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Method for dioxin detection
Dear All,
Dr. Hideaki Miyata who is Professor of Setsunan University announced
last month that toluene extracted more dioxin from contaminated
vegetables in comparison with acetone that is used as the conventional
extractant.
It seems to me that method for dioxin detection is unestablished.
Does anyone know the most reliable method for dioxin detection that is
used in USA and EU?
Many thanks,
Kenichi Azuma
Japan
At 16:16 08/13/99 +0900 Ms.Matsuzaki wrote:
>Hello! My name is Matsuzaki(ms). I sent previously "Japan Times Thu. Aug.
12
>1999---Germany to check blood for dioxin--". The following article is in
the
>same context.
>
>---------------------------------------------------------------------------
----
>Asahi Shinbun (evening version) Aug. 11 1999. (Tentative Translation)
>
>[Question on the method of Dioxin detection --- The most toxic elements may
>be lost by vaporization. Residents presented the questionnaire]
>
>Many authorities including the national government and local governments
are
>recently reporting the dioxin concentrations in human blood as a indicate
>for human exposure. But the method for the analysis of dioxin in human
blood
>is not established in our country. It was revealed by some witnesses and
>tests that almost all parts of the most toxic elements may be lost during
>the process of concentration and vaporization. People who lived near
>incineration and asked to detect dioxin in their blood to experts or a
>laboratory overseas doubted the results from Japanese authorities. The
>latter were always much lower than the former.
>
>Dr. Shigeru Suzuki, the Center for Health and Environment of Miyagi
>prefecture tested the efficiency of the vaporization by nitrogen gas in the
>collaboration with the National Institute of Environmental Studies and
>reported the result at the annual meeting of the Society of the
>Environmental Chemistry in last month, July.
>
>It was convinced that dioxins are very stable both chemically and thermally
>and not vaporized at the room temperature, so that not lost. So, test
>practitioners are used to vaporize the solution until dried up by nitrogen
gas.
>
>The experiment by Dr. Suzuki, however, indicated that vaporization by the
>nitrogen gas blew off dioxin as well as the solvent. The lighter
components,
>that is tetraclhlorides or pentachlorides, were easy to be lost. During the
>blowing of 20 minutes, 60% of the tetrachlorides were lost. In contrast
>hexachlorides and octachlorides were not blown off. They were all remained
>in the dried part. The temperature also affect the efficiency for the blow
>off. Only 4% was remained after 20 minutes blow at 60 degree centigrade,
for
>example.
>
>There can be seen the evidences for this fault in the reports of the
>authorities. One of those is the result of dioxin detection in human blood
>of the residents near the Shirotori incinerator. The blood was collected in
>last December and the result was reported in this Spring by the government
>Ibaraki Prefecture. (This project was led by Dr. Masatoshi Morita of the
>NIES. He trained the employees of the private laboratory that trusted the
>analysis.) The residents pointed out that only 8% of the 120 persons were
>detected in 2,3,7,8-TCDD and one or two picograms were detected among the
>rest of the people. The average concentration of dioxin was 9.7 picogram
>per fat gram in TEQ, which is a half of the presumable amount in general
>population in the industrial countries.
>
>Dr. Hideaki Miyata who was analyzed the blood of the residents before last
>year reported the 2,3,7,8-TCDD. The residents would present their question
>to the government, the Ministry of Heath and Welfare and the Agency of
>Environment. (Dr. Miyata doesn*t use nitrogen gas, instead leave the
>solution at room temperature for 24 hours.)
>
>(The omments in the parenthesis are from the sender.)
>------------------------------------------------------
>
>
At 2:12 07/13/99 -0400 Jane Williams wrote:
>From: Paul Goettlich[SMTP:gottlich@hotcoco.infi.net]
>Sent: Friday, July 09, 1999 11:43 AM
>To: ed-com
>Subject: ED-Com: New test shows double the dioxins in vegetables
>
>New test shows double the dioxins in vegetables
>Source: Kyodo News Service/Associated Press
>
>KITAKYUSHU, Japan, July 9 (Kyodo) -- A group of researchers at Setsunan
>University in Osaka Prefecture have developed a new method for measuring
>the level of dioxins in vegetables and found that they contained about
>twice the levels as the conventional method had revealed, the
>researchers said Friday.
>
>The researchers, led by Soichi Ota, presented the new method Thursday at
>an academic meeting held in Kitakyushu, Fukuoka Prefecture. The meeting
>ended Friday.
>
>Ota said his group created a new solvent to extract dioxins, harmful
>chloric compounds that cause cancer, from vegetables, and then compared
>the new solvent with the conventional one.
>
>For example, a leek sample that revealed 0.12 picogram of dioxins under
>the conventional method, showed 0.24 picogram under the new method. One
>picogram is one-trillionth of a gram.
>
>The new method also revealed that spinach and three other kinds of
>vegetables contained about twice the levels of dioxins as the
>conventional method had shown, Ota said.
>
>Spinach grown near plastic waste incinerators, and leeks, which are more
>exposed to the atmosphere than other vegetables because of their shape,
>were found to be substantially more contaminated than carrots and
>potatoes, which grow underground, and spinach grown in areas without
>incinerators, he said.
>
>Incinerators burning plastic waste are regarded as one of the major
>sources of dioxins.
>
>Ota said previous data may "underestimate" the level of dioxin
>contamination in vegetables.
>
>"When plants are actively photosynthesizing, their intake of dioxins
>also increases. Special attention should be paid to leafy vegetables
>grown near sources of dioxin during the summer," he said.
>
> Publication date: Jul 09, 1999
> ¡¦1999, NewsReal, Inc.
>
>--
>Paul Goettlich, Webmaster
>Hoosier Environmental Council
>http://www.enviroweb.org/hecweb
>gottlich@hotcoco.infi.net
>
>
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Kenichi Azuma
http://www.kcn.ne.jp/~azuma/ (In Japanese)
http://www.kcn.ne.jp/~azuma/English/english_index.htm (In English)
E-mail: azuma@kcn.ne.jp
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