1. That could be very important. We may not have liked the last report, but the NAS is about as objective a body as we have in this country. They are the best of the best.

  2. The radiation risk to children is more difficult to assess. One study on multiple CT scans to children with a certain heart problem suggests that about a six percent increase in cancers attributable to radiation from frequent scans in this one group of pediatric patients. I haven’t seen any studies more recent than 2006 on the issue. There is controversy on the issue of pediatric radiation. I have a former student who is a pediatric radiologist. She believes that caution is advisable when radiation is applied to children. A French group suggests that 100 mSV annually is safe for children and infants.

    1. Any future NAS BEIR reports should underscore the likely distinction, for the benefit for all regulatory agencies, between dose and dose-rate. CT scans involve a ~10 mSv acute dose applied over vary short time scales (measured in seconds, or minutes). Hormesis effects as noted by Cuttler, TD Luckey, et al, arise from chronic dose-rates equivalent to ~80 µSv/hr (<1/1,000,000 of the dose rate of a CT scan). It stands to reason that biological repair mechanisms should in any case adjust to lower dose-rates more easily. It is this chronic low-dose impact of accidental fission nuclide releases as at Fukushima & Chernobyl that constitute the principal popular concern and regulatory burden with fission energy.

      It should also be noted that Cuttler cites empirical data of early 20th century radiologists (exposed to repeated acute dosages) to arrive at his hermetic optimum estimate.

      1. @Aaron Rizzio

        While CT doses are given during a relatively short period, the total dose of 10-20 mSv is well below the acute dose threshold of approximately 100 mSv.

        1. I should correct myself here; the typical CT scan dose rates are equivalent to an annual chronic cumulative dose that is a million times greater than Cuttler’s suggested annual tolerance dose ~700 mSv. Although this figure itself is arrived at empirically largely from cumulative effects of acute doses of radiologists & the a-bomb survivor cohort (also based on an initial acute dose).

          IN 2012 Jacquelyn Yanch of MIT published a study contrasting this acute vs cumulative dose distinction involving damage to mouse DNA from 100 mSv delivered over the course of 5 weeks vs 1.4 minutes.

          So the CT scan dose-rate is probably not biologically sustainable or healthy (long-term ~88 Sv/yr), although it may not be necessarily lethal even to small children.

      2. Aaron Rizzio hits the nail on the head!

        This is THE biggest issue with the radiation hazard debate, if one could identify one. 10 mSv in 10 seconds is 1 mSv/second. 1000 microsieverts per second. For comparison the highest dose rates in Fukushima are about 0.02 microsieverts per second.

        It is hardly possible to exaggerate on the importance of the distinction. There is a massive health difference between drinking one glass of wine a day or 365 glasses in one day of the year. There is no point in talking about how much wine you drink in a year without knowing how much wine is taken on each day, it is the amount of wine taken per day that determines major health effects.

        Weirdly all major reports have utterly failed in adquately distinguishing between dose and dose rate. All those clever scientists coming together to make expensive high level reports… and no one gets the major distinction to be made. It is so obvious.

        Most data we have to work with in the high dose range is for prompt exposures. Medical, bomb survivors… none of this prompt exposure is even remotely relevant to the hormesis theory.

        I propose to only measure doses per day to circumvent the problem. A day is a logical choice because a day is about the timeframe of human body repair mechanisms. It is also a convenient unit.

        Let the BEIR group come up with data showing bad health effects below 1 mSv/day and I will shut my big mouth. All japan bomb survivors data disqualify as all of them got more than 1 mSv per day.

        1. If you go to the Curie museum in Paris, you can read a few things about the discoveries that Claudius Regaud did in the 1910s. While Marie Curie was in charge of the physical and chemical studies, Regaud was responsible for studying effects on cells and human. Yes, he already had reached the conclusion that much better results were obtained by using fractionation and spreading the exposition over a long time frame. When I wondered why Regaud wasn’t more famous for that, I found out that he wasn’t alone, and others had had very similar results in the same time frame.

    2. In this kind of study, getting rid of confounding factor is extremely hard. This kids received a CT scan because they were sick. Those who received multiple CT scan received multiple CT scan because they were very sick. Given that the correlation expected between the CT scan and cancer risk is small, this mean that even a small correlation factor between being sick and having a higher cancer risk can belie the result apparently found. We have learned a lot about cancer risks in recent times, and know they are many more factors that was thought at first. Survival rate for example is very affected by the psychological state of patient, being single instead of married is equivalent in term of risks to refusing chemotherapy ( see http://jco.ascopubs.org/content/31/31/3852.full ).

      The protocol for this kind of study should find a way to compare kids who were exactly as sick but receive an alternative to a CT scan to those who did. Even better would be to compare the result between a hospital using an older CT scan that delivers more radiations to the one with a newer that delivers less. Unfortunately, if it reduces the population, it also reduces the strength of the result 🙁

      1. Very true. Its one of the major difficulties with medical source studies.

        My dad used to joke about it. “don’t stay in bed too long”, he said. “most people die in bed”.

  3. By “on your calendar”, you mean that it would take a significant unplanned event for you to miss it, right Rod?

  4. I hope the BEIR will make two important distinctions:

    1. dose rate vs dose. That is chronic versus prompt exposures. BEIR must stop talking about dose per year (which have very low biological relevance) and start talking about dose per day.
    2. low linear energy transfer (LET) vs high LET radiation. In particular, alpha in the lung vs. gamma whole body dose. (theoretically also neutron doses but this isn’t an exposure risk in any nuclear technology risks to the public). Alpha dose to the lung such as from radon can be expected to be much more dangerous than the stupid Q factor of today’s energy-to-dose conversion assumes.

    These two are of major importance to nuclear power risks. Nuclear accidents cause chronic low dose rate exposures, mostly low LET (with the important exception of short lived radioactive iodine isotopes).

      1. Rod, the Cohen data was for low concentrations only. Only up to 240 Bq/m3 or so. Definately don’t expect significant health hazards here. This is terra firma for hormesis theory, even for alpha to the lung. This is near 0.05 mSv/day even with Q factor of 20 and continuous 24/7 exposure. In reality this data would translate to a ballpark figure of 0.02 to 0.03 mSv/day even with Q factor of 20 because people don’t spend all the time in the home.

        Data from higher exposures (miners) suggests bad health effects at much higher concentrations. Very bad health effects are seen at the 6000 Bq/m3 point for instance. Like very large increases in lung cancer (50-150% or more). Yet this should be within the hormetic range of 2 mSv/day. Hence the idea that alpha to the lung is worse than factor of 20 worse than whole body gamma from external source.

        1. @Cyril R

          The miners risks were vastly enhanced by smoking. In the 1950s-1970s smoking was prevalent in adult males, the population most likely to work in underground mines. Many uranium miners came out of coal mines where they were not allowed to smoke underground during their 12 hour shifts due to rather obvious health risks associated with fires and explosions.

          In hard rock uranium mines, smoking was generally not prohibited. Even if it was, hard-headed miners could not see the risk any more than the boys who smoked in the high school heads could.

          Deeply sucking in tobacco smoke in a dusty environment led to a high risk of lung cancer, not necessarily caused by radon concentration.

          Have you ever purchased a bag of sand from your local hardware or lumber store. All of the ones I’ve ever purchased for my children and grandchildren’s sand boxes have come with a warning about the risk of breathing the dust.

          1. True, smoking is very bad for you. There is a relationship between smoking risk and radon risk though. If you smoke, the smoke particles provide a huge surface area where radionuclides can deposit on. They then latch onto bigger smoke particles which are more likely to stick in the lung. This increases the efficiency with which radionuclides are deposited into the lung.

            There have been case control studies that controlled for smoking. Smoking, very bad. High radon plus smoking, very very bad. No smoking plus high radon, still very bad. The dose rates weren’t all that large, even the worst mines would still have dose rates below 2 mSv/day on Q factor of 20, but there were significant increases in lung cancer risk. I suspect that a Q factor of 20 for alpha in the lung is not enough. More likely it is above 100 and possibly above 200. Otherwise I can’t explain the significant increases in lung cancers (even among non smoking miners) in a dose per day area that should be in the hormetic area.

            Whether sand (in modest quantities) is bad for the lung depends on the crystalline phase of the minerals involved. Some minerals are carcinogenic and care must be taken, within reason, to reduce dose to the lung. If you are working in a dusty industrial plant, wearing breathing mask or apparatus is not paranoid.

            1. @Cyril R

              And if you are a hard rock miner, you are definitely working in a dusty environment, especially in the era before mines were well ventilated.

              Please point me to the case control studies to which you refer and also provide references that support your guesses about the radon Q factors.

          2. “And if you are a hard rock miner, you are definitely working in a dusty environment, especially in the era before mines were well ventilated.”

            Absolutely. I don’t contest this. Mining’s a dangerous job. But when you do studies within groups of miners and find correlations between estimated alpha dose to the lung and lung cancer it requires an explanation. Most rocks aren’t carcinogenic, though they can cause blocked lung and related diseases in high doses (but not cancer).

          3. Rod, are you claiming that quartz dust is very well correlated with radon concentration in mines? If so, what is your source for this?

            I’m not contesting that dust is bad for the lung. Within miners, all of which are exposed to dust, there is a correlation of lung cancer with radon, more clear at the higher radon concentration end. This is what all research points to.

            If you have reference that clearly links dusting with radon concentration in mines then you have a very good point.

            1. @Cyril R

              Both radon concentration and dust levels correlate strongly with ventilation. In a well ventilated space, neither one will build up to a dangerous concentration. Adding ventilation systems and operational requirements is what essentially eliminated elevated lung cancer rates among miners. The assumption at the EPA, the organization that has been pushing fear of radiation since its inception, is that radon was the culprit.

          4. Rod, that’s a potent theory you have there. If you are right then the miners lung cancer vs radon correlation is possibly completely spurious. By logical extension the smokers correlation with radon even in normal homes could then also be explained by poor ventilation (badly ventilated smokers homes would have poor air quality, increasing lung cancer incidence). Do you have any reference or work to go on?

            1. @Cyril R.

              Here is one example report


              Here is a second one that points out how dust concentration and radon concentration were both significantly reduced as mine safety and ventilation improved.


              And here is a third


              I agree that alpha particle emitters in lungs are a hazard, but I reject your assertion that the currently accepted QF of 20 is insufficiently high. I don’t know what it really should be, but I suspect that it is more of an overestimate than an underestimate based on studies of internal emitters like radium.

          5. “Sorry, but I can’t accept information about radon hazards from the agency that has paid to produce PSAs designed to frighten people into worrying about radon in their home.”

            That’s too bad, because argument by association and conspiracy theory has poor convincing power to most people.

  5. Rod, I’ve added your reference to the Wikipedia article on health effects of radon:


    I added the following “A confounding factor with mines is that both radon concentration and carcinogenic dust (such as quarz dust) depend on the amount of ventilation.[39] This makes it very difficult to state that radon causes cancer in miners; the lung cancers could be partially or wholly caused by high dust concentrations from poor ventilation”

    This may make the argument structure of the whole article poor, however (looks like a lot of EPA true believers have written the article).

    What do you think?

      1. Thanks Rod. I’ll make it a point to review and edit the article. Too bad there are only 24 hours in a day.

  6. Regarding Radon and Lung cancer: The miners were exposed to high doses of radiation and so they can be expected to have higher risk of lung cancer. For residential radon, it is a different situation, as the lung doses would be much lower even in homes with higher levels of radon, and the low-dose radiation adaptive protection would likely get activated reducing lung cancers when compared to regions which have very low levels of radon. If one compares maps of radon levels and corresponding maps of lung cancer risks, this becomes clear, as high radon areas would predominantly be observed to have lower lung cancer rates, and regions that have higher lung cancer rates would be observed to have lower levels of radon. Please see the link http://radon-vs-lung-cancer-in-ireland.blogspot.com/ for these maps for Ireland. When I examined the maps, I saw similar trends for England and USA. Whereas many confounding factors affect lung cancer rates including smoking, when populations of whole countries are considered over long periods of time, such factors would likely cancel out and so the observed trend would likely indicate the effect of radon levels on lung cancer.

    1. @Mohan Doss

      Though underground miners may be exposed to elevated concentrations of radon gas in mines that are not well ventilated, a lack of proper ventilation in an underground mine can also result in elevated concentrations of silica dust and other carcinogens. The tales of higher than expected rates of lung cancer in early mines in Europe and the US are mostly just that – tales that do not include any actual measurements of dose or any information about other potential contributing factors.

      Once ventilation systems were improved, both dust and radon concentrations fell dramatically. So did cancer rates. However, when you change two variables at the same time with the same physical change, it becomes quite difficult to determine which variable had the major effect on reducing cancer.

  7. I should point out that all uranium dug from these mines was for only two purposes: the navy reactor propulsion system (a small %) and for using in the military’s plutonium production during the massive build out of nuclear weapons by the U.S. None of it, to my knowledge, was dug for civilian nuclear reactor program.

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