“…Accelerator mass spectrometry (AMS) is an effective and robust technique for studying long-lived actinides (e.g., 236 U, 237 Np, 239 Pu, and 240 Pu) [12,13,14], and inductively coupled plasma mass spectrometry (ICP-MS) is currently the most widely used technique for measuring actinides because of its lower cost compared to AMS. The distribution, sources, migration, and applications of 137 Cs have attracted extensive attention over the past few decades [15,16,17,18,19,20]. 239+240 Pu and 137 Cs in the environment are rapidly and strongly adsorbed by fine soil particles and redistributed within the soil itself [21,22,23].…”