title: In-situ gamma-ray survey of rare-earth tailings dams--A case study in Baotou and Bayan Obo Districts, China.
abstract: An in-situ gamma-ray spectrometer survey with a scintillation detector of NaI(Tl) (Φ75 mm × 75 mm) was carried out in the Baotou and Bayan Obo Districts in order to estimate the levels of natural radionuclides near rare-earth (RE) tailings dams. In the RE tailings dam of Baotou, the mean concentrations of (238)U and (232)Th were 3.0 ± 1.0 mg/kg (range: 1.9-4.6 mg/kg) and 321 ± 31 mg/kg (range: 294-355 mg/kg), respectively. In the Bayan Obo tailings dam, the mean concentrations of (238)U and (232)Th were 5.7 ± 0.5 mg/kg (range: 5.3-6.1 mg/kg) and 276 ± 0.5 mg/kg (range: 275.5-276.3 mg/kg), respectively. The average (232)Th concentrations in the mining areas of the Bayan Obo Mine and the living areas of the Bayan Obo Town were 18.7 ± 7.5 and 26.2 ± 9.1 mg/kg, respectively. The (232)Th concentration recorded in the tailings dams was much higher than the global average (7.44 mg/kg). Our investigation shows that the (232)Th concentration in the tailings in the Baotou dam was 34.6 times greater than that in the local soil (in Guyang County); the average concentrations of (232)Th in the soil in the Baotou District and Bayan Obo Districts were about 1.35 and 2.82 times greater, respectively, than that in the soil in Guyang County. Based on our results, the highest estimated effective dose due to gamma irradiation was 1.15 mSv per year, estimated from the data observed in the Baotou tailings dams. The results of this preliminary study indicate the potential importance of radioactivity in RE tailings dams and that remedial measures may be required.
authors.affiliation: Geo-detection Laboratory, Ministry of Education, China University of Geosciences, China; School of Geophysics and Information Technology, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing, 100083, China.
authors.forename: Baochuan
authors.initials: B
authors.lastname: Li
authors.affiliation: Geo-detection Laboratory, Ministry of Education, China University of Geosciences, China; School of Geophysics and Information Technology, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing, 100083, China. Electronic address: npwang@cugb.edu.cn.
authors.forename: Nanping
authors.initials: N
authors.lastname: Wang
authors.affiliation: China Aero Geophysical Survey & Remote Sensing Center for Land and Resources, Beijing, 100083, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wan
authors.affiliation: China Aero Geophysical Survey & Remote Sensing Center for Land and Resources, Beijing, 100083, China.
authors.forename: Shengqing
authors.initials: S
authors.lastname: Xiong
authors.affiliation: Geo-detection Laboratory, Ministry of Education, China University of Geosciences, China; School of Geophysics and Information Technology, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing, 100083, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Geo-detection Laboratory, Ministry of Education, China University of Geosciences, China; School of Geophysics and Information Technology, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing, 100083, China.
authors.forename: Shijun
authors.initials: S
authors.lastname: Li
authors.affiliation: Geo-detection Laboratory, Ministry of Education, China University of Geosciences, China; School of Geophysics and Information Technology, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing, 100083, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhao
mesh_terms: D002681:China; D005720:Gamma Rays; D008674:Metals, Rare Earth / Q000032:analysis*; D008906:Mining; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013051:Spectrometry, Gamma
chemical_list: D008674:Metals, Rare Earth; D012990:Soil Pollutants, Radioactive
keywords: Air-absorbed dose rate; Bayan Obo; In-situ gamma-ray spectrometry; Natural radionuclides; RE tailings dam