Fukushima: U.S. EPA Radiation Monitoring Network, Japanese Nuclear Emergency:Page

The United States Environmental Protection Agency has a network of radiation monitoring stations all over the country. They have set up a page entitled Japanese Nuclear Emergency: Basic Radiation Facts From EPA. By clicking through several menus items one can get directly to:

Radiation Air Monitoring Data

• Daily Data Summary

• Summary of Data from Air Monitoring Stations

• Map of Radiation Air Monitoring Stations

The current readings in Southern california can be found here. The google maps version is here.