Is Natural Background Radiation is Safe?

Is there a safe level of radiation?Before we start I would like to restate that there is no scientific evidence whatsoever that health risks can be measured by total radiation dose alone. It is a complicated subject since it depends on the type of radiation emitted, whether it is internal or external to the body, what the chemical element is – Iodine, Uranium etc. Also since diseases such as cancer depend on a number of risk factors the risk of will also depend on what other risk factors there are.

Because the exact details a model is used. However, this is known to be seriously flawed.

….. There are important concerns with respect to the heterogeneity of dose delivery within tissues and cells from short-range charged particle emissions, the extent to which current models adequately represent such interactions with biological targets, and the specification of target cells at risk. Indeed, the actual concepts of absorbed dose become questionable, and sometimes meaningless, when considering interactions at the cellular and molecular levels.

Committee Examining Radiation Risk of Internal Emitter Majority Report Chapter 2.1 paragraph 11

This leads to many contradicting results. Some of this is because the studies are flawed but often because the underlying dose-risk model is inadequate.

Natural Background Radiation

I have often seen it argued that since we have been living with natural background radiation (about 2mSv per year) that have adapted to this and it poses no risk. Rather like we have lived with malaria or that sparrows have lived with sparrow-hawks and therefore they pose no risk.

This idea is totally unsupported by any scientific evidence. It is strange that many pro-nuclear people become complete waftey hippies claiming that because something is ‘natural’ it is fine. In fact naturally occurring radon

“is the second leading cause of lung cancer in the United States and is associated with 15,000 to 22,000 lung cancer deaths each year.”

Radon and Cancer: Questions and Answers – National Cancer Institute (USA), National Cancer Institute

About 20% of childhood leukaemia in Great Britain has been attributes to background radiation1. The theoretical estimates show that 16 % of lung cancer deaths among Canadians are attributable to indoor radon exposure2.

As ‘Safe’ As Naturally Occurring Uranium

Sometimes you will here or see statements such as ‘after X years it will  decay until the radiation levels are the same as natural uranium’. What this invariably refers to is that the radiation levels are the same as refined uranium metal.

However Uranium metal does not occur naturally. In fact a good uranium source for mining is usually less than 0.2% Uranium. There are a couple of exceptions in Canada which are 25%. However, the ore is blended with other rock to decrease the risk to workers.

Uranium ore deposits are also in the form as solid rock. The health risks to this cannot be compared with ore which has been crushed. Even worse it is often chemically treated to make it more soluble.

Thirdly these rocks tend to be underground and not on the surface.

So if they really want such things as depleted uranium or mining waste to be as ‘safe as naturally occuring Uranium’ it should be mixed with other rock (1 part Uranium to 500 parts rock), turned into a stable rock like substance and then buried deep underground.


 

1 The proportion of childhood leukaemia incidence in Great Britain that may be caused by natural background ionizing radiation.
Wakeford R, Kendall GM, Little MP (http://www.ncbi.nlm.nih.gov/pubmed/19151785).

2 Canadian population risk of radon induced lung cancer: a re-assessment based on the recent cross-Canada radon survey J. Chen*,D. Moir an dJ. Whyte (http://rpd.oxfordjournals.org/content/152/1-3/9.full)

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11 Responses to “Is Natural Background Radiation is Safe?”

  • Damian Poirier says:

    Remember, 100% of people who quit smoking die.

  • roberto kersevan says:

    Hello:

    just published on the peer-reviewed journal “Current Biology”:

    http://www.sciencedirect.com/science/journal/09609822

    … paper “Long-term census data reveal abundant wildlife populations at Chernobyl”, which can be downloaded without needing a subscription:

    http://ac.els-cdn.com/S0960982215009884/1-s2.0-S0960982215009884-main.pdf?_tid=cabf4726-6cc8-11e5-af77-00000aab0f02&acdnat=1444204715_1a1f3bbc0c74fdae720915455aee8598

    A few excerpts:

    “Hypothesis 1 proposes that mammal abundances are negatively correlated with levels of radioactive contamination at Chernobyl.
    This hypothesis was not supported by the data.

    Hypothesis 2 proposes that densities of large mammals are suppressed at PSRER (Chernobyl zone) compared with those in four uncontaminated nature reserves in Belarus.
    Again, we found that this hypothesis was not supported by the empirical data.

    Our data also did not support Hypothesis 3, which proposed that densities of large mammals declined in the period between 1 and 10 years after the accident.”

    Now… it’s a matter of rational choice vs ideological choice. The former stands on the scientific method, and its spectacular achievements over the last centuries… the latter is at the same level as popular galore or religious belief.

    Cheers,

    R.

  • Pete Pete says:

    Cardis E et al (2005) Risk of cancer after low doses of ionising radiation: retrospective cohort study in 15 countries. BMJ 2005;331:77.

    Dale L. Preston, Yukiko Shimizu, Donald A. Pierce, Akihiko Suyama, and Kiyohiko Mabuchi (2003) Studies of Mortality of Atomic Bomb Survivors. Report 13: Solid Cancer and Noncancer Disease Mortality: 1950–1997. Radiation Research: October 2003, Vol. 160, No. 4, pp. 381-407.

    Darby et al. Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies. BMJ 2005;330:223.

    Doody MM et al Land CE for the US Scoliosis Cohort Study Collaborators. Breast cancer mortality following diagnostic x rays: Findings from the US Scoliosis Cohort Study. Spine 25 (2000): 2052-2063.

    Jacob P et al. Childhood exposure due to the Chernobyl accident and thyroid cancer risk in contaminated areas of Belarus and Russia. British Journal of Cancer 80.9 (1999): 1461.

    Noschenko et al. 2001. Patterns of Acute Leukemia Occurrence Among Children in the Chernnobyl Region. Intl J of Epidemiology 30, 125-129.

    Ron E and Schneider AB. Thyroid cancer. Cancer epidemiology and prevention 3 (1996): 975-994.

    Sont WN, Zielinski JM, Ashmore JP, Jiang H, Krewski D, Fair ME, et al. 2001. First analysis of cancer incidence and occupational radiation exposure based on the National Dose Registry of Canada. Am J Epidemiol 153:309-318.

    Stevens et al Leukemia in Utah and Radioactive Fallout From the Nevada Test Site: A Case-Control Study. JAMA. 1990;264(5):585-591. doi:10.1001/jama.1990.03450050043025.

    Stewart A, Webb J, Giles D, and Hewitt D (1956) Malignant disease in childhood and diagnostic irradiation in utero. Lancet 271, 447.

    Zablotska et al (2012) Radiation and the Risk of Chronic Lymphocytic and Other Leukemias among Chornobyl Cleanup Workers. Environmental Health Perspectives. http://dx.doi.org/10.1289/ehp.1204996 Online 8 November 2012.

    These are taken from a post by Ian Fairlie – http://www.ianfairlie.org/news/a-100-msv-threshold-for-radiation-effects/

    • Pete Pete says:

      and one more very important study –
      Leuraud, Klervi et al (2015) Ionising radiation and risk of death from leukaemia and lymphoma in radiation-monitored workers (INWORKS): an international cohort study. The Lancet Haematology Published Online: 21 June 2015. (http://www.thelancet.com/journals/lanhae/article/PIIS2352-3026%2815%2900094-0/fulltext)
      Again thanks to Ian Fairlie (http://www.ianfairlie.org/).

      • robertok06 says:

        You should read everything, Peter, not only what you want to hear!

        http://www.thelancet.com/journals/lanhae/article/PIIS2352-3026(15)00113-1/fulltext

        The related correspondence linked on the same article, by Maria Blettner, a well-known scientist in this field:

        “Most of these excess risks were statistically significant, but they were based on 90% CIs. In total about 70 CIs were presented in the paper. With this high number of statistical tests the chance of finding statistically significant results is high, so the danger of false positives is not negligible and should be taken into consideration when interpreting the results.

        The study provides supportive evidence on the radiation risks of leukaemia after exposure to low doses, using a large dataset and adequate statistical analysis. But limitations of this type of cohort study of nuclear workers have been discussed by Leuraud and colleagues and other investigators before,8 and they somewhat hamper the study’s conclusions.”

        Most of all…

        “Background radiation exposure might be larger than occupational exposure and was not incorporated into the analysis.”

        Great logic!… they study only chronic low-doses of radiation, of the order of 1 mSv/year… but they do not take into account the background (deadly, as you are trying to tell us) due to natural doses of radiation… no further comments…

        • robertok06 says:

          …. forgot to link this, sorry:

          http://www.pnas.org/content/109/2/443.full.pdf

          “Evidence for formation of DNA repair centers and dose-response nonlinearity in human cells”

          “However, our discovery of DSB clustering over such large distances
          casts considerable doubts on the general assumption that risk to
          ionizing radiation is proportional to dose, and instead provides
          a mechanism that could more accurately address risk dose dependency
          of ionizing radiation.”

          Cheers.

        • Pete Pete says:

          Where you draw the significance level for CIs is quite arbitrary. Yes there is an increased danger of a false positive but when you are talking about peoples lives I would prefer a false positive to a false negative. All this means is that there is not enough data to achieve the stated level of significance (95% instead of 90%) and not that the affects are not there.
          I have not been able to access the Leuraud paper so I cannot comment on the ‘limitations of this type of cohort study’.
          Background cancer levels are undoubtedly higher than those do to exposure. Some of these may be due to background radiation. However, that does not necessarily affect the results or conclusions.
          Having said this the paper I cited may have flaws, it may be wrong – that is the nature of science. However, it is one of a growing number of studies that support LNT. If you have a problem with LNT then it may be more useful to explain that to the IAEA, UNSCEAR, NRC, ONR, ICRP and every other radiological protection agency.

          You are correct that I do not ‘read everything’. However, the results of this paper and the many others is not what I want to hear. I find them cause for extreme concern and is one of the many reasons that I am against them building another nuclear power station down the road from me. I am also concerned that there are many people like yourself who push ‘plausible denial’ of these and many other results.

          • robertok06 says:

            @peter

            “. I am also concerned that there are many people like yourself who push ‘plausible denial’ of these and many other results.”

            You have the world upside down, Pete!… the plausible-denialist is YOU, you deny that the effects of 60+ years of nuclear technology are practically impossible to see, while at the same time, by fighting against nuclear on baseless foundations, you accept the much bigger dangers, order of magnitude bigger, of the alternatives to nuclear.

            Again, Hansen and Kharekha, The Lancet… you know what it is, read them finally, OK?

            R.

            P.S.:

  • Mark Pawelek says:

    If you want to argue that 2mSv of background radiation poses a risk you need to provide evidence. Making an argument from logic, as you do here, is not science. The precautionary principle is not a scientific principle. There’s no solid evidence to suggest that radiation below 100mSv per year poses a threat.

    The proportion of childhood leukaemia incidence in Great Britain that may be caused by natural background ionizing radiation

    Or it may not be. An argument to suggest something may happen is not the same as showing something does happen.


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