Study of Port Hope radium and uranium processing workers shows longer lives

The results of a study titled Mortality (1950–1999) and cancer incidence (1969–1999) of workers in the Port Hope cohort study exposed to a unique combination of radium, uranium and γ-ray doses have recently been published on BJM Open, which describes itself as follows: “An open access, online-only general medical journal dedicated to publishing research from all disciplines and therapeutic areas”.

I like to start with the conclusion first:

In one of the largest cohort studies of workers exposed to radium, uranium and γ-ray doses, no significant radiation-associated risks were observed for any cancer site or cause of death. Continued follow-up and pooling with other cohorts of workers exposed to by-products of radium and uranium processing could provide valuable insight into occupational risks and suspected differences in risk with uranium miners.

The study took advantage of a unique population of workers who were carefully monitored for their exposures while employed in a place with a unique environment of uranium, radium and gamma ray exposures. It evaluated those workers health outcomes for 50 years. The results of the study add to the deepening pile of information that shows that the health effects of low doses of radiation and ingestion of small amounts of radioactive material are not well predicted by the linear, no threshold dose (LNT) response assumption.

As doses fall into the range associated with normal industrial handling, they also fall into the range at which the processes of adaptive response and repair mechanisms that are a evolved features of multi-cellular creatures can completely correct any damage. As is the case for small doses of almost any substance or physical activity, doses in the range of interest appear to have a somewhat beneficial overall effect due to response stimulation.

I will leave you with a quote from the “results” section of the report:

Overall, workers had lower mortality and cancer incidence compared with the general Canadian population. In analyses restricted to men (n=2645), the person-year weighted mean cumulative RDP (radon daughter product) exposure was 15.9 working level months (WLM) and the mean cumulative whole-body γ-ray dose was 134.4 millisieverts. We observed small, non-statistically significant increases in radiation risks of mortality and incidence of lung cancer due to RDP exposures (excess relative risks/100 WLM=0.21, 95% CI <−0.45 to 1.59 and 0.77, 95% CI <−0.19 to 3.39, respectively), with similar risks for those exposed to radium and uranium. All other causes of death and cancer incidence were not significantly associated with RDP exposures or γ-ray doses or a combination of both.

Additional reading

Canadian Energy Issues – Port Hope uranium workers had lower mortality and cancer than rest of Canadian population: British Medical Journal study

About Rod Adams

44 Responses to “Study of Port Hope radium and uranium processing workers shows longer lives”

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  1. Joel Riddle says:

    After just a quick glance at my RSS feeds this morning, it looks like our buddy Steve Aplin came across the exact same study and also published a post about it.

  2. Bob Applebaum says:

    Epidemiology 101 – comparing a cohort of workers to the general population will introduce a bias known as the health worker effect.

    Agnotology 101 – when promoting the denial of a science, a denier will commit the fallacy of cherrypicking.

    • Rod Adams says:

      Atomic Insights 101 – when questioning the validity of the LNT, expect a comment from Bob Applebaum within minutes.

      Thanks for your continued predictable involvement in the discussion, Bob. It’s nice to be sure of some things in an uncertain world.

      • Bob Applebaum says:

        There is a difference between denial and “questioning”.

        In an uncertain world, it’s pretty predictable that a science denier will try to blur the difference.

        • Josh says:

          Hi Bob, what are your thoughts on Peter Karamoskos and his views on low
          Level radiation and nuclear power?

      • Brian Mays says:

        Speaking of “questioning,” I’m still waiting for Bob to answer my question: how can a linear no-threshold model be incompatible with collective dose?

        • gmax137 says:

          I’d be interested in hearing Bob’s answer to that, too.

        • Rod Adams says:


          My guess is that Bob’s response will be similar to his response when Meredith Angwin asked him about the “fudge factors” used with medical fractionated doses and how they can be compatible with a linear response model.

          It is amusing to be to be accused of “confirmation bias” and science denial from such an individual. I encourage him to keep providing his entertainment value. It’s always fun to see him weave logical knots to attempt to defend his income generating assumption.

          • jmdesp says:

            Well, actually that time his response was making some sense.

            It’s the official medical theory that above a given threshold radiations have a given deterministic effect, in addition to the LNT effect :

            And that in cancer treatments, setting each exposition to a value that’s below this threshold you avoid the deterministic effect, but leaves you still with the LNT effect.

            And it’s true that the long term cancer risk does seem to be about linear above about 0,5Sv.

            The real question is why a long list of effect is accepted to have a threshold, and then an increase in intensity as dose grows, but the long term cancer risk is set apart of all the other to be the one that’s assumed to have no threshold, even though it’s perfectly possible that the threshold is there, at the dose where it’s statistically impossible to tell if there’s a linear increase or no effect at all.

            But here suddenly Applebaum claims it’s impossible for that hypothesis to be anything but absolute utter nonsense.

    • Laurence Aurbach says:

      One interesting feature of the paper is a comparison of uranium workers to radium workers at the same plant. This provides an internal comparison in which the healthy worker effect is eliminated.

      In the comparison to the general population, the study did make an effort to minimize the healthy worker effect. The workers were classified by age at risk, date at risk, duration of employment, age at first exposure, and years since first exposure. The general population comparison group was matched by age, calendar year, and sex. The study also separated tobacco-related cancers.

      In spite of these efforts, the uranium and radium workers were still found to have lower cancer rates than the general population. The authors say that result is “a likely healthy worker effect.” The authors reference a study by Howe et al. (footnote 22) which concludes,

      Many of the associations recognized for industrial compensation involve cancer as an outcome. The healthy worker effect, in general, appears to be smaller for cancer than for other causes of death. In addition, the attribution model often specifies a minimum latency period, typically of 10 years. The latency period generally is highly correlated with time since first employment; again, this tends to minimize the bias due to the healthy worker effect. Thus, for these particular situations, it is likely that any bias introduced by the healthy worker effect with the use of population rates for comparison will be minimal, and the bias in the probability of causation will be even smaller, and thus negligible.

      • jmdesp says:

        About that healthy worker effect, I’ve seen a study about some CEA workers here in France (CEA = Atomic Energy Commission).

        Seeing the result, the union started to claim that study was showing an abnormally rate of cancer.

        Actually, that was exactly the healthy worker effect. The non-cancer death rate were lower than normal, and the cancer rate was normal. Does make sense that the healthy worker effect doesn’t have much effect on cancer rates.

        So why do people claim opposite ?

        • Rod Adams says:


          I can think of approximately $18 million reasons why Applebaum refuses to admit that the LNT is wrong and that there is a level at which we should stop worrying and stop spending money to reduce doses or potential doses any further.

    • Joel Riddle says:

      A quesiton for you regarding the healthy worker effect and overall economies in general, Bob:

      Does it make sense to you to allow a minuscule (or my preferred spelling, miniscule) risk from very low levels of radiation, to effectively shackle nuclear power, immensely lowering the overall production potential of THE WHOLE WORLD’s economy, thereby reducing the number of people that can be employed in productive jobs and thus experience the benefits of the healthy worker effect?

      Please answer this with as much honesty as you can, and preferably in mostly layman’s terms if you could.

      • Brian Mays says:

        Does it make sense to you to allow a minuscule (or my preferred spelling, miniscule) risk from very low levels of radiation …

        As Rod has pointed out, Bob has made quite a bit of money from protecting against putative minuscule risks from very low levels of radiation. So if he’s honest, he’ll say yes.

      • donb says:

        And effectively shackling nuclear power so that other, more dangerous power sources continue in operation or are built new, as in Germany with the coal and lignite fired power plants.

        • Peter Bergs says:

          Exactly, compared with the damage done and being done to the biosphere by fossil fuel burning on a Mega scale, this discussion is insignificant and trite.

    • John Chatelle says:


      You have a creationists disdain for natural selection. It is amazing that the coding and code checking is part of the physical structure of DNA. Why do you suppose ionizing radiation is equally damaging to pristine DNA with perfectly matched base pairs, and damaged, mutagenic DNA with mismatched base pairs. Clearly You’re wrong.
      Why can’t you see that there clearly will be levels of Ionizing radiation that will be stocastically more distructive to mutagenic DNA than pristine DNA?

    • DV82XL says:

      I think the term you are groping for is “the healthy worker effect” and it is hard to see, given the general interpretation of the phenomenon in occupational epidemiology, how this applies to the Port Hope study. Specifically HWE is a is a sampling bias that states that the subjects are not representative of the general population because of factors that would be a precondition for becoming a subject of the study.

      Perhaps you could elaborate on just how this is manifested in this study and how the effect is skewing the results.

      • Cyril R. says:

        Well, I’ll concede this much: bomb workers tend to be well screened, if you’re a drunkard likely you won’t get hired to make bombs or process enriched uranium. I can see some healthy worker effect there. My issue with this theory is that it doesn’t make the radiation damage go away. In the Los Alamos workers, the median dose was 1250 mSv. Huge! Yet average cancer was lower than non-exposed workers. This included workers from non-bomb operations from Los Alamos, so there’s less healthy worker effect there (more screening, more higher education etc.). Basically it looks like the healthy worker effect is likely a beneficial factor, but it doesn’t remotely explain lower cancer incidence with such large doses involved. We’re taking Sieverts here.

        • DV82XL says:

          The Port Hope nuclear industry was largely involved in refining first for radium and then for uranium. The facility was established by celebrated Canadian prospectors Gilbert and Charles LaBine to extract radium from ore transported from their mine in the Northwest Territories in 1932. Now the facility converts purified uranium trioxide (UO3) to uranium hexafluoride (UF6) and uranium dioxide (UO2) for fabrication into CADU fuel.

          I doubt that the early workers were vetted any more than any other refinery workers were at the time.

          • Rod Adams says:

            My guess is that “the healthy worker effect” was far less consequential in the time before employer provided health care. Once employers started including health insurance as a benefit, they started screening workers. Before that…

  3. James Greenidge says:

    Well, expect them to dredge up the radium clock dial paint girls where ever.

    James Greenidge
    Queens NY

    • Rod Adams says:

      It would be terrific to dredge up the radium dial watch painters. The long term studies showed that all of the workers who were exposed to less than about 1000 rad (10 Gy) of cumulative skeletal dose did NOT suffer any negative health effects. (Studies of U. S. Radium Dial Workers: An Epidemiological Classic by Shirley A. Fry)

      We must remind people that the highly publicized health issues were for women who were frequently “pointing” their brushes with their lips, almost purposely ingesting substantial quantities of radium, which gives both alphas and gammas when it decays.

      Some of the painters suffered terrible illnesses, but their doses were also far higher than any allowed for anyone today as a result of occupational or accident related exposures.

  4. Ross Snuggerud says:

    For LNT to be a viable theory the vast majority of cancers induced by radiation have to be caused by damage to a cell from a single ionizing event. Based on the current understanding of cancer it is not surprising that this poor model fails. I am hopeful that inertia this theory has gained from decades of use can be overcome.

  5. Josh says:

    A ‘landmark’ study carried out in 2005/2006 claimed that there was no safe level of radiation and further stated that there was an increase incidence of cancer among nuclear workers, even at low dose. It then went on to say that leukaemia clusters found near some nuclear plants warranted further research. I have serious doubts about the legitimacy of these claims, as leukaemia clusters occur here in Australia where nuclear reactors are sadly lacking. Several studies, including this one, also appear to refute the findings of the alleged landmark study.

    • Cyril R. says:

      This has been discredited many times before. Either the researchers analysed groups/villages around nuclear plants till they found a statistically higher rate of cancer, without reporting the villages that have lower rates of cancer, ie data dredging and cherry picking. Or, the nuclear plants were placed in industrialized areas with large emissions of carcinogens, primarily from the petrochemical industry (which needs a lot of electricity). Most nuclear plants are colocated in heavy industrial areas, harbors with lots of shipping fuel emissions etc.

      Chemicals are a major source of leukaemia. Benzene is especially notorious, even the oil industry agrees it causes leukaemia in little children. You’ve got some benzene in the gasoline in your car’s fuel tank right now, if you have a gasoline powered car. Usually there’s between 0.1% and 10% benzene in gasoline (they are chemically somewhat similar so like to stick together).

      With nuclear power, you won’t get in contact with radioactive materials in any meaningful quantities. It’s handled by professionals, in an industrial facility, with many barriers of isolation. A world of difference from consumers sucking benzene fumes at the local gas station.

  6. Cyril R. says:

    This sounds very similar to the Los Alamos (US) plutonium bomb worker study:

    Twenty-six white male workers who did the original plutonium research and development work at Los Alamos have been examined periodically over the past 50 y to identify possible health effects from internal plutonium depositions. Their effective doses range from 0.1 to 7.2 Sv with a median value of 1.25 Sv. As of the end of 1994, 7 individuals have died compared with an expected 16 deaths based on mortality rates of U.S. white males in the general population. The standardized mortality ratio (SMR) is 0.43. When compared with 876 unexposed Los Alamos workers of the same period, the plutonium worker’s mortality rate was also not elevated (SMR = 0.77). The 19 living persons have diseases and physical changes characteristic of a male population with a median age of 72 y (range = 69 to 86 y). Eight of the twenty-six workers have been diagnosed as having one or more cancers, which is within the expected range. The underlying cause of death in three of the seven deceased persons was from cancer, namely cancer of prostate, lung, and bone. Mortality from all cancers was not statistically elevated.

    Notice the large doses of plutonium, and the fact that most of this would be internal dose alpha emitters (the most dangerous type). Yet the mortality is lower than the average population.

    • Josh says:

      Thanks for that Cyril. I have enjoyed reading your comments on past threads and find your grasp of nuclear related topics impressive. Its good to have this information. Whilst I understand radioactive materials are reasonably toxic, there is far worse going around. I have trouble believing studies that allegedly point the finger at nuclear power whilst ignoring the multitude of other factors (environmental or otherwise) at play.

      • Wayne SW says:

        Remember that in these kinds of things toxicity in and of itself is not the whole story. I am reminded of the one rejoinder Dr. Cohen (I think) gave to the reporter who brought up the Ralph Nader claim that one gram of plutonium could kill everyone on Earth (or some such nonsense). It was correctly pointed out that it was like saying the number of viable sperm in the average discharge of a healthy male is sufficient to impregnate the entire female population of the US of child-bearing age. The problem with that, as with the plutonium, is one of distribution. Likewise, properly distributed, the toxic gases produced by the daily operation of the furnace in your home could kill everyone in your neighborhood, or even your whole town.

        • Cyril R. says:

          Yes, the anti-nuclear fearmongerers rely on various deux ex machina distributions. There was a joke about it from pro-nuclear folk, something like, yes it’s possible, but would be very expensive to pay all the surgeons to put all that plutonium in people’s lungs to get that level of cancer.

          One of the reasons that made me pro-nuclear is that most of the really nasty radioactive stuff doesn’t want to go anywhere at all. It wants to just stay in the dry cask it sits in, unless it is fresh enough to generate sufficient self-heating. It made me realize that only fresh spent fuel, fresh radioactive stuff, is the tricky thing with nuclear power. That made the whole long lived nuclear waste issue disappear for me. 5 year old spent fuel in a dry cask isn’t going anywhere.

    • Daniel says:

      @ Cyril R.

      Your comment:

      internal alpha emitters (the most dangerous type)

      Is not accurate … Gamma rays are most lethal ….

      • Cyril R. says:

        Alpha’s are much more dangerous actually when inside the body. They are stopped by the skin so outside the body are harmless but they are not stopped by cell membranes, hence the danger of radon in the lung. This is also true of beta rays if they accumulate in a specific organ. Radio-iodine in the thyroid is the most dangerous during a nuclear accident for this reason.

        Gamma’s divide their energy over a large body mass, even when ingested, so they don’t concentrate the damage so much. There’s not much evidence of chronic gamma ray exposure doing really bad things, at all. In fact much of the evidence of chronic gamma ray exposure points towards hormesis, eg the Taiwan appartments, the nuclear shipyard workers.

  7. Daniel says:

    Reading the nuclear news today. China has enormous on going and persistent smog problems in Beijing. The population is angry. China wants to build one nuclear plant a month until 2030.

    Sounds crazy ? The proof is in the pudding. In 2011, China built 11 nuclear plants.

    I think we can expect Uranium mining and demand to remain healthy.

  8. David Walters says:

    Well, what Bob proves is that we need to make all workers “healthy”. Screening for cancer quarterly, blood workups, all sorts of preventive medicine: in other words, the same health system that ALL French workers work under. Single Payer!

    It seems to me that the answer to Bob’s faith-financial based belief in the LNT is put in the proper perspective by Joel, above when he asked rhetorically:

    Does it make sense to you to allow a minuscule (or my preferred spelling, miniscule) risk from very low levels of radiation, to effectively shackle nuclear power, immensely lowering the overall production potential of THE WHOLE WORLD’s economy, thereby reducing the number of people that can be employed in productive jobs and thus experience the benefits of the healthy worker effect?

    That is assuming EVERYTHING Bob has written in the pages provide by Atomic Insights is true, doesn’t he see that nuclear energy can provide the material basis for developing a truly healthy society?

    • Daniel says:

      @ David,

      Bob is not against nuclear energy.

    • donb says:

      Since the workers at nuclear power plants are healthier than the general population, we need more nuclear power plants so that we can have more healthy workers ;-).

      • Brian Mays says:

        Actually, I think that it’s more correct to say that we need more nuclear power plants so that more healthy people have jobs, but that also is a really good outcome. 😉

        • Rod Adams says:

          Having a good job is beneficial to human health; poverty not only sucks but it contributes to many ailments. One of my many reasons for liking nuclear energy is that the technology is so productive that the people employed in the field can almost all count on being able to afford to support a family.

          In some ways, I’m almost ok with all of our cost-deaf rules, process and security overhead; it means even more jobs for good, productive people who are trained in a culture that respects those who are safety conscious, have high integrity, and care about their fellow human beings.

          • Daniel says:

            @ Rod,

            Hence the paradox. Coal and gas and other forms of energy generates a truck load of jobs on top and above nuclear.

            Mind you transporting coal, compressing gas from point A to point B does not add value and are mostly to be considered indirect costs (storage, handling etc)

            But with massive amount of low cost energy that nuclear could provide, these useless jobs of handling coal and gas could be transferred into a new manufacturing economy.

            That’s right. Locally produced abundant nuclear energy, education, training, software and ingenuity are keys to the next manufacturing revolution.

            But who is visionary in the political arena?

  9. Andrew says:

    Dr. Ron Mitchel of Chalk River labs gave shows convincing evidence that LNT is wrong.

    “Dr. Rita Bowser from Westinghouse gave the introduction. Presentation starts around the 11:40 mark.”

    http : //

    At 20m20s he presents data showing an “inoculation” effect of low dose gamma radiation.

    I have not seen the entire presentation and don’t know if alpha & beta radiation was included in the expirements.


  10. Bruce Behrhorst says:

    It looks like this was a thorough study at Hope. But kinda wonder there’s this continuing media favorite story that anti-nuke media likes to tag & spin the Hanford, Washington nuclear reserve issue of tank leakage.

    Why isn’t Hanford licensed to re-process spent fuel? Salmon on the Columbia river still spawn and people in the area have not been invaded by radioactive aliens. So why not create some badly needed jobs in the area? Oops!! Silly me. This is the United States. It’s about an obscure political narrative of unproductive pursuits and more about compulsory gov’t dependency.