Abstract
The atomic bomb was dropped in 1945 Hiroshima and Nagasaki, the environmental radiation measurement by fallout was performed. By suffering calamity of 5th-Fukuryu-Maru by the H-bomb test of the March 1st 1954 Bikini Atoll, it became the time when the environmental radioactive contamination by the nuclear bombs in the atmosphere by the U.S.A. and old Soviet Union had been taken up greatly. The following contents are introduced about the flow of the times. 1. The measurement fallout effects in Hiroshima and Nagasaki with NEHER type ionization chamber. 2. A marine radiation measurement by the scintillation instruments according to Shyunkotu-Maru expedition in relation to a Bikini incident. 3. Environmental radioactive contamination that had not been noticed during 1945 to 1954. 4. Effect of the atmosphere nuclear explosion tests which are each of the USA and Soviet Union. 5. Effect of the greatest in our country by the 5th Chinas nuclear test in 1966. 6. Influence investigation of the Chernobyl accident acquired by national investigation. 7. The goal of investigation research of environmental radioactivity. [J Radiat Res 44:378 (2003)]
