"MAP: The Troubling Spread of Radiation in Japan"

"A map of radiation levels in Japan released by the US Department of Energy on Tuesday evening indicates that potentially dangerous levels of radioactive contamination have spread beyond the 13-mile evacuation zone surrounding the Fukushima Daiichi nuclear plant. The data is sure to further undermine confidence in Japan's response to the disaster. US authorities have recommended that Americans stay at least 50 miles from the Fukushima Daiichi plant. Here's the map, which was generated from the DOE's Aerial Monitoring System and ground sensors:"

Josh Harkinson reports for Mother Jones March 22, 2011.