RE: Stochastic vs. Non-Stochastic (from the Denver Thread)

[John Jacobus <crispy_bird@YAHOO.COM>]

Why would a population that always get cancers be

removed by natural selection?  Only those who die

before they have children would not pass on their

susceptibility.  It they lived long enough to have

children, their children would develop cancers at a

higher than the normal rate.  



--- "Crossley, Steven"

<Steven.Crossley@health.wa.gov.au> wrote:



>  A thought on this topic...

> 

> Presumably you are suggesting that there would be

> some lower than

> average (but above average background) threshold

> level for the

> susceptible members of the population.  A group that

> always get cancer

> from background levels would presumably have been

> removed by natural

> selection.

> 

> If this were the case would evidence not appear for

> radiation workers,

> in that we generally receive slightly above

> background doses and we

> would presumably have just as high a proportion of

> radio-sensitive

> persons amongst us as the general population.

> 

> Perhaps I'm over-simplifying

> 

> Steve Crossley

> Perth, Australia

> 

> -----Original Message-----

> From: owner-radsafe@list.vanderbilt.edu

> [mailto:owner-radsafe@list.vanderbilt.edu] On Behalf

> Of Richard L. Hess

> Sent: Tuesday, 21 December 2004 6:56 AM

> To: james.g.barnes@att.net; RadSafe Bulletin Board

> Subject: Re: Stochastic vs. Non-Stochastic (from the

> Denver Thread)

> 

> Hello, Jim,

> 

> Just to make sure I understand what you're saying,

> let me take it to a

> different stimulus-response situation.

> 

> I know if I eat a LOT of peanut butter, I'll get

> fatter than I already

> am and may die sooner.

> 

> However, if my son gets close to peanut butter he

> will have an allergic

> reaction and may die without treatment.

> 

> In this case, we know of the allergic sensitivity

> and suspect peanut

> butter is a serious potential trigger. We carry

> medicine for him at all

> times.

> 

> Are you suggesting that there may be some

> sensitivity (like the food

> allergy) or some lack of protective mechanism in

> some random group of

> the population that makes them more sensitive to low

> level doses?

> 

> If so, it sounds like an interesting course of

> investigation to follow.

> 

> It also may extend to cancers in general, and not

> just radiation-induced

> cancers, don't you think? Sounds like a lot more

> work on the human

> genome might tease this out.

> 

> Cheers,

> 

> Richard

> http://www.richardhess.com/tape/

> Aurora, Ontario

> 

> At 09:19 PM 12/20/2004 +0000, james.g.barnes@att.net

> wrote:

> >Dear all;

> >

> >There is a general opinion that there are

> stochastic and non-stochastic

> 

> >effects.  We say they are stochastic because the

> effects from exposure 

> >appear to be statistically distributed in the

> population (we can't 

> >predict who will experience effects, therefore we

> say it's a chance 

> >event).  We say non-stochastic, because above a

> certain threshold, all 

> >exposed persons appear to display the same set of

> symptoms.

> >

> >I've often considered this approach to have a gap

> in logic.  We are 

> >saying that the chances of experiencing effects

> from low-doses is a

> "chance"

> >thing.  What if they are not; what if they are just

> as non-stochastic 

> >as the effects at higher doses, but only to a

> sub-group of people who 

> >are more inclined to display effects than others

> (probably through 

> >genetic pre-disposition).  What if there were

> sub-groups who simply 

> >could not physiologically handle radiation exposure

> as well as 

> >everybody else, and that these "stochastic effects"

> are actually due to

> 

> >the stochastic distribution of these

> overly-sensitive individuals in an

> 

> >otherwise normal population.  The effects aren't

> stochastic; the 

> >distribution of these sensitive individuals in the

> overall population

> is the stochastic distribution.

> >

> >I have to think this alternative theory has been

> explored to some 

> >degree?  Have any of you seen any discussion /

> research into this

> concept?

> >

> >

> >Jim Barnes

> >

> 

> 

>

************************************************************************

> You are currently subscribed to the Radsafe mailing

> list. To

> unsubscribe, send an e-mail to

> Majordomo@list.vanderbilt.edu  Put the

> text "unsubscribe radsafe" (no quote marks) in the

> body of the e-mail,

> with no subject line. You can view the Radsafe

> archives at

> http://www.vanderbilt.edu/radsafe/

> 

>

************************************************************************

> You are currently subscribed to the Radsafe mailing

> list. To

> unsubscribe, send an e-mail to

> Majordomo@list.vanderbilt.edu  Put the

> text "unsubscribe radsafe" (no quote marks) in the

> body of the e-mail,

> with no subject line. You can view the Radsafe

> archives at

> http://www.vanderbilt.edu/radsafe/

> 

> 





=====

+++++++++++++++++++

"The real threat to the life of the nation, in the sense of a people living in accordance with its traditional laws and political values, comes not from terrorism but from laws such as these."

LORD HOFFMAN, of Britain's highest court, which ruled against indefinite detention of terror suspects





-- John

John Jacobus, MS

Certified Health Physicist

e-mail:  crispy_bird@yahoo.com





		

__________________________________ 

Do you Yahoo!? 

The all-new My Yahoo! - What will yours do?

http://my.yahoo.com 

************************************************************************

You are currently subscribed to the Radsafe mailing list. To

unsubscribe, send an e-mail to Majordomo@list.vanderbilt.edu  Put the

text "unsubscribe radsafe" (no quote marks) in the body of the e-mail,

with no subject line. You can view the Radsafe archives at

http://www.vanderbilt.edu/radsafe/