Laboratoire des Sciences du Climat et de l'Environnement (LSCE/IPSL), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ), Université Paris-Saclay, Gif-sur-Yvette, France.
CEA, DAM, DIF, F-91297 Arpajon, France.
Sci Total Environ. 2022 Oct 15;843:156943. doi: 10.1016/j.scitotenv.2022.156943. Epub 2022 Jun 23.
Atmospheric nuclear tests (1945-1980) have led to radioactive fallout across the globe. French tests in Polynesia (1966-1974) may influence the signature of fallout in South America in addition to those conducted by USA and former USSR until 1963 in the Northern hemisphere. Here, we compiled the Pu/Pu atom ratios reported for soils of South America and conducted additional measurements to examine their latitudinal distributions across this continent. Significantly lower ratio values were found in the 20-45° latitudinal band (0.04 to 0.13) compared to the rest of the continent (up to 0.20) and attributed to the contribution of the French atmospheric tests to the ultra-trace plutonium levels found in these soils. Based on sediment cores collected in lakes of Chile and Uruguay, we show the added value of measuring Pu/Pu atom ratios to refine the age models of environmental archives in this region of the world.
大气核试验（1945-1980 年）导致放射性沉降物遍布全球。法国在波利尼西亚（1966-1974 年）进行的核试验，除了美国和前苏联在 1963 年之前在北半球进行的核试验之外，可能还会影响到南美洲沉降物的特征。在这里，我们编译了报告的南美洲土壤中的 Pu/Pu 原子比，并进行了额外的测量，以检查它们在整个大陆的纬度分布。在 20-45°纬度带（0.04 至 0.13）发现的比值明显低于大陆其他地区（高达 0.20），这归因于法国大气核试验对这些土壤中超痕量钚水平的贡献。基于在智利和乌拉圭湖泊中采集的沉积岩芯，我们展示了测量 Pu/Pu 原子比的附加价值，以改进该地区环境档案的年代模型。
