Re: Chemi-thermomechanical pulp - Baikal

[Byron Bodo <bodo@interlog.com>]

At 02:41 AM 26/01/98 -0500, Jennie Sutton wrote:

>   Monitoring of changes in the lake is  expensive  to  undertake  and
>there is  no independent body here that has the finances to carry this
>out on a regular basis.  Local scientists carrying out  analyses  with
>the help of Bayreuth University,  however, have discovered a dangerous
>build-up of organochlorines (PCBs and dioxins) in the lake's food cha-
>in.  The  major  source  of these is most likely the present pulp mill

I'm skeptical of the claim that the Baikalsk mill is *the major source*
of PCBs to Baikal, though no doubt the associated electrical 
infrastructure has been an indirect source via insecurely disposed
old electrical equipment.

Have just finished reviewing all available lit to mid-97 or so
concerning persistent OCs in the Baikal ecosystem.  PCDD/F TEQs
for 4 Baikal seals (nerpa) average ca. 60 pg/g lw (lipid weight) vs ca.
20 pg/g lw for ringed seals (near relatives) of Canadian Arctic
& Svalbard, and >100 pg/g lw for Baltic & L. Saimaa ringed seal.  

So there's PCDD/F contamination. The Baikalsk mill is the main
suspect, but I'd expect some also originate from the Selenga River
& by air transport from Irkutsk & environs.  I've heard informal reports
that Canucks were involved in designing some sort of closed-loop
wasterwater recycling system for the smaller mill at Selenginsk, but
I've no idea whether the work actually proceeded (or even if the info
was correct).

As for PCBs, the nerpa rank behind Baltic seals in total PCBs, but
exceed Baltic seals in TEQ of dioxin-like PCBs.  That's for gross
average data.  Properly, these things should be compared on strict age/sex
classes over concurrent time periods. The PCB TEQ in Baikal nerpa 
overwhelms the PCDD/F TEQ by about 10 fold.  All of this raises some 
interesting questions, particularly as there've been some claims that
seals have capacity to catabolize PCDD/Fs.

Baikal is quite the extraordinary case-study.  For total PCBs and DDTs,
there's
a 10^8--10^10 fold bioamplification from water-to-seal at the top end.
Relatively
minor contamination of water becomes a potentially grave threat to seal &
other
heavy fish eaters.  Once contaminated, Baikal could take centuries to cleanse
itself as loss/removal processes (river outflow, volatilization,
sedimentation & 
deep burial) seem to be relatively small compared to the mass retained in
the water column (at least by rough back-of-the-envelope estimation).

-bb