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Li H, Wang Q, Zhang C, Su W, Ma Y, Zhong Q, Xiao E, Xia F, Zheng G, Xiao T. Geochemical Distribution and Environmental Risks of Radionuclides in Soils and Sediments Runoff of a Uranium Mining Area in South China. TOXICS 2024; 12:95. [PMID: 38276730 PMCID: PMC10820150 DOI: 10.3390/toxics12010095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/12/2024] [Accepted: 01/19/2024] [Indexed: 01/27/2024]
Abstract
Uranium mining activities have contributed to the distribution and uptake of radionuclides, which have increased the active concentrations of natural radionuclides in environmental media, causing elevated human health risks. The present study aims to assess the spatial distribution characteristics of natural radionuclides in the surface soils and river sediments of the typical granite uranium mining area in South China, as well as investigate the geochemical features of natural radionuclides in the soil and sediments to understand their migration processes. The activity concentrations for 238U, 226Ra, 232Th, and 40K ranged from 17-3925 Bq/kg, 50-1180 Bq/kg, 29-459 Bq/kg, and 240-1890 Bq/kg, respectively. The open-pit mining areas and tailings pond locations exhibited the highest concentrations of activity for all these radionuclides. This distribution points to an elevated potential health risk due to radiological exposure in these specific areas. Additionally, the values of radium equivalent activity (Raeq) and annual gonadal dose equivalent (AGDE) in those areas were higher than the limits recommended by ICRP (2021). 238U and 226Ra have a significant correlation (0.724), and the cluster analysis was showing a statistically meaningful cluster below 5 indicated that they have similar behavior during parent rock weathering and watershed erosion, and the distribution of 232Th and 40K were influenced by the addition of rock types. The activity ratios of 226Ra/238U, 226Ra/232Th, 238U/40K, and 226Ra/40K variation indicated that 40K more mobile than 226Ra and 238U, U(VI) was reduced to U(IV) by organic matter in the downstream area and re-entered into the sediment during the sediment surface runoff in the small watershed of the uranium ore open-pit mining area. Therefore, it is necessary to further seal up and repair the tailings landfill area.
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Affiliation(s)
- Haidong Li
- State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, China; (H.L.); (F.X.)
- Research Institute No. 290, China National Nuclear Corporation, Shaoguan 512029, China;
| | - Qiugui Wang
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; (E.X.); (T.X.)
- Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining 810008, China;
| | - Chunyan Zhang
- Disaster Reduction and Disaster Preparedness Center of Jiangxi, Nanchang 330036, China;
| | - Weigang Su
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Chinese Academy of Sciences and Environment of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810016, China
| | - Yujun Ma
- Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining 810008, China;
| | - Qiangqiang Zhong
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China;
| | - Enzong Xiao
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; (E.X.); (T.X.)
| | - Fei Xia
- State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, China; (H.L.); (F.X.)
| | - Guodong Zheng
- Research Institute No. 290, China National Nuclear Corporation, Shaoguan 512029, China;
| | - Tangfu Xiao
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; (E.X.); (T.X.)
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Wang Q, Wang H, Ma Y, Wang J, Su W, Xiao E, Du J, Xiao T, Zhong Q. Geochemical distributions of natural radionuclides in surface soils and sediments impacted by lead-zinc mining activity. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 263:115210. [PMID: 37418943 DOI: 10.1016/j.ecoenv.2023.115210] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/22/2023] [Accepted: 06/29/2023] [Indexed: 07/09/2023]
Abstract
This study investigated the distribution features of uranium-238 (238U), radium-226 (226Ra), thorium-232 (232Th), and potassium-40 (40K) and evaluated the associated environmental radiological hazards of the topsoil and river sediments in the Jinding lead-zinc (Pb-Zn) mine catchment from Southwest China. The activity concentrations of 238U, 226Ra, 232Th, and 40K ranged from 24.0 ± 2.29-60.3 ± 5.26 Bq.kg-1, from 32.5 ± 3.95-69.8 ± 3.39 Bq.kg-1, from 15.3 ± 2.24-58.3 ± 4.92 Bq.kg-1, and from 203 ± 10.2-1140 ± 27.4 Bq.kg-1, respectively. The highest activity concentrations for all these radionuclides were primarily found in the mining areas and decreased with increasing distance from the mining sites. The radiological hazard indices, including radium equivalent activity, absorbed gamma dose rate in the air, outdoor annual effective dose equivalent, annual gonadal dose equivalent, and excess lifetime cancer, revealed that the highest values were observed in the mining area and downstream, specifically in the vicinity of the ore body. These elevated values exceeded the global mean value but remained below the threshold value, suggesting that routine protection measures for Pb-Zn miners during production activities are sufficient. The correlation analysis and cluster analysis revealed strong associations between radionuclides such as 238U, 226Ra, and 232Th, indicating a common source of these radionuclides. The activity ratios of 226Ra/238U, 226Ra/232Th, and 238U/40K varied with distance, suggesting the influence of geological processes and lithological composition on their transport and accumulation. In the mining catchment areas, the variations in these activity ratios increased indicated the impact of limestone material dilution on the levels of 232Th, 40K, and 238U in the upstream region. Moreover, the presence of sulfide minerals in the mining soils contributed to the enrichment of 226Ra and the removal of 238U caused those activity ratios decreased in the mining areas. Therefore, in the Jinding PbZn deposit, the patterns of mining activities and surface runoff processes in the catchment area favored the accumulation of 232Th and 226Ra over 40K and 238U. This study provides the first case study on the geochemical distributions of natural radionuclides in a typical Mississippi Valley-type PbZn mining area and offers fundamental information on radionuclide migration and baseline radiometric data for PbZn deposits worldwide.
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Affiliation(s)
- Qiugui Wang
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China
| | - Hai Wang
- State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, Jiangxi, China
| | - Yujun Ma
- Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining 810008, China
| | - Jinlong Wang
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
| | - Weigang Su
- Qinghai Earthquake Agency, Xining 810001, China
| | - Enzong Xiao
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China
| | - Jinzhou Du
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
| | - Tangfu Xiao
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China.
| | - Qiangqiang Zhong
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China.
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Zhong Q, Wang H, Wang Q, Chen S, Lin J, Huang D, Yu T. Study of Ra desorption processes in an estuary system with high-turbidity at the Southeast China. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2023; 259-260:107108. [PMID: 36638725 DOI: 10.1016/j.jenvrad.2023.107108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 01/02/2023] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
Radium (Ra) isotopes are extensively used as geochemical tracers for studying water mass mixing and submarine groundwater discharge in marginal and coastal seas. However, river-borne particles and seafloor sediments are an important source of Ra in marine systems due to Ra desorption. Therefore, it is necessary to study the desorption behaviors of Ra isotopes in river sediment or suspended particles. Here, the desorption behaviors of four Ra isotopes (223Ra, 224Ra, 226Ra, and 228Ra) in the Zhangjiang River sediments were investigated by a series of designed variable-controlling experiments in the laboratory. Within the designed salinity range, desorption amounts of Ra isotopes increased with increasing salinity, and when the salinity was greater than 15 ppt, Ra desorption reached an equilibrium state. Overall, desorption of Ra isotopes increased with the decrease of particle grain size, however, the desorption fractions of 224Ra and 228Ra decreased with decreasing particle size due to the increase of original Ra activities in smaller sediment particles. In the experiments, we found that two sediment samples with similar mean grain size (3.8 μm and 3.3 μm) and similar grain size distributions had significantly different Ra desorption under the same conditions. The results of mineral composition analysis based on X-ray diffraction showed that these two samples had different percentages of kaolinite, quartz, and plagioclase, which indicated that the mineral composition of particles had an important effect on Ra isotope desorption. In conclusion, salinity, particle grain size, and mineral composition all had significant effects on Ra desorption behaviors of sediment particles. Based on the above desorption experiments, the desorbed fluxes of four Ra isotopes from river-borne sediments to the Dongshan Bay were estimated to be (5.95 ± 1.47) × 107 Bq yr-1 for 223Ra, (1.95 ± 0.27) × 109 Bq yr-1 for 224Ra, (2.73 ± 0.47) × 108 Bq yr-1 for 226Ra, and (1.26 ± 0.20) × 109 Bq yr-1 for 228Ra, respectively.
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Affiliation(s)
- Qiangqiang Zhong
- Third Institute of Oceanography, Ministry of Natural Resource, Xiamen, 361005, China
| | - Hao Wang
- Third Institute of Oceanography, Ministry of Natural Resource, Xiamen, 361005, China; College of Marine Sciences, Shanghai Ocean University, Shanghai, 201306, China
| | - Qiugui Wang
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Suiyuan Chen
- Third Institute of Oceanography, Ministry of Natural Resource, Xiamen, 361005, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005, China
| | - Jing Lin
- Third Institute of Oceanography, Ministry of Natural Resource, Xiamen, 361005, China
| | - Dekun Huang
- Third Institute of Oceanography, Ministry of Natural Resource, Xiamen, 361005, China; Observation and Research Station of Island and Coastal Ecosystem in the Western Taiwan Strait, Ministry of Natural Resources, Xiamen, 361005, China; Fujian Provincial Station for Field Observation and Research of Island and Costal Zone in Zhangzhou, Zhangzhou, 363216, China; Key Laboratory of Global Change and Marine-Atmospheric Chemistry, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361000, China.
| | - Tao Yu
- Third Institute of Oceanography, Ministry of Natural Resource, Xiamen, 361005, China
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