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Distribution characteristics of mercury and methylmercury in fishes in the Three Gorges Reservoir

Distribution characteristics of mercury and methylmercury in...

The 17th International Conference on Heavy Metals in the Environment (ICHMET2014)(第十七届国际环境重金属会议)

作者： Qinqin Xu Lei Zhao Dingyong Wang College of Resources and Environment Southwest UniversityChongqingChina Chongqing Engineering Research Center for Agricultural Non-point Source Pollution Control in the Three Gorges Reservoir Area Chongqing Key Laboratory of Agricultural Resources and Environment

Mercury is liable to translate into hypertoxic alkyl mercury in aquatic *** studies confirmed that reservoirs have the effect of mercury reactivity,new built reservoirs manifest the the phenomenon of abnormal higher methylmercury value in water and fishes,and the inundated sediments and plants are the important source of the increased methylmercury in fishes in *** Gorges Reservoir is the world spotlight reservoir which inundates large areas after impounding due to it's special topography,whether it can increase the methylmercury bioaccumulation rate of water and aquatic organism and emerge the mercury reactivity of reservoir is an important subject that is worth probing ***,we choose the wild fishes in Three Gorges Reservoir as respondents,analysising the total mercury(THg)and methylmercury(MeHg)in different tissues or organs(such as gill,heart,muscle and swim bladder)of fishes every other month systematically,the results as follows: The range of the THg concentration in fishes' muscles in Three Gorges Reservoir is 0.51~254.83 ng?g-1,the mean value is 51.26.±43.04 ng?g-1; The range of the MeHg concentration in muscles is 0.05~188.89 ng?g-1,the mean value is 20.56±27.84 ng?g-1;The range of the ratio of MeHg/THg in muscles is 2.65~96.84%,the mean value is 34.89±22.72%,the concentrations of THg and MeHg and the ratio of MeHg/THg are in the low levels compared with the rivers,lakes and reservoirs in China and overseas,and the concentrations of THg and MeHg are all lower than the food restricted standard of mercury(THg is 300 ng?g-1 and MeHg is 200 ng?g-1).The concentrations of THg and MeHg in different tissues or organs show higher value in muscles and hearts and lower value in swim bladders and *** concentrations of THg and MeHg,the ratio of MeHg/THg,the bioaccumulation factors of THg and MeHg in different tissues or organs perform an increase trend with the rising of trophic ***,the values o

关键词： fish methylmercury total mercury bioaccumulation factors mercury reacivity

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Dynamics of total culturable bacteria and its relationship with methylmercury in the soils of the water level fluctuation zone of the Three Gorges Reservoir

Dynamics of total culturable bacteria and its relationship w...

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The 17th International Conference on Heavy Metals in the Environment (ICHMET2014)(第十七届国际环境重金属会议)

作者： Yuping Xiang Hongxia Du Hong Shen Cheng Zhang Dingyong Wang Chongqing Key Laboratory of Soil Multi-scale Interfacial Process College of Resources and EnvironmentSouthwest UniversityChongqingChina Chongqing Engineering Research Center for Agricultural Non-point Source Pollution Control in the Three Gorges Reservoir AreaChongqingChina Chongqing Key Laboratory of Agricultural Resources and EnvironmentChongqingChina

Field investigations were conducted to study the temporal and spatial distribution characteristics of total culturable bacteria(TCB)and its relationship with methylmercury(MeHg)in the soils of the water level fluctuation zone of the Three Gorges *** altitudes(170-180 m,170-175 m,165-170 m and 160-165 m)in Zhenxi(Site 1),Shibaozhai(Site 2)and Tujing(Site 3),Chongqing,China were chosen as sampling *** indicated that TCB did not have significant difference in the top(0-10 cm)and sub(10-20 cm)soil of the non-inundated area(175-180 m),but showing a significant difference in the water level fluctuation zone(< 175 m,suggesting that water level fluctuation had an important effect on ***,TCB in soils of various altitudes of Site 1 and 2 had significant difference,while for Site 3,this difference was not *** the difference of TCB in Site 2 was much greater than that in Site *** results suggested that there were significant differences for TCB in soils of mainstream and *** addition,TCB in soils of 10-20 cm had significant or highly significant positive correlations with MeHg level(r ≥ 0.762,p ≤ 0.048),thus we assumed that there may be some aerobic microorganisms playing dominant roles in mercury methylation.

关键词： Three Gorges Reservoir soil water leverl fluctuation zone total culturable bacteria (TCB) methylmercury

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Long-term tillage effects on soil organic carbon and dissolved organic carbon in a purple paddy soil of Southwest China

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Acta Ecologica Sinica 2013年第5期33卷 260-265页

作者： Qingju Hao Binghong Cheng Changsheng Jiang Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education) College of Resources and Environment Southwest University Chongqing 400715 China Chongqing Engineering Research Center for Agricultural Non-point Source Pollution Control in the Three Gorges Reservoir Area Chongqing 400716 China

The impact of conservation tillage practices on soil carbon has been of great interest in recent years. Conservation tillage might have the potential to enhance soil carbon accumulation and alter the depth distribution of soil carbon compared to conventional tillage based systems. Changes in the soil organic carbon (SOC) as influenced by tillage, are more noticeable under long-term rather than short-term tillage practices. The objective of this study was to determine the impacts of long-term tillage on SOC and dissolved organic carbon (DOC) status after 19 years of four tillage treatments in a Hydragric Anthrosol. In this experiment four tillage systems included conventional tillage with rotation of rice and winter fallow system (CTF), conventional tillage with rotation of rice and rape system (CTR), no-till and ridge culture with rotation of rice and rape system (NT) and tillage and ridge culture with rotation of rice and rape system (TR). Soils were sampled in the spring of 2009 and sectioned into 0–10, 10–20, 20–30, 30–40, 40–50 and 50–60 cm depth, respectively. Tillage effect on SOC was observed, and SOC concentrations were much larger under NT than the other three tillage methods in all soil depths from 0 to 60 cm. The mean SOC concentration at 0–60 cm soil depth followed the sequence: NT (22.74 g kg −1 ) > CTF (14.57 g kg −1 ) > TR (13.10 g kg −1 ) > CTR (11.92 g kg −1 ). SOC concentrations under NT were significantly higher than TR and CTR ( P < 0.01), and higher than CTF treatment ( P < 0.05). The SOC storage was calculated on equivalent soil mass basis. Results showed that the highest SOC storage at 0–60 cm depth presented in NT, which was 158.52 Mg C ha −1 , followed by CTF (106.74 Mg C ha −1 ), TR (93.11 Mg C ha −1 ) and CTR (88.60 Mg C ha −1 ). Compared with conventional tillage (CTF), the total SOC storage in NT increased by 48.51%, but decreased by 16.99% and 12.77% under CTR and TR treatments, resp

关键词： Tillage Soil organic carbon Dissolved organic carbon Purple paddy soil

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Estimates of N_2O Emissions and Mitigation Potential from a Spring Maize Field Based on DNDC Model

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Journal of Integrative Agriculture 2012年第12期11卷 2067-2078页

作者： LI Hu QIU Jian-jun WANG Li-gang XU Ming-yi LIU Zhi-qiang WANG Wei Key Laboratory of Non-Point Source Pollution Control Ministry of Agriculture/CAAS-UNH Joint Laboratory for Sustainable Agro-Ecosystems Research/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Dalian Academy of Agricultural Sciences

Agricultural production plays an important role in affecting atmospheric nitrous oxide （N20） concentrations. Field measurements were conducted in Dalian City, Liaoning Province in Northeast China from two consecutive years （2009 and 2010） to estimate NzO emissions from a spring maize field, a main cropping system across the Chinese agricultural regions. The observed flux data in conjunction with the local climate, soil and management information were utilized to test a process-based model, DeNitrification-DeComposition （DNDC）, for its applicability for the cropping system. The validated DNDC was then used for exploring strategies to reduce N20 emissions from the target field. The results showed that the major N20 pulse emissions occurred with duration of about 3-5 d after fertilizer application in both years 2009 and 2010, which on average accounted for about 60% of the total N20 emissions each year. Rainfall and fertilizer application were the major factors influencing the N20 emissions from spring maize field. The average N20 flUXeS from the CK （control plot, without fertilization） and FP （traditional chemical N fertilizer） treatments were 23.1 and 60.6 gg m-2 h-~ in 2009, respectively, and 21.5 and 64.3 gg m-2 h-~ in 2010, respectively. The emission factors （EFs） of the applied N fertilizer （270 kg N ha-1） as N20- N were 0.62% in 2009 and 0.77% in 2010, respectively. The comparison of modeled daily NzO emission fluxes against observations indicated that the DNDC model had a good performance even if without adjusting the internal parameters. The modeled results showed that management practices such as no-till, changing timing or rate of fertilizer application, increasing residue incorporation, and other technically applicable measures could effectively reduce N20 emissions from the tested fields. Our study indicated that avoiding application of N fertilizers at heavy rainfall events or splitting the fertilizer into more applications would be the most feasible appr

关键词： spring maize N20 DNDC mitigation measures Northeast China

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Estrogenic effects of dissolved organic matter and its impact on the activity of 17β-estradiol

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Environmental Science and pollution Research 2012年第2期19卷 522-528页

作者： Chen, Lei Shen, Chaofeng Tang, Xianjin Chen, Chen Chen, Yingxu College of Environmental and Resource Sciences Zhejiang University 268 Kaixuan Road Hangzhou 310029 China Key Laboratory for Water Pollution Control and Environmental Safety Hangzhou 310029 Zhejiang Province China Key Laboratory of Non-point Source Pollution Control Ministry of Agriculture Zhejiang University Hangzhou 310029 China

Background and purpose: The ubiquitous dissolved organic matter (DOM) is actually not inert as we always think, and the hormone-like effects of DOM have been reported. The objective of this study was to investigate the estrogenic effects of DOM and its impact on the activity of the natural estrogen 17β-estradiol (E2). Materials and methods: DOM of three different sources, HA sodium salt, Suwannee River natural organic matter (NOM), and Nordic Reservoir NOM, were used. The estrogenic activity was detected by using the yeast estrogen screen (YES) assay. Estrogenic effects of DOM without and after solar irradiation were tested. Influences on the action of E2 by DOM were also investigated. Results: No direct estrogenic effects of the DOM used were observed in the YES assay. However, the estrogenic activities after 24 h of irradiation increased to 0. 0288, 0. 0178, and 0. 0195 μM of E2 equivalents for HA sodium salt, Suwannee River NOM, and Nordic Reservoir NOM, respectively. After incubation of DOM, the estrogenic activity of E2 was increased by low concentrations (8. 33 and 83. 3 μM) of DOM while decreased by higher concentrations (8. 33 × 102 and 8. 33 × 103 μM) of DOM. Conclusions: Though direct estrogenic effects of DOM were not observed, increase in the estrogenic activity of DOM after irradiation was significant. DOM shows amphoteric influence on the natural estrogen E2, which depends on the concentration of DOM used. Because of its ubiquity, DOM may be of great ecological significance, playing an important role in regulating the reproduction of aquatic organisms. © 2011 Springer-Verlag.

关键词： Irradiation

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Effect of dissolved organic matter on mercury release from water body

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Journal of Environmental Sciences 2011年第6期23卷 912-917页

作者： Yutao Zhang Xi Chen Yongkui Yang Dingyong Wang Xiao Liu Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education) College of Resources and Environment Southwest University Chongqing 400715 China Chongqing Engineering Research Center for Agricultural-Non-Point Source Pollution Control in the Three Gorges Reservoir Area Chongqing 400716 China Department of Chemistry Biology and Agriculture in Anshun College Anshun 561000 China

Dissolved organic matter（DOM） plays an important role in the process of mercury release from water *** this study,the influence of DOM from different sources（DOMR,DOMS and DOMH,extracted from rice straw,compost and humic soil respectively） on mercury reduction was *** molecular weight distribution and chemical composition of DOM from each source were determined using ultrafiltration membrane technique and elemental analysis *** result showed that mercury release from DOM-added samples was much lower than the control;the lowest mercury release flux was observed in the treatment of DOMH,25.02% of the control,followed by DOMS and DOMR,62.46% and 64.95% of the control,*** higher saturation degree and lower molecular weight of DOMH was responsible for the highest inhibition degree on the mercury *** link between DOMH,concentration and mercury flux was also estimated and the result showed that mercury flux was increased with DOMH at lower concentration,while decreased with DOMH at higher *** mechanism dominated the influence of DOM on mercury release with variation of DOM concentration.

关键词： dissolved organic matter mercury release inhibition molecular weight

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Heavy metal and persistent organic compound contamination in soil from Wenling: An emerging e-waste recycling city in Taizhou area, China

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Journal of Hazardous Materials 2010年第1-3期173卷 653-660页

作者： Tang, Xianjin Shen, Chaofeng Shi, Dezhi Cheema, Sardar A. Khan, Muhammad I. Zhang, Congkai Chen, Yingxu Ministry of Agriculture Key Laboratory of Non-point Source Pollution Control Institute of Environmental Science and Technology Zhejiang University Kaixuan Road 268 Hangzhou 310029 China

The present study was conducted to investigate the levels and sources of heavy metals (Cu, Cr, Cd, Pb, Zn, Hg and As) and persistent organic compounds including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in soils taken from Wenling, an emerging e-waste recycling city in Taizhou, China. The results suggested that most heavy metals exceeded the respective Grade II value of soil quality standards from State Environmental Protection Administration of China and also exceeded the Dutch optimum values. Total PAHs in soil ranged from 371.8 to 1231.2 μg/kg, and relatively higher PAHs concentrations were found in soils taken from simple household workshops. PCBs were detectable in all samples with total concentrations ranging from 52.0 to 5789.5 μg/kg, which were 2.1-232.5 times higher than that from the reference site (24.9 μg/kg). Results of this study suggested soil in the Wenling e-waste recycling area were heavily contaminated by heavy metals, PAHs and PCBs. Furthermore, compared with large-scale plants, simple household workshops contributed more heavy metals, PAHs and PCBs pollution to the soil environment, indicating that soil contamination from e-waste recycling in simple household workshops should be given more attention. © 2009 Elsevier B.V. All rights reserved.

关键词： Soils

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PCB congeners induced mitochondrial dysfunction in Vero cells

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Journal of hazardous materials 2011年第1期185卷 24-8页

作者： Kaili Shen Chaofeng Shen Jie Yu Chunna Yu Lei Chen Dezhi Shi Yingxu Chen Ministry of Agriculture Key Laboratory of Non-point Source Pollution Control Institute of Environmental Science and Technology Zhejiang University Hangzhou 310029 China.

Two PCB congeners were assessed for their cytotoxicity on Vero cells, in the attempt to compare their structure-activity relationship and to investigate the role of mitochondria involved in toxicity. Flow cytometry was used to monitor the changes of mitochondrial membrane potential (Δψ(m)), cell size and apoptosis rate. Treatments of Vero cell cultures with both PCB 126 and PCB 153 resulted in loss of cell viability in our experimental conditions. In ortho-substituted PCB 153 treated cells, loss of cell viability was accompanied by decreased Δψ(m) and cell shrinkage. The coplanar congener, PCB 126, had no significant effects on Δψ(m) or cell size in this time period of exposure. These studies showed that PCB 153 is more toxic than coplanar PCB 126 to Vero cells within 24h exposure. The cytotoxicity mechanism caused by coplanar or non-coplanar PCB congener was different, and apoptosis might be the main cell death pathway in PCB 153 treated cells.

关键词： PCBs Vero cells Mitochondria Apoptosis

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Study on adverse impact of e-waste disassembly on surface sediment in East China by chemical analysis and bioassays

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Journal of Soils and Sediments 2010年第3期10卷 359-367页

作者： Chen, Lei Yu, Chunna Shen, Chaofeng Zhang, Congkai Liu, Lei Shen, Kaili Tang, Xianjin Chen, Yingxu Institute of Environmental Science and Technology Zhejiang University Hangzhou People’s Republic of China Key Laboratory of Non-point Source Pollution Control Ministry of Agriculture People’s Republic of China Zhejiang University Hangzhou People’s Republic of China Centre for Biomedicine and Health Hangzhou Normal University Hangzhou People’s Republic of China Key Laboratory for Water Pollution Control and Environmental Safety Hangzhou People’s Republic of China

The primitive recycling of electronic waste (e-waste) in developing countries is causing serious environmental pollution. The objective of this study was to determine the contamination and toxicity of surface sediment of Nanguan River, which runs through the e-waste recycling area of Taizhou, East China. Surface sediments were collected from Nanguan River, including one from the control site, four near the household workshops, and two near the industrial parks. Levels of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals/metalloid (Ni, Pb, Cd, Cr, Zn, Cu, Hg, and As), which are most widely detected in e-waste contaminated surroundings, were determined. Acute toxicity and genetic toxicity were evaluated by luminescence inhibition assay in luminescent bacterium Vibrio qingaiensis sp. nov. (Q67) and Vicia faba roots tip micronucleus assay, respectively. The surface sediment has been seriously contaminated by PCBs, PAHs, and heavy metals/metalloid due to the e-waste disassembly process. Significant acute and genetic toxicity of the sediments presented a big threat to the aquatic life and human health through food chain, as the river is an extent water source for local residents. The environmental issue of e-waste recycling is emergent and measures should be taken to mitigate the adverse impacts of e-waste disassembly.

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Comparison of structure-dependent hormetic cytotoxicity induced by coplanar and non-coplanar PCB congeners

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Journal of hazardous materials 2010年第1-3期180卷 773-6页

作者： Yingxu Chen Kaili Shen Chaofeng Shen Lei Chen Xincai Chen Ministry of Agriculture Key Laboratory of Non-point Source Pollution Control Institute of Environmental Science and Technology Zhejiang University Hangzhou 310029 China. yxchen@***

The effect of polychlorinated biphenyls (PCBs) on Vero cell proliferation was investigated, with the attempts to assess the possible hormetic dose-response and to compare their structure-dependent toxicity. Both PCB congeners revealed low doses stimulation in our experiment. However, significant cytotoxicity was only observed in PCB 52 concentrations larger than 0.1 microg ml(-1), while there was no significant inhibition in PCB 77-treated cells at concentrations selected. Furthermore, the time-dependent cytotoxic trends were different. The comparison between PCB 52 and PCB 77 indicated that the cytotoxic mechanisms involved in coplanar or non-coplanar PCB congener exposure were different, and this difference might be associated with individual genotoxicity and the release of contact inhibition, respectively.

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