A map of citizen-measured radiation levels shows radioactivity is distributed in a complex pattern that reflects the mountainous terrain and the shifting winds across a broad area of Japan north of Tokyo, which is in the center of the of bottom of the map. Radiation limits begin to be exceeded at just above 0.1 microsieverts/hour (blue). Red is about fifty times the civilian radiation limit at 5.0 microsieverts/hour. dailykos.com

By FishOutofWater, for Japan Nuclear Incident Liveblogs
16 June 2011 […] A map of citizen-measured radiation levels shows radioactivity is distributed in a complex pattern reflecting the mountainous terrain and the shifting winds across a broad area of Japan north of Tokyo, which is in the center of the of bottom of the map. Radiation limits begin to be exceeded at just above 0.1 microsieverts/hour blue. Red is about fifty times the civilian radiation limit at 5.0 microsieverts/hour. Because children are much more sensitive than adults, these results are a great concern for parents of young children in potentially affected areas. […]

eSci: Unsafe Radiation Found Near Tokyo, Vast Area of Japan Contaminated