To
establish a 239+240Pu, 137Cs, and heavy
metal reference soil site in Northeast China, three grassland soil
cores were collected from the Lao-Ye-Ling Mountain, which is a branch
of the Chang-Bai Mountains. The activities were in the range of 0.041–2.752
mBq/g for 239+240Pu and in the range of 0.2–57.6
mBq/g for 137Cs. The 240Pu/239Pu
atomic ratios were 0.161–0.186, showing that 239+240Pu in the study area originated from the global fallout. Also, 239+240Pu, 137Cs, and excess 210Pb were
enriched in the surface soil. The convective–dispersion equation
model provided the lower apparent dispersion coefficients (D) and apparent convection velocities (v) for both 239+240Pu and 137Cs. The soil erosion
rate in this study area was estimated by an erosion model, which was
lower than that in the other area of Northeast China. 239+240Pu in the different soil fractions was analyzed by a sequential extraction
method, and the result showed that 239+240Pu was mainly
adsorbed by Fe/Mn oxides and their associated organic matter (NOMFe/Mn‑oxides fraction). Except for Fe, all other heavy
metals from the anthropogenic source were enriched in the surface
soil. The pollution level of heavy metals in this study area was lower.
In general, the alpine grassland soil of the Lao-Ye-Ling Mountain
can be used as a reference soil site to study environmental pollution
and soil erosion and provided some reference baselines for future
multidisciplinary studies in Northeast Asia.