Multivariate statistical techniques for evaluating and identifying the environmental significance of heavy metal contamination in sediments of the Yangtze River, China

The concentrations of heavy metals (Cr, Co, Ni, Cu, Zn, Pb, Cd, As, Hg, and Fe) in sediments of the Yangtze River, China, were investigated to evaluate levels of contamination and their potential sources. The lowest heavy metal concentrations were found in the source regions of the river basin. Relatively high concentrations of metals, except Cr, were found in the Sichuan Basin, and the highest concentrations were in the Xiangjiang and Shun’anhe rivers. All concentrations, except Ni, were higher than global averages. Principal component analysis and hierarchical cluster analysis showed that Zn, Pb, As, Hg, and Cd were derived mainly from the exploitation of various multi-metal minerals, industrial wastewater, and domestic sewage. Cu, Co, and Fe were derived mainly from natural weathering (erosion). Cr and Ni were derived mainly from agricultural activities, municipal and industrial wastewater. Sediment pollution was assessed using the geoaccumulation index (I _geo) and enrichment factor (EF). Among the ten heavy metals assessed, Cd and Pb had the highest I _geo values, followed by Cu, As, Zn, and Hg. The I _geo values of Fe, Cr, Co, and Ni were <0 in all sediments. EF provided similar information to I _geo: no enrichment was found for Cr, Co, and Ni. Cu, Zn, As, and Hg were relatively enriched at some sites while Cd and Pb showed significant enrichment.     

松花江上游表层沉积物中重金属元素时空分布特征

松花江是我国七大河流之一,研究其底泥重金属元素的时空分布特征对流域的水环境治理具有重要意义。本文对松花江（哈达山至松花湖段）底泥（表层沉积物）中元素As、Hg、Cr、Cd、Pb的分布特征进行了研究,并利用地累积指数分析了这些元素的污染状况。结果表明：研究区底泥几乎未受到As、Cr和Pb的污染,但多数地段内出现了Cd和Hg的污染,尤其是元素Hg,在个别地段的污染程度达到了极强;与10年前相比,一些重金属的污染得到了明显改善,但吉林市区段内Hg的污染仍非常严重。污染样品空间分布特征表明,松花江吉林市区段可能有来自工农业废水的重金属污染。     

攀西大梁子铅锌矿区水系沉积物重金属地球化学特征及源解析

长江上游是整个长江经济带的重要生态屏障。以长江上游攀西大梁子铅锌矿区水系沉积物为研究对象,查明了重金属元素含量的空间分布特征,分析了重金属来源,探讨了在不同pH条件下重金属的淋滤规律,并进行了生态风险评估。研究结果显示:攀西大桥河流域水系沉积物中重金属的空间分布极不均匀,其含量明显要高于长江水系沉积物中重金属的平均含量;重金属生态风险属于很强风险,Hg和Cd呈高度富集、严重污染;Pb和Zn呈中度富集、中等污染。淋滤实验结果表明Pb、Zn、Cd在酸性和中性条件下淋滤浓度先快速下降,后逐渐趋于平衡,而As在快速下降后又有缓慢升高的趋势。大桥河流域水系沉积物中As、Cd、Pb、Zn主要来源于大梁子铅锌矿的采选活动,Hg为岩石风化和土壤剥蚀来源,而Cu和Cr主要为农业和工业活动来源。综合对比发现,攀西成矿带铅锌矿周边土壤富Cd而贫Cr,此外Cd、Pb、Zn、Hg是主要潜在污染物,且生态风险程度较高。     

Distribution and speciation of heavy metals in surface sediments from the Yangtze estuary and coastal areas

The concentrations and speciation of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in the sediments of the nearshore area, river channel and coastal zones of the Yangtze estuary, China, were systematically investigated in this study. The concentrations of all heavy metals except Ni in the sediments of the nearshore area were higher than those of the river channel and coastal zones. In the nearshore area, the concentrations of most heavy metals except Hg in the sediments of the southern branch were higher than those of the northern branch because of the import of pollutants from the urban and industrial activities around. When compared with the threshold effect level (TEL) and geochemical background levels, Cr, Ni and As accumulated and posed potential adverse biological effects. The speciation analysis suggested that Cd, Pb and Zn in the sediments of the three zones showed higher bioavailability than the other heavy metals, and thus posed ecological risk. Significant correlations were observed among Cr, Cu, Ni and Zn (r > 0.77) in the nearshore area, Ni, Cu, Zn and Pb (r > 0.85) in the river channel and Ni, Cu, Cr, Pb and Zn (r > 0.75) in the coastal zone. Principal component analysis (PCA) indicated that the discharge of unban and industrial sewage, shipping pollution and the properties of the sediments (contents of Fe, Mn, Al, TOC, clay and silt) dominated the distribution of heavy metal in the nearshore area, river channel and coastal zones of the Yangtze estuary.     

嫩江流域水体及悬浮物重金属元素分布特征及环境指示意义

水和悬浮物是河流重金属元素迁移的主要载体.对嫩江中下游悬浮物及滤后水重金属元素分布特征进行了较系统的研究,结果表明：丰水期是嫩江流域内悬浮物迁移的主要季节,支流的汇入会影响嫩江干流悬浮物浓度,大安市生产生活对水体悬浮物浓度产生明显影响;齐齐哈尔市的生产生活对嫩江水体悬浮物重金属含量影响不大,而对水中Cr、Cu、Pb、Ni、Zn元素产生明显影响;雅鲁河是向嫩江输入重金属Cr、Ni最多的支流,年输入嫩江通量分别为1223、100．46 t;阿伦河是向嫩江输入重金属Cd、Cu、Pb最多的支流,年输入嫩江通量分别为0．08、10．93、9．96 t;嫩江向松花江年输入重金属As、Hg、Cd、Cr、Cu、Pb、Zn、Ni通量分别为113．7、0．32、0．79、438、164、152、440、224 t.     

Heavy metal pollution of coastal river sediments, north-eastern New South Wales, Australia: lead isotope and chemical evidence

 Heavy metal and metalloid concentrations within stream-estuary sediments (<180-μm size fraction) in north-eastern New South Wales largely represent natural background values. However, element concentrations (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Zn) of Hunter River sediments within the heavily industrialized and urbanized Newcastle region exceed upstream background values by up to one order of magnitude. High element concentrations have been found within sediments of the Newcastle Harbour and Throsby Creek which drains into urbanized and light industry areas. Observed Pb enrichments and low ²⁰⁸Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁶Pb/²⁰⁴Pb ratios are likely caused by atmospheric deposition of Pb additives from petrol and subsequent Pb transport by road run-off waters into the local drainage system. Sediments of the Richmond River and lower Manning, Macleay, Clarence, Brunswick and Tweed River generally display no evidence for anthropogenic heavy metal and metalloid contamination (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Zn). However, the rivers and their tributaries possess localized sedimentary traps with elevated heavy metal concentrations (Cu, Pb, Zn). Lead isotope data indicate that anthropogenic Pb provides a detectable contribution to investigated sediments. Such contributions are evident at sample sites close to sewage outlets and in the vicinity of the Pacific Highway. In addition, As concentrations of Richmond River sediments gradually increase downstream. This geochemical trend may be the result of As mobilization from numerous cattle-dip sites within the region into the drainage system and subsequent accumulation of As in downstream river and estuary sediments. Received: 5 September 1997 · Accepted: 4 November 1997     

Trace element distributions in aquatic sediments of Danang – Hoian area, Vietnam

 Distribution of the trace elements Cr, Cu, Ni, Pb and Zn in surficial sediments of the river/sea environment in Danang – Hoian area (Vietnam) was investigated to examine the degree of metal pollution caused by anthropogenic activities. Point sources from domestic and industrial wastes are identified as dominant contributors of trace element accumulation. Surficial sediments of Hoian River show extremely high total concentrations of Cu (Average Concentration 295 μg/g), Ni (AC 112 μg/g), Pb (AC 396 μg/g) and Zn (AC 429 μg/g) that exceed assigned safety levels ER-M. Similarly, the sediments of Han River show high Pb (AC 188 μg/g) and Zn (AC 282 μg/g) contents. In marine sediments of Thanhbinh beach Pb is also enriched (138 μg/g) above guideline levels. In contrast the sediments of the Cude River are dominated by trace element concentrations close to background values. Received: 17 December 1998 · Accepted: 6 May 1999     

Magnetic,geochemical and mineralogical properties of sediments from karstic and flysch rivers of Croatia and Slovenia

The aim of the present work was to investigate links between the low-field magnetic susceptibility (MS) and chemical and mineral composition of sediments from several Croatian and Slovenian rivers, as well as to determine possible anthropogenic influence on these sediments. MS measurements are a fast and simple method, which serves as a proxy for the estimation of pollution in different environmental systems. The investigated rivers are predominantly unpolluted rivers from Croatian and Slovenian karstic and flysch areas, which belong to the Adriatic or the Black Sea watersheds: the Dragonja, the Mirna, the Ra?a, the Ri?ana, the Reka, the Rak, the Cerkni?nica, the Unec and the Ljubljanica rivers. It was assumed that, due to their mostly unpolluted status, they could serve as a database for natural MS background values for this region. For comparison, several rivers and a lake from the Celje old metallurgic industrial area (Slovenia) were also investigated: the Savinja, the Hudinja, the Voglajna rivers and Slivni?ko Lake. They form a sub-basin of the Sava River drainage basin. Sediments of the clean karstic and flysch rivers showed extremely low MS values, with mass susceptibility values ranging from 0.58 × 10^?7 to 5.11 × 10^?7 m³/kg, and isothermal remanent magnetism (IRM) values ranging from 0.71 to 7.88 A/m. In the Celje industrial area, river sediments showed much higher MS values, with mass susceptibility values ranging from 1.31 × 10^?7 to 38.3 × 10^?7 m³/kg, and IRM values ranging from 0.91 to 100.42 A/m. The highest MS value was found in the Voglajna River at Teharje-?tore, a point which showed a significant number of anomalies of toxic metals in earlier investigations. Semiquantitative determination of relations between grain size and concentration of magnetite was performed using the Thompson-Oldfield method. X-ray diffraction (XRD) mineralogical analysis showed that sediments of the Celje area have mostly quartz as major mineral, with relatively small amount of carbonate minerals, while in sediments of karstic rivers carbonate minerals prevail. Statistically significant correlations were obtained between MS and Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Ba in the Slovenian karstic region and between MS and Cr, Fe, Co, Ni and Zn in flysch drainage basins. On the contrary, no correlation of MS and Hg content was obtained.     

小秦岭太峪水系沉积物重金属污染生态危害评价

以金矿开发影响的黄河二级支流太峪水系沉积物为研究对象,沿河采集16个表层沉积物样品,分层采集垂向剖面10件水库沉积物样品,测定了样品中重金属元素Hg、Pb、Cd、Cr、As、Cu和Zn的含量,采用Hakanson潜在生态指数法和Tomlinson污染负荷指数法评价重金属元素污染程度和潜在生态风险。结果表明,矿业活动是太峪水系沉积物重金属元素污染的主要因素;变异系数、富集系数和最高污染系数均反映Hg、Pb、Cd是太峪水系沉积物的特征污染重金属元素,Cr和As的质量分数接近地区背景值;太峪水系表层沉积物受到重金属元素的极强污染,山区段污染较山外更严重;整个流域的Hg、Pb、Cd具有很强的潜在生态危害,Cr、As、Zn的潜在生态危害轻微;太峪水系沉积物垂向各层沉积物都受到重金属元素的极强污染,生态问题以Hg、Pb、Cd的潜在生态危害为主,其污染和生态危害程度都高于流向上的沉积物。潜在生态危害指数评价突出了不同元素的毒性和危害程度,而污染负荷指数法侧重于样本空间上的污染程度,二者互补使用有利于实际问题的全面评价。     

广西防城港近岸表层沉积物重金属分布特征及污染评价

为了解防城港近岸海域表层沉积物重金属分布及污染特征,系统采集了19件研究区的表层沉积物样品,检测了7种重金属元素的含量.测试结果表明:研究区表层沉积物中Cu、Pb、Zn、Cd、Cr、Hg和As含量均符合政府制定的海洋功能区划要求.单因子潜在生态危害指数法评价结果显示,不同重金属潜在生态危害排序为Hg>Cu>Cd>As>...     

Impact of river damming on sediment texture and trace metals distribution along the watershed and the coastal zone of Nestos River (NE Greece)

This study examines the sediment particle size distribution and the trace metal concentrations from a dammed-river watershed (Nestos River) to its deltaic zone in NE Greece. The study area is relatively unpolluted. The distribution of trace metals (Cu, Cr, Cd, Ni, Pb, Hg) in sediments throughout the catchment area showed selective “trapping” of certain elements behind the two artificial dams (Thissavros and Platanovrisi dams) in the watershed and a sudden reduction downstream (83% for Cd, 81% for Cr, 94% for Cu, 90% for Ni, 86% for Hg and 33% for Pb). Marked sediment particle separation is observed at the upstream dam (Thissavros), where coarse material including sand is trapped (coarse fraction 12.9–49.3%). Fine-grained material (<63 μm) is trapped behind the Platanovrisi dam (68.1%), and the reservoir showed elevated metal concentrations, especially for Cu and Cd (16.3 and 0.5 μg/g, respectively). Lead exhibited a homogenous distribution throughout the watershed (20.1–32.3 μg/g). All other trace metals (Cu, Cr, Cd, Ni and Hg) decline sharply downstream of the dam complex. In the delta system, nearshore sediments consist of shallow deposits in the vicinity of river mouth and are enriched in Cr (4.4–53.0 μg/g) and Ni (2.6–44.3 μg/g), while the further offshore and slightly deeper (20–40 m) sediments illustrate elevated Hg (0–0.07 μg/g), Cd (0.09–0.18 μg/g), Cu (11.5–18.3 μg/g) and Ni (38–54.5 μg/g).     

Heavy metal accumulation in the surficial sediments along southwest coast of India

Concentration and distribution of heavy metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) in surface sediments collected from five stations located along the southwest coast of India were investigated seasonally to assess whether there is insidious buildup of heavy metals. Spatial variation was in accordance with textural characteristics and organic matter content. The concentration of the metals in sediments of the study area followed the order: Zn > Cr > Ni > Cu > Pb > Cd > Hg. The use of geochemical tools and sediment quality guidelines to account for the magnitude of heavy metal contamination revealed high contamination in monsoon and impoverishment during post-monsoon. Estimated total metal concentrations in the present investigation were comparable with other studies; however, concentrations of Ni and Zn were higher than that of other coastal regions. Concentrations of metals in sediment largely exceed NOAA effects range:low (e.g., Cu, Cr, Hg) or effects range:median (e.g., Ni) values. This means that adverse effects for benthic organisms are highly probable.     

Using regression model to identify and evaluate heavy metal pollution sources in an open pit coal mine area,Eastern Junggar,China

This study aims at identifying multi-source heavy metal pollution from natural and anthropogenic sources using a regression model, principal component analysis, and five different indices (geo-accumulation index (I _geo), the modified degree of contamination, pollution load index (PLI), enrichment factor, and ecological risk factor. Results revealed that: (1) although the average concentrations of soil heavy metals (Cu, Cr, Pb, Hg, As, Zn) were generally low, Hg, As, and Cr concentrations exceeded national standard values by approximately 0.91, 1.84, and 0.91 times with maximum concentrations up to 0.41, 78.6, and 175.2 μg/g, respectively; (2) PLI results showed that the industrial park and Wucaiwan open coal mining area were the most polluted (PLI of 1.98, 1.71). The potential ecological hazards index indicated that the E _i ^r of three heavy metals (Cu, Hg, As) in the soil were relatively high, presenting potential ecological risk factors of 74.89, 16.71, 4.15%, respectively; (3) stepwise regression model and principal component analysis suggest that Cu and Zn were primarily effected by the natural geological condition and atmospheric dust fall. Cr, Hg, Pb are mainly derived from anthropogenic sources, particularly coal mining activities and industrial sources. Results of this research have some significant implications for heavy metal pollution prevention and the sustainable development of the economy and ecology of arid regions in China.     

江苏灌河入海口附近重金属元素环境地球化学质量分析

以往对灌河口附近海域进行地球化学调查发现,海底沉积物及海水质量总体良好,但局部沉积物中Cr含量高于一类标准,Cu、As、Pb、Hg等其他重金属元素含量也明显高于其他地区,个别重金属元素已接近一类标准最高限,存在潜在生态风险。为进一步了解其与人类活动是否有关,对灌河靠近入海口40 km长的河水进行了地球化学调查,发现灌河河水中Hg、Cu、Pb等重金属元素存在一定程度的超标现象。结合其他证据认为,人类活动不仅对灌河下游河水质量产生了负面影响,还对入海口附近的海域环境质量产生了潜在威胁。借鉴内梅罗综合指数评价思路对灌河下游及入海口的重金属元素环境质量进行评价,并对如何降低、消除生态风险提出了若干建议。     

Distribution of heavy metals and pollution pathways in a shallow marine shelf: assessment for a future management

The spatial distribution and geoaccumulation indices of four heavy metals were investigated in very shallow marine sediments of southwestern Spain. Surface sediments were collected from 43 sites with water depth ranging from 3 to 20 m. High to very high pollution levels (I _geo > 4 for zinc, lead and copper) were detected near the end of the Huelva bank, whereas chromium shows a more hazardous distribution in the southwestern Spanish littoral. Low to moderate heavy metal contents (mainly zinc and lead) were also observed in other two areas at different water depths (Isla Cristina-Piedras River: 10–18 m water depth; Mazagón–Matalascañas: <10 m water depth), whereas unpolluted to moderately polluted sediments were detected in the very shallow zones (<8 m water depth) located between the mouths of the Guadiana and the Piedras Rivers. A regional scenario indicates a strong pollution of the adjacent marine areas by polluted inputs derived from the Tinto–Odiel rivers, with a partial transport of heavy metals by W–E littoral currents even 40 km eastward. The Guadiana River is an additional source of zinc–lead contamination near the Spanish–Portuguese border, mainly at water depths up to 10 m. All these rivers are affected by acid mine drainage processes, derived from millennial mining activities. This pollution affects the sediment quality even 40 km eastward.     

Heavy metals in freshly deposited sediments of the Gomati River (a tributary of the Ganga River): effects of human activities

 The concentrations of various metals (Cr, Cu, Co, Fe, Mn, Ni, Pb, Zn, and Cd) were determined in recently deposited surface sediments of the Gomati River in the Lucknow urban area. Markedly elevated concentrations (milligrams per kilogram) of some of the metals, Cd (0.26–3.62), Cu (33–147), Ni (45–86), Pb (25–77), and Zn (90–389) were observed. Profiles of these metals across the Lucknow urban stretch show a progressive downstream increase due to additions from 4 major drainage networks discharging the urban effluents into the river. The degree of metal contamination is compared with the local background and global standards. The geoaccumulation index order for the river sediments is Cd>Zn>Cu>Cr>Pb. Significant correlations were observed between Cr and Zn, Cr and Cu, Cu and Zn and total sediment carbon with Cr and Zn. This study reveals that the urbanization process is associated with higher concentrations of heavy metals such as Cd, Cu, Cr, Pb, and Zn in the Gomati River sediments. To keep the river clean for the future, it is strongly recommended that urban effluents should not be overlooked before their discharge into the river. Received: 16 February 1996 · Accepted: 29 February 1996     

Heavy metal contamination in water and sediment of the Port Klang coastal area, Selangor, Malaysia

This investigation presents the temporal and spatial distribution of heavy metals (As, Cd, Cr, Cu, Ni, Pb, Hg, and Zn), in water and in sediments of Port Klang, Malaysia. Water and sediment samples were collected from 21 stations at 3-month intervals, and contamination factor $ (C_{\text{f}} ) $ and contamination degree $ (C_{\text{d}} ) $ were calculated to estimate the contamination status at the sampling stations. Cluster analysis was used to classify the stations based on the contamination sources. Results show that concentrations of As, Cd, Hg, and Pb in sediment and As, Cd, Hg, Pb, Cr, and Zn in water were significantly higher than the background values at which these metals are considered hazardous. The main sources of heavy metal contamination in Port Klang were industrial wastewater and port activities.     

Effect of metal pollution on the water quality in Taihu Lake

Heavy metals Cu, Zn, Cr, and others were carried though Liangxi River and Xiaomei River from Wuxi City and Huzhou City into Taihu Lake. Pollution of heavy metals in the water and sediments and chemical forms of Cu, Ph, Zn, Cd, Hg, Cr in the surface sediments were analysed to predict the effect of the pollution on water quality in Taihu Lake.     

陕西潼关金矿区太峪河底泥重金属元素的含量及污染评价

通过对潼关金矿区太峪河和太峪水库底泥中重金属元素总量的调查,探讨了金矿开发活动中重金属元素对河流底泥的污染程度。研究结果表明,除As外,河流底泥中重金属元素的含量与尾矿渣中重金属元素的含量变化一致,表明其主要来源于尾矿渣,但又明显高于尾矿渣。在同一地点河流底泥中重金属元素的含量平均高出河水中的1048.61～666030.08倍,呈显著富集。以邻近地区不受工矿活动影响的河流底泥重金属元素的含量均值作为评价参比值,太峪河底泥受到了Hg、Pb、Cd、Cu、Zn元素的极度污染,单项污染超标倍数及综合污染指数法评价结果表明,Hg、Pb、Cd平均污染超标倍数达366.90、217.42和149.97,是底泥中最主要的污染元素。河流底泥重金属元素的综合污染指数高达278.97,表明河流的复合污染亦呈极度状态。太峪河底泥受重金属元素极度污染的现实提示,矿区的环境防治工作已刻不容缓。     

金矿区河水和底泥中重金属含量分布与耦合关系

河流中河水与底泥中重金属含量之间的关系对于河流污染防治意义重大。对某金矿区3种典型河流的河水与底泥中的重金属含量进行分析,发现4条河流均有超过国家标准限值的情况,河水中7种重金属元素均出现超标,Cr、As元素超标不严重;底泥中Hg、Pb、Cr、Cu、Zn超标,其中Hg超标最严重,河水和底泥中Hg最大超标倍数分别达到3099倍和244倍。河流中重金属主要赋存形态为沉积态,底泥的吸附解吸作用是河流底泥和河水中重金属沿程变化的主控因素;金矿区区域上河水和底泥中重金属很好地服从Langmuir等温吸附模式。矿业活动、地层岩性均会影响底泥对重金属的平均最大吸附容量,流径黄土区的双桥河平均最大吸附容量最大。研究结果为矿山河流污染防治与预警提供了参考依据。