[ RadSafe ] RadSafe Digest, Vol 749, Issue 1, message 3

[Doug Aitken]

Be careful, Tony! 
Worry is stress. Stress causes heart attacks (heck: there go those
confounders again.......)
;~)
Doug

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Harrison, Tony
Sent: Tuesday, September 20, 2011 12:29 PM
To: radsafe at health.phys.iit.edu
Subject: Re: [ RadSafe ] RadSafe Digest, Vol 749, Issue 1, message 3

Good questions all.  You don't need me to remind you that the Sv is a unit
intended to quantify stochastic/probabilistic effects.  Presumably the
absorbed dose (Gy) would be more meaningful.

But since Busby has yet to enumerate any heart attack data from Japan or
anywhere else, I have trouble worrying about it too much.


Tony Harrison, MSPH
Colorado Department of Public Health and Environment Laboratory Services
Division
303-692-3046



From: "Brennan, Mike  (DOH)" <Mike.Brennan at DOH.WA.GOV>
Subject: Re: [ RadSafe ] Sr-90 in Maple Syrup, Ra-226 in mineral
	waters,	Cs-137 in woodash,	etc.  was: Re:  Re. Tritium found
near VT
	Yankee 		 (panic time!)
To: "The International Radiation Protection (Health Physics)
	MailingList"	<radsafe at health.phys.iit.edu>
Message-ID:
	<37C41083D3480E4BBB478317773B845D075059F3 at dohmxtum31.doh.wa.lcl>
Content-Type: text/plain;	charset="us-ascii"

Interesting (I only have access to the abstracts).  I assume the researchers
collected some mouse ejaculate (Oh, the life of a grad
student!) for analysis, to demonstrate that Sr90 actually transferred
between the male and female.

It is a shame that the control group was injected with a salt solution,
rather than the same solution as the experimental group, but with stable
strontium.  This would have controlled for the possibility that the effects
were due to chemical rather than radiological factors.  It also would have
been interesting if the males had been given different body burdens, so it
could be determined if there was a relationship between dose and outcome (if
any of these were done in the experiment, great!
But as it was not mentioned in the abstract, I assume it was not).  

It also would be interesting for someone to calculate how many atoms of
Sr90 were on average attached to each chromosome, what the likelihood of a
decay.  

The more I think about it, the more important it is to determine how many
atoms of Sr90 adhere to the genetic material in a sperm, as each developing
mouse only has the load from one sperm (unless someone contends that the
other sperm somehow also contribute their Sr90, which is something that
would require some proof).  If one knows how many atoms of Sr90 are present
at fertilization, and the rate of decay (a given and constant for the length
of time of interest) and the rate of cell division (exponential for some
period of time, rapid thereafter), one could calculate the number of decays
per fetus per period of time, and see if that is reasonable when compared to
the observed results.  

It all depends on demonstrating that Sr90 actually adheres to the sperm, and
quantifying the amount.  It is a shame the cited studies didn't appear to do
that.  

It also would be interesting to know the mechanism by which the Sr90 cause
damage that caused "... develoipement defects mainly heart".  I would have
expected the Sr90 delivered by sperm to become randomly distributed
throughout the body (with only a small percentage of the cells having even
one atom of Sr90 in them.  

" effects here at 1mSv or less."  To what?  I don't know that dose is a
meaningful concept when talking about something like this.  It might be, but
it doesn't feel like it is.  At the very least, it isn't comparable to dose
to something like a fully developed organism.  I agree that the effects of
radiation exposure would be greater to a developing organism,
I am just not sure that dose is a useful way of quantifying it.      
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