Re: BERT, DARI, etc.

[muckerheide <muckerheide@attbi.com>]

 From: Ruth Sponsler <jk5554@YAHOO.COM>



Ruth,

Note your different BERT comparisons here! There's a critical difference.



John's BERT uses "average" dose (who's average?) as a baseline, with medical

dose added on top without context or any reason to believe it is not a

hazard; it is NOT your example of the effect of the background difference!

(Though where were you living at the time! :-)



BERT now is less effective. See previous email notes below.  (I can send a

draft physician flyer that we can produce.)



Regards, Jim

===========



> I disagree.  I think that the concept of background

> equivalent is very useful, especially in medical

> settings or when dealing with really small amounts

> (almost always very much less than yearly background)

> in public exposures.

> 

> I don't think that 'BERT' is a 'gimmick.'  I remember

> a radiologist explaining to my parents and me (when I

> was a child) that the exposure from a series of x-rays

> would be equivalent to a few weeks camping in

> Colorado. 



<snip>

> ~Ruth 2  



1.

You can better address this with great effect by stating how much time a

person in a low-dose area would spend in a high-dose area, instead of just

using numbers based on "avg background" which is harder to conceptualize

(and it's harder to justify any addition to a fixed level from the proposed

added medical exposure - why would I think  getting a years worth of

"background" in one shot is "safe?")



This approach ALSO has the great advantage of "explaining" that background

varies greatly; which is a VERY helpful and easily understood concept for

the patient. (As I've indicated before, it's not clear whether the BERT

explanation uses (should use) "local avg." background, or "nat'l avg.," or

world avg."  What if you're in high altitude Colorado or Wyoming with >10

mSv? vs. the US Gulf coast, SE coast, or San Francisco with <1 mSv?



Using natural variation also results in less BERT-time, since background

varies about 3 times the avg background (e.g., in the US, we can say

background varies from 1 to 10 mSv/yr with a 3 mSv avg. (IF you want to buy

radon lung dose as a contribution!?)  Don't know about Australia, but if you

want to use world numbers, background varies much more than 10 times avg.

You could use 30-40 mSv that expose small populations, or the extremes of

Kerala India or Ramsar Iran at100s of mSv.



Instead of saying: "This will add a years worth of background radiation."

(Your avg.? Where do you live? The US avg.? world avg. - 2.4 mSv?)



You would say:  "This is as much additional radiation as a person from San

Francisco (or Hilton Head, or New Orleans?)  gets in 3 months in Vail

Colorado." (Or 10 days in some homes in Ramsar Iran!? :-)



2.

Using BERT is orders of magnitude more informative using real variations

than using add-ons to a fixed "average."



First, it "explains" background radiation and its variation in much more

informational terms.



Second, it "explains," with reference to the "real world" (e.g., using San

Francisco or low dose areas of the US southeast coast, vs. e.g., ski areas

of Colorado and Wyoming, and if warranted with ref to Kerala, Guarapari,

Ramsar, etc.) that their dose is within a variation, it is NOT a net

increase in a fixed natural dose ( ESPECIALLY for some exposures that are

weeks, months and years of natural average dose in BERT terms - why is that

"ok?" why is it safe?)



Third, the variation in dose is much greater than the "average" (their

average? their local area average? the US average? the world average?) dose,

therefore the "equivalent time" is correspondingly much smaller!



Therefore, this 'explanation' provides infinitely more substantial

information on radiation (variation) in the real world, and the relationship

to radiation exposure.  In addition, this information in a "backgrounder"

will ALSO substantially inform persons in the medical community that do not

understand natural background radiation at all, beyond some motherhood about

"average" doses.



3.

But it's also clear that the 'professionals' need to be taught, and this

misses that opportunity. It's certainly easier to  *accurately* explain the

effect as a difference in places ("x days in Vail from SF"), and of course

that is MUCH more informative and satisfactory from any perspective of

concern for accuracy and education!



If you could get these people (who don't seem to know much about background

radiation themselves) to learn about the variation with your brief treatise

on BERT, the substance of the case against LNT for reg limits and NCRP would

be greatly improved. Unfortunately, without that, the problem is still a

"compare to background" that's being used without sound foundation in "what

is background," which hasn't succeeded in the last decades in challenging

the basis for rad protection policy.



I suggest that when the dose is seen differently, as *within the variation*

of background radiation, a greater contribution will be made to undercut rad

risk fears, especially when 'cleanup' issues get discussed.



But, the answer to the person about the real problem, the dose rate effect

difference, isn't addressed by this approach; and the dose rate is

overwhelmingly more significant than dose!? :-)  But at low doses, Sakamoto

and dozens of confirmatory studies show that 10-15 cGy x-rays in 1-plus

minute exposure (still a relatively low dose rate to the relevant biological

response) are stimulatory, and produce health benefits and cure infections

and inflammatory diseases, and reduce cancer incidence and control tumors.



That's the big story that's missing with the radiologists/RSNA. And if they

could understand that, not only does the nonsense of "risk" go away, they

would find a major new 'opportunity' which would be to the GREAT benefit of

the public (including reducing unnecessary and destructive overuse of

antibiotics - at some cost to the chemotherapists and the pharmaceutical

industry - and their FDA, NIH, etc. friends :-)



Why does that not seem to get through? Why doesn't this story get told at

RSNA?



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