Increased level of radiation in Tokyo

Geigercounts in Tokyo show increased level of radioactive particles. Although the level is still way below the health risk threshold it is significantly higher than normal background radiation level in Tokyo. The diagram show a mean particle count of 24.18 CPM. Normal background radiation for Tokyo lies around 14 CPM,

Background radiation varies a lot around the globe - some places it is as high as 60 CPM. It's not considered dangerous until it reaches approximatly 130 CPM.

The increase is probably due to the change of the change in wind direction from westerly to north-north easterly with rainshowers.

Realtime measurements can be followed here.