Re: Relevance of experts

["Jerry Cohen" <jjcohen@PRODIGY.NET>]

John,

    A few comments to clarify my position (hopefully):

1. to answer your original question, I wouldn't worry about any dose below

~1.0 rem/a. above background

2. In my estimation, the optimal dose range is somewhere between 1.0 and

100.0 rem/a.

3. At a dose of 10.0rem/a, in the unlikely event that adverse effects should

occur,  there could also be offsetting positive effects.

4. Like all other physical and chemical  agents , radiation likely causes a

wide range of dose related effects. Such effects could be either positive or

negative in nature. For a given individual at any given dose level, health

consequences reflect the sum of these effects. Certain rare hypersensitive

individuals might indeed have  adverse  effects at  low doses analogous to

allergic reactions to some chemical agents.

5. I don't believe it is prudent to set exposures standards based on effects

to the most sensitive individuals, but that is only my opinion.

6. Finally, if the maximum allowable dose were set at 1.0 rem/a (10.0

mSv/a), we would save a lot of $$$$$$, which might then be allocated toward

useful objectives.







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

From: John Jacobus <jenday1@MSN.COM>

To: RADSAFE <radsafe@list.vanderbilt.edu>

Sent: Wednesday, August 21, 2002 6:19 AM

Subject: Fw: Relevance of experts





> Jerry,

> I guess my only comment is what if you are wrong?  What if 10 rem/y

> (0.1Sv/a) has an adverse affect on health?  The studies I have seen or

heard

> about report no affect below 5 rem/y (50 mSv/a) for cohort studies of

> radiation workers.  What about studies of the general population?  While

the

> study of specific populations may give us some clues about long term

> radiation effects, do they apply to all populations?

>

> Another comment is the claim that radiation boost the immune system.  If

you

> look at these studies, I think you will see that only one component of

> immune response system is reported upon.  I have not seen anything that

> indicates the individuals are any healthier.  (I am excluding medical

> patients who may, obviously, be responding to the treatment not

necessarily

> the immune response that is being stimulated.)

>

> If my memory is correct, studies at high dose exposures show an initial

rise

> of cellular components, such as granularcytes.  However, within a short

> period of time, the response falls below normal levels.  This is a rebound

> affect to stress on the body.  At low doses, is there a similar response?

> That is, does the response of the immune system or its measured

components,

> remain high, or eventually fall below preexposure levels?

>

> -- John

> John Jacobus, MS

> Certified Health Physicist

> 3050 Traymore Lane

> Bowie, MD 20715-2024

> jenday1@email.msn.com (H)

>

> > From: Jerry Cohen[SMTP:JJCOHEN@PRODIGY.NET]

>

> > At what dose above background do you think there is no need to worry

about

> > controlling it?  These organizations suggest 100 mrem.  What would you

> like?

> > 500 mrem?  1,000 mrem?  What is the basis for your consideration?

Because

> > it "sounds" good?  Because yeast can stand hundreds of rads, do you

think

> > that should be the yardstick we should consider?

>

> John,

> As I previously discussed on radsafe, the optimal dose level would likely

> vary from person to person.  IMHO, the optimal dose  for humans ranges

from

> ~1.0 to 100 rem/a with a log-mean of ~10.0 rem/a. Doses significantly

below

> optimal (<100mrem/a) may result in radiation deficiency effects including

> impaired immunological function. So, to answer your question, I would

worry

> about doses either >10.0, or <0.1 rem/a (including background). Anything

in

> between is probably OK. What do you think?

>

>

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