A rooftop water monitoring program managed by UC Berkeley’s Department of Nuclear Engineering detected substantial spikes in rain-borne iodine-131 during torrential downpours a week ago.
As shown in the graph below, published by UC Berkeley, Iodine-131 peaked at 20.1 becquerels per liter, a measure of radioactivity, on the roof of Etcheverry Hall during heavy rains a week ago. The federal maximum level of iodine-131 allowed in drinking water is 0.111 becquerels per liter.
Source: The Bay Citizen (http://s.tt/12cPx)
http://www.baycitizen.org/japan-disaster/story/government-under-fire-radiation-milk/1/
In the most recent results:
* Richmond, CA, rainwater samples contained Iodine-131 and Tellurium-132 .
* Boise, Idaho samples contained Cesium-134, Cesium-137, and Iodine-131.
* St. Paul, MN samples contained Iodine-131.
Contaminant Levels
In the latest results:
* Richmond samples showed 138 picocuries per liter of iodine-131 and 5.96 of tellurium-132.
* Boise samples showed 242 picocuries of iodine-131, 11.2 of cesium-134, and 11.6 of cesium-137.
* St. Paul samples showed 32.3 picocuries of iodine-131
source link: http://blogs.forbes.com/jeffmcmahon/2011/04/03/radiation-found-in-rain-in-california-idaho-minnesota/