[ RadSafe ] Re: radsafe Digest, Vol 195, Issue 3

[al at solidsurfacealliance.org]

This is not the first time Mr. Connell has ran loose with the facts nor is it the first time he has used ridicule rather than accurate facts. Allow me to point out some of the mistruths he used in his post. I am serving on an national standards committee that is looking into ways to defend nuclear power and nuclear medicine, with one of the ideas being to develop a website for journalists, giving some basic information about radiation in layman terms. Just as well write something that explains the potassium issue and get some expert feedback.
 
Mr. Connell wrote : "(my goodness, a glass f (sic) milk runs at about 1,200 pCi/g!)"
 
I am finding that 1.5 to 1.3 pCi/g is the potassium level of milk or 332 to 285 pCi/serving. So Mr. Connell is off by a factor of 3.6 to 4.2 so far. If Mr. Connell is correct on the 150 grams of potassium in the human body (I think that is a bit low) only 0.012% will be K40, the balance being stable (non radioactive) potassium 41 and 39. That would be .018 grams of radioactive pottasium.
 
"YOU are irradiating 4,400 Bq (120,000 pCi) of K40,..."
 
Okay, 4,400 Bq can also be expressed as 120 nCi, and and if we are going to trivalize trillionths of a curie, we ought to trivalize billionths of a curie as well.
 
A small home will have 4,000 square feet of drywall, or 166 cubic feet. The a typical male human body has around 2.5 cubic feet, or 66 times less than the drywall in a small home. If this is natural gypsum drywall, 15 mBq/g (0.4 pCi/g), the 160 cubic feet of drywall has over 3,000,000 grams and is putting off 46,267,200 mBq from the uranium content alone. If this is by product gypsum, figure 573,713,280 mBq coming from the drywall. If you include the potassium and thorium content, multiply those figures by 1.3 to 11.4 depending upon drywal type. So ask your colleagues to live out in a field you if you love them.
 
And what effect will the half life have when comparing potassium 40 to radon? K40 has a half life of of 1.250×109 years. Radon half life is 3.8 days, which would you rather have inside your body given equal amounts? Would you rather have a stable Argon 40 daughter product in your body or would you rather have Po 218, Pb 214, Bi 214, and the rest of Radon progeny?
My point, besides showing Mr. Connells sloppy facts, is that added to the ridicule of William's post, the assumption that there was a standard deviation of 20 (would that not put this result below the minimum detection levels?), and the statement that .3 pCi/g is an "extremely" small amount, all point to an attempt to mislead the public. Mr Connell was quite skillful in leading the discusion from radon in building materials to potassium in the human body. 
 
"Remember, not one study to date, NOT ONE, has demonstrated that radon as seen in homes has been able to demonstrate that it increases the risk of cancer one iota – and remember too, that the US EPA found that as radon concentrations in a home go up, the cancer risk goes DOWN."
 
I would think that many on this list server or the Iowa Radon Professionals list server would beg to differ on the radon facts. And someone please explain why the EPA spends so much effort on radon education if increasing radon levels are good for humans?
 
ALARA requires that we lower even insignificant doses if practical, especially if it can be done at little additional cost or trouble. Knee jerk reactions to radiation being mentioned hardly serves ALARA purposes. Nor does it help to further confuse the public on radiation issues. A honest discussion of the facts is better than ridiculing those you disagree with nor should one compare an innocuous material with a dangerous one. 

A few references for Steven Dapra.
http://www.bloodindex.net/minerals.php
http://www.docstoc.com/docs/4992595/potassium-element
http://www.physics.isu.edu/radinf/natural.htm

--- On Wed, 4/29/09, radsafe-request at radlab.nl <radsafe-request at radlab.nl> wrote: