100 mSv, 10000 mrem, cancer, cancer risks, excess cancer deaths radiaton, excess cancer risks, excess cancer risks ionizing radiation, exposure to ionizing radiation, France, Hormesis, Linear No Threshold Model, LNT, low dose radiation, no safe dose of radiation, Nuclear cleanup, nuclear energy, nuclear power, nuclear worker cancer, nuclear worker cohort, nuclear workers, public exposure nuclear effluents, UK, US
The new low dose radiation exposure results, showing high cancer risks at low doses, which came out on October 20th, are very important: https://miningawareness.wordpress.com/2015/10/21/new-study-of-us-uk-french-nuclear-workers-supports-linear-no-threshold-model-radiation-is-bad-for-you-increased-dose-is-increased-risk-hormesis-debunked-funding-from-pro-nuclear-govts-nuclea/
The study, which supports that any amount of radiation is bad for you (LNT), has been largely ignored, and where not ignored it has been partially misrepresented already. The study did control for both smoking and asbestos exposure, using lung cancer, but found little difference in results. Additionally, non-nuclear workers smoked, and were exposed to asbestos. In many of the decades studied, smoking was very widespread in all social classes. Comparing to the general population, of the same age, which is the apparent definition of excess cancers, should act as a control.
In the context of this (Richardson et. al. 2015) study, Gy is equivalent to Sv. Thus, the excess relative rate of cancer DEATH per 1000 mSv is 51%. For 100 mSv it is 5.1%. Excess cancers would be roughly double or 100% for 1000 mSv (1 Sv) and 10% for 100 mSv. As can be seen, they controlled for lung cancer.
Richardson et. al., 2015, BMJ
It has been called the “most powerful study to date” and it supports the linear no threshold (LNT) model: “No matter whether people are exposed to protracted low doses or to high and acute doses, the observed association between dose and solid cancer risk is similar per unit of radiation dose.” (See press release below).
Its timing is especially important, as it came 30 days before the comment deadline (Nov. 19) for a USNRC proposal to increase public radiation exposure from the nuclear industry by 100 to 400 fold. Currently the USEPA standard is 0.25 mSv per year and the USNRC is 1 mSv per year. The proposal is for 100 mSv per year: http://www.regulations.gov/#!docketDetail;D=NRC-2015-0057 A former USNRC Counsel has commented that this 100 mSv proposal will make the US the laughing-stock of the world. As the 100 mSv would mean extermination of the US population – whether following BEIR or the more recent studies – that should be the least of anyone’s concern. It’s probably not very pleasant to be called stupid on your death bed, but probably not the biggest worry!
The study is and isn’t about nuclear workers. The exposure received by the workers was generally much lower than that which is considered acceptable for the general public in most countries. The general public has no choice about this exposure, and no benefits are accrued from it, unless they hold stocks in nuclear utilities. When the press release, below, says that around 1 per 100 of the workers died of cancer due to radiation, this is apparently based on the 20 mSv (arithmetic) average. This is a rate which appears higher than the BEIR VII report, although it is much lower (by one half) than its 15 country predecessor. The BEIR VII report gave an average excess cancer risk of 1 per 100 people (i.e. 1%) per 100 mSv radiation exposure (10 per 100 people for 1000 mSv (1 Sv). Around half will die, with their lives shortened on average by 14 to 15 years (i.e. no life after retirement). Assuming the Excess Relative Rate is the same is Excess Relative Risk, this report gives an almost three times higher lifetime excess risk than BEIR (actually BEIR’s upper limit). However, if the more appropriate 4.1 mSv median average is used, the figure is 5.1 times higher or about 15 times higher than BEIR or 15 excess cancers per 100 people for 100 mSv and 150 per 100 for 1000 mSv (1 Sv), about 1/2 will die. The 15 country predecessor of this new 3 country report is discussed in a BEIR VII appendix, but BEIR stated that they did not have time to take it into consideration.
This new study-evaluation gives a rate of 4.8% excess deaths per 100 mSv (48% per 1000 mSv), excluding leukemia. If it is lagged for 15 years, rather than 10, the number goes up higher : “The estimated rate of mortality from all cancers excluding leukaemia increased with cumulative dose by 48% per Gy (90% confidence interval 20% to 79%), lagged by 10 years.” (Richardson et. al.-BME, Oct. 2015) (If they use a lag of 15 years, according to their supplementary materials (Table A-1), the numbers jump to 58% per Sv (Gy) for all cancer, and 54% for all cancer other than leukemia. Recall that this is external, non-neutron, non-alpha, exposure so that Gy is considered the same as Sv.)
Richardson et. al., 2015, BMJ.
Thus, the study appears to indicate approximately 3 to 15% excess chance of cancer per 100 mSv! Cancer rate (morbidity) is more important than cancer deaths (mortality) from both a social and economic perspective.
Thus, it is even more critically important to comment against the US NRC proposal to raise the YEARLY radiation exposure for the general population to 100 mSv. Over the course of less than a decade this would lead to one extra cancer for everyone! Around half will die at around retirement (14-15 yr life-shortening effects). Who is going to pay for medical care and caregiving? Who will be left to provide medical care and caregiving? According to BEIR (2005), written just shortly before the nuclear worker studies were published, the 100 mSv would result in excess cancers of 1 per 100 people in the population (1%), per year exposure, which is already unacceptable. The new study appears to show that the risk is much, much higher! After less 10 years of 100 mSv this could be 100%! (Comment against the 100 mSv here: http://www.regulations.gov/#!docketDetail;D=NRC-2015-0057)
The study has doses which are actually skewed toward lower doses, clearly showing that low dose is dangerous. And by low doses they really mean low, compared to exposure to the general population by the nuclear industry. The nuclear industry is allowed to expose the general population to 1 mSv per year, in most countries. As can be seen here, most of the workers fall in very low doses categories, even though this is for their entire nuclear career!
Richardson et. al. 2015-BMJ, p. 4
The total median dose (half above, half below) of radiation exposure to workers, over the course of their career in the nuclear industry, was only 4.1 mSv; the median length of employment was 12 years and median follow-up was 26 years; median age at end of follow-up was 58 years. Thus, on average, they were exposed to 1/3rd of what is allowed for the general public.: “distribution of cumulative colon dose estimates was skewed (median 4.1 mGy, mean 20.9 mGy, 90th percentile 53.4 mGy, maximum 1331.7 mGy)“. (Richardson, et. al. Oct. 20, 2015, BMJ) It would be interesting to see if there is a mode, i.e. most frequently occurring exposure.
Most nuclear workers were men, whereas radiation risk for non-leukemia cancers is higher for women. Children and the unborn are at higher risk, as well.
In 4 years time the nuclear industry is allowed to expose the general population to what these workers were exposed to in 12 years of paid employment (4 mSv). Even if you take the arithmetic average of 20.9 mSv, the nuclear industry is allowed to expose the general public to that amount over 21 years. (To see the problems with arithmetic average (mean) add your income or wealth with that of Bill Gates or William Buffett and divide by two. Or add all three together. The average will probably say little about your income or wealth.) Furthermore, the nuclear effluent “standard” excludes consideration of accumulation in the environment and within the body! The new study does, as well, but for reasons which appear methodologically sound, rather than deception.
The earlier 15 country study by E. Cardis et. al., 2005, “Risk of cancer after low doses of ionising radiation: retrospective cohort study in 15 countries“ concluded: “Our estimates suggest that a cumulative exposure of 100 mSv would lead to a 9.7% (1.4 to 19.7%) increased mortality from all cancers excluding leukaemia and a 5.9% ( − 2.9 to 17.0%) increased mortality from all cancers excluding leukaemia, lung, and pleura compared with background rates. The corresponding figure is 19% ( < 0 to 84.7%) for mortality from leukaemia excluding chronic lymphocytic leukaemia. Less than 5% of workers in this study received cumulative doses of the order of 100 mSv over their entire career“; BMJ: British Medical Journal 331.7508 (2005): http://www.ncbi.nlm.nih.gov/pmc/articles/PMC558612/
French researchers involved in the study contributed to a summary of the study for the World Health Organization (IRAC) press release on the 21st of October. Annotated excerpts follow. Annotations are in brackets. Full press release is at the bottom.
From the WHO-IRAC:
“PRESS RELEASE N° 238
21 October 2015
Low doses of ionizing radiation increase risk of death from solid cancers” [It excludes leukemia]
“Lyon, France, 21 October 2015 – New results from a study coordinated by the International Agency for Research on Cancer (IARC), the cancer agency of the World Health Organization, show that protracted exposure to low doses of ionizing radiation increases the risk of death from solid cancers. The results, published today in The BMJ,1 are based on the most powerful study to date and provide direct evidence about cancer risks after protracted exposures to low-dose ionizing radiation.” [Ionizing radiation increases the risk of both non-fatal and fatal cancers. Non-fatal cases can be very costly to society both economically and socially.]
“The present study demonstrates a significant association between increasing radiation dose and risk of all solid cancers,” says IARC researcher Dr Ausrele Kesminiene, a study co-author. “No matter whether people are exposed to protracted low doses or to high and acute doses, the observed association between dose and solid cancer risk is similar per unit of radiation dose.” [This is very important. It has not been considered a given that one instant flash of exposure is equivalent to exposure spread over time, although this has long thought to be the case.]
“The International Nuclear Workers Study (INWORKS), a collaboration2 among international partners, evaluated the exposures of more than 300 000 nuclear workers in France, the United Kingdom, and the USA over a period of time between 1943 and 2005“. [Other countries were removed reportedly for financial reasons. However, removing Canada is apparently one major reason the risk has dropped by about half, in comparison to the earlier 15 country study. Read and take a look at Figure 2: “Risk of cancer after low doses of ionising radiation: retrospective cohort study in 15 countries“; by E Cardis, et. al. “Risk of Cancer after Low Doses of Ionising Radiation: Retrospective Cohort Study in 15 Countries.” BMJ : British Medical Journal 331.7508 (2005): http://www.ncbi.nlm.nih.gov/pmc/articles/PMC558612/ Unfortunately, it is not Creative Commons, but it is available for free online. It gives a much higher excess risk rate than the 3 country current study.]
“The average radiation dose to the colon of workers in the study was 21 mGy.“[The arithmetic dose was 20.9 mGy, and in this context of external, non-neutron radiation, it is the same as 20.9 mSv. However, as we saw above, arithmetic average can skew in the direction of outliers. The proper average is most often the median, which is 4.1 mSv for this study. Using 4.1 mSv rather than 20.9 points to a risk that is 5.1 times higher.]
“Dose to the colon is traditionally used in radiation studies to enable comparison with the results from previous studies of people acutely exposed to higher doses, such as atomic bomb survivors in Japan, from which most of the knowledge about the link between radiation and cancers has been derived.” [This table from the study shows that even using photon exposure, rather than colon dose, the excess rates are unacceptably high. 33% for 1000 mSv; 3.3% per 100 mSv for excess cancer deaths! Richardson et. al. 2015, Supplementary Materials]
The Press Release continues: “The results showed that the risk of death from solid cancers was modest” [HOW IS A 5% EXCESS DEATH RATE “MODEST”? ] “and increased by about 5% per 100 mGy“. [This means that the 1 mSv exposure allowed to the general public results in a 4% increase in cancers over the course of an 80 year life-time. This ignores build up in the environment; it excludes greater impacts on women and children; it excludes internal doses. This is excess cancer deaths and not excess cancer rates. Excess cancer rates (incidence) will be higher – probably double.] “Within the entire cohort, about 1 of every 100 observed deaths from cancer (other than leukaemia) can be attributed to the workplace radiation exposure.” [This sounds low until you consider that this is apparently based on the arithmetic average of 20 mSv, which is what the general public can be subjected to by the nuclear industry in 20 years time! This is excess cancer deaths and not excess cancer rates. Cancer takes a high economic and social toll, as well as individual toll. ]
“Among the cohort members who received at least 5 mGy of radiation dose in the workplace, an estimated 2.4 of every 100 deaths from such cancers were due to their workplace exposure.“[The 5 mGy is over the career. Otherwise, this is unclear, as so much of the study itself is. So many authors couldn’t find an editor? And what is “such cancers”? Is this comparison from the best fit line? Is this based on exposure estimates? Is this a typo? The whole point of the study is to determine excess cancers according to exposure, presumably based on comparison with cancer rates in the general population. They are paid to do this work. Are they unwilling or unable to write clearly? This does not appear to be a lost in translation problem, though it’s too bad they didn’t do a French Press Release, just in case.]
[The study itself says: “Results suggest a linear increase in the rate of cancer with increasing radiation exposure. The average cumulative colon dose estimated among exposed workers was 20.9 mGy (median 4.1 mGy). The estimated rate of mortality from all cancers excluding leukaemia increased with cumulative dose by 48% per Gy (90% confidence interval 20% to 79%), lagged by 10 years. Similar associations were seen for mortality from all solid cancers (47% (18% to 79%)), and within each country. The estimated association over the dose range of 0-100 mGy was similar in magnitude to that obtained over the entire dose range…“. “Risk of cancer from occupational exposure to ionising radiation: retrospective cohort study of workers in France, the United Kingdom, and the United States (INWORKS); David B Richardson, et. al. BMJ 2015;351:h5359]
The Press Release continues: “This study strengthens the evidence of a causal relationship between solid cancers and exposure to low doses of ionizing radiation.” [Thus it is important support to the Linear No Threshold Model, where increasing exposure, is increasing risk. There is no threshold and no safe dose. Even by removing outliers showing more risk (e.g. Canada), and apparently keeping ones which show less risk, the proof remains overwhelming – there is no safe dose of ionizing radiation and increase dose is increased risk.]
Press Release continues: “The findings are important not only for the protection of workers in the nuclear industry but also for medical staff and the general population” [This is certainly true. As noted, 4 years of 1 mSv effluents from the nuclear industry is the same as the median average of this study (4 mSv) and the mean is 20 years worth. However, Dr. Thierry-Chef takes it upon herself to twist this fact and make it nuclear workers vs. medical exposures. (Perhaps it is because she works for the International Agency for Research on Cancer, Lyon, France, as unlike two of her French colleagues from the ISRN, she appears to have not taken extra money from French Nuclear giants Areva and EDF.) There is some level of choice and benefit which accrues to workers and those undergoing a medical exam, which is not the case for the general population exposed to radioactive effluents from a nuclear industry, which they did not even choose to have!] Thierry-Chef continues: “since the level of dose received by nuclear workers in the workplace is comparable with doses received by patients who could be repeatedly exposed in multiple computed tomography (CT) scans or in interventional radiology procedures,” says IARC researcher Dr Isabelle Thierry-Chef, one of the authors of the study. “This stresses the importance of striking a balance between the risks and the benefits of such medical imaging procedures.” [While the last sentence is true, her statement is doubly deceptive because a CT scan can deliver in one shot 10 mSv, which is more mSv than the median average (4 mSv) for the nuclear workers in this study over their entire career! The US FDA states: “CT examination with an effective dose of 10 millisieverts (abbreviated mSv; 1 mSv = 1 mGy in the case of x rays.) may be associated with an increase in the possibility of fatal cancer of approximately 1 chance in 2000.” (This works out to be 0.5% cancer deaths, which appears in line with BEIR VII, which gives 1% excess cancers, and under the rates found in new study.) Some CT scans go up as high as 60 mSv, according to the FDA. http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/MedicalX-Rays/ucm115329.htm ]
[Now Dr. Thierry-Chef tries to make the problem one of age, even though this is supposed to be excess cancer cases in comparison to the general population, and as though fallout from nuclear weapons, fallout from Chernobyl, and decades of nuclear effluents into the air, water and food have nothing to do with poor health! Furthermore, this is supposed to be cancers in excess of the general population, unless we have misunderstood. It is about cancer and not about other diseases induced by radiation. Excess risk is supposed to be in comparison to the general population and normally controlled according to age (and socio-economic status, SES)! She states: “The average age of workers in the study is 58 years, an age at which the incidence of many diseases is increasing.” [Having had education in statistics, and having read their paper about 20 times, if we have misunderstood then we put that on their poor writing and explanatory skills (and of the BEIR VII report). Such an important paper should be clearly understandable to a public, which has had no statistics. Unfortunately, reading stilted academic works wrecks the writing of previously good writers, and creates a vicious downward spiral.]
[The IARC Director ends with an important statement:] “The follow-up of the cohort is of critical importance in this study,” says IARC Director Dr Christopher Wild. “Many questions remain about the impact of radiation on health. The continued monitoring of this cohort in the future will play a key role in better understanding the link between cancer and radiation.”
1 Richardson DB, Cardis E, Daniels RD, Gillies M, O'Hagan JA, Hamra GB, Haylock R, Laurier D, Leuraud K, Moissonnier M, Schubauer-Berigan MK, Thierry-Chef I, Kesminiene A. Risk of cancer from exposure to ionizing radiation: a retrospective cohort study of workers in France, the United Kingdom, and the United States (INWORKS). BMJ. 2 See Note to the Editors. Press Release is found here:
Highlight-underline added. Original Press Release here: http://www.iarc.fr/en/media-centre/pr/2015/pdfs/pr238_E.pdf
[The study-supplementary materials are found here: http://www.bmj.com/content/351/bmj.h5359. The study is reproduced with some commentary here: https://miningawareness.wordpress.com/2015/10/21/new-study-of-us-uk-french-nuclear-workers-supports-linear-no-threshold-model-radiation-is-bad-for-you-increased-dose-is-increased-risk-hormesis-debunked-funding-from-pro-nuclear-govts-nuclea/
THE ABOVE POST REPRESENTS OUR CURRENT UNDERSTANDING OF THE NEW STUDY AND BEIR. IT WILL BE UPDATED IF ANY MAJOR CHANGES IN UNDERSTANDING OCCUR. AS ALWAYS IT IS BEST TO GO TO THE ORIGINAL SOURCES. REGARDLESS THIS RESEARCH AFFIRMS THAT RADIATION IS DANGEROUS AT ANY DOSE. A BELIEF IN HORMESIS (aka some radiation is good for you) IS WISHFUL THINKING. HORMESIS IS DEADLY BS. This post was updated on December 18 2015 and a companion post explaining changes will hopefully soon appear.