Observations of Fallout from the Fukushima Reactor Accident in San   Francisco Bay Area Rainwater
  We have observed fallout from the recent Fukushima Dai-ichi reactor accident in samples of rainwater collected in the San Francisco Bay area. Gamma ray spectra measured from these samples show clear evidence of fission products - 131,132I, 132Te, and 134,137Cs. The activity levels we have measured for these isotopes are very low and pose no health risk to the public. 
Eric B. Norman, Christopher T. Angell and Perry A. Chodash
nucl-ex physics.med-ph