Transfer of radionuclides from soil to Acacia auriculiformis trees in high radioactive background areas in North Vietnam

Abstract

The Acacia auriculiformis is a tree common in tropical Asian countries, capable of growing in many different soil types, so it could be used for biomonitoring for high natural radionuclide areas in tropical and subtropical climates. The transfer factor (TF) of radionuclides from soil to A. auriculiformis in eight uranium and rare earth element (REE) mining areas of North Vietnam was investigated. The activity concentrations ²²⁶Ra, ²³⁸U, ¹³⁷Cs, ²²⁸Ra, and ⁴⁰K in both soil and A. auriculiformis showed considerable variation. The TFs of these radionuclides also varied in a wide range. In most of the eight areas, the highest TF was observed for ¹³⁷Cs and ²²⁸Ra. While the TFs for ²²⁶Ra and ²³⁸U were smallest. In addition, the TFs for radionuclides near REE mines were similar to those observed near uranium mines. The TFs for A. auriculiformis were within the ranges of TF reported for other plants, except for ¹³⁷Cs.

Keywords: Acacia auriculiformis; Activity concentration; North vietnam; Transfer factor; Uranium and REE mining.