Dr. Tsubokura's Radiation Lecture Vol.48

Author: Masaharu Tsubokura

Editors: Akihiko Ozaki M.D., Yuki Senoo

95. Standards intended to limit radioactive substances in food are different in Japan and overseas

Internal radiation exposure is caused mainly by the ingestion of radioactive substances in food. To prevent the overconsumption of food contaminated with radioactive substances, a reference value has been established.

In Japan, the reference value for radioactive cesium is 100 Becquerels/kilogram, but this value varies among countries worldwide. For example, in the EU, the reference value is 1250 Becquerels/kilogram. The codex committee, a committee established by the United Nations and the World Health Organization, and the United States consider 1,000 and 1,200 Becquerels/kilogram a universal reference value for radioactive cesium.

Some people may be surprised to learn that other countries’ reference values are much looser than Japan’s. However, these values are established based on the same principle and have the same purpose: to keep total internal radiation contamination, both from radioactive cesium and other radioactive substances, such as strontium, below 1 millisievert/year.