I understand (and acknowledge) what the authors said, Terr. They are basically saying “Yes, these values are high but this doesn’t mean he ingested polonium”. While I disagree with that interpretation and I am putting a laser-focus on the data (i.e. the numerical values). The skull fragments were radioactive, the values were positive.
My read is that the Ruskies were saying the reading was within the margin of error, and so they could not come to any conclusions. Is this incorrect?
No, they are not. They are saying “these values are not high enough for the samples to be considered radioactive”. In those words.
Terr, I don’t need instructions from the authors to interpret their data*. What I am focusing in on is the numerical values. Humor me: Which of the following items is contaminated with background levels of polonium?
Item A with 0.10 mBq
Item C with 1.4 mBq
Item D with 1.1 mBq
Item E with 1.2 mBq
<plays final jeopardy music>
Yes, I believe that is the authors’ position.
Mr. Arafat was not buried with these items. After his death, his soiled belongings were placed in a plastic bag, stored, then tested ten years later. Remember it was the positive testing of these items that started this process of exhuming his body in the first place. The novelty of the present report is that they’re finding radioactivity emanating from his bones just on his personal belongings.
Sure. You are a great scientist. You know better than they do what the standards are, what the margins of errors are, and what the data means.
Neither - if those values (as the authors state) fall below margin of error.
Honesty,
What does it tell you when you look at data and see a “positive” but everyone else, (the authors, Arafat’s widow, her lawyer, the PA represtatives, Al Jazeera’s experts, the Swiss team …) all see it as showing no evidence of polonium (and spin it instead as just that the skull was a poor place to look)?
Ah, that you are better scientist than any of them!
Jackmannii,
It really is quite striking.
The Swiss team states that they have found levels of polonium in bone (the major bone marrow ones no less, the long bones, the ilium, the ribs … where bone aspirates are taken from) of such magnitude that they conclude with at least 51% confidence that there was massive amounts there at the time of his death. And then state that maybe at the time of death polonium somehow avoided his bones thus not impacting his marrow and only impacting his GI tract.
They quote in the report a bone marrow aspirate on day 13 of illness that showed
and another one several days before his death that showed
yet speculate that maybe he had no myelosuppression because he had a hypocellular marrow.
That’s chutzpah! 
How do you know about what controls were or weren’t used?
There’s no discussion of a control in their methods section nor does the data have a control. I rescanned the paper and was unable to catch an experimental control, can you find it? I am still looking for the appendices of the Russian report and I’m hopeful it’ll contain more data. The Swiss, in contrast, used multiple controls to first establish the background contamination of polonium. This is particularly useful because if a new tooth brush from the packaging puts out 0.1 mBq of radioactivity and soiled underwear emanates >170 mBq of radioactivity, you can easily ascertain the abnormal value. With the Russian report, because they didn’t do a reading on a control, it’s more difficult, if not impossible to put their data in context. IMO, the Russians should’ve used what’s called an age-matched control with the skull fragments. Not sure why they didn’t but what’s done is done.
Just to explain the scale of measurement so that Honesty’s claim of “very high” radioactivity found in Arafat’s samples can be understood. The highest measurement in the samples was 1.4 mBq. The lowest was 0.3mBq. That’s 0.0014 Bq down to 0.0003 Bq.
To compare: according to EPA, acceptable natural Polonium concentration in drinking water is 0.037 Bq - which is more than 20 times that found by Russians in the most “radioactive” Arafat sample, and about 100 times more than in the least “radioactive” sample.
No wonder Russians wrote that this was below margin of error.
So what we’re saying is that a few investigators say, “Maybe,” while the rest say, “Probably not?” Well, I’m convinced. :rolleyes:
I believe so. From page 12 of the report:
“…standard materials with elemental composition similar to that of the tested specimen, external normalization and the Monte Carlo method were used…A 20.9 g sample weight of the specimen in a Petrie dish was placed directly on the detector and measured for 24 hours. As a reference, a certified standard material of suitable elemental composition and very low radioactivity was chosen; the material contained certain amounts of uranium, thorium and potassium. The material had gamma-ray density and absorption parameters identical to those of the sediments.”
I’m not a nuclear physicist, but those references to “standard materials” sound like controls.
Of course, we cannot rule out the possibility that the Israelis threatened Al-Jazeera, forcing them to deliberately mis-translate the Russian report to make it look like controls were used. 
:eek::dubious:
That’s a very good guess, but the “standard material” they’re referring is not a control. Standard materials are required to detect what you’re looking for. It’s a bit contrived, but you can get information about it here. Standards are also used for HPLC and other kinds of identification assays.
[QUOTE=Terr]
Just to explain the scale of measurement so that Honesty’s claim of “very high” radioactivity found in Arafat’s samples can be understood. The highest measurement in the samples was 1.4 mBq. The lowest was 0.3mBq. That’s 0.0014 Bq down to 0.0003 Bq.
To compare: according to EPA, acceptable natural Polonium concentration in drinking water is 0.037 Bq - which is more than 20 times that found by Russians in the most “radioactive” Arafat sample, and about 100 times more than in the least “radioactive” sample.
No wonder Russians wrote that this was below margin of error.
[/Quote]
Your math is wrong and so is your understanding. The proper conversion between Bq and mBq is 1Bq = 0.000001 mBq. If 1 Bq equals 0.000001 mBq and acceptable level of polonium (according to your cite) is 0.037 Bq, then that’s 3.7 x 10^-8 mBq. Now, take out a sheet of paper and draw a line, putting 1.4 mBq (skull fragment) in the numerator and 3.7 X 10^-8 mBq (maximum polonium in drinking water) in the denominator. I am at bad at math but see if your answer matches mine in the spoiler box.
1.4 / 3.7e-8 = 37 million times more polonium in Mr. Arafat’s skull fragment than the maximum allowed polonium in drinking water.
[QUOTE=dropzone]
So what we’re saying is that a few investigators say, “Maybe,” while the rest say, “Probably not?” Well, I’m convinced.
[/Quote]
You don’t have to listen to the opinions of the investigators, you can look at the data they’ve provided (however scant) and determine for yourself.
But we’re not scientists. We can’t understand data. We can, at best, understand scientists’ conclusions. None of us here have the tools we need to determine matters for ourselves.
1 Bq = 1000 mBq
I am sorry to bring this up Honesty but earlier in this thread you accused everyone else of being akin to climate change deniers … who are people who believe that the consensus conclusions of experts matters nothing compared to their amatuer read of the data.
BTW, no offense but to agree with you, you really are not very good at math. It’s your math that is a bit wrong. You are confusing mBq (a millibecqueral) with MBq (a Megabecqueral). One mBq is 1/1000 of a Bq as Terr puts forth (and on preview I see that Mithras points out) not 1,000,000 Bq as you suggest. So you are off by a mere nine orders of magnitude.
Not 37 million times as much; 0.037 as much. IOW Terr was givng your side some leeway: the actual number is that water is allowed more than 27 times as much radioactivity.
Have come up with an answer to my question yet? The one about what you conclude when only you see a positive in data that everyone else, including those most wanting to see a positive, sees a negative result?
Do you really still, like the climate change deniers, believe that the reason is that you understand the science and the data better than everyone else does?
From your link:
"These materials are designated Standard Reference Materials (SRMs) and Reference Materials (RMs), and are used to calibrate measuring instruments, to evaluate methods and systems, and to produce scientific data that can be referred readily to a common base. "
Unless you can show that measurements of the type the Russians did must be evaluated against other specific baselines, it sounds like they generated legitimate data.
You’re confusing a standard and a control. In molecular analysis, the standard is used to determine what you have and is not part of the experiment itself (e.g a drug lab that tests for THC using HPLC would have a THC standard). Unlike a standard, a control is a part of the experiment. There were no controls in the Russian report; the scientists simply measured the radioactivity of the samples. In contrast, when the Swiss measured radioactivity from soiled underwear, this was compared to unsoiled underwear and a package of new underwear. These represent two controls or two baselines for comparison, something that the Russians* have not provided.
Honesty,
You are not going to acknowledge your wee tiny math error are you? Or answer my question. It was not just rhetorical:
Do you believe that the reason everyone else involved looks at the data and sees a negative and you see a positive is because you understand the data better than they all do?
Yes, but the Swiss used Hanes briefs as controls and Arafat exclusively wore Jockey boxer shorts. You can’t compare the two.
I also love how the argument has morphed from “You can’t trust a thing the Russians say” to “The Russians haven’t released a report” to “Where are the Russian appendices? It’s meaningless without the appendices!” :dubious: