Re: EPA, risk and dose

["Stokes, James" <StokesJ@TTNUS.COM>]

 Zack:

I concure with you, that dose would be the only constant, and then, as the

risk associated with a given dose changes, the conversion would be simple.

Whereas, by the other methodolgy, it wold have to be recalculated each time

from scratch.



- -----Original Message-----

From: Zack Clayton

To: radsafe@list.vanderbilt.edu; StokesJ@TTNUS.COM

Sent: 3/29/01 10:03 AM

Subject: RE: EPA, risk and dose



Hmm - sounds like USEPA is saying risk is constant and Dose varies over

time?  (Well it does - in a predictable log decay function)



It seems that USEPA has put the cart before the horse.  Dose is the

invariable factor at a site apart from remediation activity.  It is

directly and repeatably measurable by anyone with calibrated

instruments.   The assigned risk for that dose is the variable function

based on the political/science agenda du jour.  If they go with a

calculated risk instead of a measurable quantity its easier to hide

behind absurd numbers.



Zack Clayton

Ohio EPA - DERR

email:  zack.clayton@epa.state.oh.us

voice:  614-644-3066

fax:       614-460-8249





>>> "Stokes, James" <StokesJ@TTNUS.COM> 03/29/01 09:10AM >>>

> I am going to qualify that I do NOT speak for the U.S. EPA, and the

>following is my understanding of the policy position on dose vs risk.

>

>. . . . the U.S. EPA, presents it

>this way.  Over the decades, BEIR has altered the risk associated with

a

>given level of dose.  Therefore the risk associated with a given dose

is not

>a constant.  Therefore a decision made based on a given dose now,  may

>change later, based on the same dose, as the risk associated with that

dose

>changes.  Therefore   ** dose correlates to risk only at a given point

in time,

>and therefore is not an absolute value. **   . . . .  



Huh?  Dose varies while risk stays constant?  (asterisks mine).



My thoughts only on a rainy morning on coffee break.



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