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dioxins in kaolins and ball clays.

updated tue 19 sep 00


Edouard Bastarache on mon 18 sep 00

Hello all,

1-TITLE: Exposure of populations to dioxins and related compounds.
AUTHORS: Liem AK; Furst P; Rappe C
AUTHOR AFFILIATION: National Institute of Public Health and the Environment
(RIVM), Bilthoven, The Netherlands.
SOURCE: Food Addit Contam 2000 Apr;17(4):241-59
"The most important route for human exposure to PCDDs, PCDFs and
(dioxin-like) PCBs is food consumption contributing over 90% of total
exposure, with products of animal origin and fish making the greatest
contribution to this exposure.

Countries that started to implement measures to reduce dioxin emissions in
the late 1980s, such as The Netherlands, United Kingdom and Germany, clearly
show decreasing PCDD/PCDF and PCB levels in food and consequently a
significantly lower dietary intake of these compounds by almost a factor of
2 within the past 7 years".

2-TITLE: Steps towards a European dioxin emission inventory.
AUTHORS: Quass U; Fermann MW; Broker G
AUTHOR AFFILIATION: Landesumweltant Nordrhein-Westfalen, Essen, Germany.
SOURCE: Chemosphere 2000 May-Jun;40(9-11):1125-9
CITATION IDS: PMID: 10739054 UI: 20201661

"As a result, on the European scale the largest annual PCDD/PCDF emission is
assessed to be released from municipal waste incineration, quite closely
followed by emissions from iron ore sintering. Considerable releases of
dioxins and furans--based, however, on highly uncertain data--are further
assessed for domestic burning, accidental fires and (former) use of
contaminated wood preservatives (pentachlorophenol). A lower but still
significant emission is further assigned to the sector of non-ferrous metal
production; particular processes used in this branch proved to generate very
high PCDD/PCDF flue gas concentrations".

3-According to Lennart Hardell MD PhD in Occupational Medicine, Carl Zenz
" They are ubiquitous in the environment and do not occur naturally"

4- But, if they have found naturally occurring dioxins in some kaolins and
ball clays,
then it is a new phenomenon to be explained.
My hypothesis, for what it may be worth, is that dioxins produced by a huge
pre-historic forest fire were trapped somehow in the weathering process of
making kaolins and ball clays. Hypotheses exist to be proved.

"In a regulation of 17 november 1999 the European Commission "on the
conditions for the authorisation of additions belonging to the group
'binder, anti-caking and coagulants' in feedingstuffs" states that
"...kaolinitic clays originating from certain mines situated in the Federal
Republic of Germany have been found to contain extremely high levels of
dioxine. According to available information, this could be a contamination
of geological origin... The use of feedingstuffs contaminated with dioxines
may contaminate foodstuffs of animal origin... The acceptable level of
dioxins in kaolinitic clays should be restricted to the analytical limit of
determination... The contamination could in fact also concern other
authorised additives, as indicated by the fact that ball clay, sedimentary
clays containing other minerals besides kaolin, originating from a mine in
the United States has also been shown to be heavily naturally contaminated
by dioxin of geological origin..."


Edouard Bastarache
Dans / In "La Belle Province"