Trends in the solid phase partitioning of metals in the Thames Estuary sediments during recent decades

A sequential extraction method was employed to extract the metals Al, Ag, Cd, Co, Cr, Cu, Pb, Fe, Li, Mn, Ni, and Zn from a 10-m sediment core taken from the Tilbury Basin on the Thames Estuary. Characteristics of the observed metal partitioning distributions were attributed primarily to the composition of the estuarine waters at the time of deposition. For some metals, a decrease in the bulk sediment metal concentrations from a depth of ?6.59 m ODN to the surface was also observed in one of the solid phases. This was the case for Cr, Cu, and Pb extracted from the organic phase and for Zn extracted from the carbonate phase. This decrease in sediment concentrations is thought to reflect reported improvements to water quality in this region of the Thames Estuary in the early 1960s, following updating of major sewage treatment works (STW) approximately 20 km upstream. These findings give an indication of the influence of estuarine inputs from STW on metal partitioning distributions. The order of mobility for the metals of environmental concern was Cd>Ag>Cr>Ni, Zn>Co, Cu, Pb. for Cd and Ag there was a tendency to partition towards the exchangeable phase, both at the surface and at depth, which indicates the potential for long-term leaching of these metals from the sediments.     

灌河口潮滩重金属累积特征及污染评价

河口地区潮滩是重金属重要的"汇"。测定了灌河口(燕尾港)潮滩高中低滩的33个表面样粒度、重金属数据,研究了4根柱状样的重金属和粒度特征,利用地累积指数法、潜在生态危害指数法及富集指数法等评价指标,对灌河口重金属的污染状况进行了评价,并对其结果进行了相互比较和印证。分析结果显示,灌河口潮滩重金属的分布主要受水动力影响,特别是受粘土分布的控制。Cd与粒径Ф值相关性不显著,相关系数只有0.099,而与粘土含量呈明显正相关关系,Hg的变化趋势恰恰相反,其含量随着距离河口距离的加大反而有增加的趋势;其他元素的变化趋势不明显。重金属元素Zn、Pb、Cu、Hg含量变化走势基本相同,用Li作归一化标准元素归一化后,所有重金属元素的归一化值变化波动范围均比重金属含量值明显收窄,波峰和波谷有后延的趋势。灌河口滩涂总体重金属环境尚可,但存在一定程度的Hg、Cu污染富集。柱状样Hg、Cu的地累积污染指数总体上均呈现随深度增加而降低的趋势。     

Re-evaluation of quartz vein history in the Dolgellau Gold-Belt,North Wales,United Kingdom

Conspicuous, gently inclined, lenticular quartz–carbonate veins with fibre-textured infills dissect the steep, gold-bearing quartz veins in the Dolgellau Gold-Belt. Similar quartz veins fill the necks of boudin-like structures affecting the main gold-bearing veins at Clogau mine. They also dissect the post-mineralization ENE–WSW ‘Clogau Stone’ dykes. The uniformly oriented regional cleavage shows marked deflection around the gently inclined quartz veins. These late quartz veins were emplaced whilst the mudstones of the Clogau Formation, which host the steep gold-bearing quartz veins, were undergoing ductile deformation. The stretching involved in the late vein and boudin development requires these structures to be contemporaneous with some stage in the development of the regional sub-vertical cleavage and upright fold system. The earlier gold-bearing veins show evidence of brittle fracture and still retain some drusy space-filling textures. Cleavage is deflected adjacent to these early veins and in breccia clasts within the veins. The rare minor folds seen in the gold-bearing quartz veins have axial planar cleavages. It is concluded that the gold-bearing veins pre-date cleavage development. Thus they were forming when large amounts of water were still available in the sedimentary sequence, removing the severe source and transport problems that are implicit in the previous view that the veins were post-tectonic. Copyright © 1999 John Wiley & Sons, Ltd.     

The freshwater-saltwater interface and its relationship to the turbidity maximum in the Tamar Estuary,United Kingdom

Data are presented from several experiments in the freshwater-saltwater interface (FSI) region of the Tamar Estuary. Longitudinal surveys of salinity and suspended particulate matter (SPM) at high water showed that the location of the FSI could be predicted in terms of a power-law regression with freshwater runoff. Longitudinal transects also were surveyed over periods of several hours. The FSI was observed to advect into the region on the flood with strong vertical mixing. After high water, stratification became intense as fresher water ebbed in the surface layers. The near-bed water in the stratified region began to ebb between 2 h and 3 h before low water. A model of the vertical structure of longitudinal currents showed that the enhanced stratification on the ebb, coupled with the longitudinal density gradient, partly produced this long period of slack, near-bed currents following high water. A strong turbidity maximum (TM) occurred during spring tides and was located slightly up-estuary of the FSI at high water. Longitudinal transects during a period of low freshwater runoff and large neap tide showed that at the start of the flood the TM was associated with the FSI region. As the FSI advected up-estuary on the flood there was considerable resuspension of sediment at the FSI. Some of this SPM moved with the FSI and reached the limit of saline intrusion, where it formed a slowly-eroding TM as particles settled during the long, high-water slack period. As the near-bed currents increased on the ebb and the FSI moved down-estuary, strong vertical mixing and resuspension of recently deposited sediment occurred in the unstratified water behind the FSI and the associated TM advected down-estuary. Additional effects were present with stronger tides and increased runoff.     

A monograph on the Pleistocene history of the Middle Thames Valley

Book reviewed in this article:
Gibbard, P. L. 1985: The Pleisrocene History of the Middle Thames Valley.
Joakim Donner, Department of Geology, University of Helsinki, Snellmaninkaru     

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.     

Vertical accretion rates and heavy metal chronologies in wetland sediments of the Tijuana Estuary

This study represents the first report on sediment accretion rates using¹³⁷Cs dating for a southern California salt marsh. Vertical accretion rates ranged from 0.7 to 1.2 cm yr⁻¹, which is at the high end of sediment accretion values for coastal wetlands. This has lead to increases in elevation within the estuary from 18 to 35 cm over the last 35 years. Depth profiles of metal concentrations were converted to time-based profiles using vertical accretion rates. Chronologies for most cores indicate a consistent peak in sediment lead (Pb) concentrations in the early to mid 1980s, corresponding to the historic decline in Pb use, which was completed in the U.S. by the early 1980s, but not begun in Mexico until 1991. Sediment Pb levels ranged from about 6–56 μg g⁻¹. Other metals did not show any consistent trends in sediment chronology, except for a single core from a mid-marsh site (east-mid 2), which showed a 2–3-fold increase in levels of Cu, Ni, and Zn during the past two decades. Sediment levels of copper (Cu), nickel (Ni), and zinc (Zn) ranged from 6–34 μg g⁻¹, 11–27 μg g⁻¹, and 42–122 μg g⁻¹, respectively. Despite rapid industrial development of the watershed, a comparison of the sediment metal concentrations in the Tijuana Estuary to other anthropogenically-impacted estuaries in the United States and Europe, shows that metal levels in sediments of the north arm of the estuary are relatively low.     

Diagenetic metal profiles in recent sediments of a scottish freshwater Loch

Integrated total elemental, phase-specific, and pore-water analyses of sediment cores from Loch Ba, Scotland, show that early diagenetic processes have promoted extensive metal enrichment immediately beneath the sediment-water interface. The accumulation of Mn, Pb, Zn, Cu, and Co in sedimentary solids upward of 3 cm depth is accompanied by an increasing residence of these elements in adsorbed and hydrous oxide phases. Such phases are formed through oxidative precipitation from the interstitial pore fluids, following the upward migration of metals from more deeply buried, anaerobic sectors of the sediment pile. There is good evidence that Fe and Ni are subject to similar influences, although their total abundances near the sediment surface are less conspicuously modified. In the Loch Ba sediments, the oxic conditions promoting metal precipitation are entirely confined to strata of postindustrial age. In the absence of fully diagnostic pore-water and sequential chemical data, similar diagenetic profiles could plausibly be misinterpreted as the product of anthropogenic contamination.     

Stratigraphic sequence, elemental concentrations and heavy metal pollution in Holocene sediments from the Tinto-Odiel Estuary, southwestern Spain

 The Holocene filling of the Tinto-Odiel Estuary comprises seven lithofacies over a Mio-Pliocene substrate. The sequence includes three system tracts: lowstand system (10 000 to 8700 years BP), transgressive system (8700 to 7000 years BP), and regressive system (7000 to Recent). Twenty sediment samples from the 50-m borehole were analyzed for their major components and minor element concentrations. Two multivariate analysis methods, principal component analysis and cluster analysis, were performed in the analytical data set to help visualize the sample clusters and the element associations. Samples corresponding to unpolluted, pre-mining sediments are clearly separated by cluster analysis, mainly as a result of the low content in sulphide-associated heavy metals such as Cu, Zn, As, Ag, and Pb. So, these sediments may be utilized as a background for geochemical analysis (bulk sample) in other adjacent estuaries, both in sandy and silty-clayey sediments. As a consequence of large-scale mining and smelting operations occurred since prehistoric times on the river banks, a rapid rise in the metal pollution was found in the upper 2.5 m of the natural filling, with values exceeding up to ten times the natural background levels. In addition, since the mid-1960s, large amounts of waste and pollutant effluents have been discharged from industries located around the estuary, increasing the heavy metal content in the last 0.3 m of the natural sedimentation. Received: 18 August 1997 · Accepted: 19 January 1998     

Bedding-controlled coastal landslides in Southeast Britain between Axmouth and the Thames Estuary

The coastline of Southeast Britain is formed in sedimentary rocks of Jurassic, Cretaceous and Tertiary age, the majority of these deposits containing thick strata of mudrocks, which have very low angles of dip. Where these strata are appropriately exposed, particularly at the foot of a coastal slope, they give rise to landslides where all or part of the sliding surface follows a single bed of mudrock. Where the dip of the bedding is steep, such landslides are referred to as dip-slope failures. However, landslides where the basal sliding surface is controlled by the location and orientation of a single argillaceous bed in the sequence are better termed bedding-controlled landslides. In addition, where coastal slopes contain several layers of mudrocks, geometrically similar landslides may occur with perched slide surfaces breaking out at a higher level within the slopes. Landslides with strong bedding-controlled basal shear surfaces are the predominant form of instability along the southeast coastline of Britain. Many of the individual landslide cases used in this paper have been studied separately over many years. The general similarity of the different records is discussed, drawing important inferences on a number of aspects of these landslides with a variety of basal sliding surface geometries.     

Industrialization affects heavy metal and carbon isotope concentrations in recent Baltic Sea sediments

Recent sediment cores of the western Baltic Sea were analyzed for heavy metal and carbon isotope contents. The sedimentation rate was determined from radiocarbon dates to be 1.4 mm/yr. The ‘recent age’ of the sediment was about 850 yr. Within the upper 20 cm of sediment, certain heavy metals became increasingly enriched towards the surface; Cd, Pb, Zn and Cu increased 7-, 4-, 3- and 2-fold, respectively, whereas Fe, Mn, Ni and Co remained unchanged. Simultaneously, the radiocarbon content decreased by about 14 per cent. The enrichment in heavy metals as well as the decrease in the ¹⁴C-concentration during the last 130 ± 30yr parallels industrial growth as reflected in European fossil fuel consumption within that same period of time. The near-surface sediments are affected by residues released from fossil fuels at the rate of about 30 g/m² yr for the past two decades. The residues have a pronounced effect on the heavy metal and carbon isotope composition of the most Recent sediments allowing estimates to be made for sedimentation, erosion and heavy metal pollution.     

Transport and retention of suspended particulate matter and bacteria in the Humber-Ouse Estuary, United Kingdom, and their relationship to hypoxia and anoxia

Data are presented on dissolved oxygen (DO) concentrations and their relationship to salinity, suspended particulate matter (SPM), concentrations, and the turbidity maximum in the Humber-Ouse Estuary, United Kingdom, during summer 1995. Measurements in the upper Humber during March 1995 showed DO in the range 82% to 87% of saturation. Suspended particulate matter concentrations were <5000 mg l^?1 and salinity was in the range 0.5 to 12. In contrast, a pronounced DO sag occurred in the upper reaches of the Ouse during medium and spring tide, summer conditions. The DO minimum was essentially an anoxic level and was associated with the location of the turbidity maximum, at salinities between about 0.4 and 1.5. SPM concentrations at 1 m beneath the surface reached 25,000 mg l^?1 in the turbidity maximum, between about 20 km and 40 km from the tidal limit. Suspended particulate matter concentrations were much lower at neap tides, although dense suspensions of SPM (>60,000 mg l^?1) occurred within 1 m of the bed in the turbidity maximum region. A spring-neap record showed a dramatic and tidally controlled decrease in DO at very low salinities as the tides progressed from neaps to springs. An anchor station located down-channel of the turbidity maximum showed that about 95% of the variance in DO, which varied from 28% at low-water slack to 67% at high-water slack, could be explained in terms of salinity variation. At the up-channel margins of the turbidity maximum, DO increased from zero (anoxia) near high water to 60% near low water slack, in contrast to the behavior down-channel of the turbidity maximum. About 82% of the variance in DO could be explained in terms of salinity variations alone. Only 43% of the DO variance could be explained in terms of SPM alone. Up-channel of the turbidity maximum, SPM concentrations were relatively low (<3000 mg l^?1) and DO levels varied from 48% of saturation near high water to 83% near low water slack. About 76% of the variance in DO could be explained in terms of salinity variations alone. Within the turbidity maximum region, DO varied from <2% saturation on the early flood and late ebb and maximized around 7% at high water slack. About 63% of the variance in DO could be explained in terms of salinity variation alone. This increased to 70% when suspended particulate matter was taken into account. Only 29% of the DO variance could be explained in terms of suspended particulate matter alone. Because bacteria were likely to have been the cause of the observed reduction in DO, the numbers of bacteria, both free-living and attached to particles, were measured in the turbidity maximum region. Numbers of free-living bacteria were low and most of the bacteria were attached to sediment particles. There was a linear correlation between total bacterial number and suspended particulate matter concentration, suggesting that the strong DO demand was exerted locally as a result of bacterial activity associated with increased suspended particulate matter concentrations. An order of magnitude analysis of DO consumption within the Ouse’s turbidity maximum, based on the premise that DO depletion was directly related to suspended particulate matter concentrations and that DO addition was due to reaeration, indicates that complete deoxygenation could have occurred with an oxygen depletion rate of ～0.01 mg DO h^?1/g suspended particulate matter during the residence time of waters within the turbidity maximum (～7 d). This rate was sufficiently fast that anoxic to aerobic conditions were able to develop a spring-neap periodicity within the turbidity maximum, but too slow to generate substantial intratidal fluctuations in DO. This is in accordance with the observations, which show that relatively little of the intratidal variance in DO could be explained in terms of suspended particulate matter fluctuations, whereas most of the variance could be explained in terms of salinity, which behaved as a surrogate measure for the proximity of the turbidity maximum.     

Records of radionuclide deposition in two salt marshes in the United Kingdom with contrasting redox and accumulation conditions

Single cores from two salt marshes in the United Kingdom located near different nuclear facilities were investigated to compare chronostratigraphic estimates derived from the natural radionuclide ²¹⁰Pb_excess with estimates from the known times of introduction of artificial radionuclides to the environment. Both cores selected had clear visual indications of redox zonation, and evidence for diagenetic redox perturbation of the radionuclide records was also sought. In the core from Beaulieu Marsh on the south coast of England, the redox zonation was revealed by the profiles of the redox-sensitive elements Mn + I, Fe + P + As, and S, and the records of nuclear discharges were entirely contained within oxidized conditions in the upper 40 cm. The constant flux/constant sedimentation ²¹⁰Pb_excess accumulation estimate was 76% of that derived from the 1963 fallout ¹³⁷Cs level (0.35 vs. 0.46 g cm⁻² yr⁻¹ dry mass), but the constant flux ²¹⁰Pb_excess method indicated that accumulation rates were lower at Beaulieu before ∼1950. On any timescale, ¹³⁷Cs appears earlier in the sediment record than its introduction to the environment, but although downward diffusion of ¹³⁷Cs relative to ²⁴¹Am has clearly occurred, the ¹³⁷Cs peak still appeared in place and there was negligible penetration of ¹³⁷Cs into underlying reduced conditions. This core also contained a peak of the ⁶⁰Co discharges from either or both the Winfrith and La Hague nuclear plants that peaked in 1980 and 1984, respectively. The sediments in the core from Wyre Marsh on the eastern coast of the Irish Sea had accumulated more rapidly than those at Beaulieu, and in this case the redox zonation could be established only from Mn and S profiles. Here, the constant initial activity ²¹⁰Pb_excess accumulation rate estimate was 125% of that derived from the ¹³⁷Cs peak correlated with the 1975 Sellafield discharge maximum (0.79 vs. 0.64 g cm⁻² yr⁻¹). Sellafield discharge ¹³⁷Cs swamps fallout or Chernobyl ¹³⁷Cs signals in this core, but the ¹³⁷Cs and ²⁴¹Am sediment records are well separated and remain consistent with the slightly different discharge patterns over time. This is so despite the fact that the maximum activity levels of both isotopes are now located well into reducing conditions out of which Mn must have migrated. The ²¹⁰Pb profile appeared similarly unaffected by the oxidized/reduced boundary in this case. This core was too short to define the limits of any downward ¹³⁷Cs migration. ²¹⁰Pb_excess accumulation rate estimates for salt marshes should be viewed with some caution because of the steady-state assumptions inherent in all ²¹⁰Pb_excess methods and the potential for fluctuating accumulation conditions and open system behavior in salt marshes.     

Evolution of heavy-metal profiles in river Weser Estuary sediments,Germany

Studies of heavy metal concentrations in porewaters and in sediments from the Weser Estuary, Germany, indicate that the depth distribution of Mn, Cd, and Cu in the solid phase is predominantly influenced by the subsurface redox regime, while Ni shows only moderate alteration. Based on solid-phase heavy metal data from eight locations in the study area, linear regressions of Fe, Mn, Cu, Ni, and Cd on Al allowed differences between the initial metal concentration and the concentration preserved in the sediments to be predicted. We calculate that, due to early diagenetic processes, Mn is enriched to 145 percent, while Cu and Cd are depleted to 71 percent and 46 percent, respectively, of the initial metal concentration in the near-surface sediment. Maximum depletion of Cd (84 percent), Cu (68 percent), Mn (54 percent), and Ni (24 percent) concentrations in the sediment, observed at a restricted area downcore, indicate the importance of post-depositional processes to metal preservation in the sediment. Without knowledge of the quantitative effects of diagenetic reactions on the preservation of metal concentrations in sediments, the depth distribution of metals in sediment cores may be misinterpreted as the effect of human activities.     

Coagulation and transport of sediments in the Gironde Estuary

The distribution of suspended particle size and concentration were measured along the Gironde Estuary, France, from the river seaward to the ocean. The suspended particle size and volume concentration were measured using in situ holography and onboard optical techniques utilizing special procedures in order to avoid floc breakage. Sediments discharged by the rivers coagulate upon encountering the very low salinities (0.2‰ of the upper estuary (confirmed with laboratory experiments), and are then transported and deposited by currents in the remainder of the estuary. This coagulation, coupled with estuarine circulation, produces a turbidity maximum which is offset between the surface and bottom waters. The floc size maximum is oceanward of the turbidity maximum and is, likewise, offset along the estuary by about 30 km. The estuary can be subdivided into the following zones: (1) coagulation; (2) hydrodynamic, landward of the null point; and (3) hydrodynamic, seaward of the null point. Initial coagulation appears to be completed in coagulation zone (1), and particles are transported and settled (with very little floc breakage and recoagulation) in zones (2) and (3) only. The floc settling velocities, coupled with estuarine circulation, control the concentration and size distributions of flocs in the water column, and eventually control the deposition of sediments.     

Pleistocene fluvial sediments,palaeontology and archaeology of the upper River Thames at Latton,Wiltshire, England

Pleistocene fluvial sediments of the Northmoor Member of the Upper Thames Formation exposed at Latton, Wiltshire, record episodic deposition close to the Churn–Thames confluence possibly spanning the interval from Marine Isotope Stages (MIS) 7 to 2. The sequence is dominated by gravel facies, indicating deposition by a high‐energy, gravel‐bed river. A number of fine‐grained organic sediment bodies within the sequence have yielded palaeoenvironmental and biostratigraphical data from Mollusca, Coleoptera, vertebrates, pollen and plant macrofossils. The basal deposit (Facies Association A) contains faunal material indicating temperate conditions. Most of the palaeontological evidence including a distinctive small form of mammoth (Mammuthus cf. trogontherii), together with the U‐series age estimate of >147.4 ± 20 kyr suggest correlation with MIS 7. The overlying deposits (Facies Associations B and C) represent deposition under a range of climatic conditions. Two fine‐grained organic deposits occurred within Association B; one (Association Ba) in the northern part of the pit as a channel fill and the other (Association Bb) in its southern part as a scour‐fill deposit. The coleopteran assemblages from Ba, indicate that it accumulated under temperate oceanic conditions, while Bb, which also yielded a radiocarbon age estimate of 39 560 ± 780 ¹⁴C yr BP, was formed under much colder and more continental climatic conditions. The sequence is considered to represent deposition within an alluvial fan formed at the Churn–Thames confluence; a depositional scenario which may account for the juxtaposition of sediments and fossils of widely differing age within the same altitudinal range. Copyright © 2006 John Wiley & Sons, Ltd.     

Phosphorus speciation and availability in intertidal sediments of the Yangtze Estuary,China

In order to better understand P cycling and bioavailability in the intertidal system of the Yangtze Estuary, both surface (0–5 cm) and core (30 cm long) sediments were collected and sequentially extracted to analyze the solid-phase reservoirs of sedimentary P: loosely sorbed P; Fe-bound P; authigenic P; detrital P; and organic P. The total sedimentary P in surface and core sediments ranged from 14.58–36.81 μmol g⁻¹ and 17.11–24.55 μmol g⁻¹, respectively, and was dominated by inorganic P. The average percentage of each fraction of P in surface sediments followed the sequence: detrital P (54.9%) > Fe-bound P (23.7%) > organic P (14.3%) > authigenic P (6.3%) > loosely sorbed P (0.8%), whereas in core sediments it followed the sequence: detrital P (61.7%) > Fe-bound P (17.0%) > authigenic P (13.1%) > organic P (7.5%) > loosely sorbed P (0.7%). Post-depositional reorganization of P was observed in both surface and core sediments, converting organic P and Fe-bound P to authigenic P. The accumulation rates and burial efficiencies of the total P in the intertidal area ranged from 118.70–904.98 μmol cm⁻² a⁻¹ and 80.29–88.11%, respectively. High burial efficiency of the total P is likely related to the high percentage of detrital P and the high sediment accumulation rate. In addition, the bioavailable P represented a significant proportion of the sedimentary P pool, which on average accounted for 37.4% and 25.1% of the total P in surface and core sediments, respectively. This result indicates that the tidal sediment is a potential internal source of P for this P-limiting estuarine ecosystem.     

Tetra- and pentacyclic,naturally-occurring,aromatic hydrocarbons in recent sediments

Several polycyclic aromatic hydrocarbons (PAH) have been identified in recent Amazon River and Cariaco Trench sediments. The skeletal structures of these compounds suggest triterpenoid precursors. The tetracyclic compounds seem to result from A-ring cleavage and the pentacyclic compounds from aromatization which begins with ring A and proceeds through ring D. These compounds are another example of the environmental occurrence of natural PAH.     

鸭绿江河口及近岸地区沉积物中重金属分布的影响因素分析

对鸭绿江河口不同地区沉积物中重金属分布特征和埋藏通量的垂向变化进行了分析;探讨了其独特的动力环境等因素对重金属分布的影响;评价了鸭绿江河口地区重金属污染状况及潜在生态风险程度.结果显示,自1920年代到2000年以来,除了Cu的含量和埋藏通量逐年减小之外,Cr、Ni、Zn、Cd、Pb、As和Hg的浓度和埋藏通量具有逐渐增加的趋势;鸭绿江河口地区重金属总体污染程度为重到严重,其中西水道沉积物的重金属总体污染程度和总潜在生态风险程度均最高,重金属污染已经对鸭绿江河口地区的生态环境构成了严重的危害;粒度控制效应不是鸭绿江河口地区重金属分布的最主要影响因素;Cu和其他几种重金属有着不同的来源;最大浑浊带独特的动力机制是造成中水道重金属(除Cu外)的高值分布区和最大浑浊带内的高悬沙浓度分布区相对应的最主要原因.