Effects of Radioactive Fallout due to Atmospheric Nuclear Testing
Large amounts of artificial radionuclides were released into the environment during the era of atmospheric nuclear testing. These artificial radionuclides were spread all around the world as they were carried by air currents, and gradually fell onto the surface of the Earth from the atmosphere. Such radioactive falling matter is called fallout. The amount of fallout was highest in 1963, just before the ban of atmospheric nuclear testing, and has been decreasing since then.
Because there is a time lag between contamination of foods with cesium and their consumption, the amount of radioactive cesium in daily diets was highest in 1964, then dropped sharply by 1967, and has been decreasing relatively slowly since then.
Like the amount of cesium in daily diets, the amounts of Cesium-137 in urine and the body were also highest in 1964. An increase in the amount of cesium in the body was also found among Japanese people as a result of the influence of the Chernobyl nuclear disaster.
*Curie (Ci): Unit of radioactivity; 1 nanocurie (1 nCi) is 10-9 of one curie (1 Ci), i.e., a billionth of one curie.
- Included in this reference material on March 31, 2013
- Updated on February 28, 2018