Summary: As usual, the internet buzzes with fear-mongering about the radiation released from the Fukushima reactors. Here’s a note from the Woods Hole Oceanographic Institute that puts this in context. It does not address the larger danger of future releases of radioactivity, perhaps on a much larger scale than the initial surge and the leaks since then. See the links at the end for more about the dangers of Fukushima
- The good news about the ocean
- Bad news for people in Japan
- About Woods Hole Oceanographic Institute
- For More Information
(1) The good news about the ocean
“Radioisotopes in the Ocean – What’s there? How much? How long?”
By David Pacchioli, Oceanus Magazine, Spring 2013
Published by the Woods Hole Oceanographic Institute
The release of radioisotopes from the Fukushima Dai-ichi nuclear power plant in March 2011 amounts to the largest-ever accidental release of radiation to the ocean. It came mostly in the form of iodine-131, cesium-134 and cesium-137, the primary radioisotopes released from the reactors, reported Ken Buesseler, a marine chemist at Woods Hole Oceanographic Institution.
All of these substances can cause long-term health problems, said Buesseler, but iodine-131 has a half-life of just eight days and so would be effectively gone from the environment in a matter of weeks. It was cesium-134 and cesium-137, with their half-lives of two and 30 years, respectively, which would remain in the ocean for years and decades to come.
In fact, most of the cesium present in today’s oceans, Buesseler noted, is a remnant of atmospheric nuclear weapons testing conducted by the United States, France, and Great Britain during the 1950s and ’60s. Lesser amounts are attributable to the Chernobyl nuclear accident in 1986 and to local sources, such as the dumping of low-level waste from England’s Sellafield nuclear facility into the Irish Sea.
… “Dilution due to ocean mixing should be enough to cause a decrease in concentration down to background levels within a short period of time,” Buesseler told his audience at the Fukushima and the Ocean conference in November 2012. “Yet all the data we have show that measurements around the site remain elevated to this day at up to 1,000 becquerels per cubic meter.”
He hastened to put that number into context. “A thousand becquerels is not a big number for cesium. Just for comparison, that’s lower than the U.S. Environmental Protection Agency’s limit for drinking water. At that level, Buesseler stressed, the cesium in Japanese coastal waters is safe for marine life and for human exposure.
“It’s not direct exposure we have to worry about, but possible incorporation into the food chain,” he said. That, and the ongoing high levels of radioactive cesium. “The fact that they have leveled off and remained higher than they were before the accident tells us there is a small but continuous source from the reactor site.”
(2) Bad news for people in Japan. Is there more to come?
“Thyroid cancers up in Fukushima“, Japan Times, 23 December 2013 — “Experts say link to disaster not yet established” Excerpt:
Screening of Fukushima residents who were 18 or younger at the time of the 2011 nuclear disaster had found 26 confirmed and 32 suspected cases of thyroid cancer as of Sept. 30, according to the Fukushima Prefectural Government.
The number of confirmed cases was up by eight from August, while the suspected cases rose by seven, the prefecture-led study found. About 226,000 people have undergone the screening program since it kicked off in October 2011. The 26 confirmed cases underwent surgery and are doing well, according to the prefecture.
A panel of experts at the prefecture concluded Tuesday that it is too early to link the cases to the nuclear disaster, given that papillary thyroid cancer — the type found in the 26 people — develops at a very slow pace, according to prefectural officials. Following the 1986 Chernobyl catastrophe, it took about four to five years for thyroid cancers in significant number to be detected.
Thyroid cancer is considered a major health concern for children because radioactive iodine spewed by the crippled nuclear plant tends to accumulate in thyroid glands, especially among young children.
Following the Chernobyl disaster, more than 6,000 children were diagnosed with thyroid cancer, according to the U.N. Scientific Committee, which attributed many of the cases to consumption of contaminated milk.
According to media reports, thyroid cancer normally strikes about 1 to 2 people aged 10 to 14 per million in Japan, far less than about 115 in 1 million cases in Fukushima. However, the figure cannot be simply compared, because the screening in Fukushima targets all children under 18, most of whom are without any symptoms, and no such screening is being done elsewhere in Japan.
(3) From the “About” page of the Woods Hole Oceanographic Institute
For nearly a century, WHOI has been one of the best known and most trusted names in ocean science and exploration. Our scientists and engineers have played a part in many of the discoveries that form the modern understanding of the ocean and how it interacts with other parts of the planet, including human society.
(4) For More Information
(a) Articles about radiation from Fukushima in the ocean
- “Pacific bluefin tuna transport Fukushima-derived radionuclides from Japan to California“, Daniel J. Madigana, Zofia Baumannb, and Nicholas S. Fisher, PNAS, 22 June 2012
- Debunking the scary stories: “Is the sea floor littered with dead animals due to radiation? No.“, Craig McClain (Asst Director of Science for the National Evolutionary Synthesis Center), Deep Sea News, 4 January 2014 — Tracking the story back to the original study, which does not match the later headlines
- See links to other research in the August post in section (b) below.
(b) Posts about Fukushima:
- We fear what we’re told to fear, not what we should fear. Like Fukushima., 11 August 2013
- Should we worry about eating fish irradiated by Fukushima?, 1 September 2013
(c) Other posts about pollution:
- Good news: air quality in the US has improved!, 12 March 2010
- Valuable background information about oil slicks: excerpts from Science, 2 May 2010
- About the long-term effect of giant oil spills, 17 May 2010
- Let’s watch the oceans die while we worry about other things!, 16 July 2013
- Let’s defend the oceans, before it’s too late, 13 December 2013