March 21 I blogged about a report from the IAEA indicating elevated beta gamma radiation measurements up to 58 km from the Fukushima Daiichi plant.   I’ve also blogged several times, most recently here, about high radiation readings at monitoring post [32] 30 km to the northwest of Fukushima Daiichi.

On March 30 the IAEA reported on the activities of two IAEA teams that are currently monitoring radiation levels and radioactivity in the environment in Japan.

“On 29 March, one team made gamma dose-rate measurements in the Tokyo region at 8 locations. Gamma-dose rates measured ranged from 0.02 to 0.19 microsievert per hour, which is within or slightly above the background.

“The second team made additional measurements at distances of 32 to 62 km, at directions North to Northwest from the Fukushima nuclear power plant. At these locations, the dose rates ranged from 0.5 to 6.8 microsievert per hour. At the same locations, results of beta-gamma contamination measurements ranged from 0.05 to 0.45 Megabecquerel per square metre.

“Based on measurements of I-131 and Cs-137 in soil, sampled from 18 to 26 March in 9 municipalities at distances of 25 to 58 km from the Fukushima Nuclear Power Plant, the total deposition of iodine-131 and cesium-137 has been calculated. The results indicate a pronounced spatial variability of the total deposition of iodine-131 and cesium-137. The average total deposition determined at these locations for iodine-131 range from 0.2 to 25 Megabecquerel per square metre and for cesium-137 from 0.02-3.7 Megabecquerel per square metre. The highest values were found in a relatively small area in the Northwest from the Fukushima Nuclear Power Plant. First assessment indicates that one of the IAEA operational criteria for evacuation is exceeded in Iitate village. [emphasis mine] We advised the counterpart to carefully assess the situation. They indicated that they are already assessing.”

According to NHK, Iitate village is 40 km northwest from Fukushima Daiichi. NHK said that the IAEA had reported radiation levels twice as high as its criterion for evacuation were detected in Iitate village, which lies outside the 20 kilometer exclusion zone and the 20-to-30 kilometer alert zone where the Japanese government advises voluntary evacuation.

NHK also reported that Chief Cabinet Secretary Edano told reporters that the government has been notified by the IAEA of its radiation findings.  Edano said the reported radiation levels in Iitate will not have an immediate impact on human health but could be harmful if exposed over a long period of time. He said the government will closely assess the long-term impact and take appropriate action.