What Doctors Don't Tell (wddty) is such a marvelous site that I might have to do a regular post on it. It is completely batty and carries about as much misinformation as you could imagine. What interests me is the mindset of people attracted to the site: it peddles a mixture of alternative flimflam coupled with conspiracy theory. It is essentially a fantasy site that allows its subscribers to imagine that they have gained access to secret health information that the world government is trying to suppress from them on behalf of Big Pharma and other vested interests. For a subscription fee, you can gain knowledge that will allow you to 'take control of your own health' and get one over on elitist and corrupt doctors and scientists.
The only problem is it just full of ill researched and one-sided nonsense. And I suppose it has to be if it is to maintain the sense of revelation and superiority.
I could dissect any one of their articles, but I thought I would pick on just one news item as it is so wrong that it could not be wronger if it tried. Everything about it is nonsense. It is so short, yet chocka with misinformation. Here is the item in full:
Cancer: Nuclear workers exposed to same radiation levels as Hiroshima
16 January 2009
More proof – if any were needed – that radiation can cause cancer comes from a new UK government report that workers in the nuclear industry are more likely to develop the disease than those in other industries.
The cancer rate among workers regularly exposed to ionising radiation is similar to that of the survivors of the Hiroshima and Negasaki A-bomb attacks in 1945, say researchers.
The workers are more likely to develop cancers such as leukaemia, the UK’s Health Protection Agency (HPA) has reported in a new study. The HPA has, since 1976, been tracking the health of around 175,000 workers exposed to radiation in workplaces around the UK.
(Source: British Journal of Cancer, 2009; 100: 206-12).
Just about every statement made in this news article is wrong and it is interesting to explore why. Now, I only have access to the abstract of the paper quoted (here) but this is enough to tell me that WDDTY have badly misinterpreted the results.
Let's start with the title: "Nuclear workers exposed to same radiation levels as Hiroshima". From the beginning, this is obviously a nonsense statement. Victims of the Hiroshima bombing were exposed to huge variations in radiation levels. Some got massive acute exposures that would have killed them in days to weeks. Lower doses are not fatal but give rise to enhanced risk of cancers later in life. If you were far enough away from the blast and subsequently not too exposed to fall out, your radiation dose from the bomb might be very low. It is only in this sense that the WDDTY headline comes close to being true.
Next - "More proof – if any were needed – that radiation can cause cancer". This is hardly controversial or denied by anyone. However, there is still debate about how much radiation is dangerous, how long term exposure might be different from acute exposure and which types of radiation are most important. You see, we live in a radiation rich environment. Rocks are radioactive. Brazil nuts - quite high. Our own bodies contains lots of natural 40K so sleeping with someone will add to your lifetime dose - don't do it - I bet your doctor does not tell you that. The point is that at doses close to what we might typically receive from our natural environment it is quite difficult to tell what harm they might be doing (if any). Our knowledge of the risks from ionising radiation do come from populations like atomic bomb survivors, but there are problems here in interpreting the data. Firstly, surviving an atomic bombing is a pretty impressive feat. The surviving population is likely to be fitter than the average population and this might skew the results. Secondly, guessing what peoples exposure was is quite hard and, in general, these doses were considerably higher than what you might be exposed to as a nuclear worker, x-ray technicians, or Concorde pilot. Thirdly, survivors got their doses in a relatively short space of time, from miliseconds to months - this is a quite different exposure pattern to occupationally exposed workers.
So, over the years, researchers have monitored survivors and counted how many extra cancers they got. The excess numbers are surprisingly low and so we now have to make some assumptions that we can extrapolate back to the sort of occupational doses that people receive and hence estimate the risks of doing various jobs. Radiation protection measures have typically assumed the worst and extrapolated back linearly from high doses to low doses and that there are no 'threshold' effects. The study quoted by WDDTY is looking to see if these assumptions are correct.
So, onwards: "a new UK government report that workers in the nuclear industry are more likely to develop the disease than those in other industries." Wrong. Straight up we are told that "SMRs for all causes and all malignant neoplasms were 81 and 84 respectively, demonstrating a 'healthy worker effect'. " What this means is that workers in the study group got fewer cancers and a lower standardized mortality ratio (SMR) than the control (presumably the general population.) Nuclear workers live longer and get fewer cancers than average.
It has been well known for a while that this is the case. Workers in nuclear facilities have stable jobs and relatively good incomes, and this means that may well be healthier than the general population. (Wealth is a good predictor for how long you will live.) Furthermore, nuclear workers are aware of any health risks and are likely to be well monitored, so any problems might well be picked up early. This is the 'healthy worker effect'. So, we are not told about the relative risks of working in the nuclear industry compared with other jobs, but we can see that any differential is not going to be huge.
The next sentence is a little better, but still wrong: "The cancer rate among workers regularly exposed to ionising radiation is similar to that of the survivors of the Hiroshima and Negasaki [sic] A-bomb attacks in 1945, say researchers."
They do not say this. What they say is that "Estimates of the trend in risk with dose were similar to those for the Japanese A-bomb survivors". This does not mean that workers got the same level of cancers as A-bomb survivors, but that the dose-response curve was consistent. A very different statement.
WDDTY goes on to say "The workers are more likely to develop cancers such as leukaemia, the UK’s Health Protection Agency" but they do not tell us more than what. The report says that leukaemia incidence increases with occupational dose, again consistent with what is assumed in radiation protection. However, the report goes on to suggest some difficulties in the study which What Doctors Don't Tell You Don't Tell Us. The researchers were not able to take into account confounding factors such as smoking. The reasons for this are probably simple. In any nuclear facility, the higher you are up the payscale, the less likely you are to get a larger dose. Lower paid workers are probably the ones routinely getting doses. Managers, are for the most part, sat in their comfy offices. If lower paid workers are more likely to smoke then your dose-response curve might artificially suggest radiation is causing more cancers when actually smoking is to blame. It's a hard one to tease apart in the data.
The report concludes "The cancer risk estimates are consistent with values used to set radiation protection standards." So, after all that, the report is rather reassuring to nuclear workers. Radiation limits for workers are set so that the extra risk of dying from a radiation induced cancer is likely to be no more than the risk of coming to harm in other comparable occupations. Nuclear workers know that their day to day risks are probably similar or lower to their friends down the pub who drive busses, work on farms, fly planes or decorate your home.
Why people find this nonsense on such sites as WDDTY so alluring is just depressing. Real science, with all its subtelties and nuances, is so much more interesting. And you do not have to pay a subscrition to find out about it. You just need to be curious.
Labels: WDDTY, What Doctors Don't Tell You
I have got to share this with you. The fabulously bonkers web site What Doctors Don't Tell You has a news report about a breakthrough in acupuncture with a story entitled, "New therapy helps cancer patients". 
