Radiation From Fukushima Accident Revised Up In New Report

CNN.com reports here:

Japan's largest utility said Thursday that more radiation than previously thought was released into the atmosphere in March 2011, in the days after the nuclear disaster that followed an earthquake and tsunami. TEPCO (Tokyo Electric Power Co.) estimates about 900,000 terabecquerels of radioactive materials were released between March 12 and March 31, according to Japan's Kyodo news agency. ... In one town in the Fukushima area, the estimated thyroid doses to infants are within a dose band of 100 to 200 millisieverts (mSv), the preliminary report said. This level of radiation exposure could be associated with an increased likelihood of developing cancer. However, in the rest of Japan, the estimated thyroid doses are within a dose band of 1 to 10 mSv, the report said. Outside the country, the estimated thyroid doses are less than 0.01 mSv, and are usually far below this very low level, it said.

PBS.org had a fuller report here, comparing the accident's severity to Chernobyl and assessing the health consequences of the radiation releases:

Tokyo Electric, the plant’s operator, said on Thursday that reactor meltdowns at the Fukushima Daiichi plant released approximately 900,000 terabecquerels of radioactive substances into the air in the immediate aftermath of the March 2011 accident. By comparison, approximately 5.2 million terabecquerels of total radiation were emitted in the 1986 Chernobyl disaster. ... In terms of the accident’s health implications, the World Health Organization said on Wednesday that the amount of radiation released fell below cancer-causing levels in nearly all of Japan. Outside of “no-go zones” in Fukushima prefecture, residents were exposed to radiation levels between 1 millisievert and 10 millisieverts, the W.H.O. said. The annual average amount of exposure from naturally occurring background radiation is 2.4 mSv globally, according to the report ... . Cumulative exposure to 100 mSv is generally thought to raise a person’s risk of cancer death by 0.5 percent.

Reuters.com reports here that Namie and Iitate were the two towns hardest hit:

In a preliminary report, independent experts said that people in two locations in Fukushima prefecture may have received a radiation dose of 10-50 millisieverts (mSv) in the year after the accident at the power station operated by TEPCO. ... The areas estimated to have received the highest doses of radiation were Namie town in Futaba county and Iitate village in Soma county, northwest of the stricken plant, the report said. Infants in Namie were thought to have received thyroid radiation doses of 100-200 mSv, it added. The thyroid is the most exposed organ as radioactive iodine concentrates there and children are deemed especially vulnerable.

Follow the labels at the end of this post for this blog's reporting on the accident from the beginning.

One Year Out, Radiation in Futaba Japan 5 km from Nuke Accident Remains Dangerous

Here's a screen shot from Fukushima Diary showing recent, very high radiation readings measured at ground level and in a car in Futaba town, 5 km north and west from the melted-down reactors at Fukushima:

If you reduced a typical American's exposure to radiation in a year from all sources, including medical and flight sources, to an hourly level it would be 0.7 microsieverts per hour. The air level in the car to the left is nearly 45.0, and next to the soil 518.2, nearly 12 times worse, both far in excess of safe. Just breathing the air there for less than two years would give you more than a single lifetime's exposure.

(source)

Here's a map showing the nuke plant on the coast at the lower right and Futaba's Town Office to the northwest of it marked by the green arrow:

Top 5 Radiation Hot Spots of 50 Air Measurement Points Inside Fukushima 20 km Zone

Okuma town is the hardest hit at points 2.5 to 5 km distant from the nuclear power plant:

Koirino 93.9 microSv/hour

Ottozawa 68.4 microSv/hour

Kumagawa 41.2 microSv/hour

Shimonogami 35.6 microSv/hour.

Futaba town, 5 km distant, also has many points with high readings, the highest of which is:

Nagatsuka 30.8 microSv/hour.

The measurements were made June 3 and reported here.

Normal readings would be more like 0.11 microSv/hour.

It's been three months since the tsunami and meltdowns.