金沙江(攀枝花段)水系沉积物中重金属的形态特征

采用连续提取法,并用原子吸收光谱法进行分析研究了金沙江攀枝花段水系沉积物中重金属的形态及分布特征。研究发现:①各重金属的形态以残渣态为主,离子交换态含量很少;②各元素的形态有自己的特点。铜在有机硫化物结合态中的含量较高,钴在碳酸盐结合态中的含量较高,铅锌钴的铁锰氧化物结合态均较高;③有效态对水环境质量具有潜在的危害。     

白音诺尔铅锌矿区河流沉积物重金属的形态分布特征

为了研究内蒙古赤峰市巴林左旗白音诺尔铅锌矿区采矿对哈力黑河生态环境造成的影响,从上游向下游采集了6个河流沉积物样品,测定其pH、LOI、粒度以及As、Cu、Pb、Zn、Cd等5种重金属的总量和赋存形态,并对测试结果进行分析。研究结果表明:（1）1#尾矿库是造成沉积物中Pb、Zn和Cd等重金属显著升高的主要原因。（2）沉积物重金属与粗粉砂（16~63 μm）的相关系数为0.79~0.95,表明重金属易富集于粗粉砂上,而沉积物的pH和有机质对重金属总量的变化影响不显著。（3）沉积物中As和Pb以残渣态和铁锰结合态为主,分别占总量的78.82%~89.87%和36.96%~78.20%。Cu和Zn以残渣态、强有机结合态和铁锰结合态为主,分别占总量的76.38%~85.96%和74.94%~90.34%。Cd则以离子交换态、碳酸盐结合态和强有机结合态为主,占总量的51.15%~79.53%,而离子交换态Cd占了总量的5.72%~49.63%。因此,Cd对河流生态环境的潜在威胁最大。（4）离子交换态Cd与沉积物pH相关系数为-0.813,两者呈极强负相关性。当沉积物pH由弱酸性转化为弱碱性时,离子交换态Cd含量从33.44%降低至5.72%,显著减小。     

Magnetic properties of urban topsoils and correlation with heavy metals: a case study from the city of Xuzhou, China

Heavy metals in urban topsoils have been shown to be very useful tracers of environmental pollution. Thus, their detailed studies are of great importance. Apart from expensive and time-consuming chemical methods, several simple, rapid and cheap proxy methods have been developed recently, one of them being based on rock-magnetic parameters. This examines the use of rock-magnetic methods designed to assess the degree of heavy-metal pollution of urban topsoils from the city of Xuzhou (China). The aim was to identify the magnetic properties and to link the “magnetic pollution” to the concentrations of the heavy metals. Since a strong correlation has been found between saturation isothermal remanent magnetization (SIRM) and the heavy metals, namely, Fe, Se, Ti, Sc, Ba, Bi, Pb, Cu, Zn, Cr and Mo, an anthropogenic contamination origin is thought to be the cause. The present study shows that SIRM is a fast, inexpensive and non-destructive method for the detection and mapping of heavy-metal-contaminated urban topsoils.     

Distribution and source identification of heavy metals in the sediments of a river flowing an urbanization gradient,Eastern China

Heavy metal contamination is of great concern in rapidly urbanizing areas. A basin-basis study on the impacts of urbanization on the heavy metal contamination in surface sediments from the Qinhuai River, Eastern China, was conducted, focusing on the spatial variation and source appointments. All of the sampling sites can be divided into three groups based on the hierarchical cluster analysis (HCA) results, which correspond well to the pollution levels of the studied heavy metals in the sediments of the rural, suburban, and urban sections of the Qinhuai River. The relationship between the heavy metal and the Al/Si ratio of sediments varied distinctly with the metal species and urbanization degree of the river sections. Correlation analysis and HCA highlighted that zinc appeared to be a fairly efficient geochemical signature of urban-related heavy metal contamination. The contributions derived from urban activities ranged from 35.9% for Ni to 96.1% for Cu, as estimated by a multilinear regression of the absolute principal component score method (MLR-ACPS). Agricultural activities had a clear impact on As, Pb, and Cu contamination of the sediment. Lithologic sources contributed a significant portion of Ni, Cr, and As to the sediment.     

Magnetic signature of heavy metals pollution of sediments: case study from the East Lake in Wuhan,China

Detailed magnetic measurements and geochemical analyses were performed on 114 sediment samples collected from the East Lake, Wuhan city, China, to establish a possible link between the enhanced concentration of anthropogenic magnetic particles and heavy metals with known sources. Relatively higher magnetic susceptibility values (mass-specific, χ, >150 × 10⁻⁸ m³ kg⁻¹) were observed for samples near the pollution sources: e.g. the Wuhan Iron and Steel Company (WISC), the Qingshan Thermal Power Plant (QTPP), the banks (driveways) of the lake and near the sightseeing route of yachts on the lake. Moreover, χ is positively correlated to the concentration of Pb (correlation coefficient r = 0.682), but negatively or weakly correlated with both Zn and Cu. In contrast, anhysteretic remanent magnetization (ARM) is significantly correlated with these major heavy metals (r = 0.645 for Zn–ARM, 0.699 for Pb–ARM and 0.841 for Cu–ARM, respectively), which indicate that ARM serves a better indicator for the pollution of heavy metals in this lake. Thermomagnetic analysis combined with magnetic hysteresis measurements revealed that magnetites in the pseudo-single-domain/multidomain grain-size regions are dominant. Scanning electron microscopy and energy dispersive X-ray examinations of the magnetic extracts showed that these Fe-rich particles have different morphologies: orange-peel structure, hollow structure with adhered smaller particles, Zr-rich melted-like irregular particles, pear-shaped spherules and spherules with slick surfaces. These features are typical for particles produced by anthropogenic activities. Because of the genetic relationship between the environmental setting of the East Lake and the nearby pollution sources, this study suggests that in situ magnetic surveys are sensitive to evaluate the environmental pollution on the lake bottom.     

Heavy metals and polychlorinated biphenyls in sediments of the Yangtze river estuary,China

Typical pollutants in sediments from 22 sampling sites of the Yangtze river estuary in 2006 were investigated in the present study. Arsenic, mercury, cadmium, copper, chromium, zinc, lead, and polychlorinated biphenyls of the Yangtze river estuary sediments were found as 6.49–17.6, 0.0164–0.0987, 0.059–0.319, 11.7–46.6, 10.5–113, 44.5–125, 14.8–32.7, and 0.0006–0.0026 mg/kg, respectively. Results indicated the presence of a contamination in the Yangtze river estuary. Through analyzing the contents of typical pollutants in sediments with adopting the index number techniques of Muller geoaccumulation index and Hakanson ecological risk factors and index, the quality status of these sediments were evaluated. Furthermore, the potential ecological risks of the estuary were determined quantitatively. The overall environmental quality of typical pollutants was generally in a good condition in most sites. The results showed that arsenic was the main environmental pollution factor, and cadmium was the main potential ecological factor. The highest potential ecological risk index appeared in the south branch of the Yangtze river, which was mainly due to terrestrial pollution in Shanghai. The results of this study can be used for decision makers to prioritize measures to control the pollution for these typical pollutants.     

滇西沘江流域水体中重金属元素的地球化学特征

通过测定流经兰坪金顸铅锌矿区的沘江水体中Pb、Zn、Cd、As的含量和底泥中重金属元素的化学形态的含量,分析了重金属元素的分布和化学形态的变化。结果表明,沘江水遭到了Cd污染,底泥已经成为重金属元素的蓄积库,以国家土壤环境质量标准（Ⅲ级）衡量,Pb、Zn、Cd和舡分别超标3．4倍、15．8倍、106倍和2．6倍。沘江水中重金属元素含量的峰值在矿山附近的下游,而底泥中重金属元素的峰值在矿山下游30-50km的地方,矿业活动、水流变缓、pH等水体环境条件的变化都能影响水和底泥中重金属元素的含量。底泥中的Pb以碳酸盐结合态为主,Zn和Cd以铁锰氧化物结合态为主,而As以残渣态为主。Pb、Cd、Zn三种元素的环境有效态含量比较高,对沘江流域生态环境具有潜在的巨大的危害。     

中国东部入海河流沉积物磁性矿物化学特征及物源意义

大量陆源碎屑物质主要通过以长江、黄河为代表的大江大河和以瓯江、浊水溪为代表的山溪性小河流的携带输移至中国东部海域,海域沉积物的物源识别是当前的研究热点。本文通过原子吸收光谱法测试了磁性矿物中的11种元素（Ti、Fe、Cr、Mg、Al、V、Ca、Co、Zn、Mn和S）,旨在探讨这些河流沉积物（ < 45μm）的磁性矿物群体化学特征,提取其物源指示意义,为边缘海沉积物物源判别提供依据。研究结果表明,这些河流沉积物的磁性矿物主要是以铁氧化物（磁铁矿）为主,铁硫化物含量很低（ < 2%）,只有台湾浊水溪沉积物中含有相对较多的铁硫化物（主要是磁黄铁矿）,为1.84%。除此之外,各河流沉积物磁性矿物中铁氧化物的化学元素组成（Ti、Mg、Ca、Al、Cr、V、Mn、Co和Zn）差异也很明显,其中黄河富含Mg和Ca,长江富含Ti,钱塘江富含Al,瓯江富含Cr,台湾浊水溪相对来说富含Al和Co,而其余元素含量远低于其他河流。从磁性矿物成因图上看,黄河沉积物中磁性矿物落在碱性岩浆岩成因区,但这并不是反映了流域磁性矿物的母岩为碱性岩浆岩,而是由于流域中黄土土壤化过程中产生的细颗粒磁性矿物中含有较高的碱土金属元素（如Mg和Ca）所致;其他河流磁性矿物成因与其流域母岩关系密切,如长江和浙闽河流主要为超基性-基性-中性岩浆岩成因,浊水溪为沉积变质-接触交代成因,都与其所处流域的磁性矿物的母岩类型较为一致。利用Ti+V-S+Co-Ca+Mg三角图可以有效地区分黄河、长江和浙闽河流、浊水溪沉积物物源。磁性矿物群体中的Mn、Zn、Al、Cr元素的差异有助于进一步确定长江和浙闽河流的泥沙来源。同时,发现磁性矿物单颗粒和群体化学组成特征具有一定差异性,很可能是由于分析方法不同所造成。

     

Distribution and behavior of heavy metals in a river polluted by acid mine drainage in the Dabaoshan mine area, China

Acid mine drainage （AMD） has been recognized as a major environmental pollution problem over past decades. This pollutant effluent is complex and is characterized by elevated concentrations of iron and sulfate, low pH, and high concentrations of a wide variety of metals depending on the host rock geology. Massive inadvertent discharges from acid mines have given rise to dramatic cases of ecological damage. These events indicate an improved understanding of the mechanism controlling metal transport to the river is important, since the aquatic ecology will be affected, to some degree, dependent on the phase （dissolved or particulate） in which the metal is transported. In this study, polluted water samples were collected along the Hengshi River near the Dabaoshan mine, Guangdong, China, in April 2005. The concentrations of dissolved Cu, Zn, Cd and Pb have been determined using ICP-MS and the chemical speciation of those metals in suspended particles was examined using BCR methods and SEM/EDX mineralogical analysis. Combining these two sets of data, the intention was to develop geochemical concepts, which explain the behavior of Cu, Zn, Cd and Pb in particle-water interactions of heavy metals in AMD. The results show that the dissolved heavy metals exhibited non-conservative behavior in the Hengshi River. The dissolved and particulate Cu, Zn, Cd and Pb have the similar spatial distribution, which decreased gradually along the river except in the lower reaches because of the absorption-desorption between dissolved and particulate phases. Although the metal concentrations in both phases were elevated, dissolved metals were dominant and had the maximum concentrations in the low pH region.     

Contamination and potential mobility assessment of heavy metals in urban soils of Hangzhou,China: relationship with different land uses

Concentration and distribution of heavy metals (Cd, Cu, Pb and Zn) in urban soils of Hangzhou, China, were measured based on different land uses. The contamination degree of heavy metals was assessed on the basis of pollution index (PI), integrated pollution index (IPI) and geoaccumulation index (I _geo). The 0.1 mol l⁻¹ HCl extraction procedure and gastric juice simulation test (GJST) were used to evaluate the potential mobility and environmental risk of heavy metals in urban soils. The average concentration of Cd, Cu, Pb and Zn in urban soils was measured at 1.2 (with a range of 0.7–4.6), 52.0 (7.4–177.3), 88.2 (15.0–492.1) and 206.9 (19.3–1,249.2) mg kg⁻¹, respectively. The degree of contamination increased in the order of industrial area (IA) > roadside (RS) > residential and commercial areas (RC) > public park and green areas (PG). The PIs for heavy metals indicated that there is a considerable Cd, Cu, Pb and Zn pollution, which originate from traffic and industrial activities. The IPI of these four metals ranged from 1.6 to 11.8 with a mean of 3.5, with the highest IPI in the industrial area. The assessment results of I _geo also supported that urban soil were moderately contaminated with Cd and to a lesser extent also with Cu, Pb and Zn. The IP and I _geo values reveal the pollution degree of heavy metal was the order of Cd > Pb > Zn ≈ Cu. It was shown that mobility and bioavailability of the heavy metals in urban soils increased in the order of Cd > Cu > Zn ≈ Pb. Owing to high mobility of Cd and Cu in the urban soils, further investigations are needed to understand their effect on the urban environment and human health. It is concluded that industrial activities and emissions from vehicles may be the major source of heavy metals in urban contamination. Results of this study present a rough guide about the distribution and potential environmental and health risk of heavy metals in the urban soils.     

辽东湾河口底质重金属环境地球化学

对辽东湾诸河口底质样进行了 Pb、Zn、Cu、Cd等含量分析.辽东湾底质重金属污染物主要是 Cd、Zn、Pb,尤其是 Cd平均含量为 1.16 mg/kg,超过土壤环境质量三级标准; Zn平均含量为 105.28 mg/kg,超过土壤环境质量一级标准.运用地累积指数法对其污染程度评价,认为辽东湾西北及北部河口底质污染严重,葫芦岛市五里河桥下> 大凌河口北> 辽河口> 双台子河口等处.与历史资料的对比表明,4种重金属的平均含量均有所提高.     

Speciation and potential remobilization of heavy metals in sediments of the Taihu Lake, China

The species of Cu, Pb, Zn, Cd and Cr in sediments of the Taihu Lake, China, have been analyzed using the sequential chemical extraction method. Variations in the chemical fractions of these metals and their geographic distributions have also been studied. For all five metals, the residual fraction is highest but the exchangeable fraction is lowest among all the fractions. Compared to other metals, Cd has the highest percentage in the exchangeable fraction, and Cr is associated mainly with the residual fraction. Cu in the organic fraction and Pb in the Fe-Mn fraction are the important species, whereas the lowest percentages are found for Cd in the organic fraction, Cu in the Fe-Mn oxide fraction and Pb in the carbonate fraction. With respect to spatial differences, the total contents in the non-residual fractions of the metals in bay sediments are found to be higher than those in other sediments. The fractions of Cd, Cu and Cr showed significant variations in different regions. The fractions of Pb and Zn, however, did not show significant variations in spatial distribution, suggesting different amounts and different paths of anthropogenic input for the metals. Comparisons of the metal speciation indicated that Cd might be the most bioavailable metal, followed by Pb.     

Competitive adsorption,release and speciation of heavy metals in the Yellow River sediments,China

The competitive adsorption and the release of selected heavy metals and their speciation distribution before and after adsorption in the Yellow River sediments are discussed. The adsorption of metals onto sediments increases with increasing pH value and decreases with increasing ionic strength. The competitive coefficient K _c and the distribution coefficient K _d are obtained to analyze the competitive abilities of selected heavy metals, which are ranked as Pb > Cu >> Zn > Cd. The competition among selected heavy metals becomes more impetuous with increasing ion concentration in water. Speciation analysis was done by an improved analytical procedure involving five steps of sequential extraction. Cu, Pb and Zn were mainly transformed into the carbonate-bound form (50.8–87.7%) in adsorption. Most of (60.7–77.3%) Cd was transformed into the exchangeable form, and the percentage of carbonate-bound Cd was 19.7–30.4%. The release reaction was so quick that the release capacity of selected heavy metals from sediments to aqueous solution reached half of the maximum value only in 30 s. As opposed to adsorption, the release capacities of selected heavy metals were ranked as Cd > Zn >> Cu > Pb. In this study, Cd produces the most severe environmental hazards, because its concentration in the release solution is 85.8 times more than the human health criteria of US EPA.     

Heavy metals contamination in water and sediments of an urban river in a developing country

Water and sediment samples were collected from 20 location of the Buriganga river of Bangladesh during Summer and Winter 2009 to determine the spatial distribution, seasonal and temporal variation of different heavy metal contents. Sequential extraction procedure was employed in sediment samples for the geochemical partitioning of the metals. Total trace metal content in water and sediment samples were analyzed and compared with different standard and reference values. Concentration of total chromium, lead, cadmium, zinc, copper, nickel, cobalt and arsenic in water samples were greatly exceeded the toxicity reference values in both season. Concentration of chromium, lead, copper and nickel in sediment samples were mostly higher than that of severe effect level values, at which the sediment is considered heavily polluted. On average 72 % chromium, 92 % lead, 88 % zinc, 73 % copper, 63 % nickel and 68 % of total cobalt were associated with the first three labile sequential extraction phases, which portion is readily bioavailable and might be associated with frequent negative biological effects. Enrichment factor values demonstrated that the lead, cadmium, zinc, chromium and copper in most of the sediment samples were enriched sever to very severely. The pollution load index value for the total area was as high as 21.1 in Summer and 24.6 in Winter season; while values above one indicates progressive deterioration of the sites and estuarine quality. The extent of heavy metals pollution in the Buriganga river system implies that the condition is much frightening and may severely affect the aquatic ecology of the river.     

Concentrations and contamination trends of heavy metals in the sediment cores of Taihu Lake,East China,and their relationship with historical eutrophication

To assess the contamination trends and potential bio-availability of sediment-bound heavy metals, concentrations of heavy metals in acid-leaching fraction and in bulk sediments from the two typical bays (the Meiliang Bay and Xuhu Bay) of the Taihu Lake, East China, were studied. Pb and Zn showed elevated concentrations in the sediments from both areas, although sedimentation history and degree of pollution are different between the two bays. In the Meiliang Bay, both Pb and Zn pollutions started in the late 1970’s, the same time as the beginning of eutrophication of the lake, while the in the Xuhu Bay the metal contamination started since recent 10 years. The concentrations of acid-leachable Pb in the sediments from the Meiliang Bay are correlated with the historical eutrophication process. Before the eutrophication and heavy metal pollution, the chemical properties of the lake sediments were the same as the source compositions of the Xiashu loess. Both Pb and Zn in the sediments mainly occur in leachable forms by nitric or hydrochloric acid, whilst most of Cu is in residual fraction. The results indicate that both Pb and Zn may have higher mobility and bioavailability in water and biology than Cu.     

Influence of parent sediments on the concentration of heavy metals in urban and suburban soils in Turku,Finland

The purpose of this study was to examine the influence of parent sediment material on soil geochemistry and to locate possible pollution sources in the area of Turku town in southwestern Finland. The study area is glaciated terrain and subsurface samples were chosen to represent five different parent sediment materials: glacial till, glaciofluvial or littoral sand, clay, peat and marine mud. Elemental concentrations of surface (100 samples) and background soil (50 samples) were analysed by ICP-AES (Al, Ba, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Sr, Ti, V) and by graphite furnace AAS (As, Cd, Mo, Se). Loss-on-ignition was determined as an indicator of organic matter. Analytical results were examined using multivariate statistical methods. The results indicate that the studied soils are not heavily contaminated; there were only few sample sites with elevated heavy metal concentrations. High Pb concentrations were observed along main traffic routes, and also in places where there has been small-scale use of antifouling paints. However, concentrations of heavy metals in topsoil were in general significantly lower than those measured in large cities elsewhere. The parent material strongly affects the geochemical character of the soils. Clays naturally have a significantly higher concentration of heavy metals than sands or till material. This is also reflected in concentrations in organic topsoil. When assessing target levels for polluted soil, the primary sediment appears to be a more important factor than the amount of organic matter.     

Petrographic and geochemical characteristics of organic matter associated with stream sediments in Trail area British Columbia,Canada

Fifty-six samples of stream sediments from 12 creeks in the vicinity of Trail, British Columbia, Canada were examined to determine their origin, characterize their organic matter and their relation to natural/geogenic and anthropogenic sources. The samples were initially screened by Rock-Eval® 6 pyrolysis for their TOC, HI, and OI contents and then examined by both reflected (polarized) and fluorescent light microscopy. It was found that organic matter in stream sediments is mostly from natural/biological sources from local vegetation, such as woody tissue, suberin, spores, and pollen, as well as altered natural/biological input from char formed due to forest fires. Anthropogenic organic matter, mostly coke particles, was also found in the stream sediments. The coke particles have anisotropic properties with medium grained texture formed from medium volatile bituminous coal. The occurrence of coke particles is limited to Ryan Creek located close to an area were some small gold, nickel, and lead smelting operations previously occurred. There is no evidence to indicate that the coke particles found in the creek are emitted from the lead and zinc smelter currently in operation in the area. There are no coal-bearing strata in the area that may have a direct input of coal fragments in any of the creeks.     

Conditions of the accumulation of organic matter and metals in the bottom sediments of the Chukchi Sea

The chemical composition of bottom sediments in the Chukchi and, partly, East Siberian Seas was studied. In the south and west of the Chukchi Sea, a zone has been detected with the accumulation of sediments rich in organic carbon, an increased background content and anomalies of sulfophile metals (Mo, Zn, Hg, Ag, Au), iron-group metals (V, Ni, Co), and some PGE (Ru, Pt). This zone is confined to the neotectonic active system of rift troughs extending from the Bering Strait and eastern Chukchi Peninsula to the continental slope, where it is bounded by the Cenozoic Charlie rift basin of the Canadian hollow. The geochemical features of the carbon-enriched sediments evidence that they formed under oxygen-deficient conditions and, sometimes, in suboxic and anoxic environments near endogenic water and gas sources. The high carbon and metal contents suggest that the very fine-grained sediments in the rift troughs of the Chukchi Sea are a possible analog of some types of ancient highly carbonaceous sediments belonging to black shales.     

Geochemical features of heavy metals in core sediments of northwestern Taihu Lake, China

Sequential core sediments from northwestern Taihu Lake in China were analyzed for grain size, organic carbon and heavy metal content. The sediments are composed of organic-poor clayey-fine silts. The chemical speciations of Cu, Fe, Mn, Ni, Pb, and Zn were also analyzed using the BCR sequential extraction procedure. Cu, Fe, Ni, and Zn are mainly associated with the residue fraction; Mn is concentrated mainly in exchangeable/carbonate fraction and residue fraction; and Pb mainly in Fe/Mn oxide fraction and organic/sulfide fraction. The exchangeable/carbonate fractions of Cu, Fe, Ni, Zn and Pb are lower. The fractions of Ni, Pb and Zn bound to the Fe/Mn oxide have significant correlations with reducible Mn; the organic/sulfide fractions of Cu, Mn, Ni, Pb, and Zn have significant correlations with TOC. The extractable fractions of Cu, Mn, Ni, Pb, and Zn are high at the top 4 cm of the core sediments as compared to those in the deeper layers, showing the anthropogenic input of heavy metals is due to rapid industrial development. The heavy metal pollution history of the sediments has been recorded since the late 1970s, determined by the result of ^137Cs dating.     

Assessment of heavy metals contamination in urban topsoil from Changchun City,China

Due to the rapid urbanization and industrialization that has occurred in China over the last few decades, metals have been continuously emitted into the urban environment and now pose a serious threat to human health. Indeed, there is a growing concern over the potential for pollution of urban soils with heavy metals. Therefore, an extensive soil survey was conducted in urban areas of Changchun, China, to evaluate the current status of heavy metal contamination in soils and to evaluate its potential sources. A total of 352 samples of urban soils were collected from urban areas of Changchun using a systematic sampling strategy in which one sample per km² was taken (0 ~ 20 cm). The levels of Cu, Pb, Zn and the major elements (Mn, Al₂O₃, CaO, Fe₂O₃, MgO, SiO₂, K₂O and NaO) were then determined by X-Ray fluorescence spectrometry (XRF), while the level of Cd was determined by graphite furnace atomic absorption spectrometry (GF-AAS), and the Hg and As concentrations were determined by atomic fluorescence spectroscopy (AFS). The results indicated that, when compared with the background values of topsoil in the Changchun region, the topsoil in urban areas were enriched with metals, particularly Cu, Cd, Zn, Pb and Hg. The results of correlation coefficient analysis showed that Hg, As, Cd, Cu, Pb and Zn were significantly positive correlated with each other, while Cr and Mn formed another group. Moreover, significantly positive correlations were observed between pH and Zn, Pb, Cu, Cd, As and Hg, indicating that pH influences the distributions of these metals in urban soils in Changchun. Principal component analysis (PCA) was conducted to identify sources of heavy metals and the results revealed distinctly different associations among the trace metals and the major elements in the urban soils. The concentration of Cr appeared to be controlled by the parent material (natural sources), while Cu, Pb and Zn were mainly from vehicle emissions, with Zn primarily coming from vehicle tires. Additionally, Hg and As primarily originated from coal combustion, while Cd was mainly associated with industrial sources. According to the pollution index (PI) of each metal, the overall levels of metal pollution were not especially high, but there were clearly contaminated sites concentrated in the central and northeast portion of the studied region. The Nemerow integrated pollution index (NIPI) of the seven metals also indicated that urban soils in Changchun city were classified as having low level of pollution.