From: steinman@is.morgan.com (Jan Steinman)
Subject: Re: Are Your Light Bulbs Radioactive?
Organization: Morgan Stanley & Company
	<STEINMAN.92Aug24173740@hawk.is.morgan.com> <10503@sun13.scri.fsu.edu>
Distribution: na
Date: Wed, 2 Sep 1992 13:44:40 GMT

In article <10503@sun13.scri.fsu.edu> jac@ds8.scri.fsu.edu (Jim Carr) writes:
   In article <STEINMAN.92Aug24173740@hawk.is.morgan.com> steinman@is.morgan.com (Jan Steinman) writes:
   >Teach your children how to use a geiger counter!

   Good idea.  But do not stop there.  Suggest that they put a bottle of 
   GatorAde (sorry you folks at UF, any of the "replacement" sport drinks) 
   next to it.  <quite a nice effect, BTW>  Compare to CF bulb.  Look for 
   any warning label on the respective packages.  A learning experience!
   Also might compare to a banana and your own body.  

I didn't think Mr. Carr knew what he was talking about, but was
unwilling to reply without some data. (After all, this is a "sci"
group.) The following is not meant to be an utterly flawless
experiment, but I was as careful as I could be.

I compared the ambient background radiation with that of a banana.
They were completely indistinguashable on a geiger counter's normal
mode, so I did a long timed count. I placed the counter on a steel
ironing board in the middle of a room. (I had previously "calibrated"
the ironing board against a large, empty cardboard box. This tells us
either that steel and cardboard have the same relative radioactivity,
or that neither is significant compared to background radiation.)

I positioned the alpha window of the geiger counter 1 cm from the
center of a unpeeled banana and began a timed count at night. I
repeated the procedure during the day. (From previous experimints, I
knew there was a significant difference between day and night ambient
radiation.) I then removed the banana, leaving everything else
untouched, and repeated both trials. Here's the results, in counts per
minute:

	banana	not	nuke	flight
day	15.71	15.69	56.11	404.1
night	15.39	15.36

In other words, extremely little difference. From timed readings I've
done in the past, I can assure you there is no statistical
significance beyond three places. For comparison, I included a reading
I made (with PGE's permission, for which I am greatful) during a
nuclear plant tour -- their readings coincided closely with mine. Also
for comparison is a reading I made during a cross-country flight. I
also passed the counter through an international terminal X-ray
machine, but it saturated at 19999 counts, making an accurate timed
reading impossible!

Possible problems:

1) if the peel of the banana has little potassium, and the meat is an
   alpha or beta emitter, the radiation could be blocked by the peel.
   (I don't have my CRC handy, but I doubt this is the case. I'm
   willing to repeat with a peeled banana to avoid a flame fest.)

2) GM tubes merely detect ionizing events, and are not calibrated for
   measuring their energies unless the source is known. A highly
   damaging alpha particle and a lightly damaging gamma ray count the
   same. Therefore, GM tubes are not reliable indicators of the
   biological impact of radioactive materials.

I don't have a CFB to test. Someone wanna send me one? I intend to do
the same test on a bottle of GatorAde, since Mr. Carr asserts there
will be "quite a nice effect". (To *really* see "quite a nice effect",
try lantern mantles, which are not labelled as radioactive.) Stay
tuned...

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