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updated thu 19 oct 00


Theresa L. JOnes on thu 12 mar 98

My understanding is that dioxins occur from the bleaching process of paper
(I'm not implying this is the only source). Bleached coffee filters, facial
and toilet tissue, paper plates and all these other bleached paper product
people use daily are coated with dioxins. In addition, dioxins from the
bleaching process are dumped into rivers, etc. SO, with this in mind, my
concerns about dioxin contact are not related to clay or chicken feed but
more with products that I might use daily. (I do not use bleached coffee
filters, I have a non-disposable one). We are bombarded with dioxins and
other toxic substances from so many other sources, any possible contact from
clay may be insignificant in comparison. Still, I confess I do not want to
eat eggs or meat from dioxin-fed chickens and wonder if this contaminant is
in other feeds.

Theresa L. Jones

Gavin Stairs on fri 13 mar 98

Dioxins and related compounds are just chlorinated (halogenated) carbon
ring compounds (benzene, phenol...). Just put these two together (Cl and
CxHyRz) and you will get some chlorinated hydrocarbons, dioxin among them.
These compounds are now very common traces around us. Most of what we see
comes from things like vinyl chloride, bleaching, pesticides, many
industrial processes. However, there is no reason that these compounds
cannot form in nature. Just put salt together with organic material, in
the presence of an enzyme or catalyst (like clay), and you will likely form
some dioxin. Likely we have been living with it forever, at trace levels.

In our clay, this is just another volatile. It will probably not break
down in the kiln, but will be emitted along with the rest of the stuff.
Don't breathe kiln gas.


Gavin Stairs
Toronto, Ontario, Canada

Nancy Galland on wed 18 oct 00

I am posting thiis with the permission of the author:

Reply-To: ""
From: ""

HI Nancy,

I'm sorry I must have missed the original post on dioxins or I would have
responded. I spent a great deal of time a decade ago fighting the siting of
a hazardous waste incinerator in a neighboring county and part of my studies
included the effects of dioxins that could be burned in such a facility.

I am curious to know if ball clays from other areas have also been reported
as containing dioxins or is it just in the Southeast US? I also live in the
south, central North Carolina, and have had a good dioxin scare here several
years ago. You are very right to sound an alarm. It can, and will change how
we do our work. From what I have learned, the world really doesn't
understand what harm can come from dioxins and why we should be worried.

If you aren't familiar with the this part of the country, it is aerially
north of "cancer alley" and has several large paper mills that now are quite
governed, but for years were overlooked as many things in the south were. I
think we're just beginning to reap the "rewards" of our years of ignorance
and turning our heads to not see when the evidence proved we should take

As you undoubtedly have found out, the world at large doesn't want to know
about this topic. It's as if silence will protect us. And it won't!

Sara O'Neill
Geometrix Clay Designs
Durham, NC

----- Original Message -----
From: Nancy Galland
Sent: Sunday, October 15, 2000 8:52 AM
Subject: dioxin

> I am disturbed that Clayarters have not taken seriously the news that
> dioxin has been found in Ball Clay from mines in Mississippi, Kentucky,
> Tennessee. Except for Edouard Bastarache's entries, no significant
> discussion has developed. As a person who has been an organic farmer for
> years and who has studied the effects of dioxin from both pesticides and
> the many paper mills that surround our otherwise beautiful area in rural
> Maine, I take the news very serioulsy. The fact is that we are exposed to
> dioxins already from many industrial processes (incinerators, paper mills,
> etc.) and most commonly through pesticide residues in the food we eat (90%
> of our intake).
> I have made many calls to clay suppliers, Ceramics Monthly, and
> of pottery-related health hazards and have come up with the picture that
> the ceramics world is going through the denial phase that usually
> accompanies news that threatens to turn one's world upside down.
> It takes the EPA many years and many studies to come out with classifying
> any substance as a carcinogen. Studies on dioxins began in 1977. Dioxin
> has been recognized as a carcinogen by the EPA through studies since 1985.
> Driven by dioxin-producing industrial interests, the EPA has gone through
> many "reassessments" of their original findings that the threshold level
> exposure is 0.006 picograms per killograms of body weight - or .42 pg per
> 150 lbs. This means that our human bodies can tolerate only this amount of
> exposure daily until the accumulation of dioxin becomes carcinogenic in
> tissues, especially fatty tissues such as found in breasts and the liver.
> But on the average, we are already carrying far above this threshold of
> exposre in our bodies. According to EPA studies, we are already consuming
> 119 pg per day. (A picogram is 1,000 times smaller than a nanogram.)
> At 1991 the Eleventh International Symposium on Chloriniated Dioxins, the
> EPA's original 1985 assessment was confirmed. More importantly, it was
> determined from the vast scientific data submitted, that the accumulated
> levels of dioxin currently found in the population (the "background body
> burden") are already so high that " as body burdens increase within and
> above this range, the probability and severity as well as the spectrum of
> non-cancer effects most likely will increase". This means that not only
> dioxin a carcinogen, but other health effects also occur when we are
> exposed to dioxins. These include infertility ( dioxin is an "estrogenic
> compound", meaning it acts as a weak hormone and has been shown to be
> linked to male infertility), diabetes, learning disabilities, childhood
> cancers, and breast cancer ( breast milk is typically high in dioxins,
> which are transferred to infants during breast feeding). All of these
> health problems are on the rise in this country.
> It also means that as a society, we have been accumulating dioxins in our
> bodies and as a result, it will take only small additional exposures to
> push some people's dioxin levels to trigger adverse health effects. Low
> doses build up in the body over time. EPA studies also show how damage
> dioxin exposure to infants and children my not be "expressed" until much
> later in life. Are schools using dioxin-contaminated clays ?
> I have abstracted all this information from "Dying from Dioxin", by Lois
> Marie Gibbs, who some may recognize as the one-time happy mom who turned
> into an activist when her family and neighbors became terminally ill
> living near the infamous Love Canal.
> The conclusion any logic will lead us to is that there is no safe level of
> exposure to dioxins since our bodies already carry a high dose of "
> background burden".
> We need answers to many questions, but how the dioxin got into the Ball
> clay is not a helpful one at this point.
> * We need to know if a substitute can be found for Ball Clay - I was told
> that it could , by technicians at the Laguna clay factory. We need to let
> them know we want it to be done.
> * We need to know if dioxin remains in the clay after firing, and if so,
> can it leach through glazes. Do glazes and slips containing Ball Clay
> dioxins?
> * We need to know what happens to the dioxin in clay and glazes when we
> fire it - does it burn out, does it emit toxic fumes ?
> * It is esablished that dioxin enters the body through any path
> breathing dust and fumes, skin contact, ingestion. How can we protect
> ourselves from exposre?
> I have changed my clays to only those not containing ball clays. I suggest
> calling your suppliers and finding out which clays do not contain ball
> and changing to those until more answers are found and a substitute for
> the ball clay is found. Think of the miners who are exposed to dioxin as
> they mine this stuff! These mines may be closed if OSHA decides they are
> too toxic. Be prepared!