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Tom, This didn’t make it through to the list due to the attachment. I
suggest you send the attachment directly to Cong and if others would like it,
they can request it. Jon ~~~~~~~~~~~~~~~~~~~ Jon Dettling 734-274-5183 dettling@glc.org From: Tom Velalis
[mailto:tom.velalis@epa.state.oh.us] Jon I believe you
provided an accurate response to Cong's question. Also, that is the
arrangment used by NEI.
Attached is Ohio's table of Pollutants which is based on the NEI
table. The Dioxin and Furan groups exclude the
TEQs. The Explanation is provided in the
HAP_CATEGORY_NAME. The TEQs have their own CAS number and enjoy their own
space in the pollutants table. As far as
units go, I have converted all Webfire units into unit of mass,
pounds (except radiocative units). Tom. Cong, These are great questions and fit in well with the fact that
PCDD/F are among the chemicals we’ve identified to spend some effort on
revising our treatment of in the near future. Here are my initial responses,
which are open to discussion and correction by the group: 1) As
with everything else, we store this data at the regional level in pounds. Some
inventories store these as grams or another smaller unit to avoid the problem
that we sometimes encounter that the values are often so small when expressed
in pounds that the 12 digit field limits in our database can cause loss of data.
For these compounds, the input we’ve gotten from toxicologists is that even
very small quantities are important and we should not assume that if something
is many orders of magnitude less than a pound that it is insignificant. I do
not believe that we are including any data as TEQs. It’s possible that we
should be and that is one reason for wanting to revisit our approach to these 2) Yes,
the PCDD and PCDF groups represent the sum of all congeners (by weight, not
TEQ). The only exception is below. Someone correct me if I am wrong. 3) No.
Where we can quantify the 2378 congeners alone, those are reported in
these separate categories. The PCDD/F categories should not include those
numbers to avoid double counting. Again, someone correct me if I’m wrong. The answers above reflect how I believe we currently are dealing
with these categories, but that does not imply that this is how we should be
dealing with them. I think there is good rationale and data available to be
treating these categories differently than we do. Reviewing this, especially in
light of the EPA’s recent report, is on the to-do list for the future. Jon ~~~~~~~~~~~~~~~~~~~ Jon Dettling 734-274-5183 dettling@glc.org From: Doan, Congtru (ENE)
[mailto:Congtru.Doan@ontario.ca] Hi
Jon, We
have discussed about conventions on PCDD and PCDF few times. Could you please
let me know what conventions used by the group regarding the units and
congeners of PCDD, PCDF?
Thanks. Cong, |