Stontium-90 fallout from surface and underground nuclear tests.
Deposition of strontium-90 per unit area per unit fission energy from surface blast of the first Chinese atomic bomb was several times heavier than that from an earlier atmospheric test series. The venting of a Russian large-scale underground test also significantly increased deposition of strontium-90 at Niigata, Japan.
D002681:China; D007564:Japan; D011847:Radioactive Fallout; D013325:Strontium Isotopes; D014586:USSR
D011847:Radioactive Fallout; D013325:Strontium Isotopes