Natural radionuclides in volcanic activity

Natural radionuclides of 222Ra, 210Pb and 212Pb present in the magma are emitted during the eruption of volcanoes. Depletion of 222Rn in pumices and in lava showed that significant amounts of 222Rn were released from erupting magmas. Atmospheric 210Pb originating from the 1991 eruption of Mt. Pinatubo was detected in Japan and in Korea as a temporal increase in the atmospheric concentration after the eruption. Atmospheric 212Pb originating from the 2000 eruption of Mt. Miyake-jima was also detected as an abrupt rise in atmospheric concentration after the event.