Dr. Tsubokura's Radiation Lecture Vol.3

Author: Masaharu Tsubokura

Editors: Izumi Yoshida, Mariko Irie, Yuki Senoo

5. Potassium is not the only radioactive substance

　A little potassium contained in animals, plants, and foods is radioactive potassium, and we are exposed to radiation through ingestion in our daily diet. Foods contain not only radioactive potassium but also radioactive polonium and radioactive carbon, and we are exposed to radiation from before the nuclear accident.

The level of radioactive potassium increases when we eat lots of vegetables and the level of radioactive polonium increases when we eat seafood. Japanese people, who eat a lot of seafood, are known to have much higher radiation exposure in comparison with the world average.

However, this does not mean that we should not eat vegetables or seafood. Balance is crucial in the diet. Even if there is food contamination in Fukushima, it is a well-known fact that it is sufficiently less than radioactive substances ingested through daily eating habits.