French map of cesium-137 deposition from Fukushima shows the US more contaminated than Western Japan

According to France's CEREA simulation map of ground deposition of cesium-137 after Fukushima], the US, particularly the West Coast and particularly California, may be more contaminated with radioactive cesium than the western half of Japan or Hokkaido.

The simulation was performed with a specific version of the numerical atmospheric chemistry and transport model Polyphemus/Polair3D. The magnitude of activity concentration field is uncertain and could be significantly different from the actual one. In particular, the source term remains uncertain. Therefore, these results should be seen as preliminary and they are likely to be revised as new information become available to better constrain the source term and when radionuclides data can be used to evaluate the model simulation results.