From: "Steve Harris" <sbharris@ix.RETICULATEDOBJECTcom.com>
Subject: Re: Norwegian Fish (and fish oil) Radioactive ?
Date: Tue, 22 Apr 2003 18:00:09 -0700
"Max Watt" <firstname.lastname@example.org> wrote in message
> email@example.com (Paul Wakfer) wrote in message
> > http://news.bbc.co.uk/1/hi/business/2941073.stm
> Also see http://www.bellona.no/en/energy/nuclear/sellafield/24388.html
> They conclude the fish are safe, but shellfish are not: "Although the
> Norwegian waters, fish and other seafood in general can be considered
> clean, the seaweed and lobsters can not. This clearly demonstrates the
> actual environmental problems caused by Sellafield, and there should be
> no doubt that this source must cease. "
Yes, but the data they give doesn't support their own
conclusion. They write:
Based on these results, and previously published data, the
radioactive contamination of the northern marine environment
is in generally low, this is also valid for the levels in
fish and other seafood in general. This fact is clearly
underlined when compared to the actual limits of Cs-137 for
consumption as recommended by the EU and the Norwegian
authorities, respectively: 600 Bq/kg for food articles (with
the exception of milk and baby food which is 370) and 3000
Bq/kg for game, reindeer and wild, fresh water fish.
Okay. A Bq is one disintigration per second, 27 picocuries.
A damned small amount of radiation. For reference, your own
natural K-40 and C-14 each contribute around 50 to 60 Bq per
kg of your body. So together just these two natural
radioisotopes contribute 3 times the Bq of the amount of
Tc-99 the article is getting upset about in lobster.
IOW, why go bananas about an extra 30 Bq in lobster which
has at least 100 Bq anyway from its own K-40 and C-14, and
is going to be eaten by people who have at least the same?
Yes, the seaweed had 500 Bq/kg (dry) but not too many people
are going to be consuming kg of dry seaweed. And even if
they did, it wouldn't go over the European limit for
radiocontamination food, which as we see above is 600 Bq.
(If you're feeding your babies dry seaweed, look out.)
*Note: There is one aspect we didn't go into, which is
conversion of Bq into mrem, a difficult exercise which is
dependent on the isotope and the kind of radiation it gives
off, and how energetic it is. For example, yourbody's 16 mg
of K-40 provide 40 times the amount of rem (actual damage)
as your body's total burden of C-14, even though the Bq rate
(disintigrations per sec) are roughly the same for each. So
there is an offset possible for Tc-99, but I'm guessing
without having done this calculation that overall that Tc-99
will not be all that much more damaging per Bq than K-40.
They make much the same kind of radiation (betas and low