[ RadSafe ] Low dose paper provides strong evidence of positive associations between protracted low-dose radiation exposure and leukaemia.

Tue Jun 30 18:08:18 CDT 2015

I agree that conclusions based on numbers that are not only guesses, but layers of guesses with some shaky assumptions thrown in for good measure, should not have been published.  If your data doesn't let you control for the important variables, then perhaps you need to get better data.  If better data isn't available, that's a problem, but it still doesn't mean using the poor data will give you useful results.

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Doss, Mohan
Sent: Tuesday, June 30, 2015 4:01 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] Low dose paper provides strong evidence of positive associations between protracted low-dose radiation exposure and leukaemia.

Dear Mike,
    The average annual occupational dose is claimed to be 1.1 mSv over the years in the Lancet article.  During 1990s and 2000s it would be lower than this value as the occupational doses were much higher in the 1970s and earlier years compared to later years.  Let us assume it was 0.5 mSv in 1990s and 2000s. Since dose from one CT scan is about 1 cSv,  if one in 100 workers received a CT scan, it would change their average dose by 0.1 mSv or 20%.  Ignoring it would skew the dose-response curve derived from the data. We don’t know the numbers (all above assumed numbers are guesses. Average occupational dose as a function of year was not given in the article) but if there are such large errors in doses, the dose-response curve derived would have large errors. At the least they need to provide the average occupationl dose as a function of year, and estimate average medical radiation dose in nuclear workers as a function of year, and show that it was too low to influence the dose-response curve, since it increased in later years when occupational doses were lowest. Until they do this, their conclusion that there is strong association between dose and leukemias is suspect.  Such suspect conclusions should not be published nor publicized.
    With best regards,
                                            Mohan

-----Original Message-----
From: radsafe-bounces at agni.phys.iit.edu [mailto:radsafe-bounces at agni.phys.iit.edu] On Behalf Of Brennan, Mike (DOH)
Sent: Tuesday, June 30, 2015 5:51 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] Low dose paper provides strong evidence of positive associations between protracted low-dose radiation exposure and leukaemia.

I have a couple of problems with including "Medical" in the mix with calculating population dose.  

While it is indisputable that medical uses of radiation, both for imaging and for treatment, has greatly increased in the last several decades, the nature of the exposure is to individuals, not spread out over the population.  As an example, take my parents and the five children in my generation.  Both of my parents (now deceased) had extensive medical problems, and received many, many x-rays, including a large number of cat scans.  My mother had radiation treatment for a brain tumor.  I don't know the total dose they received, but it was doubtlessly in the "huge" range.  Neither of them died of anything related to the radiation they received.

In my generation, on the other hand, there have been the usual number of dental x-rays, the occasional knee or foot image, and I assume mammograms for my sisters (I've never asked).  All of these have, according to my colleagues in the X-ray section, decreased in dose over the last several decades (while increasing in image quality, and therefor usefulness in reducing overall risk).  

Averaging the dose of my parents with my generation of the family would provide a number, but not one of any value in predicting or characterizing anything.  I contend the same is true over the general population: the big doses to individuals receiving intense medical exposure has no effect on the much larger part of the population not receiving such treatment.

One of my professors in grad school had a memorable line:  "The average American has one functional testicle and one functional ovary."  I view "average dose" over a large population only slightly more useful.  

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Doss, Mohan
Sent: Tuesday, June 30, 2015 1:26 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] Low dose paper provides strong evidence of positive associations between protracted low-dose radiation exposure and leukaemia.

Dear Philip,
   Thanks for spreading this information, coming from what is considered to be a reputable journal, Nature, which in turn refers to an article in Lancet, another highly regarded journal. However, a simple analysis would show that the Lancet article should never have been published (see below).  Journals should be asked to watch out for such manuscripts that claim increased risk of cancer from low-dose radiation, because publishing such manuscripts with faulty data/analyses (which results in the claim of increased cancer risk from low-dose radiation) bring down the value and credibility of the journals.  
   I have submitted Comments to nature.com in response to the article as follows:
"A major but simple error in the publication (K. Leuraud et al. Lancet Haematol. 2015) is that the authors did not take into consideration the increase in medical radiation dose (e.g. from CT scans) that occurred during 1944-2005, the period of the study. The annual per capita medical radiation dose increased during this period. For USA, it was approximately 0.25 mSv in the 1960s, 0.5 mSv in 1980, and 3 mSv in 2006. On the other hand, the occupational radiation doses to nuclear reactor workers were relatively higher in the 1960s and were very low in the 2000s. The average occupational dose to the workers over the whole period was about 1.1 mSv per year. In the dose-response analysis of the publication, the authors completely ignored the medical radiation dose, which the nuclear workers would have received also at levels similar to that of the general population during this period. In the 1960s and earlier, it would be fine to ignore the medical radiation dose since it would be small compared to the occupational doses in those years. But near the end of the study period (2005), their use of occupational dose alone in their dose-response analysis would create a major error in the shape of inferred dose-response, since they ignored medical radiation dose, which would be larger than the occupational dose (or be of similar magnitude). Therefore, their conclusion should be dismissed. This paper should never have been published because this error, being a simple but major one, should have been caught by one or more of the authors and/or one or more of the peer-reviewers. This Nature news item gives credibility and publicity to the erroneous conclusion of this publication. Publications which claim increased risk of cancer from low-dose radiation, whose faults get identified and conclusions get negated at a later date, do tremendous harm by perpetuating the myth of cancers caused by low-dose radiation, since the corrections do not get any publicity in comparison to the huge publicity to the original faulty publication. I wish to suggest to Nature that this Nature News item be marked as erroneous and be withdrawn and be replaced by another Nature News item that identifies the above flaw in the publication. Thanks."
    If you have any counter-arguments, or consider my criticism is unjustified, please do let me know.  Thanks.
                                           Mohan

Mohan Doss, Ph.D., MCCPM
Medical Physicist,
Associate Professor, Diagnostic Imaging, Fox Chase Cancer Center,
333 Cottman Avenue,
Philadelphia, PA 19111-2497.
Phone: 215 214-1707
Website: http://www.fccc.edu/research/pid/doss/
Blogs: http://mohan-doss-home-page.blogspot.com/

-----Original Message-----
From: radsafe-bounces at agni.phys.iit.edu [mailto:radsafe-bounces at agni.phys.iit.edu] On Behalf Of Egidi, Philip
Sent: Tuesday, June 30, 2015 1:06 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: [ RadSafe ] Low dose paper provides strong evidence of positive associations between protracted low-dose radiation exposure and leukaemia.

Don't shoot - I just pass 'em along....

The Lancet Haematology
Available online 21 June 2015
http://www.sciencedirect.com/science/article/pii/S2352302615000940 

http://www.nature.com/news/researchers-pin-down-risks-of-low-dose-radiation-1.17876

Summary
Background

There is much uncertainty about the risks of leukaemia and lymphoma after repeated or protracted low-dose radiation exposure typical of occupational, environmental, and diagnostic medical settings. We quantified associations between protracted low-dose radiation exposures and leukaemia, lymphoma, and multiple myeloma mortality among radiation-monitored adults employed in France, the UK, and the USA.

Methods

We assembled a cohort of 308 297 radiation-monitored workers employed for at least 1 year by the Atomic Energy Commission, AREVA Nuclear Cycle, or the National Electricity Company in France, the Departments of Energy and Defence in the USA, and nuclear industry employers included in the National Registry for Radiation Workers in the UK. The cohort was followed up for a total of 8·22 million person-years. We ascertained deaths caused by leukaemia, lymphoma, and multiple myeloma. We used Poisson regression to quantify associations between estimated red bone marrow absorbed dose and leukaemia and lymphoma mortality.

Findings

Doses were accrued at very low rates (mean 1·1 mGy per year, SD 2·6). The excess relative risk of leukaemia mortality (excluding chronic lymphocytic leukaemia) was 2·96 per Gy (90% CI 1·17–5·21; lagged 2 years), most notably because of an association between radiation dose and mortality from chronic myeloid leukaemia (excess relative risk per Gy 10·45, 90% CI 4·48–19·65).

Interpretation

This study provides strong evidence of positive associations between protracted low-dose radiation exposure and leukaemia.

*****

PVE
Philip Egidi
Environmental Scientist
U.S. Environmental Protection Agency
Radiation Protection Division
Washington, DC
(202) 343-9186 (work)
(970) 209-2885 (Cell)

“The health of the people is the highest law.”
Cicero (106 - 43 BC)

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