Document n9QbE3mZx2w9Vr2jDOrGn1mKm
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Background levels
1-5 ppt i-TEQs
Forest levels
. 35 ppt (% TCDD not
Industrial sites
18 ppt indicated)
(illegible line)
Historical sludge application 200 ppt
Near metal recycling plants 100-1000 ppt
Lake sediment samples suggest low levels of CDDs/CDFs in the
environment since 1900, with a big Increase beginning in 1950
Archived soils samples show levels of CDDs/CDFs back to at
least 1877. But the levels were much lover than in today's
samples.
Long-range transport seems to taking place
The UK has completed Its survey on a 50 km grid shoving about 5
ppt TEQs in the top 5 cm,
4. Air levels
There was a consensus that a background level of 2,3,7,8-TCDD in the air Is on the order of 1-10 pg/m3. therefore, inhala tion would account for 1-10% of the total daily intake.
Sweden The government has lifted its moratorium on the building of
mwcs. They have established an emission target of .1 ng
{TEQs?)/m3 for all new, big plants; .5 ng/m3 for small plants. They are also aggressively exporting that
technology, including the US. The cdds/CDFs end up in the
fly ash.
United Kingdom Action level of 1 pg/kg-d. This. Is based upon reproductive toxicity
Austria Nev MWCs: .1 ng TEQs/m3 Greater than 1.4 ppt TEQs In milk fat is bad
The Netherlands TEFs for FCBs .should be developed in 1990s . Proposed regulations: residential soil (l'ppb); grazing areas (10 ppt); agricultural and sediment (100 ppt)
The FDA
Denmark
Germany
At the hearing it van observed that Germany accepts RsD(10-4) levels for urban air containing PAHs. It hardly makes sense, say the speaker, to target 10-6 level for CDDs/CDFs.
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