I missed this June 21 update from NIRS, a map which indicates that radiation has spread well beyond the evacuation zone, at a level which should be of concern to the public: click here for report!

"A new version of the map we posted Friday of radiation readings in Japan sheds more light on the vast contamination of the northern part of the country and new evidence that the government's response has been woefully inadequate. The map is here. (Warning, this is a very large—15mb—pdf file; not recommended for slow connections).

For perspective, a radiation level of about 0.19 MicroSieverts/hour is roughly equivalent to the maximum allowable radiation exposure level (1 MilliSievert/year or 100 Millirems/year (note 0.19 actually comes out to 166 mrem/year) for the United States. Until March 2011, that was also the allowable exposure level in Japan."

Charley Noble