The following are results for milk samples obtained from a Bay Area organic dairy where the farmers are encouraged to feed their cows local grass.

Best by date of April 16, 2011:

Cs-134 @ .10 Bq/L
Cs-137 @ .22 Bq/L
I-131 @ .22 Bq/L

Cesium-137 has a half-life of 30 years. danger, radioactive food, cesium-137, cs-137, food contamination, radiation, california

http://www.nuc.berkeley.edu/UCBAirSampling