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RE: CNN article
Hi Russ,
I agree that it all happens in galaxies far far away..., but
the most intense gamma ray bursters have only been identified in
2001 (I think!) to lie in star nurseries and those occur particularly
often in colliding galaxies or their leftovers as some the dramatic
Hubble Heritage pictures show. But you are right. Those X-rays are
red-shifted so far that they are actually in the red part of the
visual spectrum!
But you are right, I would not want to be caught at 12,000 m in
an airplane, and far less way out in space. At least the plane can be
warned and run down into the atmosphere for cover, but people on their
way to Mars could not, and that would be a problem!
Best
Fritz
*****************************************************
Fritz A. Seiler, Ph.D.
Sigma Five Consulting: Private:
P.O. Box 1709 P.O. Box 437
Los Lunas, NM 87031 Tome', NM 87060
Tel.: 505-866-5193 Tel. 505-866-6976
Fax: 505-866-5197 USA
*****************************************************
-----Original Message-----
From: Russ Johnson [mailto:rujohnso@nmsu.edu]
Sent: Wednesday, July 07, 2004 1:31 PM
To: Fritz A. Seiler
Cc: radsafe@list.Vanderbilt.Edu
Subject: Re: CNN article
Hi Fritz;
I just read a response that galactic radiation is different from cosmic
radiation, and that the FAA monitors airline crews in terms of "galactic
radiation". OK then, so I've left them a query about what doses they are
getting
on their crews.
Even more galactic than just regular galactic? Far out. I had in mind
pulsars,
x-ray binaries, neutron and radio stars, etc. I should be thinking along
lines
like white and black holes, and perhaps the leading edge of two colliding
galaxies (very bright gamma bursters). But you know all that stuff from way
out
there has got to really be doppler-shifted by the time it gets here. The
ionizing potential as well as proportion relative to local/solar radiation
has
got to be tiny. I still think the more local form of cosmic radiation from
our
own sun is more of a dose risk..Remember the last big solar flare a while
back
that knocked down automated bank tellers and messed up cell phone due to
heavy
satellite ionization? I don't think I'd want to be flying at 40K plus when
that
happened!
-Russ
"Fritz A. Seiler" wrote:
> Hi Russ,
>
> How about cosmic radiation of extragalactic origin?
> Examples are Type 1a supernovae, and gamma ray bursters
> also called Hypernovae. We can be glad that they are so
> far away and happened such a long time ago!
>
> Best regards,
>
> Fritz
>
> *****************************************************
> Fritz A. Seiler, Ph.D.
> Sigma Five Consulting: Private:
> P.O. Box 1709 P.O. Box 437
> Los Lunas, NM 87031 Tome', NM 87060
> Tel.: 505-866-5193 Tel. 505-866-6976
> Fax: 505-866-5197 USA
> *****************************************************
>
> -----Original Message-----
> From: owner-radsafe@list.Vanderbilt.Edu
> [mailto:owner-radsafe@list.Vanderbilt.Edu]On Behalf Of Russ Johnson
> Sent: Tuesday, July 06, 2004 5:29 PM
> To: Jim Hardeman; radsafe@list.Vanderbilt.Edu
> Subject: Re: CNN article
>
> Good ol' CNN.
>
> The "N" in LANL does not stand for nuclear. Its irritating to see and hear
> that repeatedly, not only on CNN but other outlets as well! LANL has a 2
> rem safety dose limit while other federal agencies have a 5 rem safety
dose
> limit? Want to try that one again?
>
> What is "galactic cosmic radiation"? Sounds a bit redundant.
>
> I would be surprised in a clear association of melanoma with high energy
> cosmic radiation, but I guess I can't rule it out. I was under the
> impression skin melanoma is generally associated with much lower energies,
> like UV-B (like the ozone hole issue) or even low energy x-ray or beta.
>
> I'm curious now what the actual doses are to full-time international
airline
> crews. Does anyone know, per flight or per annum? I've been asked this
> question before in the radiation safety class I teach, but I don't know.
If
> european agencies monitor crew doses, then they must fly with TLD or
similar
> badges.
>
> -Russ
>
> Jim Hardeman wrote:
>
> > Colleagues -
> >
> > Article appeared on CNN.com today ...
> >
> > URL =
http://www.cnn.com/2004/TRAVEL/07/06/life.radiation.reut/index.html
> >
> > Jim Hardeman
> > Jim_Hardeman@dnr.state.ga.us
> >
> > ================
> >
> > Air crews look at radiation risk from flying
> > Tuesday, July 6, 2004 Posted: 12:35 PM EDT (1635 GMT)
> >
> > DALLAS, Texas (Reuters) -- Airline crews already have their hands full
> with concerns about stepped up security, congested airports and tipsy
> travelers.
> >
> > One more item to add to that list may be radiation exposure.
> >
> > The union for pilots at American Airlines is trying to increase
awareness
> among air crews that they are being exposed to enough cosmic radiation to
> fall into a U.S. government regulated category of radiation workers.
> >
> > The longer a person travels on a jet, the higher the jet travels and the
> closer the jet flies to the north or south poles, increase exposure to
> cosmic radiation, which comes from deep space and the sun. The Earth's
> atmosphere largely shields us from cosmic radiation, but planes fly where
> the atmosphere is thin.
> >
> > "It is clear that there are health risks associated with a career of
> flying," Federal Aviation Administration researchers wrote in a 2002
report
> on radiation exposure of air crews.
> >
> > Some of the routes that had the highest radiation exposure included
> flights between Tokyo and New York, London and Los Angeles, as well as
> between Athens and New York, it said.
> >
> > The exposure levels for air crews fall well within federal guidelines
for
> safe exposure for a healthy adult but the Allied Pilots Association said
the
> radiation exposure could present risks for the fetus of a pregnant woman.
A
> fetus has developing cells that are more likely to be damaged by exposure
to
> radiation than an adult.
> >
> > "For your average passenger, who flies occasionally, it is not an issue.
> For air crew members who fly more than 75 hours or more a month, that
> certainly adds up," said Capt. Joyce May, an American Airlines pilot who
is
> the deputy chairwoman of the APA's Aeromedical Committee.
> >
> > Higher altitudes, increased risk
> > The problem has become more acute recently as jets are flying at higher
> altitudes. The high-altitude flights help to cut down on jet fuel use, but
> they also increase exposure to cosmic radiation.
> >
> > May said that total radiation exposure doubles with every 6,500 feet of
> climate altitude.
> >
> > "For a jet cruising at 39,000 feet, the total radiation is about 64
times
> higher than at sea level. If you drop down to 33,000 feet, it is only
about
> 35 times greater than sea level," she said.
> >
> > May and the union are calling for more thorough training for air crews
so
> that they better understand their exposure risks to radiation. They are
> asking for better tracking of the radiation exposure of crew members and
> studies to see if the exposure presents any long-term health risks.
> >
> > A typical air crew member may experience about 200 millirems to 400
> millirems more exposure to ionizing radiation than the general population
> per year. The pilots and flight attendants working routes over the Pacific
> or Atlantic Ocean will likely top 500 millirems of radiation exposure.
> >
> > Galactic cosmic radiation is high energy and penetrates all parts of an
> aircraft equally, scientists said. It is also ionizing radiation, meaning
it
> can penetrate the human body and disrupt the healthy function of cells.
> >
> > Radiation workers
> > The United States does not have any regulations for air crews pertaining
> to radiation exposure, but several European countries classify air crews
as
> radiation workers and monitor their exposure levels.
> >
> > There are no definitive studies linking cosmic radiation exposure for
air
> crews with health risks, May said, but she did note one medical study
showed
> that pilots had three to four times the rate of malignant melanoma -- a
type
> of skin cancer -- than the general population.
> >
> > In order to give some perspective, workers at the Los Alamos Nuclear
> Laboratory, the birthplace of the atomic bomb, have an annual safety limit
> of 2,000 millirems of exposure, while the preeminent nuclear research lab
> tries to limit radiation exposure for a pregnant woman to 500 millirems
for
> the term of her pregnancy.
> >
> > Other federal agencies have a safe, annual exposure level of 5,000
> millirems.
> >
> > Tom Buhl, a top health physicist at Los Alamos said that while air crews
> may meet the U.S. minimum standard of radiation workers, he does not think
> they should be classified as such because they do not face the risk of a
> large, unexpected dose of radiation. "On an airplane, the radiation field
is
> pretty well known. You have a pretty good understanding of what that
> radiation is," Buhl said.
> >
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