Enrichment effect of Hypnum plumaeforme on 210Po and 210Pb.

The mosses have been widely used as bioindicators to investigate pollution and changes of heavy metals in different countries and regions. In this research, the field surveys were carried out for understanding the moss community and enrichment effects of the dominant species of mosses around the uranium mill tailings impoundment in South China, especially for the enriched contentions of 210Pb and 210Po in soil and Hypnum plumaeforme. The results showed that the maximum concentrations of U and 226Ra in the study sites were 93 mg kg-1 and 1130.8 Bq kg-1, respectively. The exhalation rate of 222Rn (ERRn), soil U, and 226Ra contents in SS1, SS2, and SS3 were higher than CKS. With the increase of the distance from the central well, the contents of nuclides (U and 226Ra) in soils and H. plumaeforme were both decreased. And, the bioconcentration factors of H. plumaeforme for 210Pb and 210Po ranged from 1.05 to 1.49, and 1.25 to 1.40, respectively, indicating an accumulation of 210Po and 210Pb from soil by H. plumaeforme. These results indicated that H. plumaeforme is hopeful to become an accumulator plant for remediation of radon pollution, and also can be used as a potential indicator plant for radon pollution monitoring.