Tuesday, February 10, 2009
Thank you for your enquiry about the radium contamination that has been found at Dalgety Bay.
While I recognise that radium-226 is a naturally occurring radionuclide, being part of the uranium-238 decay series, the concentration of radium found at Dalgety Bay is many orders of magnitude higher than is found in nature, and as such is a consequence of a man-made activity.
For example one of the particles identifed had an activity of 147,000 Bq of Radium-226 with a weight of just over 1 gram. This compares with activity levels of a few hundred Bq per Kg for the most active granites. There is therefore roughly a factor of 1 million between natural concentrations and the activity found in the items reciovered at Dalgety Bay in this case. Other particles found also present large factors between the radium concentration found and those that occur naturally. The information on particle activity is contained within the report found on SEPA's web site. On this basis the presence of the radium found at Dalgety Bay cannot be attributed to natural sources. This is the evidence to which I referred during the interview on Radio Scotland last week.
The lack of high concentrations of the higher members of the uranium-238 series consistent with the radium found also points to the radium being of man made origin.
Over the years, many items have been recovered from the Dalgety Beach including luminised dials, a vial of active material, and there is therefore strong circumstantial evidence for there being luminised paint items on the beach. Previously much of the activity recovered was associated with clinker which demonstrated that the material had been burned in the past. The burning of luminised items was once a common disposal practice and I have experience of that type of contamination at another site which has now been remediated. We are also aware that the small particles or flakes that have been found on the beach are similar to those described to us by someone who worked on the airfield after the second world war when luminised intrumnetrs continude to be maintained and repaired.
The sentence to which you refer in your email about our belief is not about whether or not the contamination is due to luminised paint, but relates to the degree of proof that it is due to activities of the MoD.
I trust that this addresses your questions.
Radioactive Substances Manager
Thank you for your letter Mr Tilly which, on first reading sounds impressive. Less so on seeing what it actually says & equally what it doesn't.
The claim that radium must be artificial because it is "orders of magnitude" (i.e. 10s of times) greater than background is dubious. When Henri & Marie Curie processed many tons of pitchblende to find enough radium to cover the bottom of a cup they were starting with something orders of magnitude more concentrated than background - indeed that is implicit in the ore of any rare material. Had the measuring instruments existed at the time the Curies would certainly have found particles within the pitchblende which was in turn orders of magnitude more radioactive than that - indeed that is ultimately what they did. I would be interested to know whether you have investigated Kerala, Yellowstone Park or Guarapart bech in Brazil, all with natural radiation levels much higher than official safe limits without even statistiical evidence of any harm, to determine that similar levels do not occur naturally there?
Your claim to have found actual dials is more spectacular. On the other hand it raises the question - if you have found such radioactive dials, in the plural, lying about on the beach why does your report limit itself to claiming "A total of 37 items were retrieved from 29 locations in the survey area. The depth at which these items were retrieved ranged from surface to 270 mm below ground level. The size of the recovered items varied from 1 mm to 120 mm, whilst the weight range was less than 1 g to 380 g." This is like saying you found evidence of mice behind the skirting board but never thought to mention the herd of elephants. Even more surprising is the claim to have found a vial of (radio)active material. If this is a vial of radium paint, as you imply, which had lain unbroken on the shore for over 50 years it would be a most remarkable specimen - particularly since the painting of the dial took place prior to the manufacture of the aircraft, rather than when it was being flown so there is no conceivable reason why it would have been on the airfield in the first place.
As to what you don't say. Firstly you don't say that the claim, made nationally & still being maintained by SEPA, to have analysed actual radioactive particles & proven them to have been paint, is actually in any way true. Even if some non-radioactive paint particles have been found this does not prove they came from the airfield, let alone from the aircraft in question, let alone from the cabin of the aircraft, let alone from numbers painted on the interior of a few dials. Is the claim to have had these microscopic particles tested & proven to be paint true or false? If it is false when did SEPA ask the BBC to report this & fire the man who said it?
Secondly SEPA have refused to answer my question about background radiation in the area & adjoining beaches. Is Dalgety Bay's significantly above that found elsewhere? Does it even approach the levels found elsewhere, including in popular tourist attractions like Yellowstone mentioned above?
If the answer to any of these questions is No then SEPA have clearly lied & are maintaining the lie, in a manner bound to inspire false fears in the public & to have a positive effect on your own budget. As Mencken said "The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, all of them imaginary." What actual evidence have you that this particular hobgoblin is not imaginary.
On a slightly different matter was the statement by SEPA representative Colin Bayes, reported by you that the MOD have recognised that the radiation comes from them & it is their responsibility to clear it up actually true?
This has been proven to the extent required by sane people. The evidence is in the 2006 SEPA report as detailed in the comment trail to your 7 February post.
In addition, you have again not read what you cite. At page 13 of the 2006 Report, at section 3.2.1. page 13, SEPA note that they have screened their samples for background radiaition thus "assuming a background radiation level of 150 counts per second (cps), and a threshold for positive identification of a radioactive item producing a count rate of 75 cps above background level....
You assert SEPA are lying with no proof. You assert the Sunday Herald is lying with no proof.
Your own questions are answered so you ask new ones designed to be unaswerable.
Whatever else is proved here, it is abundantly clear you are no scholar.
2. Here is a good satire of the British H&S authorities and political correctness.
There is also a useful map at page 17 of the May 2006 Report at the same URL.
Your link to how Trafalgar would have gone under PC rules is all to true.
They also have standard civil defense meters (like mine) that are accurate up to 400 rads here. Of course, if you are standing on a beach in Scotland and begin picking up that much radiation then The End is Near.