Chris Rupp on fri 3 jan 03
Hello,
I have an old piece of ceramic work by Laura Andreson, which has an Otto
Natzler, orange uranium-based glaze on it. It is a beautiful bright orange,
but I am wondering if it is safe.
I would have to figure that they could only get depleted uranium in the
early to mid 1950's, but who knows? Is it possible that the piece has any
continuing radioactivity due to its content?
I don't care if it is food safe, as I would not be using it for food.
Rather, I just want to know if it is safe around the house, safe to handle,
and safe to keep.
Any suggestions? Any thoughts or, better yet, knowledge on the subject would
be greatly appreciated.
Chris Rupp
Sunny Santa Barbara
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Snail Scott on sat 4 jan 03
At 10:25 PM 1/3/03 -0800, Chris Rupp wrote:
>I have an old piece of ceramic work by Laura Andreson, which has an Otto
>Natzler, orange uranium-based glaze on it....Is it possible that the piece
has any
>continuing radioactivity due to its content?
Since you are in Santa Barbara, why not take it
to UCSB and ask the physics or engineering
folks if they might test it? In my experience,
even some ceramics engineers find our uses of
clay to be novel and amusing, and most of them
have never heard of the old uranium glazes.
They might get a kick out of it!
-Snail
Earl Brunner on sat 4 jan 03
geiger counter. If you can't find one, stick some film next to it for a
day and then have it developed. Anyone that works with x-ray equipment
ought to have something to check for radiation. Even a rad counter
would probably do the trick.
Chris Rupp wrote:
> Hello,
>
> I have an old piece of ceramic work by Laura Andreson, which has an Otto
> Natzler, orange uranium-based glaze on it. It is a beautiful bright orange,
> but I am wondering if it is safe.
>
> I would have to figure that they could only get depleted uranium in the
> early to mid 1950's, but who knows? Is it possible that the piece has any
> continuing radioactivity due to its content?
>
> I don't care if it is food safe, as I would not be using it for food.
> Rather, I just want to know if it is safe around the house, safe to handle,
> and safe to keep.
>
> Any suggestions? Any thoughts or, better yet, knowledge on the subject
> would
> be greatly appreciated.
>
> Chris Rupp
> Sunny Santa Barbara
>
> _________________________________________________________________
> The new MSN 8 is here: Try it free* for 2 months
> http://join.msn.com/?page=dept/dialup
>
> ______________________________________________________________________________
>
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
Carl Finch on sat 4 jan 03
At 10:25 PM 1/3/03 -0800, Chris Rupp wrote:
>I have an old piece of ceramic work by Laura Andreson, which has an Otto
>Natzler, orange uranium-based glaze on it. It is a beautiful bright orange,
>but I am wondering if it is safe.
>
>I would have to figure that they could only get depleted uranium in the
>early to mid 1950's, but who knows? Is it possible that the piece has any
>continuing radioactivity due to its content?
Dunno for sure, Chris, but just to be on the safe side, I suggest you
carefully double box that pot (don't want that nasty radiation to drive any
more USPS workers postal) and mail it off to me. I will scan it for
radiation (using my high-precision Umax Astra 1220P scanner) and let you
know just how very dangerous it is--and dispose of it.
I will be happy to do this for you at no cost. Just my way of "giving
back," as they say.
--Carl Finch
P.O. Box U235RUs
Medford, Oregon
BeardiePaw on sat 4 jan 03
Call the local hospital and ask if they have a Nuclear Medicine Dept. There
are always Geiger counters there. Ask if they would test it on a GM. Or
stick it underneath the gamma camera. It is sensitive enough to see
background radiation. Sherry Morrow
BeardiePaw Pottery
Edouard Bastarache on sat 4 jan 03
1) Accidental contamination from uranium compounds through contact with
ceramic dinnerware, by Ralph W. Sheets, Clifton C. Thompson
ABSTRACT: Examination of orange-colored dinnerware samples purchased in
antique stores and flea markets has revealed the occasional presence of
surface uranium compounds that are readily transferred to the hands and
clothing. We have further been able to produce soluble uranium compounds on
the surfaces of clean dishes by exposing them to household vinegar or
bleach. We estimate that handling of a contaminated dish can transfer up to
1-2 becquerels or more or uranium compounds to the hands. Uranium
contamination is of concern because the element is not only an alpha emitter
but also a chemical nephrotoxin. Although the amount of uranium likely to
be ingested as a result of casual handling may be small, it could still
exceed by several times the amount occurring in the average diet (about 40
mBq/day). Furthermore, since fresh surface compounds are readily formed, it
is possible that a person who regularly handles or eats from uranium-glazed
dinnerware can accidently ingest significant amounts of uranium.
2) Release of uranium and emission of radiation from uranium-glazed
dinnerware, by Ralph W. Sheets, Sandra L. Turpen
ABSTRACT: Samples of orange, yellow, beige, ivory and blue-green ceramic
dinnerware glazed with uranium compounds have been examined. Measurements at
glaze surfaces yielded exposure rates of 3.8-16 mR/h (1-4 uC/kgh) for orange
glazes and rates of 0.04-1.3 mR/h (0.01-0.3 uC/kgh) for ivory, beige, and
yellow glazes. Whole body exposure from a shelf display of 40 orange dishes
was estimated to be 0.1-0.5 mR/h(0.03-0.13 uC/kgh), or up to 50 times the
room background radiation level, at a distance of 1 meter. Twenty-four hour
leaching tests of orange, yellow, and ivory dishes were carried out with
various concentrations of acetic and citric acids. Uranium concentration in
leachates of some orange dishes exceeded 450 mg/L. Uranium is a chemical
nephrotoxin and the United States Environmental Protection Agency has
proposed a maximum contaminant level for drinking water of 0.020 mg/L. Based
on this value a person consuming 2.2 L of drinking water per day would
ingest 0.31 mg of uranium per week. A person eating once a week from an
orange glazed dish could easily ingest 10 or more times this amount.
Later,
"Ils sont fous ces Quebecois"
Edouard Bastarache
Irreductible Quebecois
Indomitable Quebeker
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
http://sorel-tracy.qc.ca/~edouardb/
http://perso.wanadoo.fr/smart2000/index.htm
James Bledsoe on sat 4 jan 03
> >I would have to figure that they could only get depleted uranium in the
> >early to mid 1950's, but who knows? Is it possible that the piece has any
> >continuing radioactivity due to its content?
depleted uranium is U238 with most of the 235 taken out it is not safe
don't be fooled stay away
jim
Catherine White on sat 4 jan 03
Uranium in the '60s:
Rhodesia, 1965 (Zimbabwe 1978). Prime Minister Ian Smith proclaimed the
country's independence. Britain retaliated with a trade embargo. That was
the end of readily available uranium, at least for me. I had a small
quantity that I may never have used given that I don't glow in the dark.
;-)
Catherine in Yuma, AZ
Two ancient electric kilns. Both outside.
It never rains here at the Mexican border.
One partner, one kid, one dog, two cats. All inside.
=====================================================
> 1) Accidental contamination from uranium compounds through contact with
> ceramic dinnerware, by Ralph W. Sheets, Clifton C. Thompson
Edouard Bastarache
Pink Boy on sat 4 jan 03
Chris Rupp,
> I have an old piece of ceramic work by Laura
> Andreson, which has an Otto Natzler, orange uranium
> based glaze on it. It is a beautiful bright orange,
> but I am wondering if it is safe.
> I don't care if it is food safe, as I would not be
> using it for food. Rather, I just want to know if
> it is safe around the house, safe to handle, and
> safe to keep.
Yeah it's safe enough. Just don't eat off it. It's
radio active but not very in the big scheme of things.
Mr Foo
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Dannon Rhudy on mon 6 jan 03
Gavin Stairs said:
> The emissions from most natural and depleted uranium are more complex than
> just the alphas. Daughter elements (the result of uranium decays and
> fissions) also emit, and they emit betas (electrons), gammas (photons) as
> well as neutrons and fission fragments. .........the older the item, the
more likely it is to emit these particles at higher levels, as levels of
daughters rise to saturation levels........
Gavin, we don't take enough time to thank you, and others
with exceptional technical information, for your constant help
in identifying what needs identification and helping us keep our
wits about us.
Mostly, though, it is your ability to make complex issues clear
to those without all that information that deserves thanks.
So thanks. To you, and Tom Buck, and Ron Roy, John Hesselberth,
June Perry, Lily Krakowski, Craig Martell, Eduourd Bastarache,
and many others,thank you for your continual help, explanation,
clarification, information, and generosity to this list.
regards
Dannon Rhudy
Janice M. Boyd on mon 6 jan 03
My 2 cents worth:
Chris,
The uranium in your ceramic piece is the naturally occuring mineral uranium,
which means it is about 99 percent uranium-238 and 1 percent the fissionable
(i.e. bomb-grade) isotope uranium-235. Both of those isotopes are
radioactive. I recommend having your ceramics monitored (call any big
university in your area and ask for the Radiation Safety department), to
tell for sure.
Now the good news:
Uranium decays by emitting alpha particles. This is "soft" radioactivity.
It can't get through a piece of tissue paper. It can't get through your
skin. It only travels a few inches in the air. So looking at your ceramic
pieces on a self is no danger. If you are worried by it, put it behind a
glass window.
You probably already have other items in your house that contain uranium.
It is in most smoke detectors. It is in the elements for Coleman lanterns.
Depending on the age of your house, it may be in the floor tiles. Aside
from being a little creepy, it's not a big problem.
HOWEVER: (otherwise known as the downside)
Those ceramic pieces are NOT FOOD SAFE. Alpha particles (and uranium) are
very safe outside your body. Alpha particles inside your body are not
good. They'll knock the stuffing out of your important molecules like DNA
and proteins. You won't get radioactive sickness or lose your hair or
anything horrific like that, but you will increase your risk of cancer.
Granted, eating out of uranium-glazed vessels is probably less risky than
smoking, or spending lots of time breathing silica particles, but why take a
risk, when you don't need to?
Conclusion:
So - don't eat out of these pieces and wash your hands after handling them -
and all should be OK.
Janice Boyd
jmmboyd@hotmail.com
BTW - my PhD is in molecular biology, and my particular research involved
using radioactivity to label proteins and DNA. I'm a neophyte at pottery
(I've only been doing it 3 years), but I know a fair amount about
radioactivity, cancer, DNA and proteins. If anyone has more specific
questions feel free to email me.
On Fri, 3 Jan 2003 22:25:29 -0800, Chris Rupp
wrote:
>Hello,
>
>I have an old piece of ceramic work by Laura Andreson, which has an Otto
>Natzler, orange uranium-based glaze on it. It is a beautiful bright orange,
>but I am wondering if it is safe.
>
>I would have to figure that they could only get depleted uranium in the
>early to mid 1950's, but who knows? Is it possible that the piece has any
>continuing radioactivity due to its content?
>
>I don't care if it is food safe, as I would not be using it for food.
>Rather, I just want to know if it is safe around the house, safe to handle,
>and safe to keep.
>
>Any suggestions? Any thoughts or, better yet, knowledge on the subject
would
>be greatly appreciated.
>
>Chris Rupp
>Sunny Santa Barbara
>
>_________________________________________________________________
>The new MSN 8 is here: Try it free* for 2 months
>http://join.msn.com/?page=dept/dialup
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Pink Boy on mon 6 jan 03
Janice M. Boyd sez,
> You probably already have other items in your house
> that contain uranium. It is in most smoke
> detectors. It is in the elements for Coleman
> lanterns.
Actually is Californium in Smoky detectors and thorium
in gas mantles. But the above it true nuff. Uranium
ain't very radioactive and most of the radiation
won't go more than a few inches in air. So it's
safe to have lying around.
> HOWEVER: (otherwise known as the downside)
>
> Those ceramic pieces are NOT FOOD SAFE. Alpha
> particles (and uranium) are very safe outside your
> body. Alpha particles inside your body are not
> good. They'll knock the stuffing out of your
> important molecules like DNA and proteins.
Agreed on that, from the nuclear engineering class I
took in school, basically you never want to get
radioactive elements inside you.
> You won't get radioactive sickness or lose your hair
> or anything horrific like that, but you will
increase
> your risk of cancer.
True nuff.
> Granted, eating out of uranium-glazed vessels is
> probably less risky than smoking, or spending lots
> of time breathing silica particles, but why take a
> risk, when you don't need to?
Yes basically in this case you'd be accepting a low
low risk, even if you were eating off a uranium-glazed
plate every day and sleeping with it every night.
> So - don't eat out of these pieces and wash your
> hands after handling them - and all should be OK.
Ya!
> BTW - my PhD is in molecular biology, and my
> particular research involved using radioactivity to
> label proteins and DNA. I'm a neophyte at pottery
> (I've only been doing it 3 years), but I know a fair
> amount about radioactivity, cancer, DNA and
> proteins. If anyone has more specific questions
> feel free to email me.
Cool! Me, one semester class in Intro to Nuclear
Engineering back in 1986 or so.
Mr Foo
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Gavin Stairs on mon 6 jan 03
At 02:15 PM 06/01/2003 -0500, you wrote:
>Uranium decays by emitting alpha particles. This is "soft" radioactivity.
>It can't get through a piece of tissue paper. It can't get through your
>skin. It only travels a few inches in the air. So looking at your ceramic
>pieces on a self is no danger. If you are worried by it, put it behind a
>glass window.
>
>You probably already have other items in your house that contain uranium.
>It is in most smoke detectors. It is in the elements for Coleman lanterns.
>Depending on the age of your house, it may be in the floor tiles. Aside
>from being a little creepy, it's not a big problem.
These statements are only partly correct.
The emissions from most natural and depleted uranium are more complex than
just the alphas. Daughter elements (the result of uranium decays and
fissions) also emit, and they emit betas (electrons), gammas (photons) as
well as neutrons and fission fragments. It is the 1MeV photons which are
the most penetrating. Only chemically refined uranium lacking these
daughters is a relatively pure alpha emitter. So it is very likely that
you will get a small exposure just by standing next to a uranium glaze
plate. And the older the item, the more likely it is to emit these
particles at higher levels, as levels of daughters rise to saturation levels.
The radioisotope in smoke detectors (actually ionization chamber detectors,
or volatile vapour detectors) is usually Americium. The primary
radioactive element in lamp mantles is Thorium.
However, Uranium is found in traces in virtually all rocks, and therefore
is present in concrete and plaster walls, etc. Except for local suppliers
changing sources of their aggregates when they become aware of an excessive
level, and the use of various concentrates like blast furnace slag in
concrete, the amount of Uranium in these materials will fluctuate, but will
on average be about at the relative atomic abundance level.
Sorry to nit-pick. The science of radiation exposure and danger of future
illness is relatively poorly developed. There is no widely accepted
epidemiology on low level exposures. We are all exposed more or less
continuously to cosmic rays and to background radiation. It may be an
intrinsic part of the process of speciation, through acting as the primary
source of germ line changes. It may also be a determinative cause of many
cancers. However, a dose-response relationship in low level radiation is
not established, so far as I know. Most advice is based on an assumption
of dose-response linearity to low levels. This is the conservative
assumption, ie., the assumption of the worst case.
The conservative advice is therefore to minimize all exposures to
radiation, whatever the source. This would include uranium glaze
plates. I would avoid using uranium glaze plates for serving or storing
wet food. Simple storage and display of a piece of uranium glaze pottery
would not be an excessive hazard, provided the exposure was not
continual. Habitually sleeping beside such a plate might be less of a good
idea.
The primary risk to potters is inhalation, ingestion or introduction into
open wounds of uranium oxide powder. This is a much higher risk than that
posed by simply keeping a pot in a home display. While most such exposures
may be cleared quickly by ordinary bodily defences, such introductions into
the body permit various organs to be directly exposed to alpha radiation,
which is the most damaging kind of body radiation exposure.
Also, and finally, keeping a potentially dangerous item like a uranium
glaze plate around with the intention not to use it to serve food is fine
so long as the original owner is around. Strangers may not be
knowledgeable, and may use the plates in ignorance. Label it clearly with
the danger and advisable uses.
All the best, Gavin
Gavin Stairs
Stairs Small Systems
525 Canterbury Road
London, Ontario
Canada N6G 2N5
telephone: (519) 434-8555.
email: stairs@stairs.on.ca
Chris Rupp on mon 6 jan 03
Hello Everyone,
Well, I will try and let you all know the verdict tomorrow!
Tomorrow morning I have an appointment with a physics professor at Westmont
College, here in Santa Barbara. I took a few classes in the area, but I was
an art major and don't know enough about the stuff(uranium) to feel safe
around it. Anyway...
The professor told me that not only can we measure how much particles
(radiation, alpha particles, etc...) the piece is emitting, but he has some
sort of devise that will indicate exactly what elements were used in the
glaze. He will give me some advise as to how to handle it and display it,
which I am sure will be very close to the advise I have received from all my
Clayart friends!
Thanks for the help and I will keep you all posted.
Take Care,
Chris Rupp
Sunny Santa Barbara, in the high 70's today!
>From: "Janice M. Boyd"
>Reply-To: Clayart
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: Are old URANIUM based glazes safe?
>Date: Mon, 6 Jan 2003 14:15:16 -0500
>
>My 2 cents worth:
>
>
>Chris,
>
>The uranium in your ceramic piece is the naturally occuring mineral
>uranium,
>which means it is about 99 percent uranium-238 and 1 percent the
>fissionable
>(i.e. bomb-grade) isotope uranium-235. Both of those isotopes are
>radioactive. I recommend having your ceramics monitored (call any big
>university in your area and ask for the Radiation Safety department), to
>tell for sure.
>
>Now the good news:
>
>Uranium decays by emitting alpha particles. This is "soft" radioactivity.
>It can't get through a piece of tissue paper. It can't get through your
>skin. It only travels a few inches in the air. So looking at your ceramic
>pieces on a self is no danger. If you are worried by it, put it behind a
>glass window.
>
>You probably already have other items in your house that contain uranium.
>It is in most smoke detectors. It is in the elements for Coleman lanterns.
>Depending on the age of your house, it may be in the floor tiles. Aside
>from being a little creepy, it's not a big problem.
>
>HOWEVER: (otherwise known as the downside)
>
>Those ceramic pieces are NOT FOOD SAFE. Alpha particles (and uranium) are
>very safe outside your body. Alpha particles inside your body are not
>good. They'll knock the stuffing out of your important molecules like DNA
>and proteins. You won't get radioactive sickness or lose your hair or
>anything horrific like that, but you will increase your risk of cancer.
>Granted, eating out of uranium-glazed vessels is probably less risky than
>smoking, or spending lots of time breathing silica particles, but why take
>a
>risk, when you don't need to?
>
>
>Conclusion:
>
>So - don't eat out of these pieces and wash your hands after handling them
>-
>and all should be OK.
>
>
>Janice Boyd
>jmmboyd@hotmail.com
>
>BTW - my PhD is in molecular biology, and my particular research involved
>using radioactivity to label proteins and DNA. I'm a neophyte at pottery
>(I've only been doing it 3 years), but I know a fair amount about
>radioactivity, cancer, DNA and proteins. If anyone has more specific
>questions feel free to email me.
>
>
>
>
>
>
>
>On Fri, 3 Jan 2003 22:25:29 -0800, Chris Rupp
>wrote:
>
> >Hello,
> >
> >I have an old piece of ceramic work by Laura Andreson, which has an Otto
> >Natzler, orange uranium-based glaze on it. It is a beautiful bright
>orange,
> >but I am wondering if it is safe.
> >
> >I would have to figure that they could only get depleted uranium in the
> >early to mid 1950's, but who knows? Is it possible that the piece has any
> >continuing radioactivity due to its content?
> >
> >I don't care if it is food safe, as I would not be using it for food.
> >Rather, I just want to know if it is safe around the house, safe to
>handle,
> >and safe to keep.
> >
> >Any suggestions? Any thoughts or, better yet, knowledge on the subject
>would
> >be greatly appreciated.
> >
> >Chris Rupp
> >Sunny Santa Barbara
> >
> >_________________________________________________________________
> >The new MSN 8 is here: Try it free* for 2 months
> >http://join.msn.com/?page=dept/dialup
> >
> >______________________________________________________________________________
> >Send postings to clayart@lsv.ceramics.org
> >
> >You may look at the archives for the list or change your subscription
> >settings from http://www.ceramics.org/clayart/
> >
> >Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
_________________________________________________________________
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Ernesto Burciaga on mon 6 jan 03
"
> My 2 cents worth:
>
Back in my youth , when I had lots of hair, in college the ceramics studio had a
bag of uranium oxide as a colorant. I used it once and it produced a strong
almost garish yellow. Where that pottery is now????????????
Depleted uranium is another question. It is a very deadly stuff. It killed many
Iraqis during Desert Storm about ten years ago. The A-10 Wort Hog aircraft used
40 mm DU bullets. Because of its density it would penetrate 6+ inch armored
tanks. There are other weapons in this category.
The only real danger to the potter would be heavy metal hazards, i.e. lead.
Ernesto
Pink Boy on mon 6 jan 03
Gavin Stairs sez,
> The emissions from most natural and depleted uranium
> are more complex than just the alphas. Daughter
> elements (the result of uranium decays and fissions)
> also emit, and they emit betas (electrons), gammas
> (photons) as well as neutrons and fission
> fragments. It is the 1MeV photons which are the
> most penetrating.
Well yes, the decay of natural uranium is complicated.
You end up with a whole soup of radioactive daughter
products with then decay into more daughter products
until you end up with stable stuff.
All of which made my head hurt 15 years ago and is
more than most people want to know or more to the
point more than I want to go into here. Cause I'd
have to look it up and stuff.
From the web though:
http://www.hps.org/publicinformation/ate/q1633.html
"For a homeowner who did not use the dinnerware, but
simply had it on display, NUREG-1717 estimated the
effective dose equivalent to be 0.06 mrem per year."
As an point of reference the NRC regulations limits
for the general public is 25 mrem per year or about
400 times higher.
Mr Foo
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Gavin Stairs on tue 7 jan 03
At 05:56 PM 07/01/2003 -0800, Snail wrote:
>At 12:04 PM 1/7/03 -0800, you wrote:
>
> >However, sometime in the next week we are going to test the piece further,
> >using a Geranium Detector...
>
>
>Normally, a simple visual test will suffice to
>determine the presence of geraniums in a pot.
Germanium. Germanium detector. Commonly used with neutron activation to
do elemental analysis by photon energy spectrum. May also be used to
survey weak emitters like the supposed uranium glaze in question. Should
be good fun.
Gavin
Chris Rupp on tue 7 jan 03
For all of you following this Clayart thread, the verdict is in!
I had the Orange Laura Andreson piece tested this morning, using a Geiger
Counter. Compared to the background room radiation, there was NOTHING! No
detectable radiation, and no detectable alpha particles. We compared it to
"safe" radioactive samples encased in plastic and the counter lit up, but
when held up against the piece, nothing! A delight indeed.
However, sometime in the next week we are going to test the piece further,
using a Geranium Detector. This devise is filled with liquid nitrogen and
hooked up to a computer that monitors it for an hour. The results should
tell us exactly what elements are present in the piece and give further
insight into its composition, including daughter isotopes and different
particles.
A BIG THANK YOU to all of you that responded to this posting and gave your
advise it was very helpful! I will let you know what the results of the
Geranium test are.
Take Care,
Chris Rupp
Sunny Santa Barbara
>From: Gavin Stairs
>Reply-To: Clayart
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: Are old URANIUM based glazes safe?
>Date: Mon, 6 Jan 2003 17:20:12 -0500
>
>At 02:15 PM 06/01/2003 -0500, you wrote:
>>Uranium decays by emitting alpha particles. This is "soft" radioactivity.
>>It can't get through a piece of tissue paper. It can't get through your
>>skin. It only travels a few inches in the air. So looking at your
>>ceramic
>>pieces on a self is no danger. If you are worried by it, put it behind a
>>glass window.
>>
>>You probably already have other items in your house that contain uranium.
>>It is in most smoke detectors. It is in the elements for Coleman
>>lanterns.
>>Depending on the age of your house, it may be in the floor tiles. Aside
>>from being a little creepy, it's not a big problem.
>
>These statements are only partly correct.
>
>The emissions from most natural and depleted uranium are more complex than
>just the alphas. Daughter elements (the result of uranium decays and
>fissions) also emit, and they emit betas (electrons), gammas (photons) as
>well as neutrons and fission fragments. It is the 1MeV photons which are
>the most penetrating. Only chemically refined uranium lacking these
>daughters is a relatively pure alpha emitter. So it is very likely that
>you will get a small exposure just by standing next to a uranium glaze
>plate. And the older the item, the more likely it is to emit these
>particles at higher levels, as levels of daughters rise to saturation
>levels.
>
>The radioisotope in smoke detectors (actually ionization chamber detectors,
>or volatile vapour detectors) is usually Americium. The primary
>radioactive element in lamp mantles is Thorium.
>
>However, Uranium is found in traces in virtually all rocks, and therefore
>is present in concrete and plaster walls, etc. Except for local suppliers
>changing sources of their aggregates when they become aware of an excessive
>level, and the use of various concentrates like blast furnace slag in
>concrete, the amount of Uranium in these materials will fluctuate, but will
>on average be about at the relative atomic abundance level.
>
>Sorry to nit-pick. The science of radiation exposure and danger of future
>illness is relatively poorly developed. There is no widely accepted
>epidemiology on low level exposures. We are all exposed more or less
>continuously to cosmic rays and to background radiation. It may be an
>intrinsic part of the process of speciation, through acting as the primary
>source of germ line changes. It may also be a determinative cause of many
>cancers. However, a dose-response relationship in low level radiation is
>not established, so far as I know. Most advice is based on an assumption
>of dose-response linearity to low levels. This is the conservative
>assumption, ie., the assumption of the worst case.
>
>The conservative advice is therefore to minimize all exposures to
>radiation, whatever the source. This would include uranium glaze
>plates. I would avoid using uranium glaze plates for serving or storing
>wet food. Simple storage and display of a piece of uranium glaze pottery
>would not be an excessive hazard, provided the exposure was not
>continual. Habitually sleeping beside such a plate might be less of a good
>idea.
>
>The primary risk to potters is inhalation, ingestion or introduction into
>open wounds of uranium oxide powder. This is a much higher risk than that
>posed by simply keeping a pot in a home display. While most such exposures
>may be cleared quickly by ordinary bodily defences, such introductions into
>the body permit various organs to be directly exposed to alpha radiation,
>which is the most damaging kind of body radiation exposure.
>
>Also, and finally, keeping a potentially dangerous item like a uranium
>glaze plate around with the intention not to use it to serve food is fine
>so long as the original owner is around. Strangers may not be
>knowledgeable, and may use the plates in ignorance. Label it clearly with
>the danger and advisable uses.
>
>All the best, Gavin
>
>Gavin Stairs
>Stairs Small Systems
>525 Canterbury Road
>London, Ontario
>Canada N6G 2N5
>
>telephone: (519) 434-8555.
>email: stairs@stairs.on.ca
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
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>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
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Snail Scott on tue 7 jan 03
At 12:04 PM 1/7/03 -0800, you wrote:
>However, sometime in the next week we are going to test the piece further,
>using a Geranium Detector...
Normally, a simple visual test will suffice to
determine the presence of geraniums in a pot.
(Similar methods are often used to check for
the presence of marigolds, chrysanthemums, and
begonias.) However, should invisible geraniums
be detected via modern scientific methods, it
may be advisable to water them immediately, as
significant wilting may occur if left untended.
The recurrence of future geraniums is typically
prevented by careful exclusion of geranium seeds
or cuttings from the vicinity of the pot. Removal
of existing geraniums may generally be achieved
by inverting the pot over a compost bin and
shaking vigorously. ;)
-Snail
Ernesto Burciaga on mon 13 jan 03
That fellow in Los Alamos is one of the local "characters" He worked for the Lab
about 30 years ago as an elec. tech. He collected government salvage from the lab,
resold it and eventually became a millionaire. The can of food he sent to the prez
was rapped with a new label identifying it as radioactive waste. The prez's men
thought it was a threat. The FBI talked with him and found out he was an
anti-lab,nuke, nut case and walked away with a good laugh. He is getting quite
older and slowing down but has been intertaining anyway over the years.
Ernesto
Find a health physicist for information on the safety of the uranium glaze.
John Rodgers on mon 13 jan 03
This is a little aside, slightly humorous, but on the subject of
radioactive materials.
During President Clinton's terms in office a gentleman, a resident of
Los Alamos, NM and former employee at the Los Almos Laboratories, had a
beef with the labs and the atomic work that had been done in the state
over the years. He had a concern about the environment and the food
supply being contaminated with radioactivity. He sent to then president
Clinton, a gift of canned produce grown in New Mexico. Within the hour
after the box was opened, the FBI was at his door and seized him and
his place of business, which was a surplus/salvage operation and sold
mostly stuff that had been surplused out of the Labs when a project
would close. There was quite an uproar but it finally blew over, and
things settled back down, but he was always "looked in upon"
periodically by "The Boys" after that. He gained considerable local
notoriety for the episode, got his story in the newspapers, and gave
everyone something to talk about for a while. Had lots of people coming
by after that. His place of business was wonderful for people who were
scavengers of old machines and equipment., etc., to build things.
Unfortunately, as I understand, he lost it in the big Los Almos Wildfire
that occurred a couple of years ago.
What had he done to cause such an uproar?
To make a point, he had written on the cans of beans the words ..........
"Organic Plutonium Bombs"!!
***********************
Just a little radioactive tale from out west.
John Rodgers
Birmingham, Al
Janice M. Boyd wrote:
>My 2 cents worth:
>
>
>Chris,
>
>The uranium in your ceramic piece is the naturally occuring mineral uranium,
>which means it is about 99 percent uranium-238 and 1 percent the fissionable
>(i.e. bomb-grade) isotope uranium-235. Both of those isotopes are
>radioactive. I recommend having your ceramics monitored (call any big
>university in your area and ask for the Radiation Safety department), to
>tell for sure.
>
>Now the good news:
>
>Uranium decays by emitting alpha particles. This is "soft" radioactivity.
>It can't get through a piece of tissue paper. It can't get through your
>skin. It only travels a few inches in the air. So looking at your ceramic
>pieces on a self is no danger. If you are worried by it, put it behind a
>glass window.
>
>You probably already have other items in your house that contain uranium.
>It is in most smoke detectors. It is in the elements for Coleman lanterns.
>Depending on the age of your house, it may be in the floor tiles. Aside
>from being a little creepy, it's not a big problem.
>
>HOWEVER: (otherwise known as the downside)
>
>Those ceramic pieces are NOT FOOD SAFE. Alpha particles (and uranium) are
>very safe outside your body. Alpha particles inside your body are not
>good. They'll knock the stuffing out of your important molecules like DNA
>and proteins. You won't get radioactive sickness or lose your hair or
>anything horrific like that, but you will increase your risk of cancer.
>Granted, eating out of uranium-glazed vessels is probably less risky than
>smoking, or spending lots of time breathing silica particles, but why take a
>risk, when you don't need to?
>
>
>Conclusion:
>
>So - don't eat out of these pieces and wash your hands after handling them -
>and all should be OK.
>
>
>Janice Boyd
>jmmboyd@hotmail.com
>
>BTW - my PhD is in molecular biology, and my particular research involved
>using radioactivity to label proteins and DNA. I'm a neophyte at pottery
>(I've only been doing it 3 years), but I know a fair amount about
>radioactivity, cancer, DNA and proteins. If anyone has more specific
>questions feel free to email me.
>
>
>
>
>
>
>
>On Fri, 3 Jan 2003 22:25:29 -0800, Chris Rupp
>wrote:
>
>
>
>>Hello,
>>
>>I have an old piece of ceramic work by Laura Andreson, which has an Otto
>>Natzler, orange uranium-based glaze on it. It is a beautiful bright orange,
>>but I am wondering if it is safe.
>>
>>I would have to figure that they could only get depleted uranium in the
>>early to mid 1950's, but who knows? Is it possible that the piece has any
>>continuing radioactivity due to its content?
>>
>>I don't care if it is food safe, as I would not be using it for food.
>>Rather, I just want to know if it is safe around the house, safe to handle,
>>and safe to keep.
>>
>>Any suggestions? Any thoughts or, better yet, knowledge on the subject
>>
>>
>would
>
>
>>be greatly appreciated.
>>
>>Chris Rupp
>>Sunny Santa Barbara
>>
>>_________________________________________________________________
>>The new MSN 8 is here: Try it free* for 2 months
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>>
>>______________________________________________________________________________
>>Send postings to clayart@lsv.ceramics.org
>>
>>You may look at the archives for the list or change your subscription
>>settings from http://www.ceramics.org/clayart/
>>
>>Moderator of the list is Mel Jacobson who may be reached at
>>
>>
>melpots@pclink.com.
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
>
>
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