[ RadSafe ] xkcd: Relative Radiation Dose chart

[shima]

On 03/29/11 03:16, Doug Huffman wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Genevieve Matanowski's Naval Shipyard Workers Study, 'Health Effects of
> Low Level Radiation Exposure in Naval Shipyard Workers'
>
> This is the most thoroughly disappeared technical literature that I know.
>
> On 3/28/2011 20:00, Ed Hiserodt wrote:
>> Sandy,
>>
>> You may recall in the Johns-Hopkins study of nuclear vs. non-nuclear
>> shipyard workers that the cohort of some 70,000 participants were paired at
>> random.  "You there, go to the nuclear ships, and you there to the
>> non-nuclear."  How could a "healthy worker affect" be possible under these
>> circumstances?  But the nuclear workers had a Standard Mortality Ratio of
>> 0.74 when compared to the non-nuclear cohort.  Not what the study was
>> expected to show.  (And probably why it was not published for almost 20
>> years after analysis of the data.)
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v2.0.14 (MingW32)
> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
>
> iQEcBAEBAgAGBQJNkTLuAAoJEIpOLnult3mgKK0H/RuvVhXaEHEQcHOfg4JtpIlT
> 95Rzy/rHYVS8K8HrYkZ3y1Uadig5YsvkiSPGv0fJYL+9MrkmIIO+Acth3Hpd0EWm
> RCIB/WXNvcG3Zkmq63+U9E0YPNqB5xbfye9QJQfWYAsix0kTnt6DK1vEWbZzRnit
> qodMI6QIwkzfH/w2MA/VdMcrXQ5b4wLMSQ6CbA/FylAkcxQX5WdxSxL1yPNvuSI5
> bI4m9VfLI/nO6+jsEdyOtSWVbiXgzI0I84r21imA4rPeFG+rV0ykUgkjpczvk+vg
> v1M7PhlKf8Pq6fdoPthOQleG9ARMrIpsBlmeTA4glvWDMSbLNtNm6Cf9m80oa0g=
> =FvXI
> -----END PGP SIGNATURE-----
> _______________________________________________
> You are currently subscribed to the RadSafe mailing list
>
> Before posting a message to RadSafe be sure to have read and understood the RadSafe rules. These can be found at: http://health.phys.iit.edu/radsaferules.html
>
> For information on how to subscribe or unsubscribe and other settings visit: http://health.phys.iit.edu
>


Hi,

"studies have demonstrated "

Is this *a study* (the one cited) or have several studies shown this and 
no studies shown the opposite? I get the strong impression there is some 
selective thinking going on here.


However, such a result deserves to be examined like any other, 
remembering that a study is just a study. Arbitrarily selecting one 
study does not make it an eternal truth.

The result is at first impression rather surprising. Even if there were 
no significant extra risk from the doses to which the cohort was exposed 
one would not expect a significant reduction in risk. So what are the 
possible causes?

1. The study was defective, the result invalid.

2. The level and types of doses to which they were typically exposed 
reduces the risk of cancer.


There is some other work in the sense of 2 in specific treatments so 
this is not impossible, though not as a general result applicable to all 
exposure. It remains an unlikely explanation.


The first point raises several possibilities.

1a. Lack of rigorous method gave a spurious result.

1b. Intentional or sub-concious bias on the part of the authors.

Just one aspect that would come under 1a is that the general environment 
to which the nuclear workers were exposed was more rigorously controlled 
on all levels and general shipyard workers. Many toxic products go 
through shipyards and it is a macho context were only "faggots" would be 
bitching about silly health and safety rules.

It is possible that general shipyard workers are exposed to more 
carcinogens than those working in more disciplined  contexts.

A comparison of other injuries or fatalities on the same groups may help 
put this into context.


Strict levels of security are practised in the nuclear industry 
precisely because it is so dangerous. This culture will almost certainly 
affect other health and safety dangers.


As always a whole study will be reduces to one sentence and then quoted 
out of context by those who feel it fits their agenda.


rgds.