Showing posts with label Fukushima. Show all posts
Showing posts with label Fukushima. Show all posts

Tuesday, March 12, 2013

Fukushima Fears Unfounded

Fukushima Radiation Proves Less Deadly Than Feared
And what of the lasting threat from radiation? Remarkably, outside the immediate area of Fukushima, this is hardly a problem at all. Although the crippled nuclear reactors themselves still pose a danger, no one, including personnel who worked in the buildings, died from radiation exposure. Most experts agree that future health risks from the released radiation, notably radioactive iodine-131 and cesiums-134 and - 137, are extremely small and likely to be undetectable.

Even considering the upper boundary of estimated effects, there is unlikely to be any detectable increase in cancers in Japan, Asia or the world except close to the facility, according to a World Health Organization report. There will almost certainly be no increase in birth defects or genetic abnormalities from radiation.

Even in the most contaminated areas, any increase in cancer risk will be small. For example, a male exposed at age 1 has his lifetime cancer risk increase from 43 percent to 44 percent. Those exposed at 10 or 20 face even smaller increases in risk -- similar to what comes from having a whole-body computer tomography scan or living for 12 to 25 years in Denver amid background radiation in the Rocky Mountains. (There is no discernible difference in the cancer rates between people who live in Denver and those in Los Angeles or New York.)

Rather than stand as a warning of the radiation danger posed by nuclear power, in other words, Fukushima has become a reminder that uninformed fears aren’t the same as actual risks.

Why are the anticipated risks from Japan’s nuclear accident so small? Perhaps the most important reason is that about 80 percent of the radiation released was blown into the ocean. Radioactive contamination of the sea sounds dreadful, but because oceans naturally contain large amounts of radioactive materials, the net increase in oceanic radioactivity is minuscule.
Uh, and because the ocean is incredibly large, by the standards of our human scales, even a lot of something can get lost in it.  Or at least incredibly diluted.

True story.  My first graduate degree was obtained in a group that called itself "Marine Radioecology", and my research project concerned the uptake of several radionuclides by marine organisms in large cultures.  When I started my project, I received a shipment of 10 millicuries each of 59Fe, 65Zn, and 54Mn, all relatively powerful gamma ray emitters. Each isotope came in a lead pig in a box in regular mail (or UPS; I can't remember, it's been a while).   When I took each isotope out of it's lead pig, the Geiger counter on the other side of the room began to scream EVEN THOUGH I WAS BETWEEN THE ISOTOPE AND THE COUNTER. The radiation was shining through me and reaching the counter on the other side of the room.

Now, I wouldn't want to have been there for a long time, but in reality, and these facts are pretty well known, it takes a substantial dose of radiation to produce even a small increase in the probability of developing cancer.

The entire Fukushima incident was seized upon by people who would rather have you freeze to death in the dark than be warm and well lit by nuclear power and blown out of proper proportion.

Be like Almudena and fear not.




Thursday, August 16, 2012

Fuskushima Radiation Causes Mutant Butterflies

Mutant Butterfly, not found in Japan
Fukushima 'caused mutant butterflies'
Genetic mutations have been found in three generations of butterflies from near Japan's crippled Fukushima nuclear plant, scientists said Tuesday, raising fears radiation could affect other species.

Around 12 percent of pale grass blue butterflies that were exposed to nuclear fallout as larvae immediately after the tsunami-sparked disaster had abnormalities, including smaller wings and damaged eyes, researchers said.

The insects were mated in a laboratory well outside the fallout zone and 18 percent of their offspring displayed similar problems, said Joji Otaki, associate professor at Ryukyu University in Okinawa, southwestern Japan.
Given the Japanese obsession with gigantic, monsters caused by radiation (Godzilla), a humanoid butterfly just seem so obvious...
That figure rose to 34 percent in the third generation of butterflies, he said, even though one parent from each coupling was from an unaffected population.

The researchers also collected another 240 butterflies in Fukushima in September last year, six months after the disaster. Abnormalities were recorded in 52 percent of their offspring, which was "a dominantly high ratio", Otaki told AFP.

Otaki said the high ratio could result from both external and internal exposure to radiation, from the atmosphere and in contaminated foodstuffs.
I suppose butterflies make a pretty good sentinel species for radiation damage in the wild.  Fast growing, their caterpillars eat green vegetation apt to be both contaminated from atmospheric sources and from contaminated soil, and this get a dual dose; fortunately the exposure for people appears to have been much less:

First study reports very low internal radioactivity after Fukushima disaster
Japanese researchers have found very low amounts of radioactivity in the bodies of about 10,000 people who lived near the Fukushima Daiichi power plant when it melted down.

The first published study that measured the radiation within a large number of residents reassured health experts because the numbers reported imply only negligible health risks. The threat appeared to be considerably lower than in the aftermath of the Chernobyl accident, the experts agreed.