And some more bad news for rice farmers in Japan, who were already told that planting of this key crop would be banned in contaminated soil ahead of the rice planting season which begins in April and May. The problem so far has been the nobody really knows how to classify contaminated soil, and how far it spreads. Now a new study from Hiroshima and Kyoto Universities has found that the radioactive content of soil samples beyond the 30 km semi-evacuation zone is as much as 400 times the normal. From Asahi: "The predicted changes in the level of radiation at the ground surface were calculated after analyzing the amounts of eight kinds of radioactive materials found in the soil and taking into consideration the half-lives of each material. The study results are considered more accurate than the study conducted by the science ministry, which only released information concerning two types of radioactive material. [Scholars] collected soil samples from five locations in the village at depths of five centimeters. All the locations were outside the 30-km radius and were by roadways in various hamlets. The study found cesium-137 at levels between about 590,000 and 2.19 million becquerels per cubic meter." Comparing this to Chernobyl: "After the Chernobyl nuclear accident in the former Soviet Union in 1986, residents who lived in areas where cesium-137 levels exceeded 555,000 becquerels were forced to move elsewhere. The amounts of cesium-137 found in Iitate were at most four times the figure from Chernobyl." Which begs the questions: just who will be allowed to plant rice, who will have faith that the rice they are eating is not contaminated, and how soon before rice prices surge? And how long before the fully impaired disaster zone, which could possibly spread as far as 50 km away from Fukushima, be told about the inherent risks to their lives?
If more radioactive materials are emitted from the crippled Fukushima plant, the level of cesium-137 could rise even further.
Calculations were also made of changes in the radiation level in the air one meter above contaminated ground over a three-month period from March 15, when an explosion occurred at the Fukushima plant.
The study found that even after three months there would be between 7 and 21 microsieverts per hour being emitted from the contaminated soil into the air.
If an individual remained outdoors for the entire three-month period, the person would be exposed to between 30 and 95 millisieverts over the period.
Assuming the cesium remains in the soil, the accumulated level of radiation after one year could be between about 70 and 220 millisieverts.
The central government is considering using an accumulated radiation exposure figure of 20 millisieverts over the course of a year as one indicator of whether an evacuation instruction should be issued.
The cesium-137 could move or be washed away by rain and wind, so there is the possibility that the actual accumulated radiation exposure figure could fall below the study's estimates.
Studies by the science ministry have found that contamination of the soil by radiation does not spread out in concentric circles, but is more irregular due to wind direction and other factors.
And more on the critical rice harvest from the AP:
Vegetables and milk were the first foods that sparked concerns about the safety of Japanese agriculture after the March 11 tsunami flooded the nuclear plant and its reactors began to overheat and spew radiation. But those worries intensified when highly radioactive water was spotted gushing from the complex into the Pacific and contaminated fish showed up in catches.
Those concerns have abated somewhat after the leak was plugged and bans on produce from some areas were lifted.
But rice has now come under the microscope as the planting season begins in April and May.
"We had to come up with a policy quickly because we are in planting season," said Agriculture Minister Michihiko Kano, who announced the ban Friday.
The ban will apply to any soil found to contain high levels of radioactive cesium, and farmers who cannot grow rice will be compensated. Rice grown in uncontaminated soil will be screened.
Yoshiyuki Ueda, a 47-year-old rice farmer from the town of Futaba, where the damaged nuclear plant is located, said he had already given up on trying to plant this year's crop because of radiation fears.
"The ground is ruined," Ueda said. "I think it will be a long time until things return to normal."
We wonder how long before the rice HFT crew processes this information and bangs the rice close limit up for several consecutive sessions.