抄録
The author will discuss on "What did the investigators on environmental radioactivityleave behind?". Discussions will be concentrated on behavior of artificial radionuclides in the atmosphere and ocean.Two distinctive feature of radionuclides, no artifical radionuclides exist before the 20th century and specific half-life of each radionuclide, has been working as tracers in the meteorology and oceanography. Many new findings on these fields obtained by means of tracer use of radionuclides by investigators in these field. On the other hand, investigators of environmental radioactivity had concentrated their interest in restricted fields of their own. The investigators leave some basic and important issues those should be solved. For example, it is commonly used that the 137Cs/90Sr activity ratio in the fallout is 1.6, however, this ratio should vary depending on the type of the explosions. The global inventory of artifical radionuclides such as 90Sr was estimated only from land base measurements. Advection and diffusion works much in the ocean, however, previous discussions on the inventory of artifical radionuclides in the ocean sometimes neglect these effect. [J Radiat Res 44:386 (2003)]
