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Curtis CJ, Rose NL, Yang H, Turner S, Langerman K, Fitchett J, Milner A, Kabba A, Shilland J. Contamination of depressional wetlands in the Mpumalanga Lake District of South Africa near a global emission hotspot. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 938:173493. [PMID: 38796003 DOI: 10.1016/j.scitotenv.2024.173493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/20/2024] [Accepted: 05/22/2024] [Indexed: 05/28/2024]
Abstract
The Mpumalanga Lake District (MLD) of South Africa hosts a regionally unique cluster of water bodies of great importance for wetland biodiversity. It is also located close to a global hotspot for coal-fired power station emissions but the local impacts from these sources of pollution are poorly understood. Sediment cores from three contrasting wetlands were 210Pb dated and analysed for a range of contaminants linked to fossil fuel combustion, including trace elements, Hg, sulphur and spheroidal carbonaceous fly-ash particles (SCPs). At the two sites with pre-industrial (1900) baseline sediments, Pb, Zn and especially Cr concentrations and fluxes showed significant increases in the impact period (post-1975). Mercury showed the greatest proportional increase in flux (>4-fold) of all trace metals. Mercury and sulphur concentrations and fluxes showed highly significant correlations with emissions over the corresponding periods, while SCPs in sediments also closely tracked emissions. In a global context, levels of sediment contamination are relatively minor compared with other heavily industrialised regions, with only Cr exceeding the sediment Probable Effects Concentration for biological impact post-1975. Despite the relatively large increases in Hg, concentrations do not reach the Threshold Effects Concentration. The unexpectedly low levels of contamination may be due to i) low levels of many trace contaminants in South African coals compared to global averages, ii) prevailing recirculation patterns which transport pollution away from the study area during the wet season, minimising wet deposition, and iii) pollutant remobilisation through desiccation of wetlands or volatilization. The effects of hydrology and sediment accumulation rates lead to differential transport and preservation of organic-associated and more volatile contaminants (e.g. Hg, S) relative to non-volatile trace elements in wetlands of the MLD. The greatest fluxes of Hg and S are recorded in the site with the highest catchment: lake area ratio, lowest salinity and greatest sediment organic matter content.
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Affiliation(s)
- C J Curtis
- Department of Geography, Environmental Management and Energy Studies, University of Johannesburg, Auckland Park, 2006 Johannesburg, South Africa.
| | - N L Rose
- Department of Geography, Environmental Management and Energy Studies, University of Johannesburg, Auckland Park, 2006 Johannesburg, South Africa; Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London WC1E 6BT, UK
| | - H Yang
- Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London WC1E 6BT, UK
| | - S Turner
- Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London WC1E 6BT, UK
| | - K Langerman
- Department of Geography, Environmental Management and Energy Studies, University of Johannesburg, Auckland Park, 2006 Johannesburg, South Africa
| | - J Fitchett
- School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, 1 Jan Smuts Avenue, Braamfontein 2050, South Africa
| | - A Milner
- Department of Geography, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - A Kabba
- Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London WC1E 6BT, UK
| | - J Shilland
- Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London WC1E 6BT, UK
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Wang X, Jiang Q, Zhao Z, Han X, Liu J, Liu Q, Xue B, Yang H. Comparison of spatiotemporal burial and contamination of heavy metals in core sediments of two plateau lakes with contrasting environments: implication for anthropogenic-driven processes. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1178. [PMID: 37690077 DOI: 10.1007/s10661-023-11764-y] [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: 05/08/2023] [Accepted: 08/21/2023] [Indexed: 09/12/2023]
Abstract
Investigating the impacts of climatic factors and human activities on sedimentary records of heavy metal (HM) contamination in lakes is essential for decision-making in global environmental monitoring and assessment. Spatiotemporal distributions of grain size (GS) and HM (Al, Cr, Mn, Ni, Cu, Zn, As, and Pb) concentrations have been conducted in core sediments that are collected from two adjacent plateau fault-bound lakes in southwest China with contrasting environments, i.e., deep oligotrophic Lake Fuxian (FX) and shallow hypertrophic Lake Xingyun (XY). Results showed that the average value of d50 in FX (4.61 μm) was lower than that in XY (8.35 μm), but the average concentrations of HMs (except Cr and Mn) in XY were higher than those in FX. Heavy metal burial rates (HMBR) were mainly controlled by sediment accumulation rates (SARs) rather than HM concentrations. The correlation coefficients between GS and HM concentrations became strong as the increasing water depths were associated with a stable sedimentary environment. Time-integrated enrichment factors (EF) and source identification of HMs between FX and XY represented that Cr, Ni, and Cu originated from natural sources but Mn, Zn, As, and Pb from anthropogenic sources, respectively. Regardless of FX and XY, the transition times of HMs from natural to anthropogenic sources occurred in the mid-1960s. Comparison of qualification impacts of climatic factors and human-induced factors on increased anthropogenic HMBR by the partial least squares path modeling (PLS-PM) implied that socio-economic activities, such as population density (PD) and gross domestic product (GDP), provided higher contributors to increased anthropogenic HMBR in XY (0.23/0.71) than FX (0.11/0.18). The comparative results of this study provided new insights into environmental monitoring and management of HM contamination for adjacent lakes with contrasting environments.
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Affiliation(s)
- Xiaolei Wang
- School of Environmental Sciences, Nanjing Xiaozhuang University, Nanjing, 211171, China
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Qingfeng Jiang
- School of Geographical Sciences, Nantong University, Nantong, 226019, China.
| | - Zihan Zhao
- School of Geographical Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Ximou Han
- School of Environmental Sciences, Nanjing Xiaozhuang University, Nanjing, 211171, China
| | - Jinliang Liu
- School of Environmental Sciences, Nanjing Xiaozhuang University, Nanjing, 211171, China
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Qun Liu
- School of Environmental Sciences, Nanjing Xiaozhuang University, Nanjing, 211171, China
| | - Bin Xue
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Hao Yang
- School of Geographical Sciences, Nanjing Normal University, Nanjing, 210023, China
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Chukwuka AV, Ogbeide O, Otomo PV. Trend relationship between mountain normalized difference vegetation index (NDVI) and aerosol optical depth (AOD) across two decades: implication for water quality within the Lesotho Highlands, Drakensberg, South Africa. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:584. [PMID: 37072567 DOI: 10.1007/s10661-023-11110-2] [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: 04/30/2022] [Accepted: 03/09/2023] [Indexed: 05/03/2023]
Abstract
There are growing concerns on contribution of vegetation dynamics to atmospheric turbidity and quality of regional water towers. The study sought to determine the trends in the MODIS/TERRA-derived normalized difference vegetation index (NDVI) and aerosol optical depth (AOD) for Lesotho Highland over 2000-2020. The predictive relationship between the two variables was also examined using regression analysis. Irrespective of yearly AOD patterns, the AOD showed biphasic patterns peaking between mid-winter to early spring (July-October) (highest) and autumn (Feb-April) (next highest), and lowest in the summer (Nov-January). The monthly NDVI was largest in January-March (summer-early fall) with smaller values in winter and spring. This seasonality can be related to the peak of anthropogenic biomass combustion during the winter and strong winds during the spring and early summer. The AOD relationship with NDVI showed quadratic patterns peaking and plunging with changes in season. About 30-80% (R2 = 0.3-0.8%) changes in annual AOD from 2000 to 2020 were explainable by the dynamics of NDVI indicating that increased NDVI contributes to about a 50% decrease in AOD in the Lesotho Highlands. However, an outlier trend was observed in 2007 (R2 = 13%). Incidences of high AOD in months of high NDVI may be indicative of traveling aerosols, i.e., aerosols from non-local sources/activity. On the other hand, high AOD in months of low NDVI implicates local aerosol sources. Trend relationship studies on vegetation loss and AOD in mountain areas of other regions could improve knowledge of contaminant dynamics and risk implications for downstream populations.
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Affiliation(s)
| | - Ozekeke Ogbeide
- Department of Environmental Management and Toxicology, University of Benin, Benin City, Nigeria
| | - Patricks Voua Otomo
- Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa
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Gurgatz BM, Garcia MR, Cabral AC, de Souza AC, Nagai RH, Figueira RCL, de Mahiques MM, Martins CC. Polycyclic aromatic hydrocarbons in a Natural Heritage Estuary influenced by anthropogenic activities in the South Atlantic: Integrating multiple source apportionment approaches. MARINE POLLUTION BULLETIN 2023; 188:114678. [PMID: 36764149 DOI: 10.1016/j.marpolbul.2023.114678] [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: 06/09/2022] [Revised: 12/29/2022] [Accepted: 01/25/2023] [Indexed: 06/18/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) were analysed in the sediments of one of the most well-preserved estuaries in South Brazil, the Paranaguá Estuarine System (PES), using several source apportionment tools. The ∑PAH ranged from < DL to 125.6 ng g-1 dw (dry weight) (average 29.9 ± 26.1 ng g-1 dw), and the lowest levels detected were similar to those found in other protected areas of the world. In general, the PAH concentrations indicated excellent environmental quality for the entire estuary. Principal component analysis indicated that fine sediments and total organic carbon were the main factors controlling PAH concentrations in the PES. Multiple PAH sources were identified in the study area; biomass burning and fossil fuel combustion predominated but considerable amounts of petrogenic residues were also observed. We identified evidence of a contribution from an adjacent watershed resulting from the construction of interconnections between large rivers and from years of intense deforestation in the local Atlantic Forest.
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Affiliation(s)
- Bruno Martins Gurgatz
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil.
| | - Marina Reback Garcia
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil
| | - Ana Caroline Cabral
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil
| | - Amanda Câmara de Souza
- Programa de Pós-Graduação em Oceanografia, Instituto Oceanográfico, Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-900 São Paulo, SP, Brazil
| | - Renata Hanae Nagai
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil; Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 8325-976 Pontal do Paraná, PR, Brazil
| | - Rubens C L Figueira
- Programa de Pós-Graduação em Oceanografia, Instituto Oceanográfico, Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-900 São Paulo, SP, Brazil
| | - Michel Michaelovitch de Mahiques
- Programa de Pós-Graduação em Oceanografia, Instituto Oceanográfico, Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-900 São Paulo, SP, Brazil
| | - César C Martins
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil; Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 8325-976 Pontal do Paraná, PR, Brazil.
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Kalneniece K, Gudra D, Lielauss L, Selga T, Fridmanis D, Terauds J, Muter O. Batch-mode stimulation of hydrocarbons biodegradation in freshwater sediments from historically contaminated Alūksne lake. JOURNAL OF CONTAMINANT HYDROLOGY 2023; 253:104103. [PMID: 36435695 DOI: 10.1016/j.jconhyd.2022.104103] [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: 05/11/2022] [Revised: 09/30/2022] [Accepted: 11/01/2022] [Indexed: 06/16/2023]
Abstract
Historical contamination of freshwater lakes with hydrocarbons (HC) due to anthropogenic activities represents a serious problem worldwide. This study was focused on hydrocarbons-contaminated sediments sampled in Lake Alūksne of glacial origin in Northeast Latvia. The batch experiments were aimed at evaluating the effect of bio-stimulation and bioaugmentation on the biodegradation of hydrocarbons in lake sediments (LS), as well as changes in microbial community structure and metabolic activity. The sediments were sampled from two points of the lake, 4-5 m and 8 m depth, respectively. These samples slightly differed by colour, count of diatoms, microbial respiration intensity and colour intensity of 2,6- dichlorophenolindophenol. Nevertheless, the trend in biodegradation activity was similar for both LS samples. The concentration of HC in LS during the 32-day incubation decreased in average from 465 mg/kg to 165 mg/kg and 117.5 mg/kg in the LS amended with nutrients and nutrients+microbial community, respectively. Different treatment types of LS resulted in differences in microbial respiration and HC-degrading activity. The Shotgun sequencing has revealed the main phyla present in the intact LS being Proteobacteria (48.8%), Actinobacteria (24.4%), Firmicutes (10.4%) and Bacteroidetes (5.0%). Incubation of LS for 32 days resulted in increasing abundance of Proteobacteria from 48.8% in the raw LS to 58-62%, mainly due to the increase of Betaproteobacteria. The functional annotation of gene families revealed that the most abundant gene families were associated with ATP binding, metal ion, magnesium ion, sulfur cluster, zinc ion binding, DNA binding and other essential components for cell functioning. The Shannon biodiversity index of culturable microorganisms in EcoPlates™ ranged from 2.28 to 2.85. The data obtained in this study indicated that the suggested approach is a potent remediation technology for further ex situ scaling up.
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Affiliation(s)
- Kristine Kalneniece
- Department of Microbiology & Biotechnology, Faculty of Biology, University of Latvia, 1 Jelgavas Str., Riga LV-1004, Latvia
| | - Dita Gudra
- Latvian Biomedical Research and Study Center, 1 Ratsupites Str., Riga LV-1067, Latvia
| | - Ludvigs Lielauss
- Baltijas Juras Geologijas Centrs Ltd., 67A Ieriku Str., LV-1084 Riga, Latvia
| | - Turs Selga
- Faculty of Medicine, University of Latvia, 1 Jelgavas Str., Riga LV-1004, Latvia
| | - Davids Fridmanis
- Latvian Biomedical Research and Study Center, 1 Ratsupites Str., Riga LV-1067, Latvia
| | - Janis Terauds
- Baltijas Juras Geologijas Centrs Ltd., 67A Ieriku Str., LV-1084 Riga, Latvia
| | - Olga Muter
- Department of Microbiology & Biotechnology, Faculty of Biology, University of Latvia, 1 Jelgavas Str., Riga LV-1004, Latvia.
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Bai Y, Yu H, Shi K, Shang N, He Y, Meng L, Huang T, Yang H, Huang C. Polycyclic aromatic hydrocarbons in remote lakes from the Tibetan Plateau: Concentrations, source, ecological risk, and influencing factors. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 319:115689. [PMID: 35816959 DOI: 10.1016/j.jenvman.2022.115689] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/19/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) have received worldwide attention due to their potential teratogenic, persistent, and carcinogenic characteristics. In this study, the PAHs concentrations in two dated sediment cores taken from central Tibetan Plateau (TP) were analyzed to study the deposition history, potential sources, ecological risks, and influencing factors. Total concentration of PAHs (∑PAHs) ranged from 50.0 to 195 ng g-1 and 51.9-133 ng g-1 in sediments of Pung Co (PC) and Dagze Co (DZC), respectively. 2-3-ring PAHs were dominant in the two lake sediments, accounting for an average of 77.5% and 80.1%, respectively. The historical trends of ∑PAHs in the two lakes allowed to distinguish three periods, namely, relative stability before the 1950s, a gradual increase between the 1950s and the 1990s, and then a decline to the present-day. In addition, the trend in the concentration level of each PAH composition was consistent with ∑PAHs before the 1990s, while they exhibited different trends since the 1990s, which may be the result of a combination of anthropogenic activities and climate change in recent years, whereas before the 1990s the PAH profile was mainly influenced by atmospheric deposition. The results of source apportionment examined according to diagnostic ratios and positive matrix factorization were consistent and revealed that PAHs were primarily derived from biomass and coal combustion. Significant correlations between PAHs and organic carbon (OC) indicate that OC might be a key factor influencing the concentration of PAHs in sediments. The ecological risk assessment demonstrated that PAHs in TP sediments occurred at a low risk level. Results of this study could be helpful to develop a deeper insight into the deposition history of PAHs in remote lakes of the TP region and explore the response of these variations to climate change and human activities.
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Affiliation(s)
- Yixin Bai
- School of Geography, Nanjing Normal University, Nanjing 210023, PR China
| | - Heyu Yu
- School of Geography, Nanjing Normal University, Nanjing 210023, PR China
| | - Kunlin Shi
- School of Geography, Nanjing Normal University, Nanjing 210023, PR China
| | - Nana Shang
- School of Geography, Nanjing Normal University, Nanjing 210023, PR China
| | - Yao He
- School of Geography, Nanjing Normal University, Nanjing 210023, PR China
| | - Lize Meng
- School of Geography, Nanjing Normal University, Nanjing 210023, PR China
| | - Tao Huang
- School of Geography, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Ministry of Education, Nanjing 210023, PR China; State Key Laboratory Cultivation Base of Geographical Environment Evolution (Jiangsu Province), Nanjing 210023, PR China
| | - Hao Yang
- School of Geography, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Ministry of Education, Nanjing 210023, PR China; State Key Laboratory Cultivation Base of Geographical Environment Evolution (Jiangsu Province), Nanjing 210023, PR China
| | - Changchun Huang
- School of Geography, Nanjing Normal University, Nanjing 210023, PR China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Nanjing 210023, PR China; Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Ministry of Education, Nanjing 210023, PR China; State Key Laboratory Cultivation Base of Geographical Environment Evolution (Jiangsu Province), Nanjing 210023, PR China.
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Liang M, Liu E, Wang X, Zhang Q, Xu J, Ji M, Zhang E. Historical trends in atmospheric metal(loid) contamination in North China over the past half-millennium reconstructed from subalpine lake sediment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 304:119195. [PMID: 35339617 DOI: 10.1016/j.envpol.2022.119195] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 02/20/2022] [Accepted: 03/20/2022] [Indexed: 06/14/2023]
Abstract
Trace metal (loid) contamination in the atmosphere is widely monitored, but there is a gap in understanding its long-term patterns, especially in North China, which is currently a global contamination hotspot mainly caused by heavy industry emissions and coal combustion. Herein, historical trends of atmospheric As, Cd, Cr, Cu, Hg, Ni, Pb and Zn contamination in North China over the past ∼500 years are comparatively studied with sediment cores from two subalpine lakes (Gonghai and Muhai). Arsenic, Pb, Cd and Hg were main pollutants according to Pb isotopes and enrichment factors. Mercury contamination has increased continuously since the late 1800s and increasing As, Pb and Cd contamination started in the 1950s in Gonghai. In contrast, the contamination in Muhai lagged two decades for As, Cd and Pb and a half-century for Hg behind that in Gonghai, although the trends were similar. This contamination lag was attributed to the low sensitivity of Muhai sediment to early weak atmospheric metal contamination under 2.1-fold higher detrital sedimentation. As, Pb and Cd contamination has intensified since the 1980s, and the metals showed similar sedimentary fluxes in the cores. However, sedimentary fluxes of Hg contamination were 3.4-fold higher in Gonghai than in Muhai due to combination with organic matter. No obvious Cr, Cu and Ni contamination in the cores was mainly because of the low atmospheric deposition from anthropogenic sources relative to detrital input, although some of their atmospheric emissions were higher than those of As, Cd and Hg. Atmospheric As, Pb and Cd contamination was mainly from domestic sources of coal combustion and nonferrous smelting. Mercury contamination was mainly from global and Asian sources in the first half of the 20th century, and domestic emissions gradually dominated Hg contamination after the mid-1900s.
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Affiliation(s)
- Mengyao Liang
- College of Geography and Environment, Shandong Normal University, Ji'nan, 250358, PR China; College of Marine Geosciences, Ocean University of China, Qingdao, 266100, PR China
| | - Enfeng Liu
- College of Geography and Environment, Shandong Normal University, Ji'nan, 250358, PR China.
| | - Xiaoyu Wang
- College of Geography and Environment, Shandong Normal University, Ji'nan, 250358, PR China
| | - Qinghui Zhang
- College of Geography and Environment, Shandong Normal University, Ji'nan, 250358, PR China
| | - Jinling Xu
- College of Geography and Environment, Shandong Normal University, Ji'nan, 250358, PR China
| | - Ming Ji
- School of Chemistry, Biology and Environment, Yuxi Normal University, Yuxi, 653100, PR China
| | - Enlou Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China
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Zhang S, Wang W, Wang F, Zhang D, Rose NL. Temporal-spatial variations, source apportionment, and ecological risk of trace elements in sediments of water-level-fluctuation zone in the Three Gorges Reservoir, China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:18282-18297. [PMID: 34687419 DOI: 10.1007/s11356-021-17066-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 10/12/2021] [Indexed: 06/13/2023]
Abstract
The Three Gorges Reservoir (TGR) plays a crucial role in providing electricity for mega-cities across China. However, since the impoundment was completed in 2006, attention to environmental concerns has also been intensive. In order to determine the distribution, sources, and pollution status of trace elements in the water fluctuation zone of the TGR following ten years of repeated "submergence" and "exposure", we systematically collected 16 paired surface sediment samples (n = 32) covering the entire main body of the TGR in March 2018 (following 6 months of submergence) and September 2018 (after 6 months of exposure), and quantitatively analyzed 13 elements (e.g., Mn, Fe, V, Cr, Ni, Cu, Zn, As, Sr, Y, Zr, Ba, and Pb) using X-ray fluorescence spectrophotometry (XRF). The results showed that, except for Sr, concentrations of trace metals following submergence were generally higher than those after exposure due to the less settling of suspended solids at the faster flow velocity during the drawdown period. Assessment using enrichment factors (EFs) and a geo-accumulation index (Igeo) both characterized a relatively serious anthropogenic pollution status of metals in the upper reaches of the TGR with respect to the middle-lower reaches. Source apportionment by positive matrix factorization (PMF) analysis indicated that agricultural activities (24.8 and 24.3%, respectively) and industrial emissions (24.5 and 22.9%, respectively) were the two major sources in these two periods, followed by natural sources, domestic sewage, and ore mining. Ecological risk assessment showed that metalloid arsenic (As) could be the main potential issue of risk to aquatic organisms and human health. A new source-specific risk assessment method (pRI) combined with PMF revealed that agricultural activities could be the major source of potential ecological risk and should be prioritized as the focus of metal/metalloid risk management in the TGR.
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Affiliation(s)
- Siyuan Zhang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400030, China
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400030, China
- Department of Environmental Science, College of Environment and Ecology, Chongqing University, Chongqing, 400030, China
| | - Weiru Wang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400030, China
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400030, China
- Department of Environmental Science, College of Environment and Ecology, Chongqing University, Chongqing, 400030, China
| | - Fengwen Wang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400030, China.
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400030, China.
- Department of Environmental Science, College of Environment and Ecology, Chongqing University, Chongqing, 400030, China.
| | - Daijun Zhang
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400030, China
- Department of Environmental Science, College of Environment and Ecology, Chongqing University, Chongqing, 400030, China
| | - Neil L Rose
- Environmental Change Research Centre, University College London, Gower Street, London, WC1E 6BT, UK.
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