Bananas More Radioactive Than Fukushima Tuna

[Marlin]

Bananas More Radioactive Than Fukushima Tuna

Last spring, a certain study was released, and the media headlines blared, over 1,100 in all. They all went a little something like this:

"Tuna carry Fukushima Japan quake radiation across Pacific to California."

Most of the stories delivered alarmism, but relayed little context. All most readers learned was that Pacific bluefin tuna -- fish that many Americans consume -- were tainted with radioactive cesium from the Fukushima-Daiichi nuclear accident. Sounds scary, doesn't it?

But there's almost no need to worry, say Nicholas Fisher and Zosia Baumann, the same researchers who conducted the original study. In a new study which appeared Monday in the Proceedings of the National Academy of Sciences, they demonstrate that the effective radiation dose received by humans based on the annual consumption of contaminated Pacific bluefin tuna is comparable to, or less than, the dose routinely obtained from "many food items, medical treatments, air travel, or other background sources."

For example, say you're at a fancy restaurant and you sit down to an exquisite meal of Fukushima-tainted Pacific bluefin tuna. Your radiation dose would be approximately 7.7 nanosieverts. That's about 5% of the dose acquired from the Potassium in an uncontaminated store-bought banana.

Even a hypothetical subsistence fisherman living in the United States consuming 273 pounds of bluefin tuna annually (more than five times typical American consumption of seafood) shouldn't lose much sleep. The research team calculated that such a demographic would suffer an additional two cases of fatal cancer per 10,000,000 people.

The research team used measurements of radioactive cesium taken from Pacific bluefin tuna caught in 2011 near San Diego, California for their calculations. They also caught specimens in 2012 and found that cesium levels had significantly diminished to less than half of those found the previous year. Thus, the almost nonexistent radiation risk faced by Americans may be even more diminutive.

http://www.realclearscience.com/journal_club/2013/06/05/bananas_more_dangerous_than_fukushima_tuna_106549.html

[61nomad]

Sounds like a commercial for Monsanto. I would be more interested in seeing the dose estimates the Japanese people are receiving from eating in-shore species of fish, shellfish, seaweed, etc.  Tuna are a pelagic species and travel far and wide. I would suspect their radiation levels to be almost negligible.

[Marlin]

Tuna are a pelagic species and travel far and wide. I would suspect their radiation levels to be almost negligible.

I think that was the point of the article in contrast to reports to the contrary.

[Marlin]

Sounds like a commercial for Monsanto. I would be more interested in seeing the dose estimates the Japanese people are receiving from eating in-shore species of fish, shellfish, seaweed, etc.  

Here is what you are looking for I think, the article above is from this paper. The entire paper can be seen from a link in the link below.

Abstract

Radioactive isotopes originating from the damaged Fukushima nuclear reactor in Japan following the earthquake and tsunami in March 2011 were found in resident marine animals and in migratory Pacific bluefin tuna (PBFT). Publication of this information resulted in a worldwide response that caused public anxiety and concern, although PBFT captured off California in August 2011 contained activity concentrations below those from naturally occurring radionuclides. To link the radioactivity to possible health impairments, we calculated doses, attributable to the Fukushima-derived and the naturally occurring radionuclides, to both the marine biota and human fish consumers. We showed that doses in all cases were dominated by the naturally occurring alpha-emitter 210Po and that Fukushima-derived doses were three to four orders of magnitude below 210Po-derived doses. Doses to marine biota were about two orders of magnitude below the lowest benchmark protection level proposed for ecosystems (10 µGy⋅h−1). The additional dose from Fukushima radionuclides to humans consuming tainted PBFT in the United States was calculated to be 0.9 and 4.7 µSv for average consumers and subsistence fishermen, respectively. Such doses are comparable to, or less than, the dose all humans routinely obtain from naturally occurring radionuclides in many food items, medical treatments, air travel, or other background sources. Although uncertainties remain regarding the assessment of cancer risk at low doses of ionizing radiation to humans, the dose received from PBFT consumption by subsistence fishermen can be estimated to result in two additional fatal cancer cases per 10,000,000 similarly exposed people.


http://www.pnas.org/content/early/2013/05/30/1221834110

[61nomad]

People should limit their intake of bluefin tuna due to mercury content. That hypothetical fisherman who ate 273 lbs of bluefin tuna is probably having neurological problems.

Now, what about the nori in my sushi rolls?  The article has some useful facts but does not address seafood (or any food) harvested in Japan and exported to the USA. Personally I am not concerned unless it causes me to alarm the portal monitor when I am leaving work.