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I
suspect you would have had more reactions to the latex gloves. However, your
comment reminds me that we did just have some discussion recently about
microwave ovens and plastic. Certainly sounds more plausible than a
paper-related reaction, and the mail is being irradiated in bulk, trapping any
off-gases.
Jack Earley
Radiological
Engineer
Ruth -
Based on what I saw about the "irradiation machines", I think you're
probably looking at electron beams rather than gamma or X-rays. I would
suspect the reaction of electrons w/ the organic sulfides would be similar to
that of alphas.
I've heard stories (that's the best I can characterize them) of the clear
plastic windows on irradiated envelopes being browned / charred, other
plastics (floppy disks, CD's, etc.) being "melted" or deformed. To my mind the
chemical reactions in irradiated plastics are as likely, if not more likely,
to be responsible for the production of "irritants" as the irradiation of
paper ... assuming for the sake of argument, of course, that some sort of
irritants are actually produced by the irradiation process.
For what it's worth, when I was working on the Radiation Sterilizers,
Inc. (RSI) cleanup here in Decatur, GA seemingly a lifetime ago (it was only
1988), we were working with paper products, predominantly cardboard boxes,
that had been sterilized with gamma doses in the megarad range ... and we
handled those products with no ill effects. Now granted, we were surveying
them for contamination, so we did have latex gloves, etc. ... so that may not
be a valid data point ... but in the thousands of person-hours that we worked
with these products, I don't recall anybody saying anything about any sort of
irritant.
My $0.02 worth ...
Jim Hardeman
Jim_Hardeman@dnr.state.ga.us>>>
<RuthWeiner@AOL.COM> 8/28/2002 14:04:54 >>> Re the government report
that suggests that radiation may have caused some chemical changes in paper,
which then produces skin irritation.
High-wet-strength hard-surface
paper is produced by the "kraft" process ("Kraft" is the German word for
"strength"), in which the lignins are removed from wood using organic reduced
sulfur compounds -- sulfides related to H2S. The sulfides are
responsible, incidentally, for the noxious odor from kraft pulp mills.
Paper pulp is wood with the lignins removed. White paper is
bleached with chlorine dioxide or related oxidizing compounds.
Low-wet-strength paper, like a lot of cardboard (and egg cartons, and
the center roll for paper towels and toilet paper) is produced by a process
that uses sulfites (SO3-) and removes lignins an oxidative rather than a
reducing process.
Alphas would almost certainly react with organic
sulfide residues, but I expect the irradiation of mail would be gamma or
x-ray, not alpha, if you are going to kill anthrax bacteria. Gammas
would also react with organic sufides as well as with the cellulose in
the paper itself, but I doubt if enough irritant would be produced to cause a
physiological effect. I did my dissertation work in this area, and we had to
really zap a small molecule to detect any chemical change at all.
The irradiation that produces color changes in crystals is
appreantly not enough to produce chemical changes that can be detected without
instrumentation.
X-rays produce chemical changes in
photographic film, and might produce some ancillary changes that could cause
irritation, but I don't know that x-ray technicians complain about irritation.
Xerox is a chemical process that leaves a discernible residue (so does
ink, for that matter) and I don't know of generalized complaints about
chemical irritation from either. If x-rays or gamma radiation were
producing an irritant in paper products, wouldn't that irritant be different
for white paper, colored paper, cardboard, Xeroxed labels, handwritten
envelopes, black ink, and colored inks? I'd like to see a double-blind
experiment where mail handlers handle unirradiated mail that they think has
been irradiated, and irradiated mail that they think hasn't been irradiated.
Ruth
Ruth Weiner, Ph. D.
ruthweiner@aol.com
Ruth Weiner, Ph. D.
ruthweiner@aol.com
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