首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 80 毫秒
1.
分析了阳宗海柱状及表层沉积物中Al、Fe、Mn、Zn、Cr、Co、Ni、Cu、As、Cd、Pb等金属元素的含量,结合沉积年代学,研究了沉积物重金属污染的时空变化和潜在生态风险特征.结果表明,表层沉积物中重金属含量具有一定的空间差异性,As、Cd、Cu、Pb和Zn在中东部湖区含量较高,而Cr、Co、Ni含量高值位于南、北湖区的近岸区域;柱状沉积物中,1990s之前As、Cd、Cu、Pb和Zn含量较为稳定,1990s中后期以来,其含量逐渐增加,并在2009-2010年前后达到最大值,此后逐渐下降;而柱状沉积物中Cr、Co、Ni含量变化趋势与Al、Fe相似,总体上由下向上逐渐降低,这主要与沉积物质地(粒度)逐渐变粗有关.重金属富集系数表明,阳宗海沉积物中主要污染元素为As、Cd、Cu、Pb和Zn,1990s中后期污染程度快速增加,2009-2010年前后达到峰值,此后污染程度逐渐降低;表层沉积物中Cu为未污染至"弱"污染水平;Zn、Pb为"弱-中等"污染水平,As为"中等-强"污染水平,Cd为"弱-强"污染水平,中东部湖区污染程度高于其他湖区,这可能与该湖区缺少入湖径流、自然碎屑物质沉积速率较低以及砷污染事件等人为源的重金属贡献影响更为显著有关.生态风险评价结果表明,在2002-2010年前后沉积物重金属达到"中等-强"潜在生态危害,主要贡献因子是Cd和As,近年来其生态风险等级逐渐降低;表层沉积物中重金属在中东部湖区具有"中等"程度潜在生态危害,而其他湖区表层沉积物重金属具有较低程度的潜在生态风险.  相似文献   

2.
为识别表层沉积物重金属的来源以及量化源贡献,选取鄱阳湖丰水期表层沉积物为研究对象,测定14种重金属(V、Cr、Co、Ni、Cu、Zn、Sr、Mo、Cd、Sb、W、Pb、Hg和As)的含量,分析其污染及空间分布特征,并利用主成分分析法(PCA)和正定矩阵因子分解法(PMF)对沉积物重金属进行源解析.结果表明:除V和Cr外,Cd、Mo、Hg、Cu、Pb、Zn、W、Sr、As、Ni、Co和Sb的平均含量分别为江西省土壤背景值的5.7、2.2、1.9、1.8、1.5、1.5、1.4、1.3、1.3、1.2、1.0和1.0倍; Cd、Hg、Cu、Mo、Pb、Sr和Zn超出江西省土壤背景值的比例相对较高,分别为100%、100%、100%、100%、97%、97%和93%,所有沉积物样品中Cd含量超过农用地土壤污染风险筛选值的比例为51%; V、Cr、Co、Ni、Cu、Zn、Sr、Mo、Sb、W、Pb、Hg和As含量呈未污染至弱污染水平,而Cd含量属于中等污染水平,接近于重污染水平.总体而言,Cd的污染相对较严重.重金属的分布具有显著的区域特征,其中Cr、Cu、Zn、Sr、Pb、Hg和As的空间分布十分相似,表现为在赣江、抚河、信江和饶河入湖口附近区域含量较高,而Co、Ni、Mo和Sb明显在湖区南部、东北部和修水入湖附近这3个区域聚集,Cd和W的空间变异性相对较大,V的含量分布相对较均匀.PCA和PMF解析结果都表明鄱阳湖丰水期表层沉积物重金属受4种来源的共同影响,其中,矿业和工业活动的影响最大,相对贡献率为38%,其次是尾矿和废渣,相对贡献率为28%,再是农业活动,相对贡献率为19%,最后是自然来源的相对贡献率为14%.  相似文献   

3.
River water and sediment embody environmental characteristics that give valuable eco-environmental information.Due to rapid industrialization,the aquatic environment of any urban river can be seriously polluted by heavy metals（HMs）.The global concern is caused by heavy metal pollution because of its potential harm to aquatic ecosystems and human health.In the Bhairab River,Bangladesh,surface sediment concentrations of globally alarming toxic metals such as arsenic（As）,chromium（Cr）,cadmium（Cd）,an...  相似文献   

4.
苏州河网区河道沉积物重金属的污染特征   总被引：5，自引：0，他引：5  
分析测定了苏州河网区河道底泥十个剖面样点60个样品中Cu、Pb、Zn、Cr、Al、Fe、K、Mn、有机质、TP、TN、粒度、pH及含水量,采用地累积指数、生态风险指数和相关分析等方法研究其重金属污染特征.结果表明:Cu和Zn处于中或中-强度污染,Pb处于无-中污染,没有Cr污染;垂直分布特征显示:Cu和Zn污染逐年变化较为一致,Pb污染有逐年加重趋势;重金属潜在生态风险处于轻微污染状态;相关性分析显示,有机质是影响其分布的重要因素,Mn、Cr、Cu、Zn、Pb五种重金属相关性显著;通过与国内外河流、水库和湖泊沉积物中重金属含量比较,苏州河网区河道重金属的累积受多种因素影响.  相似文献   

5.
To assess the potential ecological and health risks of trace elements(Hg,Cd,As,Mn,Sb,Pb,Cu,Ni,Cr,and Zn),a total of 138 soil samples from rice paddies were collected during the rice harvest season in the Wanshan mining area,Guizhou Province,Southwest China.Factors of the pollution load index(PLI),geo-accumulation index(I-Geo),enrichment factor(EF),and risk index(RI)were determined.High concentrations of Hg,Sb,As,Zn,Cd,Cu,and Mn were observed in the soils.The PLI,I-Geo,and EF results all showed high levels of contamination by Hg and Sb and moderate levels of contamination by As,Pb,Zn,Cu,Cd,and Mn.There was no significant contamination from Ni and Cr.The RI was very high,with Hg as the dominant pollutant,as expected,indicating that the historical large-scale Hg mining,as well as artisanal mining,has had a significant impact on the Wanshan area.Moreover,coal combustion,manganese factories,and the use of agrochemicals by the local population could also have an impact on the soil through the introduction of heavy metal loads.To address the current state of contamination,pollutant remediation and the regulation control of the anthropogenic activities in Wanshan are urgently needed.  相似文献   

6.
Lei Gui  Peng  Shu-Chuan  Chen  Tian-Hu  Wang  Ji-Zhong 《Water Resources》2019,46(4):614-623
Water Resources - Heavy metal pollution in lacustrine sediments is a worldwide environmental issue. In the present study, eight heavy metals including Zn, Pb, Co, Cr, Cd, Mn, As and Cu in sediment...  相似文献   

7.
This study is based on the assessment of distribution,source apportionment and risk assessment of selected metals in freshly deposited sediments from freshwater lake,Pakistan.Composite sediments were collected and processed to assess Ca(NO_3)_2-extractable and acid-extractable levels of the metals in the sediments using flame atomic absorption spectrophotometry.Enrichment factors(EF),geoaccumulation indices(I_(geo)),contamination factors(C_f) and degree of contamination(C_(deg)) were computed to estimate the degree of contamination.The potential ecological risk was assessed using sediment quality guidelines and mean-ERM-quotient(m-ERM-Q).On the average basis,acid-extractable metals followed the decreasing concentration order:CaMgFeKMnNaSrZnPbCrCoCu-LiCd,whereas,the Ca(NO_3)_2-extractable levels were:NaPhCdSrCoCrKMg-CuZnLiCaFeMn.The highest Ca(NO_3)_2 extractable concentrations were observed for Na,Pb and Cd,while that of Ca,Fe and Mn were the least.EF showed very high and extremely high enrichment of Pb and Cd,respectively,while Ca,Co,Cr,Li,Mg,Mn,Sr and Zn manifested moderate enrichment:the I_(geo) results revealed moderate to strong and strong to extreme pollution for Pb and Cd,respectively;and the C_f study showed moderate,considerable and very high contamination by Co,Pb and Cd,respectively.The C_(deg) revealed very high degree of contamination in the sediments as a whole.Principal component analysis(PCA) and cluster analysis(CA) showed considerable anthropogenic contributions of Cd,Pb,Co,Mn,K,Zn and Li in the sediments.Measured levels of Cd and Pb exceeded ERL values,manifesting occasional adverse biological effects to the dwelling biota.Moreover,the mERM-Q study manifested 21%probability of toxicity in the sediments.  相似文献   

8.
The objective of the current study was to assess the contamination of potentially toxic metals (PTMs) in weathered surface sediment, along stream tributaries, and surrounding area of the river Chitral, Shyok suture zone district Chitral, Pakistan. To understand the geochemical features of 113 sediment, samples were collected from the Mirkhani and Drosh area. Then, different statistical tools including the geo-accumulation index (Igeo), cluster analysis (CA), principal component analysis (PCA), and ecological risk assessment (ERA) were used to unravel the origin, intensity, and exposure level of PTMs to control risk and restore the ecosystem within the study area. The results for the PTMs namely nickle (Ni), chromium (Cr), copper (Cu), cadmium (Cd), lead (Pb), zinc (Zn), and cobalt (Co) in Mirkhani and Drosh were in the following ranges: 10–150, 15–210, 15–250, 0.08–1.00, 10–70, 76–240 and 14–51; and 13–240, 17–210, 15–150, 0.08–0.60, 7–140, 47–150 and 13–36 mg/kg, respectively. In consequence, the potential ecological risk caused by Pb, Ni, Cu, Co, Cr, and Zn is reflected by the percentages of samples with an ecological risk index (ERI) greater than one which were 100%, 91%, 100%, 100%, 92%, and 100%, respectively. However, the overall mean decreasing order of ecological risk of PTMs in the district Chitral was Pb > Ni > Cu > Co > Cr > Zn > Cd. Moreover, the PCA yielded 78% variability which indicated that mineral prospects play an important role in the contamination of sediment. Furthermore, the mineral phases of Pb and Zn suggested supersaturation, while that for Cd revealed unsaturation. The results of Igeo, ERI, and CA indicated contamination of PTMs in the study area. The ERI value of Pb, Ni, Cu, Co, Cr, and Zn was higher than 1 suggesting an ecological risk in the study area. Moreover, the current study showed the dominance of geogenic contamination with major contributions from ultramafic rock and known mineral prospects. Therefore, contaminated sediment of the Shyok suture zone is extremely detrimental to the aquatic ecosystem of the study area.  相似文献   

9.
Metal pollution study on sediments of North Bay of Bengal sediments presented in this paper is based on existing Lithostratigraphy of upstream,mineralogy and geochemical analysis of 42 sediment samples.The statistical analysis identifies the metal pollution as well as its apparent source in the off shore regions.Samples were analyzed for grain size,organic content and heavy metals(Fe,Mn,Cr,Cu,Ni,Pb,Cd,Zn and Co) using the sequential extraction method to evaluate geochemical processes and pollution load.In an effort to surmise anthropogenic input,several approaches including classification by quantitative indexes such as enrichment factor,contamination factor,degree of pollution,pollution load index and geo accumulation index,were attempted.Metal speciation results indicate high%of Cd in exchangeable fraction of Mahanadi transect sediments where as a considerable amount of oxidizable fraction of Cr was detected at Dhamra.Quantitative indexes place North Bay of Bengal under moderately polluted zone due to high level of Cd.Normalization of metals to Fe indicated relatively high enrichment factors for Cd and Cr.Factor analysis identified seven possible types of geochemical associations where sediment pH plays a major role for the heavy metal mobility.The higher Cd concentration in exchangeable fraction as well as the higher EF for Cd and Cr present in sediment may pose a risk of secondary water pollution under slightest disturbance in the geo-chemistry of sediments.Comparison study with available data of near costal zones and upstream stratigraphy revealed that open cast mining,overburden dumping,mineral based industrial effluents were the major source of pollution for catchment area contamination.Bay of Bengal is likely to face a serious threat of metal pollution with the present deposition rates unless rigorous pollution control norms are applied.  相似文献   

10.
为了解巢湖湖区及主要出入湖河流沉积物中重金属的污染特征,对表层沉积物中重金属元素含量进行分析,基于地积累指数法、潜在生态风险指数法和沉积物质量基准法对沉积物污染风险进行评价,并对沉积物重金属来源进行初步分析.结果表明,河流沉积物中重金属的平均含量显著高于湖区,是湖区沉积物重金属含量的1.18~5.15倍,其中南淝河Cu、Zn、Pb、As和Hg含量较高,分别是背景值的3.53、16.98、3.98、5.84和23.11倍,西半湖Cu、Zn、Pb、Cd和Hg平均含量要高于东半湖,是全湖平均的1.04~1.45倍.地积累指数法和Hkanson潜在生态风险指数法评价结果均表明,Cd和Hg是主要的生态风险贡献因子,在所调查的表层沉积物中Cd和Hg数值分别为43.17~3870.94和29.96~924.57,已处于较大风险数值.此外,源分析结果表明,巢湖湖区及主要出入湖河流表层沉积物中Cu、Zn、Pb、Cr、Hg和As相关性显著,具有相似的来源,可能来自于工业废水与生活污水.  相似文献   

11.
In order to investigate the pollution levels, sources and ecological risks of arsenic (As) and heavy metals (Cr, Ni, Cu, Zn, Pb and Cd) in inshore sediments of the Yellow River estuary, the surface sediment in areas of inshore coastal waters were sampled in October 2014 as the flow-sediment regulation project (FSRP) was implemented for 13 years. Results showed that the concentrations of As and heavy metals in inshore sediments of the Yellow River estuary were in the order of Zn?>?Cr?>?Cu?>?Ni?>?Pb?>?As?>?Cd. Higher levels of As, Cr, Ni, Cu, Zn and Pb generally occurred in fine-grained sediments of the Yellow River estuary and the southeast region, which was consistent with the spatial distribution of clay. In contrast, higher concentrations of Cd were generally observed in northwest area of the Yellow River estuary and near the Qingshuigou estuary, which showed similarly spatial distribution with that of sand. The sediment quality guidelines (SQGS) and geoaccumulation indices (Igeo) indicated that the inshore sediments were polluted by Cu, Cd, As, Pb and Zn, and, among them, Cd pollution was more serious. Ecological risk indices (E r i ) demonstrated low risks for Cr, Ni, Cu, Zn, Pb and As, and high potential toxicity by Cd. The integrated ecological risk index implied that 6.8% of stations presented moderate risk, 4.5% of stations exhibited disastrous risk, and 88.7% of stations demonstrated considerable risk. Principal component analysis indicated that Ni, Cu, Zn, Pb and As might originate from common pollution sources, while Cr and Cd might share another similar sources. With the continuous implementation of FSRP, As and heavy metal levels in inshore sediments of the Yellow River estuary could be classified as stage I (2002–2010) and stage II (2010–2014). In the stage I, As, Cr, Ni, Cu, Zn and Pb levels fluctuated but decreased significantly, whereas Cd concentrations showed little variation. In the stage II, As and heavy metal levels significantly increased although some little fluctuations occurred. The continuous accumulation of As and heavy metals (especially for Cd) in inshore sediments of the Yellow River estuary would occur again as the FSRP was implemented for 9 years (since 2010). The ecotoxicological risk of Cd, As, Ni and Cu in inshore sediments might be more serious since the accumulation of the four elements would be continuously occurred in future years. Next step, there will be long-term potential consequences for marine organism if effective measures are not taken to control the loadings of metal pollutants into estuary.  相似文献   

12.
Dil Deresi stream is a highly contaminated stream passing through the most heavily industrialized area of Izmit Bay. In this research, surface sediments in the <63-microm fraction collected from 34 sites at western part of Izmit Bay, Northeastern Marmara Sea, Turkey were analyzed by ICP-AES for Al, As, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sn and Zn. Metal concentrations were compared with the marine sediment quality standards (SQS) and literature data to assess the pollution status of the sediments. Enrichment factors (EFs) were calculated to assess whether the concentrations observed represent background or contaminated levels. The analysis revealed three groups of elements: (1) Sn is the most enriched element; (2) As, Cd, Pb and Zn are minor enriched elements; and (3) Co, Cr, Cu, Fe, Mg, Mn and Ni are at background concentrations. The distribution maps of the concentrations and enrichment factors for all heavy metals were also produced as a contour plot based on Geographic Information System (GIS) technology.  相似文献   

13.
In the recent years,the Red Sea coast of Yemen has been severely affected by intensive anthropogenic activities.The current study constitutes a thorough inquiry to evaluate the extent of heavy metals pollution in Yemen's Red Sea coast sediment and identifies the possible sources of pollution.The concentrations of five metals(copper(Cu),zinc(Zn),cadmium(Cd),lead(Pb),and nickel(Ni))collected from nine sites along the Red Sea coast of Yemen were assessed using an atomic absorption spectrophotometer(ASS).Sediment quality indices,such as the sediment quality guidelines(SQGs),potential ecological risk(RI),contamination factor(CF),pollution load index(PLI),geoaccumulation index(Igeo),and modified degree of contamination(mCd)were computed.In addition,multivariate statistical techniques(principal component analysis(PCA),hierarchical cluster analysis,and Pearson's correlation analysis)were applied to identify the potential sources of metals.The mean concentrations of Cu,Zn,Cd,Pb,and Ni were 51.3,61.9,4.02,9.9,and 33.4 mg/kg dry wt,respectively.The spatial distribution revealed that the metals concentrations were high at the middle zone and low southward of Hodeida city.According to the SQGs,the adverse biological effects of metals were occasionally associated with Cu and Cd,frequently associated with Ni,and not expected to occur with Zn and Pb.The RI indicated that the sediment of the studied sites pose low(RI<50)to considerable(100≤RI<200)ecological risk.The mean effect range-median quotient(M-ERM-Q)indicated that the combination of the studied metals had the toxicity probability of 21%at all studied sites.Igeo and CF indicated that the metals concentrations were in the descending order of:Zn>Ni>Pb>Cd>Cu,whereas the PLI and mCd indicated that Ras Isa(Site 5)and Urj village(Site 6)were the most polluted sites.PCA,cluster analysis,and correlation analysis found that Cd,Pb,and Ni mostly originated from anthropogenic sources while Cu and Zn were mainly derived from natural sources.Thus,it is evident that the intensive anthropogenic activities had negative influence on metals accumulation in the sediment of the Red Sea coast of Yemen leading to detrimental effects to the whole ecosystem.These comprehensive findings provide valuable information and data for future monitoring studies regarding heavy metals pollution and sediment quality at the Red Sea coast of Yemen.  相似文献   

14.
Surface sediment samples collected from the inner shelf region of the Bay of Bengal, were analysed for the major elements and total and acetic acid available trace elements (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Si, Zn) to evaluate geochemical processes influencing their distribution. Major elemental analysis showed that the sediments had high concentrations of Si and relatively low concentrations of Al and Fe. Both major elemental and trace metal concentrations indicated that the sediments represent weathered products of granite and charnockite. Normalization of metals to Al indicated relatively high enrichment factors for Pb, Cd, Zn and Cr. The higher proportions of nondetrital Pb (66%), Cd (41%) and Co (28%) reveal metal contamination due to anthropogenic inputs. Factor analysis (FA) identified six possible types of sedimentological and geochemical associations. The dominant factor accounting for 26.9% of the total variance identifies an anthropogenic input and accumulation of nondetrital Cd, Co, Cr, Ni and Pb. Association of these metals with CaCO3 reveals that shell fragments in the surface sediments are likely act as a carrier phase for nondetrital metals. The results are discussed in the context of the sources and pathways of elements in the Bay of Bengal.  相似文献   

15.
The aim of this study was to study ecological risk assessment of trace elements (As, Cd, Cr, Cu, Ni, Pb and Zn) in Izmit Bay surface sediments in the <63 microm fraction. Sediment samples were collected from 8 sites along the north coastline of the bay. Samples were subjected to a total digestion technique and analyzed for major (organic carbon) and minor (As, Cd, Cr, Cu, Ni, Pb and Zn) elements. Sediments heavily contaminated are evaluated by the Sediment Quality Guidelines (SQG) of US EPA. The degree of contamination (Cd) is estimated as very high at each site. Two sets of SQGs, effect range-low/effect range median values and TEL/probable effect level (PEL) values were used in our study. Sediments from the each site are judged toxic when two or more of the PEL values exceed EPA guidelines. Our results are in agreement with previously reported sediment toxicity test results.  相似文献   

16.
According to the List of Hazardous Substances of the Agency of the Toxic Substances and Disease Registry(ATSDR 2017),some metallic elements such as Pb or Cd are still considered as the most polluting elements in the world.These elements accumulate in sediments,and there are various methods available that differentiate lithogenic sources from anthropogenic sources.For that,the natural geochemical background is required,however,its definition is far from unanimous:it can be a global or local value,single or statistically estimated value,depending on the studies.Our study is focused on the Subae River in the state of Bahia,Northeastern Brazil,which was historically contaminated by lead metallurgy.The river sediments were sampled at 21 locations:one at the discharge point of the plant's rainwater basin,ten upstream,and ten downstream.The total contents of Fe,Ti,Mn,Pb,Zn,Cu,Cr,particle-size distribution,and organic matter were analyzed.The conventional geochemical indexes,i.e.,the pollution degree(mCd),pollution load index,and enrichment factor indicated contamination by Zn,Pb,Cr,and Cu.Then,a new enrichment factor is introduced,assuming that the sediments come from erosion of soils in the watershed.After obtaining the natural concentrations of metals in the clay,silt,and sand fractions of uncontaminated reference soils,we corrected the pollution indexes by calculating a new individual background in each sediment sample,according to its grain size distribution.This new approach provided more precise indexes in the assessment of sediment pollution,by highlighting higher contamination of Zn and Pb(around 50%)and at the same time the absence of Cr and Cu contamination,two metals not involved with the metallurgical activity.  相似文献   

17.
The objective of this study was to evaluate the concentration and distribution of heavy metals in the sediments of Paulo Gorski Lake, as well as the metals’ bioavailability and potential ecological risk, and to define the anthropogenic and natural heavy metal contributions to the lake. The chemical elements calcium (Ca), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), nickel (Ni), lead (Pb), and zinc (Zn) were quantified by flame atomic absorption spectrophotometry with two extraction methods to quantify the bioavailable and non-bioavailable fractions. The data were evaluated using multivariate statistics and sediment quality indices. All sediment collection points (S1, S2, S3, S4 and S5) are different in terms of the concentration of heavy metals, except for S4 and S5, which were statistically equal. The bioavailable fraction of the elements in the sediment follows the sequence Pb>Cu>Mn>Zn>Ni>Cr>phosphorus (P) for all points. The elements Co, Cr, Pb, and Zn showed moderate to considerable contamination at all points. Only points S3 and S5 had moderate ecological risk. Urbanization has been affecting Paulo Gorski Lake via the input of chemical elements, especially Co and Pb. The points most affected by heavy metal contamination are S3 and S5 when the sedimentological sensitivity factor is considered. The lake has high hydrodynamics, causing some of the contaminants that enter the system to leave it, leading to potential negative impacts downstream.  相似文献   

18.
基于筛分水平浓度法的洞庭湖沉积物质量基准初步分析   总被引：1，自引：0，他引：1  
基于2013 2015年调查获取的129个洞庭湖表层沉积物和底栖生物的调查数据,应用筛分水平浓度法初步探讨了洞庭湖沉积物几种重金属沉积物质量基准的推荐值.结果表明,洞庭湖沉积物砷(As)、镉(Cd)、铬(Cr)、铜(Cu)、铅(Pb)和锌(Zn)含量均值为17.2、2.63、56.9、32.4、38.4和96.3 mg/kg(DW);筛分水平浓度法获取的洞庭湖沉积物As、Cd、Cr、Cu、Pb和Zn质量基准分别为11.97、1.13、42.03、19.17、23.63和67.54 mg/kg(DW).通过与不同国家及地区指定的重金属质量基准推荐值以及本地区采用其他方法推导的重金属基准推荐值进行比较,推算出本研究获取的6种重金属沉积物质量基准推荐值接近所有数据的中间值.对于洞庭湖流域,不同方法获取的沉积物重金属质量基准具有可比性.然而,鉴于用于推导沉积物质量基准的数据采集涉及的区域较为有限,且除了重金属污染外,影响底栖生物分布的因素较为复杂,导致获取的沉积物重金属质量基准推荐值存在一定的不确定性.  相似文献   

19.
The total concentrations of Cd,As,Pb,Cr,Ni,Co,Zn,Cu,Ag,Hg,and Mo were determined in the atmospheric dust of the city of Yerevan by atomic absorption spectrometry(AAnalyst PE 800).Heavy metal pollution levels were evaluated by calculating geo-accumulation(I_(geo)) and summary pollution(Z_c) indices.Potential human health risk was assessed using the United States Environmental Protection agency's human health risk assessment model.The results show that mean contents of all elements tested except Ni and Cr were substantially higher than local geochemical background values.According to the I_(geo),Yerevan territory is strongly-to-extremely polluted by As,Ag,Hg,Mo,and Cd.The Z_c assessment indicated that very high pollution was detected in 36%of samples,high in 32%,average in 12%,and low in 20%.The health risk assessment revealed a noncarcinogenic risk(HI 1) for children at 13 samplings sites and for adults at one sampling site.For children the risk was due to elevated levels of Mo,Cd,Co,and As,while for adults,only Mo.Carcinogenic risk(1:1,000,000) of As and Cr via ingestion pathway was observed in 25 and 14 samples,respectively.This study,therefore,is the base for further detailed investigations to organize problematic site remediation and risk reduction measures.  相似文献   

20.
This study presents trace elements levels in surface and deep sediments of the Toulon bay (SE France) subjected to anthropogenic inputs (navy base, harbors, etc.). The studied elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) are defined as priority contaminants in aquatic systems. Fifty-five points scattered on the entire bay were sampled, allowing the determination of contaminants distribution with a high resolution. Several approaches were used to assess the degree of contamination and the potential toxicity of the Toulon bay sediments: comparison to the French legislation, surface-weighted average metal concentrations, enrichment factors (EF), geoaccumulation indices (Igeo), trace element stock calculation and comparison to sediment quality guidelines. A principal component analysis was performed to reveal common behavior of the studied contaminants. Results demonstrated the very high contamination of the small bay, especially in Hg (EF up to 1500), Cu, Pb and Zn, with export to the large bay further governed by hydrodynamics.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号