Plutonium fallout reconstructed from an Antarctic Plateau snowpack using inductively coupled plasma sector field mass spectrometry

Heejin Hwang; Soon Do Hur; Jeonghoon Lee; Yeongcheol Han; Sungmin Hong; Hideaki Motoyama

doi:10.1016/j.scitotenv.2019.03.105

Plutonium fallout reconstructed from an Antarctic Plateau snowpack using inductively coupled plasma sector field mass spectrometry

Sci Total Environ. 2019 Jun 15:669:505-511. doi: 10.1016/j.scitotenv.2019.03.105. Epub 2019 Mar 9.

Authors

Heejin Hwang¹, Soon Do Hur¹, Jeonghoon Lee², Yeongcheol Han³, Sungmin Hong⁴, Hideaki Motoyama⁵

Affiliations

¹ Korea Polar Research Institute, Incheon 21990, Republic of Korea.
² Department of Science Education, Ewha Womans University, Seoul 03760, Republic of Korea.
³ Korea Polar Research Institute, Incheon 21990, Republic of Korea. Electronic address: yhan@kopri.re.kr.
⁴ Department of Ocean Sciences, Inha University, Incheon 22212, Republic of Korea.
⁵ National Institute of Polar Research, Tokyo 190-8518, Japan; SOKENDAI (The Graduate University of Advanced Studies), Tokyo 190-8518, Japan.

PMID: 30884272
DOI: 10.1016/j.scitotenv.2019.03.105

Abstract

Anthropogenic plutonium (Pu) in the environment is a result of atmospheric nuclear testing during the second half of the 20th century. In this work, we analyzed a 4-meter deep Antarctic Plateau snowpack characterized by a low snow accumulation rate and negligible snow impurities. These sample conditions enabled us to measure the snowpack Pu fallout by applying inductively coupled plasma sector field mass spectrometry to a few mL of snow melt without purification or preconcentration. Pu concentrations in the reconstructed Pu fallout record for the period after 1956 CE increased and decreased in agreement with past atmospheric nuclear testing. Two peaks and two dips associable with historical events were observed, and the highest peak in 1964(±1) CE approximately coincided with the maximum concentration of non-sea-salt sulfate caused by the Mt. Agung eruption in 1963 CE. Enhanced Pu fallout in the 1970s was attributed the geographical proximity of the Southern Hemispheric nuclear test sites. Our results suggest that by improving the instrumental sensitivity and precision, the potential of the Antarctic ice sheet as an archive of Pu fallout can be further explored and utilized for understanding atmospheric dispersion and for dating ice cores.

Keywords: Antarctic snow; Atmospheric nuclear test; Dome Fuji; Ice core; Radionuclide.