events, and less apt to interpret events as high dose.  Even assuming no such bias, some those estimated as being exposed to x amount of radiation, will in fact have been exposed to 10x amount radiation, and others to 0.1x amount of radiation, smearing out any threshold effect. 

If indeed those estimated as having 150-300mSv have higher rates of leukemia (and the result was not statistically significant) it may well be because some of those estimated as 300 mSv in fact had 1000 mSv.

Comparing studies that give different results, we see a consistent pattern:  The better the data, the higher the threshold, and the threshold is at least 100 mSv, and quite likely 1000 mSv
Title: Re: Radiation hormesis?
Post by: Oneil on July 05, 2012, 01:43:29 am
I don't know the facts about routine general medical and dental X-ray's.  Yet I still can't help but cringe when I see children in particular with a cellular phone smashed against their skull. Or using notebooks with high power wireless in their laps.   Why not just have them stand in front of a worn out microwave oven?  ::)
Title: Re: Radiation hormesis?
Post by: paddyfool on July 05, 2012, 04:48:33 am
More relevantly, though, to the doses in question, you're talking small effects and limited scope to observe them without close observation.

That is a criticism of all studies before Chernobyl.  Chernobyl was an experiment on a gigantic scale.  If there were low dose effects, they would show up.

If low dose effects, should have killed about four thousand people, a large proportion of them in a few small towns near Chernobyl.  That would be statistically detectable.
[/quote]

What are you basing this statistic on?

Quote
The Chernobyl results are:  No indication of a low dose effect below 200 mSv.  Questionable evidence of a low dose effect for thyroid cancer from 200 mSv up - which thyroid cancer cluster, supposing it to be real rather than a result of over diagnosis, killed nine people.

Where are you getting these stats from?  And fine, the cluster didn't kill that many people, because thyroid cancer doesn't generally kill that many people, but you're still talking a cluster of 5,000 cases of thyroid cancer.  Some of which may have been overdiagnosis, but a lot of which may well have been the simple fact that Chernobyl released radioactive iodine, and iodine is straightaway taken up by the thyroid (which is why giving radioactive iodine is one option for killing off hyperactive thyroid glands).

Quote
Above 1000 mSv, people start dying all over the place.  There is no doubt whatever that 1000 mSv or more is really seriously bad for you.   If the effect was linear between 200 mSv and 1000 msV, we would see plenty of excess deaths in the 200 mSv - 1000 mSv range, which is roughly what most of the evacuees got.  We don't.

The figures you're giving for what the populations affected by Chernobyl got are all significantly larger than anything I'm seeing when I look this up (e.g. here http://www.who.int/ionizing_radiation/chernobyl/backgrounder/en/index.html).  Where are you getting them from?

Quote
Which there seems to have been to a better extent with the Japanese Survivor Survey (from those exposed to another very large natural experiment, which is what the linear model is based on).

But the Japanese survivor survey does not support the linear model:  From the survivor survey, looks like radiation protects against cancer and improves general health in doses of 50 - 100 mSv, begins to have harmful effects on one's chances of cancer at around 100 - 200 mSv, and increases linearly thereafter.  It supports the linear model above 100 mSv, with a threshold around 100 mSv.

However, in the Japanese survivor survey, radiation shows no linear effect on total deaths, with an increase of total deaths setting in at about 1000 mSv, consistent with the conjecture that doses of radiation above 100 mSv result in a small increased risk of being diagnosed with cancer and having one's death blamed on cancer, and a decreased risk of having one's death blamed on something else.

Source, please.  What you're saying would seem to contradict the paper I linked to before on this data.

Quote
Quote
Anyone claiming linear is refuted by Chernobyl, an unintended experiment carried out on a gigantic scale.  If the effect was linear, then we would see enormous patches of excess deaths

It would seem to contradict this data (where they saw a significant increase in leukaemia among those with 150-300 mSv of exposure) http://www.bmj.com/rapid-response/2011/10/29/elevated-leukemia-rates-chernobyl-accident-liquidators

There is no liquidator subpopulation that is known to have been exposed to only 150-300 mSv.  The radiation exposure was guesswork.  Radiation exposure of liquidators is uncertain and unreliable.

OK, so you're challenging this dose estimate.  What's your evidence that it was higher than that estimated by the study in question?

Quote
The liquidator study gives "bordering level of significance" - in other words not really significant.

No, the results weren't merely borderline. From the study results: "Both the external (SIR=2.5, P<0.001) and internal comparisons (RR=2.2, P=0.03) indicate significantly elevated risks in the 150-300 mGy dose group."

p<0.001 is a very strong level of evidence - not borderline at all.  p=0.03, meanwhile, is still pretty strong.

Quote
Further, the significance assumes that "dose reconstruction" is precise, but the dose reconstruction was guesswork, and guesswork made by people who knew the outcome.  If someone is suffering from leukemia, people will be more apt to recall higher dose events, and more apt to interpret events as high dose events.  If someone is in fine health, people will be less apt to recall higher dose events, and less apt to interpret events as high dose.

Recall bias is always a potential issue, and might explain away some of the internal comparison, but no so much the external comparison (the excess risk between liquidators and non-liquidators).

Quote
Even assuming no such bias, some those estimated as being exposed to x amount of radiation, will in fact have been exposed to 10x amount radiation, and others to 0.1x amount of radiation, smearing out any threshold effect. 

Random errors in dose estimation are at least as likely to bias a study's findings towards the null as they are to bias them away from it.

Quote
If indeed those estimated as having 150-300mSv have higher rates of leukemia (and the result was not statistically significant) it may well be because some of those estimated as 300 mSv in fact had 1000 mSv.

Comparing studies that give different results, we see a consistent pattern:  The better the data, the higher the threshold, and the threshold is at least 100 mSv, and quite likely 1000 mSv

Please show me a study claiming a safe threshold of 1000 mSv.

By the way, I did some more research, and found another, more recent paper summing up what's been found among all the different cohorts of liquidators.  Not sure if you'll find it interesting or not, but here you are: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904977/?tool=pubmed

Their conclusions were pretty conservative: "A significantly elevated OR was seen for all hematological malignancies combined at doses of 200 mGy and above."  (For our purposes, we can think of Grays as basically equivalent of Sieverts, so far as I understand it).

I don't know the facts about routine general medical and dental X-ray's.  Yet I still can't help but cringe when I see children in particular with a cellular phone smashed against their skull. Or using notebooks with high power wireless in their laps.   Why not just have them stand in front of a worn out microwave oven?  ::)

I wouldn't worry about it.  Mobile phones emit radio waves, not gamma or x-rays, and large epidemiological studies have shown no link whatsoever between use and cancer statistics.

As for medical x-rays etc.: back in the old days, medical X-rays and their sources could be properly dangerous (both Roentgen and his wife dying from exposure, for instance), they are kept to really very safe levels now.  Please see here for a rough comparison of exposure levels: http://www.hpa.org.uk/Topics/Radiation/UnderstandingRadiation/UnderstandingRadiationTopics/DoseComparisonsForIonisingRadiation/

Note that the debate between me and Sam has been largely on the risks of exposures over 100 mSv.  Below that, there isn't much evidence of risk, which is what the threshold hypothesis is all about, and advocates of hormesis claim there may even be some benefit.  And medical scans range from, say, 0.005 mSv for a dental X-ray (meaning that you'd need, oh, about 20,000 of them to top 100 mSv in exposure) to 10 mSv for a full body CT scan (which would very rarely be carried out anyway, and generally only if you had something much more serious than low-dose radiation exposure to worry about).
Title: Re: Radiation hormesis?
Post by: myrkul999 on July 05, 2012, 05:17:49 am
I don't know the facts about routine general medical and dental X-ray's.  Yet I still can't help but cringe when I see children in particular with a cellular phone smashed against their skull. Or using notebooks with high power wireless in their laps.   Why not just have them stand in front of a worn out microwave oven?  ::)

I wouldn't worry about it.  Mobile phones emit radio waves, not gamma or x-rays, and large epidemiological studies have shown no link whatsoever between use and cancer statistics.

Come to that, isn't microwave RF, too? Worst case scenario is you overheat a little bit. Kid's to dumb to step away from the thing making his balls warm up, it's probably better he not have use of 'em anyway.
Title: Re: Radiation hormesis?
Post by: mellyrn on July 05, 2012, 06:21:47 am
Quote
I wouldn't worry about it.  Mobile phones emit radio waves, not gamma or x-rays, and large epidemiological studies have shown no link whatsoever between use and cancer statistics.

Oh, reeeeally.

OK, I'm torqued.  Bernie Cohen did a study (http://www.world-nuclear.org/sym/1998/cohen.htm) comparing home radon levels to lung cancer mortality, a very large study of 1600+ counties across the US.  This is a large epidemiological study.  His data showed a negative correlation -- higher home radon levels corrrelated with lower lung cancer mortality.  To be thorough, he took some 54 different possible confounding factors into consideration, and still found a negative correlation.

His critics objected -- correctly, mind you -- that correlation is not causation, and cited still more factors that might be skewing his data.

Cohen reworked his stuff, this time with maybe 102 factors accounted for, and still found a negative correlation.

His critics objected again and cited still more possibly-skewing factors.

He gave a talk here where I work a few years ago; by that time he & his team had looked at something north of 130 possible confounding factors, and were still finding the correlation negative.

Mind you, it's still correlation and doesn't prove anything.  And yet, isn't it by now damned suggestive correlation?  Like, suggestive that the idea is worth serious research, instead of being (as it is in my field) blithely dismissed because it belies the prevailing theory (linear/no threshold)?

Now, what torques me here is that Cohen's epidemiological study gets wrung through the wringer -- an entirely appropriate wringer -- and yet is still written off, but elsewhere -- like here with your cell phone studies -- epidemiological studies get cited as if they were actual evidence of something, something more than correlation (or the apparent lack of it).  Have your studies been subjected to anywhere near this level of criticism?  Or are they being taken at first blush, as Cohen's would have been had it supported the prevailing theory instead of challenging it?  If the studies show what we want to hear, we are inclined to assume they're good, yes?

"Stoning nonconformists is part of science.  Stoning conformists is also part of science.  Only those theories which can stand up to a merciless barrage of stones deserve consideration."   ---Tero Sand

Until your mobile phone studies get seriously critiqued, I have to say that we don't know jack about cell phone effects, and those who rely on those studies are, in effect, operating on purblind faith.
Title: Re: Radiation hormesis?
Post by: mellyrn on July 05, 2012, 06:55:49 am
Quote
Source, please.  What you're saying would seem to contradict the paper I linked to before on this data.

Don't know what sam is referencing, but here's what Cohen has to say (emphasis added):

"The principal data that have been cited ... (Ref 11 and Ref 12) to support the LNT are solid tumours (all cancers except leukaemia) among the Japanese A-bomb survivors, and an International Agency for Research on Cancer (IARC) study of occupational doses to radiation workers. The former data (Ref 13) are shown in Figure 1, where the error bars represent 95% confidence limits (two standard deviations). If error bars are ignored, the points do indeed suggest a linear relationship with intercept near zero dose. However, when error bars are considered, they give little statistically significant indication of excess cancers for doses below 25 cSv.

"In fact, it has been shown (Ref 14) that considering the three lowest dose points alone, the slope of the dose-response curve has a 20% probability of being negative (risk decreasing with increasing dose). The analysis utilised by Reference 13 [Pierce D.A. et al, Studies of the mortality of atomic bomb survivors, Report 12, Part 1, Cancer 1950—90, Radiation Research, vol. 146, p1—27, 1996] is very elaborate, involving fitting models with many variables — city (Hiroshima, Nagasaki), sex, age at risk, year, age at exposure, time since exposure, and dose — to determine both background expected deaths and excess deaths for each of the thousands of combinations of these variables. It is very difficult to understand the uncertainties in this analysis, but intuitively it is hard to accept that strong conclusions can be drawn from this data below 20 cSv, involving a total of 6312 observed deaths compared with the 6251 expected background deaths derived from the model."

He also notes (emphasis added again),

"While the solid tumour data on A-bomb survivors and the leukaemia data on monitored radiation workers are said to support the LNT (although the leukaemia data on the former group and the solid tumour data on the latter group do not), there are several studies that seem to contradict the LNT. The data on leukaemia among A-bomb survivors (Ref 13) are shown in Figure 3, with error bars indicating 95% confidence limits. These data strongly suggest a threshold above 20 cSv."

Title: Re: Radiation hormesis?
Post by: mellyrn on July 05, 2012, 06:58:36 am
Finally, this is what I'm personally operating from:

1) Earth holds both "primordial" radionuclides (ones formed in stellar fusion & novas &c) and "cosmogenic" ones (being constantly created by incoming protons), and we aren't getting any more primordial ones.  Therefore yesterday was slightly more radioactive than today, and 3.5 billion years ago was exponentially more radioactive than today.  Thus, life began in a significantly higher radiation field than it now finds, and any given species today is adapted to a slightly higher ("yesterday's") background radiation.  As far as I can tell, it's just not possible that living systems can't handle the special stresses of low-level radiation.  I mean, dude!

1a) Oxygen is terribly reactive & corrosive; when it first appeared in quantity on the planet, it was a serious toxin.  Of course the same thing made it quite the energy source.  And what did life do about that?  <inhale>  So, how could it not do something of the sort with something even more ubiquitous?

2) The Navy Nuclear Shipyard Workers' study of ?1960s? 70s? looked at something like 70,000 workers, all doing much the same job; the ones with nuclear clearance had lower cancer rates & lower cancer mortality than the non-nuclear workers.  I kind of think this was never published, but it gets discussed in Health Physics Society ezines and things.

3) Personal conversation:  at a conference, a guy told me of work he & his group did with I think chlorella cells, where they reduced the background radiation to an amazing degree -- separating the K-40 (which is probably the biggest contributor to your personal daily dose) out of the K in the nutrient brine, as well as heavily shielding the lab and so on.  He said the cells they grew were just beautiful -- textbook-perfect, every little organelle just so.  And they didn't do sh*t -- very sluggish to move, very slow to divide and often badly dividing when they did.  And zero resistance to the bacteria they introduced.

4) Same guy as in 3 also described the "mega mouse" experiment, done in Oak Ridge, so named for the million mice involved.  One group was raised in, again, a heavily shielded area with food from which the K-40 had been removed; then a control group, of course; and then 3-4 more groups in successively-higher radiation fields.  According to my informant, the group in 3x the control group's rad field was the healthiest in terms of individual longevity of the mice plus production of offspring; iirc, the longevity of this group was quite striking, like twice the lifespan of the control group but don't quote me on that.

5) Cohen's well-wrung study is not alone.  Elsewhere in the world, two large (35,000+ pop.) regions of China, demographically similar, and the high-radon province has the lower lung cancer mortality; Finland has higher radon than the rest of Europe and also lower lung cancer mortality (either that or t'other way around:  lower-than-Europe radon + higher-than-Europe lung cancer mortality; I forget).

6) Rad workers in the US are limited to 5R (0.05 Sv) annually; "public dose" workers are not to get more than "background" (150-300 milliR).  But there are areas on Earth where the natural background radiation is about 5R (0.05Sv) per year, and these areas are not associated with unusually high cancer incidence or mortality.  It's true that one of these areas has significantly elevated mental retardation, but it's also a desperately poor, famine-ridden area (Kerala in India).

7) 25R (0.25Sv) in one acute dose is the lowest at which nonstochastic effects can be medically detected; 100R (1Sv) in one acute dose will lead to nausea in a few hours.  In the range from 10R to 70R, there is an increased risk of leukemia -- and a decreased risk of breast cancer.  This I got from reading one BEIR report or another, so, seriously mainstream.

Don't have cites for you.  This is what I've learned from 20 years as a health physics (radiation-safety) technician, and I wasn't accumulating it with an eye towards ever convincing someone else one way or another.  Do as you like with it.


Title: Re: Radiation hormesis?
Post by: sam on July 05, 2012, 07:20:40 am
However, in the Japanese survivor survey, radiation shows no linear effect on total deaths, with an increase of total deaths setting in at about 1000 mSv, consistent with the conjecture that doses of radiation above 100 mSv result in a small increased risk of being diagnosed with cancer and having one's death blamed on cancer, and a decreased risk of having one's death blamed on something else.

Source, please.  What you're saying would seem to contradict the paper I linked to before on this data.

You are reading the official spin, and ignoring the actual data.  Whenever a scientific paper says something politically incorrect, it begins and ends with a pious affirmation of the official truth in simplistic and colorful language, while explaining the actual truth somewhere in the middle using arcane scientific  language, which progressives are seldom capable of following, and are therefore unlikely to punish the scientist for.  The simplistic language is intended as a signal "I am just  saying this to avoid punishment for heresy and sinful thoughts", while the obscure scientific language is intended as a signal "this is the actual science"

http://www.nap.edu/openbook.php?record_id=11340&page=143 (http://www.nap.edu/openbook.php?record_id=11340&page=143)

TABLE 6-1 Number of Subjects, Solid Cancer Deaths, and Noncancer Disease Deaths by Radiation Dose

dosenumber exposedsolid cancer deathsnon cancer deaths
0 5 mSv37,4583,83313,832
5 100 mSv31,6503,27711,633
100 200 mSv5,7326682,163
200 500 mSv6,3327632,423
500 1000 mSv3,2994381,161
1000 2000 mSv1,613274506
2000 mSv up48882163

Now let us calculate from that total deaths and percentages
               
doseNumber exposedsolid cancer deathsnon cancer deathstotal deathspercent solid cancer deathspercent non cancer deathspercent total deaths
0 5 mSv37,4583,83313,83217,66510.236.947.2
5 100 mSv31,6503,27711,63314,91010.436.847.1
100 200 mSv5,7326682,1632,83111.737.749.4
200 500 mSv6,3327632,4233,18612.038.350.3
500 1000 mSv3,2994381,1611,59913.335.248.5
1000 2000 mSv1,61327450678017.031.448.4
1000 mSv up2,1013566691,02516.931.848.8
2000 mSv up4888216324516.833.450.2

As you can see, there is a threshold effect in the Japanese survivor data for total solid cancer deaths at 100 mSv, and though above 100 mSv, cancers go up, non  cancer deaths go down by about the same amount, indicating that exposure to radioactivity improves ones health in other ways despite increasing one's risk of cancer, or that Japanese people exposed to high levels of radiation are over diagnosed for cancer, or that those not so exposed are under diagnosed for cancer.

The fact that the increase in the one is nearly equal to the decrease in the other suggests that diagnosis is the problem.



Title: Re: Radiation hormesis?
Post by: Andreas on July 05, 2012, 07:23:44 am
We are the survival engine. Of course we can take radiation in some amount, we're constantly bombarded with it, anyway.
Barring radioactive isotopes of key elements, or their ringers, I do think it stands to reason that the body's autorepair can cope with basic radiation quite well.
UV is the bigger cancer killer, right? And we can't live without UV either.
Title: Re: Radiation hormesis?
Post by: SandySandfort on July 05, 2012, 09:40:33 am
I don't know the facts about routine general medical and dental X-ray's.  Yet I still can't help but cringe when I see children in particular with a cellular phone smashed against their skull. Or using notebooks with high power wireless in their laps.   Why not just have them stand in front of a worn out microwave oven?  ::)

My father was a dentist and when he took an x-ray he used a machine that looked liked something from Dr. Frankenstein' s lab. He manually held the film caddy in place every time he took an x-ray; year after year after year...

I also have fond memories of going to the shoe store and putting my shod feet into the "fluoroscope" and looking at the bones in my feet as I wiggled my toes, again and again and again...

For a fascinating article about fluoroscopes (with pictures!) see:

http://www.orau.org/ptp/collection/shoefittingfluor/shoe.htm
Title: Re: Radiation hormesis?
Post by: Helian on July 05, 2012, 10:10:11 am
Here's a quick dosage comparison chart I like to spread around, so more than 4 or 5 people have an idea of the amounts were talking about.
http://xkcd.com/radiation/

The cellphone thing really pisses me off.  It fails a basic logic test.  Cells are most vulnerable to radiation when they are dividing.  Brains are the slowest dividing organ in the body, in fact most believed it didn't divide at all until recently.  The organs that divide the most are eyes and gonads (roughly tied).  If cellphones cased cancer it would most likely be eye cancer, or skin cancer in the ear right next to the transmitter (radiation follows an inverse square law).  All the studies are about brain cancer, and all but the latest have been disproven (give it time).

If radio waves cause cancer, I'd be totally screwed, what with standing next to transmitting aircraft antennas to check them on a daily basis.  But since the guy I replaced retired after 30+ years with no issues, I'm not worried.  Aircraft radios put out 5 to 20 watts, most cellphones put out less than .1 watts, avonics guys have been doing this for decades with no noticed trends.

edit: for spell check fail
Title: Re: Radiation hormesis?
Post by: paddyfool on July 05, 2012, 11:20:36 am
@mellyrn,

"Torqued" is a new expression to me.  I quite like it.

As for mobile phones: without wishing to get sidetracked too much, it's not just that large epidemiological studies have been conducted.  It's that every single bit of actual evidence I've seen agrees that there's no risk.   All I've seen for the other side is media scaremongering, and some really tiny and terribly designed studies. If you can actually pull up some evidence of risk, that'd be interesting.  But until then... chalk me down as unconvinced.

Now, to the wealth of other stuff you've presented on the main topic of discussion:

OK, fine, it's a bit of a hotch-potch, but enough to pique my interest.  However... let me make my point clear.  I'm not saying OMG low level radiation.  I'm saying levels above 100 mSv are not low-level, and actually dangerous, based on a trawl of Pubmed etc.  Lower than that, and yes, there isn't much evidence for harm.  Although there's also precious little evidence for benefit - I'm far from convinced by such animal studies etc. as have been presented.

And the thing about Cohen's findings on radon and lung cancer is that they haven't been reproducible.  The vast majority of studies on this seem to find the exact opposite - an increase in lung cancer risk, particularly among non-smokers.

@Sam,

Thank you for linking to that data.  I particularly like that you showed your working.  However... I have been looking at the data.  I just disagree with the selectivity you've shown in which data to consider.

For instance, one thing which your table omits is the number of people dying from leukaemia (leukaemia deaths fit into neither the "solid cancer" nor the "non-cancer" categories, and show a much stronger association with increasing dose of radiation than either http://www.nap.edu/openbook.php?record_id=11340&page=144, although in terms of looking at the total deaths, if we actually had a figure for that, it's also worth noting that these would form a pretty small piece of the whole).

We are the survival engine. Of course we can take radiation in some amount, we're constantly bombarded with it, anyway.
Barring radioactive isotopes of key elements, or their ringers, I do think it stands to reason that the body's autorepair can cope with basic radiation quite well.
UV is the bigger cancer killer, right? And we can't live without UV either.

In some amount, of course.  On average, we each get about 3 mSv each year, and some people live fine in areas of the world where the background is rather higher.  But there's no such known mechanism for benefit as there is for UV (which is used for Vitamin D generation, although not essential for it; with the right diet, it seems you can indeed manage fine without sunlight, although personally I wouldn't choose to).
Title: Re: Radiation hormesis?
Post by: customdesigned on July 05, 2012, 11:36:37 am

The cellphone thing really pisses me off.  It fails a basic logic test.  Cells are most vulnerable to radiation when they are dividing.  Brains are the slowest dividing organ in the body, in fact most believed it didn't at all until recently.  The organs that divide the most are eyes and gonads (roughly tied).  If cellphones cased cancer it would most likely be eye cancer, or skin cancer in the ear right next to the transmitter (radiation follows an inverse square law).  All the studies are about brain cancer, and all but the latest have been disproven (give it time).

If radio waves case cancer, I'd be totally screwed, what with standing next to transmitting aircraft antennas to check them on a daily basis.  But since the guy I replaced retired after 30+ years with no issues, I'm not worried.  Aircraft radios put out 5 to 20 watts, most cellphones put out less than .1 watts, avonics guys have been doing this for decades with no noticed trends.

In populist ignorance, the word "cancer" stands for any scary illness that could be caused by the environment.   Just understand the word in the sense in which it is used - it is not always necessary to correct peoples scientific understanding.   Cell phone radio does have measurable effects on the brain - just no measurable (real medical) cancer.  The most obvious effect is brain heating.  Every device is required in the US to carry a label detailing exactly how much it heats your brain when held directly to your ear (I always use speaker phone or earphones to avoid worrying about it).  While no ill effects have been definitively found, such heating on a daily basis is worrisome. 

Every more interesting, the 900Hz band has demonstrated non-thermal effects.  Volunteers played a video game while being exposed, or not exposed to 900Hz cell phone radiation at normal cell to ear levels.  Neither participants, nor researchers, knew when the radiation was on (controlled and recorded by computer).  With radiation on, reflexes used in the video game became up to several times *faster* than when it was off.  I.e., the radiation *improved* hand eye coordination.  That's something I would consider using in a soldier situation - but again, I'd be worried about long term effects with constant daily use.
Title: Re: Radiation hormesis?
Post by: sam on July 05, 2012, 07:22:31 pm
For instance, one thing which your table omits is the number of people dying from leukaemia (leukaemia deaths fit into neither the "solid cancer" nor the "non-cancer" categories, and show a much stronger association with increasing dose of radiation than either http://www.nap.edu/openbook.php?record_id=11340&page=144,

Your source draws a PC conclusion from alleged data, without, however, showing us the data which supposedly supports the PC conclusion, which is pretty much a guarantee that they are stretching the truth or lying barefaced.  If the data actually supported the PC, they would show it to you, indeed it would be up on posters.

Your link tells us:

Quote
Leukemia risks increased with dose up to about 3 Sv, with evidence of upward curvature; that is, a linear-quadratic function fitted the data significantly better than a linear function. With this linear-quadratic function, the excess risk per unit of dose at 1 Sv was about three times that at 0.1 Sv.

In other words the slope of the alleged curve was three times steeper at 1000 mSv than at 100 mSv.  This sounds very much like saying leukemia rates were dominated by a threshold at 1000 mSv.

If there is a threshold at 1000 mSv, then, given diagnostic and dosage uncertainties, hard to detect the supposed effect at 100 mSv.  It is always hard to detect an alleged weak effect in the presence of a strong effect.  We are told that the pattern was "complex" but are not shown the complexity.  "Complex" sounds like torturing the data for politically correct results.  

Take a look at the next page, where it shows solid cancer risk.  Looks linear, does it not?  Looks like solid cancer risk is linear in radiation dosage.  That is because they have played clever with the scaling and the size of the dots, so as to obscure the fact that their line is indistinguishable from flat below 100 mSv.

And if they had graphed total deaths, it would be apparent that there was something odd about their seemingly linear hazard from 100 mSv to 1000 mSv

Title: Re: Radiation hormesis?
Post by: Oneil on July 05, 2012, 11:38:07 pm
I don't know the facts about routine general medical and dental X-ray's.  Yet I still can't help but cringe when I see children in particular with a cellular phone smashed against their skull. Or using notebooks with high power wireless in their laps.   Why not just have them stand in front of a worn out microwave oven?  ::)

I wouldn't worry about it.  Mobile phones emit radio waves, not gamma or x-rays, and large epidemiological studies have shown no link whatsoever between use and cancer statistics.

Come to that, isn't microwave RF, too? Worst case scenario is you overheat a little bit. Kid's to dumb to step away from the thing making his balls warm up, it's probably better he not have use of 'em anyway.

Don't discount RF in that end of the scale so fast, especially when your looking at 802.11a/h/j/n all using 5ghz.   First Harmonic is at 10ghz at 1/2 original radiated power, and another second is 15ghz at 1/2 the power of 1st.  

My point, powerful micro wavelength energetic pulses jarring chromosomes back and forth really fast.   Personally I want my great-great-grand children to not consider extra appendages as "Features."

And not so much fear of Cancer as explained above, changes to prodigy or lack their of.    Microwaves have verified effect as far as I have seen.  Former roommate and friend considered suing a branch of the military for 'Low Sperm Motility' from working in the radar spaces.  He gathered signatures from other retirees with similar issue to support his case.  His wife was not exactly pleased with it's effect.

BTW, sorry to sidetrack this from pure radiation..  
Back to what happens when we have a bad day like Harry K. Daghlian, Jr. (http://en.wikipedia.org/wiki/Harry_K._Daghlian,_Jr.)
Title: Re: Radiation hormesis?
Post by: mellyrn on July 06, 2012, 01:36:02 pm
Quote
it's not just that large epidemiological studies have been conducted.  It's that every single bit of actual evidence I've seen agrees that there's no risk.   All I've seen for the other side is media scaremongering, and some really tiny and terribly designed studies. If you can actually pull up some evidence of risk, that'd be interesting.  But until then... chalk me down as unconvinced.

Chalk in hand -- now, unconvinced of what?  Did you read what I said as claiming there is risk from cell phone usage?  Could you please quote me where I said or implied that, so I can fix it?

You write that "every bit of actual evidence" says there's "no" risk.  Great!  But you'd only mentioned "large epidemiological studies" before.  They, like Cohen's review, are subject to what I understand is called the "ecological fallacy" (at least, that's the term my old boss used) -- meaning, if you have not taken all possible confounding factors into account, your study shows nothing meaningful, like ye olde murder rate rising together with banana imports.  A mere lack of correlation on the first pass does not count as "actual evidence" of no risk; it's only evidence of "this is interesting; now, could [this result] be being caused by something else (as the murder rate and the banana import rate were both driven by season)?"  I'm asking if those studies have been subjected to serious rigor.  I don't give a flaming donkey about evidence "for the other side" at this point; I'm wanting to know if the "no damage" studies have been well conducted, and properly scrutinized, or have they been accepted at first blush just because it's what we'd like to see?

A guy who can't kick his own theory in the teeth to see if it can take it is not a scientist worthy of his lab coat.

Quote
And the thing about Cohen's findings on radon and lung cancer is that they haven't been reproducible.

What, you mean that counties with higher average radon levels do have higher lung cancer mortality rates?  How on Earth did the man ever find that they were lower, then?  The only complaint I've heard here in the industry about his work was the bit noted before, as to whether he considered all possible factors that might be causing the inverse relationship; they've said, "Maybe the low-lung-cancer-mortality counties have fewer smokers, or better health care, or more young people, and it's not radon driving it."  I've never before heard anyone dispute the observed relationship -- only whether radon was the driving factor or not.

So, what, specifically what, was "not reproducible"?

Quote
On average, we each get about 3 mSv each year, and some people live fine in areas of the world where the background is rather higher.

I guess "higher by a factor of 17"  (3mSv vs 50 mSv) counts as "rather" higher.

Quote
But there's no such known mechanism for benefit as there is for UV

Well, gosh golly gee, how about we go look for one?  There is logical reason to assume life can deal with "rather" more than "background", as well as tangible evidence.  There is precedent -- 3.5 billion-year-old precedent -- for life taking a serious toxin and turning it into a vital necessity, a source of energy -- and the ambient radiation field was around looong before life discovered oxygen.  "We don't (currently) know how it could be helpful, so it isn't" isn't much of an argument, is it?
Title: Re: Radiation hormesis?
Post by: sam on July 06, 2012, 11:45:59 pm
There are areas where the natural radiation background is quite high

http://www.probeinternational.org/Ramsar.pdf (http://www.probeinternational.org/Ramsar.pdf)

People have been living for generations in areas where they get about 200 mSv per year.

200 mSv per year is about what you would get if you lived right next door to the Japanese Fukushima nuclear "disaster", about what you currently get at the gate to the Fukushima nuclear reactor.

This is about one third of the level you get standing right beside the Chernobyl reactor today and about equal to the level you get pretty close to the Chernobyl reactor.  This is about what you would get if we stored high level nuclear waste for sixty years or so to cool down, and then just dumped it on a tip like any other trash, and you hung around on the tip.

This means that over 20 years, they get 4000 mSv, which dose will pretty reliably kill you if you get it all at once, and in five years they get 1000 mSv, a dose that no one doubts will likely cause serious risk of cancer and various ailments if you get it all at once.

There are no obvious differences between their health, and the health of people in nearby low radiation areas.  That they are not dying like flies indicates a substantial threshold effect.
Title: Re: Radiation hormesis?
Post by: paddyfool on July 07, 2012, 03:45:26 am
For instance, one thing which your table omits is the number of people dying from leukaemia (leukaemia deaths fit into neither the "solid cancer" nor the "non-cancer" categories, and show a much stronger association with increasing dose of radiation than either http://www.nap.edu/openbook.php?record_id=11340&page=144,

Your source draws a PC conclusion from alleged data, without, however, showing us the data which supposedly supports the PC conclusion, which is pretty much a guarantee that they are stretching the truth or lying barefaced.  If the data actually supported the PC, they would show it to you, indeed it would be up on posters.


My source is actually your source, two pages further on.  (I'd gone looking for their leukaemia data when it wasn't in the table, while also wanting to check where the data in that table came from and what other evidence they were looking at and analyses they had run).

Quote

Your link tells us:

Quote
Leukemia risks increased with dose up to about 3 Sv, with evidence of upward curvature; that is, a linear-quadratic function fitted the data significantly better than a linear function. With this linear-quadratic function, the excess risk per unit of dose at 1 Sv was about three times that at 0.1 Sv.

In other words the slope of the alleged curve was three times steeper at 1000 mSv than at 100 mSv.  This sounds very much like saying leukemia rates were dominated by a threshold at 1000 mSv.

If there is a threshold at 1000 mSv, then, given diagnostic and dosage uncertainties, hard to detect the supposed effect at 100 mSv.  It is always hard to detect an alleged weak effect in the presence of a strong effect.  We are told that the pattern was "complex" but are not shown the complexity.  "Complex" sounds like torturing the data for politically correct results.  

Take a look at the next page, where it shows solid cancer risk.  Looks linear, does it not?  Looks like solid cancer risk is linear in radiation dosage.  That is because they have played clever with the scaling and the size of the dots, so as to obscure the fact that their line is indistinguishable from flat below 100 mSv.

And if they had graphed total deaths, it would be apparent that there was something odd about their seemingly linear hazard from 100 mSv to 1000 mSv

You seem very confident about what data you haven't seen would show.  And I'm really not seeing the problem with the graph.  What alternative scaling are you saying they should have used?

There is, however, one key problem on the leukaemia issue which I've uncovered.  I just went looking for the mechanism behind the high degree of vulnerability to leukaemia observed... and it seems that what happens is that various alpha-emitting radioactive elements go straight to the bone (particularly polonium-210, or rather its precursor, lead-210, and radon-222).  (A similar issue to the increased thyroid cancer, which stems from radioactive iodine being taken up along with all the other iodine by the thyroid gland).  So the increased vulnerability of people exposed to nuclear fall-out to leukaemia may not actually be of massive relevance to, say, gamma-exposure.  http://books.google.co.uk/books?id=DO4_ur2tOiAC&pg=PA2&lpg=PA2&dq=table+sieverts+leukaemia&source=bl&ots=DiHbSnWoye&sig=TUJ-lSrS0JK7pqedmR4Lah24HAg&hl=en&sa=X&ei=8Oz3T_KbJ-Ox0QXE0cihBw&ved=0CFoQ6AEwBA#v=onepage&q=table%20sieverts%20leukaemia&f=false

Chalk in hand -- now, unconvinced of what?  Did you read what I said as claiming there is risk from cell phone usage?  Could you please quote me where I said or implied that, so I can fix it?

You write that "every bit of actual evidence" says there's "no" risk.  Great!  But you'd only mentioned "large epidemiological studies" before.  They, like Cohen's review, are subject to what I understand is called the "ecological fallacy" (at least, that's the term my old boss used) -- meaning, if you have not taken all possible confounding factors into account, your study shows nothing meaningful, like ye olde murder rate rising together with banana imports.  A mere lack of correlation on the first pass does not count as "actual evidence" of no risk; it's only evidence of "this is interesting; now, could [this result] be being caused by something else (as the murder rate and the banana import rate were both driven by season)?"  I'm asking if those studies have been subjected to serious rigor.  I don't give a flaming donkey about evidence "for the other side" at this point; I'm wanting to know if the "no damage" studies have been well conducted, and properly scrutinized, or have they been accepted at first blush just because it's what we'd like to see?

To be fair, I haven't been looking into this in as much detail as the main topic, and it's sufficiently far outside my main area of research (when I worked in research) that I can't really claim to be an expert anyway.  So I can't really answer your question on the extent of rigour to which each and every study has been put through; sorry.  All I've really done is sum up what I remembered from looking into this once before, a few years ago.

Quote
A guy who can't kick his own theory in the teeth to see if it can take it is not a scientist worthy of his lab coat.

I couldn't agree more (I'd be tempted to accuse you of teaching your grandmother to suck eggs here, but that would risk turning this into a contest of academic dick-waving).

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And the thing about Cohen's findings on radon and lung cancer is that they haven't been reproducible.

What, you mean that counties with higher average radon levels do have higher lung cancer mortality rates?  How on Earth did the man ever find that they were lower, then?  The only complaint I've heard here in the industry about his work was the bit noted before, as to whether he considered all possible factors that might be causing the inverse relationship; they've said, "Maybe the low-lung-cancer-mortality counties have fewer smokers, or better health care, or more young people, and it's not radon driving it."  I've never before heard anyone dispute the observed relationship -- only whether radon was the driving factor or not.

So, what, specifically what, was "not reproducible"?

There have been plenty of studies on radon showing a link with lung cancer, both occupational (e.g. in miners) and residential (living in high-radon areas).  But really, what you should do is look at those studies by Cohen in their historical context, as summarised in this article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3073196/?tool=pubmed

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On average, we each get about 3 mSv each year, and some people live fine in areas of the world where the background is rather higher.

I guess "higher by a factor of 17"  (3mSv vs 50 mSv) counts as "rather" higher.

Indeed, but it's still below the range we're arguing over (100 to 1000 mSv).  Also, 50 mSv or above is, so far as I'm aware, confined to a few very small areas within the coastline of Kerala, some areas within a single county in Iran (Ramsar) and a very few other places.

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But there's no such known mechanism for benefit as there is for UV

Well, gosh golly gee, how about we go look for one?  There is logical reason to assume life can deal with "rather" more than "background", as well as tangible evidence.  There is precedent -- 3.5 billion-year-old precedent -- for life taking a serious toxin and turning it into a vital necessity, a source of energy -- and the ambient radiation field was around looong before life discovered oxygen.  "We don't (currently) know how it could be helpful, so it isn't" isn't much of an argument, is it?

Be my guest.  But the burden of proof lies on those claiming this effect; no benefit is the null hypothesis.  And biological plausibility in the form of a mechanistic explanation is among the Bradford-Hill criteria for a reason.
Title: Re: Radiation hormesis?
Post by: sam on July 08, 2012, 08:45:35 am
You seem very confident about what data you haven't seen would show. 

For two reasons:

1.  I expect it to show what data I have seen shows.

2.  If they don't show it, it is data that would get them in trouble.

There have been plenty of studies on radon showing a link with lung cancer, both occupational (e.g. in miners) and residential (living in high-radon areas). 

No.  There have been plenty of people who loudly and confidently drew the conclusion that living in high radon areas increases lung cancer, which conclusions were allegedly based on studies that they declined to show us, but no studies showing that living in high radon areas increases lung cancer.

But really, what you should do is look at those studies by Cohen in their historical context, as summarised in this article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3073196/?tool=pubmed

Which tells us that after torturing the data, they somehow managed to draw the required conclusion, despite the fact that no particular specific identifiable study supported the required conclusion.

They pooled data from different studies operating on different principles, with the unsurprising result that the pooled data showed something different from what any particular study showed.

When you pool data from different studies operating on different principles, the number of ways of "analyzing" the data increase combinatorially, guaranteeing that you can find an analysis that shows whatever you want.

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On average, we each get about 3 mSv each year, and some people live fine in areas of the world where the background is rather higher.

I guess "higher by a factor of 17"  (3mSv vs 50 mSv) counts as "rather" higher.

Some substantial populations get 250 mSv per year.
Title: Re: Radiation hormesis?
Post by: paddyfool on July 09, 2012, 03:59:36 am
You seem very confident about what data you haven't seen would show. 

For two reasons:

1.  I expect it to show what data I have seen shows.

What data have you seen from the JSS on leukaemia, then? 

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2.  If they don't show it, it is data that would get them in trouble.

They're reviewing the research done on the leukaemia data over a few different prior studies.  It's not exactly commonplace to reproduce the raw data from said studies when you're doing this.

Meanwhile, what do you make of this, the most thorough review I've yet found of the other data on low-dose (specifically, 100 mSv) effects on leukaemia risk? http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3095477/?tool=pubmed

There have been plenty of studies on radon showing a link with lung cancer, both occupational (e.g. in miners) and residential (living in high-radon areas). 

No.  There have been plenty of people who loudly and confidently drew the conclusion that living in high radon areas increases lung cancer, which conclusions were allegedly based on studies that they declined to show us, but no studies showing that living in high radon areas increases lung cancer.

Meh.  You're leaving aside the evidence linked to in that review.

See here for a meta-analysis and summary of 13 European studies (particularly figure 2): http://www.ncbi.nlm.nih.gov/pmc/articles/PMC546066/?tool=pmcentrez

And here for a meta-analysis and summary of 7 North American studies: http://www.ncbi.nlm.nih.gov/pubmed/15703527/

But really, what you should do is look at those studies by Cohen in their historical context, as summarised in this article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3073196/?tool=pubmed

Which tells us that after torturing the data, they somehow managed to draw the required conclusion, despite the fact that no particular specific identifiable study supported the required conclusion.

Required by whom for what purpose?  This is a conspiracy theory without any obvious benefit for the conspirators.

They pooled data from different studies operating on different principles, with the unsurprising result that the pooled data showed something different from what any particular study showed.

I've looked into the methodology of the two main meta-analyses behind the conclusions reached in that review on household exposure and no, they really didn't.  The criteria for inclusion were clear, and the mode of analysis consistent.  Also, they included extensive sensitivity analyses to ensure that they weren't biasing the outcome by any particular methodology.

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When you pool data from different studies operating on different principles, the number of ways of "analyzing" the data increase combinatorially, guaranteeing that you can find an analysis that shows whatever you want.

The risk is not so high as when you don't pool the data from all the valid studies, or consider prior reviews of the evidence, but cherrypick the studies you like, based on the conclusions you want to find.

Some substantial populations get 250 mSv per year.

Source, please.
Title: Re: Radiation hormesis?
Post by: sam on July 10, 2012, 06:24:10 am
2.  If they don't show it, it is data that would get them in trouble.

They're reviewing the research done on the leukaemia data over a few different prior studies.  It's not exactly commonplace to reproduce the raw data from said studies when you're doing this.

You, and they, are not producing evidence, but making claims about what authority claims, authority telling us that authority tells us. That is not science, and on a question as politically dangerous as the effects of low dose radiation, authority is not evidence.  If Authority had evidence for the politically correct view, they would show us that evidence, instead of assuring us it exists somewhere some unspecified place in some form we are insufficiently learned to understand.

Radon gas is extremely patchy, and the patches have no correlation with other population characteristics that might affect cancer.  If radon gas caused cancer, the correct approach is to look at populations exposed to high levels of radon gas because of the rocks that happen to be underneath them, not because of lifestyle or employment characteristics.  That is the only kind of survey that counts, and all such surveys shows no harmful radiation effects, and arguably beneficial radiation effects.  Using any other kind of data is deliberately looking for bad data to grind your axe - just as looking at responders rather than evacuees is deliberately looking for bad data to grind your axe.

And if you are going to use bad data, show us the bad data.  Don't show us what authority says about what authority says about what authority says about the bad data.  Bad data is bad science, but what authority says about bad data is not even science.

Meanwhile, what do you make of this, the most thorough review I've yet found of the other data on low-dose (specifically, 100 mSv) effects on leukaemia risk? http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3095477/?tool=pubmed

This is not a review.  It is a meta-analysis.  Meta-analyses are notoriously worthless even on entirely uncontroversial topics.  On a controversial topic, everything that makes meta-analyses worthless makes them not merely worthless, but of negative value.

Even in a non political meta analysis of non political data, publication bias in favor of significant results is going to produce bogus results:

Here is one problem with even non political meta-analysis:  Suppose a penny coming ten heads in a row is statistically significant, and therefore publishable, but random behavior is unpublishable.  You get one hundred published papers each reporting a penny coming up ten heads in a row, no published papers showing undramatic penny behavior.  You do a meta-analysis, and now you have a published paper showing a penny coming up one thousand heads in a row!  Someone else does a meta-analysis, including that previous meta-analysis as original independent data, when in fact it is re-analyzing the same data, and now you have a published paper showing a penny coming up two thousand heads in a row!   Rinse and repeat! 

A meta-analysis generates bogus statistical significance, fabricating strong statistical significance from a multitude of analyses each with weak statistical significance.  People use meta-analyses when they cannot get analyses that show strong significance - but the usual reason that they can never get strong significance is because there is really no correlation at all.  If low level radiation actually caused leukemia, no one would be reduced to doing meta analyses on each other's analyses, because they would be able to attain statistical significance without being reduced to such extremes.

Thus the very existence of meta analysis papers showing a correlation between x and y is evidence for the complete lack of any correlation between x and y.  When people use statistical methods that are well known to be bad, it is evidence that they are hard up for evidence that shows what they want to show.

As with evidence for flying saucers, the abundance of fishy smelling evidence is itself evidence for the absence of non fishy evidence.

If people provide meta analysis as evidence for x, that is itself evidence against x.  Because of various forms of publication bias, meta analysis is naughty, and well known to be naughty. If people do naughty things to prove x is true, x is probably untrue.

I've yet found of the other data on low-dose (specifically, 100 mSv) effects on leukaemia risk? http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3095477/?tool=pubmed

Another meta analysis.  Funny thing that.   

I repeat:  meta analyses are well known to be bad evidence.  Reliance on bad evidence is itself evidence for the absence of good evidence.  If low doses caused leukemia, there would be good evidence.

Meh.  You're leaving aside the evidence linked to in that review.

See here for a meta-analysis and summary of 13 European studies

Again with the meta analysis.

If anyone had any good evidence that radon caused harmful effects in low doses they would present that survey.  Since they don't present any one specific survey that shows what they want to show, we may conclude that no such survey exists.

If there were non fishy, statistically significant surveys showing what they wanted, they would not be reduced to meta analysis.

(particularly figure 2): http://www.ncbi.nlm.nih.gov/pmc/articles/PMC546066/?tool=pmcentrez

which tells us:

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Collectively, though not separately, these studies show appreciable hazards from residential radon, particularly for smokers and recent ex-smokers, and indicate that it is responsible for about 2% of all deaths from cancer in Europe.

Firstly.  Meta analysis is bad.

Secondly.  Ill ventilated houses will have higher radon levels than well ventilated houses, and if those houses also have smokers ...

The correct approach is not house by house, but area by area.  The question that should be asked is:  Do people have higher cancer rates if they live in houses built over rocks that tend to emit radon, as compared to houses built over rocks that do not tend to emit radon.

And when this question, the right question is asked, we get the result that radon is good for your health.

To get the desired result, radon bad for health, we have to ask questions that do not directly reflect just radiation levels.

To get the desired result, have to ask a different question.

I've looked into the methodology of the two main meta-analyses behind the conclusions reached in that review on household exposure and no, they really didn't.

Yet oddly, when I just looked into the methodology, I found use of notoriously unreliable methods that have a tendency to magnify and rest upon publication bias, (meta analysis) and the deliberate search for radiation data that is likely to reflect factors other than radiation (house by house radon levels rather than area by area radon levels, and the use of radiation responders, rather radiation evacuees).

When you pool data from different studies operating on different principles, the number of ways of "analyzing" the data increase combinatorially, guaranteeing that you can find an analysis that shows whatever you want.

The risk is not so high as when you don't pool the data from all the valid studies

Pooling data is from different studies is well known to be bad practice, for numerous reasons, most notoriously publication bias, even on questions that are not politically sensitive.  It is a well known problem.

Quoting from data pooled from multiple different studies done in multiple different ways as evidence for the danger of low dose radiation is like quoting from mental patients as evidence for visits from flying saucers.  That one is reduced to such evidence is pretty good evidence for lack of visits.

Some substantial populations get 250 mSv per year. [of natural background radiation]

Source, please.

http://www.ncbi.nlm.nih.gov/pubmed/11769138
Title: Re: Radiation hormesis?
Post by: paddyfool on July 10, 2012, 07:03:57 am
2.  If they don't show it, it is data that would get them in trouble.

They're reviewing the research done on the leukaemia data over a few different prior studies.  It's not exactly commonplace to reproduce the raw data from said studies when you're doing this.

You, and they, are not producing evidence, but making claims about what authority claims, authority telling us that authority tells us. That is not science, and on a question as politically dangerous as the effects of low dose radiation, authority is not evidence.  If Authority had evidence for the politically correct view, they would show us that evidence, instead of assuring us it exists somewhere some unspecified place in some form we are insufficiently learned to understand.


Grr.  OK, if you insist on taking this argument in that direction:

Your comments show an instinctive, rather than a reasoned, dismissal of every single bit of data I put in front of you simply because it disagrees with your a priori beliefs.  You use little bits of evidence like a drunkard uses a lamp-post - for support rather than illumination - and when I show you how that evidence is incomplete, alongside other information from the very same source you dismiss that too.  And now you're accusing me of arguing from authority, when I have claimed none, while you persist in making a host of unsubstantiated claims and making a series of strawman arguments about my position on this, when you aren't trying to move the goalposts.

What can you possibly learn if you aren't interested in actually putting your beliefs to the test, but only in finding things that prop up what you already believe?

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Radon gas is extremely patchy, and the patches have no correlation with other population characteristics that might affect cancer.  If radon gas caused cancer, the correct approach is to look at populations exposed to high levels of radon gas because of the rocks that happen to be underneath them, not lifestyle characteristics.  That is the only kind of survey that counts, and all such surveys shows no harmful radiation effects, and arguably beneficial radiation effects.  Any other kind of data is deliberately looking for bad data to grind your axe - just as looking at responders rather than evacuees is deliberately looking for bad data to grind your axe.

No, it really isn't.

The issue with radon and lung cancer is that radon is a much smaller risk factor than smoking.  So its effect is easy to miss if you don't control for smoking properly.  And you can't get complete smoking data out of the ecological data that Cohen used, which is why they had to do the case-control studies (I'm much less convinced by the studies on miners, because radon is far from the only additional carcinogen which miners would be exposed to).
Title: Re: Radiation hormesis?
Post by: sam on July 10, 2012, 08:57:44 am
Your comments show an instinctive, rather than a reasoned, dismissal of every single bit of data I put in front of you simply because it disagrees with your a priori beliefs.  

If you want to determine whether radon causes harmful effects, you compare houses built over high radon rocks with houses built over low radon rocks.  In which case you get the result that high radon levels improve health.

If instead you compare high radon houses with low radon houses, rather than houses built over high radon rocks with houses built over low radon rocks, you are primarily comparing low ventilated houses with highly ventilated houses.  Lo and behold, surprise surprise, low ventilated houses have harmful effects.

In which case, if you knowingly use obviously bad data, it is pretty obvious you want a particular result.

This is not "Instinctive dismissal of data that disagrees."  It is rational dismissal of data cooked up with a blatantly obvious axe to grind.
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