From: "Steve Harris" <sbharris@ix.RETICULATEDOBJECTcom.com> Newsgroups: sci.life-extension,sci.med.nutrition Subject: Re: Norwegian Fish (and fish oil) Radioactive ? Date: Tue, 22 Apr 2003 18:00:09 -0700 Message-ID: <b84oio$uaq$1@slb2.atl.mindspring.net> "Max Watt" <maxwatt2002@yahoo.com> wrote in message news:870a5d01.0304211106.3062eea2@posting.google.com... > paul.wakfer@iobox.com (Paul Wakfer) wrote in message news:<51430230.0304191253.4e4b77d@posting.google.com>... > > 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. " COMMENT 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.) Steve *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 energy gammas). SBH |