Radioactive bluefin tuna crossed the Pacific to US
LOS ANGELES — Across the vast Pacific, the mighty bluefin tuna carried radioactive contamination that leaked from Japan's crippled nuclear plant to the shores of the United States 6,000 miles away — the first time a huge migrating fish has been shown to carry radioactivity such a distance.
"We were frankly kind of startled," said Nicholas Fisher, one of the researchers reporting the findings online Monday in the Proceedings of the National Academy of Sciences.It's only after the alarmist headline that we find out that the real story is the migration of the tuna, not the radioactivity - which is still well in the acceptable range. It's just that the radioactivity has allowed the tuna to be more conveniently tracked. There's concern over the levels of radioactivity given that the tuna supposedly can "shed" radioactivity but still have elevated levels, but this may be a combination of poor reporting and grant-hungry institutes... I mean, these are fish that pregnant women are warned not to eat because of the elevated mercury levels, yet they get rid of radioactivity?
Why do I hear shades of "The grunion are running!" here?
That is all.
7 comments:
Long-time reader here, thought I might pass along some information that you might find interesting.
The problem isn't just "radioactivity", but rather, what elements are present.
Radioactive potassium-40 is constant in the environment, and while any radioactivity is technically harmful, is pretty normal, and has been for millions of years.
Cesium-134 and Cesium-137 are the subject of the article. Both are excreted reasonably quickly from the body, although they are calcium analogs in the body, and some will remain in the bone.
However, wherever Cs-134 and Cs-137 are found, you will also find Strontium-90. It is released almost as much as Cs-137 in a fission reaction, and has a comparable half-life (28 years).
Notably, none of the materials circulating the news media mention strontium.
The problem with Sr-90 is that the 20-30 percent that is not excreted is absorbed into the bone as a calcium analog. There, more than Cs-137, Sr-90 has the distinction of causing leukemia and bone cancer.
Strontium-90 is a whole different animal than Cesium-anything, or mercury. You don't want any of it in your body, and it does bioaccumulate. The article says nothing about Sr-90 levels in tuna, and it is not clear that the researchers even tested for it.
To be fair, you would need to consume more than 30 pounds of tuna to reach the FDA limit for Sr-90, extrapolating from the 10 Bg/kg of cesium contamination measured by the researchers. That is a lot of tuna.
But 30 pounds is not 300 pounds.
How much do you trust the FDA?
The figures are from last year's fish, which had only been swimming in contaminated water for a few months. Tuna caught this summer will have been swimming in increasingly-contaminated waters for their entire lives. For this year's catch, it might take a lot less then 30 pounds to put you in danger. 3 pounds? 3 ounces?
Remember, it wasn't just one or two of the fish that were found to be contaminated. Every fish was contaminated.
If you put tuna in your mouth, unless the can predates summer of 2011, you are definitely ingesting Sr-90. As of this week, we know that last year's catch didn't have very much.
Will they tell you how much radiation is in this year's fish before you eat it? Or months afterwards, like they did this year?
As usual, the story is not what the media is saying, but in what they are pointedly not saying.
Be safe out there. There is a lot more going on with the Fukushima meltdowns than is mentioned in the news. The semi-official figure from Japan is that total release is more than 4.5 times Chernobyl. Initial release was about 20 percent of Chernobyl, but since the melted cores are still undergoing fission, now without containment, radioactive isotopes are still being released, slowly increasing the total contamination across the northern hemisphere.
You forget, Mr. Osler, that radioactivity is constantly decreasing, in that context.
There's no new source coming into the water there.
(And let's not talk about total "release" without talking mode and dispersion; radioisotopes that escaped the containment vessel and didn't leave the site were "released" but are in practical terms harmless and irrelevant.
"Slowly increasing the total contamination" is a convenient turn of phrase but equally irrelevant; it's equally true to say it's constantly decreasing due to radioactive decay. After all, radioisotopes are dangerous precisely as they decay - if they're not decaying they're harmless, as radiation sources.
There's a lot less to worry about than you want me to think, is my analysis; I've heard people hyperventilating* about a "media blackout", but the reason for it?
It's not actually dangerous.
* I recall some idiot complaining about "inhaling 360 atoms a day" of a radioisotope in Canada... 360 atoms. This is approximately as dangerous as not dangerous at all, seriously, what the hell is wrong with you people.)
When Charlie the Tuna stomps onto Los Angeles in the form of Sushizilla, then I'll start to worry.
Till that happens? Sorry Charlie, it's tuna steaks on the grill!
Jim
Sunk New Dawn
Galveston, TX
The only thing I thought when I read this is: "Boy, I could sure go for some sushi."
I'm with Jason. And Wed is fish delivery day out here.
From what my father saw when he was working with people affected by Chernobyl, let's just say that there's a lot we don't know about why the plants, animals and people in the Chernobyl "dead zone" are still alive and doing pretty well. Exceedingly well in some cases. Yes, radioactive materials are serious business, but let's keep the big picture in mind.
LittleRed1
"How much do you trust the FDA?"
How much do you trust the media?
Seriously, pretty much every single frickin' article I've seen talking about Fukushima has gotten the science wrong, so why the heck should we trust anything else they've said about it?
As Sigivald noted, mode and dispersion are significant when talking about "total release", and the specific elements and isotopes released are also important. Chernobyl was such a huge disaster because the reactor vessel itself exploded - there are (or were, they may have been cleaned up by now) actual chunks* of the core's graphite moderator scattered across the landscape at Chernobyl, and the graphite itself caught fire, releasing highly radioactive smoke plumes (including particles of the fuel itself) for miles.
At Fukushima, on the other hand, all the explosions took place outside the reactor vessels. Some were damaged, and the buildings were nearly or completely destroyed, but the actual damage isn't anywhere near comparable to Chernobyl.
Remember, the media loves to jump on and exaggerate anything involving Fukushima, because they believe that "nuclear = bad" and the actual facts are irrelevant. Also keep in mind that the amounts of radiation that we can detect are very miniscule - it's not unheard of for shipments of bananas or cat litter to set of the detectors in shipping ports, for example.
While certainly something to be aware of, this story is certainly not worthy of the fear and hand-wringing you seem to be encouraging.
* Check the Wikipedia page for the Chernobyl disaster. There's a good picture of a piece of graphite large enough that the control rod channel is still intact.
I guess I wasn't clear enough. The reactor cores melted through containment, and are still releasing material, so there is very much a source of fresh radioisotopes, since the cores have not been contained as Chernobyl was.
Additionally, bioaccumulation takes time to work up the food chain.
The average human experiences somewhat over 4,000 radioactive decay events every second. Of those, 50 (per second!) involve Carbon-14 atoms in DNA. Obviously, we cope with some degree of natural radiation without much difficulty.
Life after Chernobyl does go on. But for subsequent generations, life is different, with increased rates of birth defects, sterility, retardation, and circulatory problems. Unfortunately, the Fukushima event was large enough to affect us here in the United States.
The infant mortality rate on the west coast spiked 35 percent after the Fukushima meltdowns, but we won't know for another few months, at least, how bad the birth defect rate is going to be.
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