We are presenting here a transcription of an NHK TV documentary (note1) on insoluble radioactive particles found in Fukushima and in the Tokyo metropolitan region. Since it is quite heavy with images, it will be uploaded in 3 parts.

These particles contain cesium, which has the property to dissolve in water. However, in the case of these particles, the cesium was taken into glass-like particles during the Fukushima Daiichi NPP accident before it was blown away by the explosion. These particles do not dissolve in water, and as a consequence the cesium will remain longer both in the environment and in the human body, which will modify the impact of radioactive materials on the environment and on health.

Here the video in Japanese: https://youtu.be/ipOEfS-06FM

Takeda: A round particle like a marble.
Rugged particles like asteroids.
Presently, the researchers are paying attention to them.

Very small particles contain radioactive cesium.