NOAA Study: Radiation From Fukushima Very Dilluted, Seafood Safe 267
JSBiff writes "Ars Technica is reporting on a study by NOAA scientists who surveyed the ocean near Fukushima, which concludes that while a lot of radioactivity was released into the water, as would be expected, it diluted out to levels that pose little risk to wildlife or humans, and that the seafood is safe to eat. Perhaps we needn't worry so much about "millions of gallons of radioactive water" being released into the ocean, like it's a major environmental disaster, as it's really not — the ocean is many orders of magnitude larger than any accidental release of radiation which might happen from a nuclear plant."
Re:Sanity vs. politically motivated scaremongering (Score:4, Interesting)
It's all relative (Score:5, Interesting)
1 million gallons of dirty water sounds bad--until you dilute it into 350 quintillion gallons of clean water.
And hey, compared to all the fecal matter you're eating with your seafood, a little cesium is nothing.
Re:Conveniently ignoring the fact (Score:4, Interesting)
Oh, I'm sure the NOAA people never thought of that, or thought to check higher predators in the food chain. Right.
I don't claim to be an expert, but my understanding is that various living things don't absorb everything in the environment around them - they chemically reject certain elements or compounds they have no use for. My further understanding is that the main isotope of worry after a few months is Cesium-137, and Strontium. If I understand correctly, cesium and strontium tend to react like calcium, and tend to concentrate in bones and teeth, which most predators don't digest - they digest the meat and soft tissues, and leave the bones.
So, bioaccumulation may not be much of an issue, if the radioactive materials are all in the bones. Again, I'm no biologist or radiation health expert, but that's what I've heard.
Re:Sanity vs. politically motivated scaremongering (Score:5, Interesting)
If you're worried about contaminated fish, worry about mercury, from fossil fuel usage. Eating fish every day is basically a no-no these days thanks to the LACK of nuclear power.
Re:Conveniently ignoring the fact (Score:5, Interesting)
Sure, but I don't think it's like Minimata Bay (the textbook example of toxic bioconcentration).
Firstly, the important isotopes will not be heavy metals. Therefore
* They will not tend to accumulate in marine life as they will be excreted as fast as they are ingested
* They will not tend to accumulate in the local bottom sediment, but be dispersed more rapidly
Secondly, radioisotopes decay, unlike mercury.
Re:Conveniently ignoring the fact (Score:5, Interesting)
Cesium doesn't linger in the human body. It has a biological "half-life", that is half the cesium taken in will be excreted between 50 to 120 days depending on what sort of tissue is collects in (bone, muscle, fat etc.). Strontium can collect in the bones but again it gets excreted over a period of time. Very little strontium was released from the Fukushima reactors as it is not particularly mobile unlike cesium compounds which make up nearly all of the radioactive contamination remaining in the environment since the short-lived iodine-131 (also mobile) died away.
Seawater is naturally radioactive due to potassium-40 (10 Bequerels/litre) and rubidium-87 (about 1 Bq/litre). Potassium is biologically conserved in the body and maintained at roughly stable levels absent disease. Measurements of seawater samples taken about 200km off Fukushima Daiichi a couple of months ago resulted in a combined value of cesium-134 and cesium-137 of around 0.1 Bq/litre, or 1% of the radioactivity from naturally-occurring potassium. It's possible some of the cesium-137 detected in these tests is not from the Fukushima reactors but residue from the 150 megatonnes or so of atmospheric thermonuclear weapons tests fired off by the US in the Pacific in the 1950s and 1960s.
Re:Sanity vs. politically motivated scaremongering (Score:5, Interesting)
Where do we put the waste from fossil fuels? Remember, a lot of those byproducts are toxic or carcinogenic, too. But we just pump them into the atmosphere.
Fossil fuels make a lot of moderately deadly waste that just goes everywhere. Nuclear power makes a little waste, which is admittedly very deadly, but we know exactly where it is. So far as storing it, the only reason it's a problem at all is that we're so scared of radioactive waste that we end initiatives to safely store it. How sick is that? If we had Yucca Mountain, we could stop storing nuclear waste at the plants and put it out in the middle of Fuckall Nevada under a mountain! How much safer can you get?
Re:Sanity vs. politically motivated scaremongering (Score:5, Interesting)
As best I can see, yes - the products are much safer than mercury. As best I can tell, from the article and a bit of digging on the big radioisotopes released into the water and air around the Fukushima plant, there's just not a lot to worry about, even as these materials decay.
Cesium 134 decays down to Barium which is highly reactive with water to form Barium Hydroxide, which in turn reacts with Carbon Dioxide to form Barium Carbonate which in turn reacts with acids to form highly water-soluble salts (e.g., Barium Chloride) - which is toxic, but requires a 1-5g dose for toxicity in an 'average' person, and this amount of concentration in other life forms would pretty much render them dead long before they reached your table.
Iodine 131 will decay down to inert Xenon (and rapidly - about 8 day half life). Tellurium 129 has a half life of 6 days, and decays to low-energy Iodine 129, which has a half life in the millions of years, and will eventually decay to inert xenon-129.
Cesium 137 and Strontium 90 are the two "long-lived" isotopes released, and present the largest danger, but the materials are diluted to levels below even background radiation from isotopes normally found in seawater (e.g. Potassium-40), meaning you should be much more worried about naturally occurring radioactive potassium in your fish than you should be about the Cesium and Strontium released by Fukushima.
Not a chemist by training or trade, so feel free to offer corrections, but it certainly doesn't seem like there's much cause for concern.