Three Principles of Reduction of External Exposure

There are three ways to reduce external exposure doses.

The first is to keep away from radioactive materials such as by removing soil contaminated with radioactive materials and isolate it from people's living environment.

The second is to shield radiation such as by staying indoors, replacing topsoil contaminated with radioactive materials with subsoil, and using uncontaminated soil as a shielding material.

The third is to shorten the time to stay at places with high ambient dose rates.
(Related to p.50 of Vol. 1, “Characteristics of External Exposure Doses”)

• Included in this reference material on March 31, 2013
• Updated on March 31, 2019