Impacts of Yellow River Irrigation Practices on Trace Metals in Surface Water: A Case Study of the Henan-Liaocheng Irrigation Area,China

Large-scale irrigation practices may disturb local hydrologic cycles and distribute trace metals throughout the environment. Reported here is the spatial pattern of trace metals and associated health risks in an agricultural area of China, which has a long history of irrigation with water from the Yellow River. Multivariate statistical analyses and a risk-assessment model were employed to interpret the environmental data. It indicated that Zn, Se, B, Ba, Fe, Mn, Mo, Ni, V, Al, Li, Sr, Be, Cd, Cr, Cu, and Pb were all detected in the surface waters. Compared to drinking water guidelines, the primary trace metal pollution components (Al, Fe, Se, B, Mn, and Zn) exceeded drinking water standards by 40.7%, 14.8%, 29.6%, 25.9%, 11.1%, and 14.8%, respectively. Except for one site that exhibited anomalous metal concentrations, landscape features of trace metals identified a uniform distribution of trace metals for all sample sites. The calculated mean value of Hazard Quotients (HQs) exceeded the USEPA's recommendations by a factor of 2.9 times the threshold value. Primary sources of trace metals were associated with natural deposition, industrial and agrochemical processes, and a mixed source of both geogenic and anthropogenic origins.     

Ecological Risks Assessment and Pollution Source Identification of Trace Elements in Contaminated Sediments from the Pearl River Delta, China

Sediments from 14 stations in the Foshan Waterway, a river crossing the industrial district of Guangdong Province, South China, were sampled and subsequently analyzed. The 14 stations were selected for the pollution discharging features of the river, such as the hydrology, the distribution of pollution sources, and the locations of wastewater outlets. The ecological risks were assessed, and the pollution sources were identified to provide valuable information for environmental impact assessment and pollution control. The spatial variability was high and the range were (in milligrams per kilogram dry weight): Pb, 46.0~382.8; Cu, 33.7~ 482.3; Zn, 62.2~1,568.7; Ni, 28.5~130.7; Cr, 34.7~1,656.1; Cd, 0.50~8.53; Hg, 0.02~8.27; and As, 5.77~66.09. The evaluation results of enrichment factor and potential ecological risk index indicate that the metal pollution in the surface and bottom sediments were severely polluted and could pose serious threat to the ecosystem in most stations. Although the hazard levels of the trace element differed among the stations, Hg was the most serious pollutant in all stations. The results of principal component analysis (PCA) show that the discharge of industrial wastewater is the most important polluting factor whereas domestic sewage, which contains a large amount of organic substances, accelerates metal deposition. And potential pollution sources were identified by the way of integrating the analysis results of PCA and data gained from the local government. Therefore, the conclusion is drawn that Foshan Waterway is seriously polluted with trace elements, both in the surface sediment (0 to 20 cm) and the bottom sediments (21 to 50 cm) are contaminated.     

Source apportionment of pollution in groundwater source area using factor analysis and positive matrix factorization methods

By means of factor analysis (FA) and positive matrix factorization (PMF) methods, groundwater pollution sources were identified in the Jinji groundwater source area, which is beside the Yellow River and is the only urban water supply source for the city of Wuzhong in Northwestern China. The sources of groundwater were quantified based on 16 samples of shallow groundwater from the source area. The source apportionment with the PMF model identified three dominant groundwater pollution sources. These were anthropogenic activities of agricultural and industrial pollution with a pollution contribution of 53.0%, water–rock interaction of 24.6%, and evaporation and concentration of 22.4%. The source apportionment with the FA model identified four sources which were evaporation and concentration, with the largest contribution (42.6%), followed by anthropogenic activities (29.2%), mineral dissolution and industrial pollution (22.4%), and natural effects (5.8%). Specific attention should be paid to these natural (fluoride, TH, etc.) and anthropogenic sources (NH₄⁺, NO₂^?, turbidity, total bacterial count, etc.), and pertinent measures should be taken to control local groundwater pollution. The most significant trait of the PMF is its scientific interpretation and physical explanation of the results, depending on non-negative restriction of the pollution source profiles and contributions.     

湘西河流表层沉积物重金属污染特征及其潜在生态毒性风险

花垣河和峒河是湘西地区受到锰矿和铅锌矿生产影响严重的两条河流。通过表层沉积物采样分析了Cd、Pb、Cu、Ni、Cr、Zn和Mn的总量,根据BCR连续提取程序分析沉积物样品中重金属的地球化学赋存形态,采用内梅罗指数法和地积累指数法评价了沉积物重金属污染特征,根据重金属的富集程度探讨了重金属污染来源,采用淡水生态系统沉积物质量基准(SQGs,TEL/PEL)和毒性单位评价了花垣河和峒河沉积物中重金属元素的生态毒性风险。结果表明,花垣河和峒河绝大多数位点的表层沉积物中Cd、Pb、Cu、Ni、Cr、Zn和Mn的总量高于参照点,形成严重的复合污染,花垣河沉积物中重金属的污染水平明显高于峒河,但沿程变化规律不明显,而峒河沉积物中重金属的沿程变化较有规律,即上游含量低,中下游含量较高。两条河流表层沉积物中富集程度居前列的均为Cd、Pb、Zn和Mn。花垣河和峒河沉积物重金属污染主要来源于矿业生产所产生废渣和废水的点排放。在花垣河和峒河的大多数位点,Cd、Pb和Mn的形态具有共同特征,其生物可利用态均较大程度地超过生物不可利用态,而且Mn和Cd的生物可直接利用态所占比例远高于其它重金属,而Cu和Cr的生物可直接利用态所占比例很低。花垣河沉积物中Cd、Pb和Zn在所有位点极大地超过PEL,在峒河中下游,Cd、Pb、Ni和Zn超过PEL,具有较大的潜在生物毒性。除上游S1位点外,花垣河的其余各位点都具有明显的急性毒性,峒河中下游各位点具有明显的急性毒性,这些河段需要重点治理。     

Integrated assessment of the heavy metal pollution status and potential ecological risk in the Lagos Lagoon,South West,Nigeria

This study was carried out to assess the heavy metal pollution status and potential ecological risk in the Lagos lagoon, Nigeria. The concentrations of twelve heavy metals commonly associated with environmental pollution were determined in the sediments of the lagoon by Atomic Absorption Spectrophotometry (AAS) and the cold vapor method was employed for Mercury (Hg). Nonempirical risk indices and empirical Sediment Quality Guidelines (SQGs) were used to assess the ecological risk associated with heavy metal in the sediments. The nonempirical risk indices showed that Hg, Arsenic (As), and Cadmium (Cd) are the major contributors to the ecological risk associated with heavy metal pollution in the ecosystem. Comparison of heavy metal concentrations to the Screening Quick Reference Table (SQuiRT) showed that mean concentration of Cd (5.22 and 4.88 mg kg^?1 in dry and rainy seasons, respectively) exceeds the effect range low (ERL) value (1.20 mg kg^?1) in effect to biota. Industries sited around the lagoon have effluent output points in the lagoon serving as a major source of heavy metals coupled with indirect discharges from other sources. Heavy metals are nonbiodegradable, toxic and have the potential to alter ecosystem health, thus pollution sources should be effectively monitored and contained.     

Application of Pb isotopic mapping to environment evaluation in China

Abstract

Quantitative criterion of Pb pollution sources and levels from Pb isotopic tracing must depend on the establishment of a natural Pb isotopic background. Lead isotopic mapping for Continental China and the neighborhood sea areas is being completed. Seven major isotopic provinces in the continent (Cathaysia, Indochina, Yangtze, North China, Northeast China, North Xinjiang and Tibet) have been identified. The Pb isotopic mapping in the South China Sea shows two depositing areas; sediments from the Red River is related to the Indochina geochemical province; sediments from the Pearl River system is related to the Cathaysia geochemical province. Pb isotopic evidence indicates that the major Pb pollution sources of aerosols in the Eastern China are from local Pb–Zn–Cu resource consumption in various industries. The Pb pollution from aerosols, eolian dusts, and acid leachable components in soils and sediments around the South China Sea shows two major sources: application of lead metal in various industries and automobile exhausts.     

Distribution and risk assessment of heavy metals in river surface sediments of middle reach of Xijiang River basin,China

Xijiang River is the main surface water source in Guangxi province, South China. This study was carried out to investigate the distribution and potential ecological risks of seven heavy metals (Cu, Pb, Zn, As, Cd, Ni, and Cr) in surface sediments in Xijiang River basin. The results illustrated that the average concentrations of Zn, Pb, Cd, Cu, As, Ni, and Cr were 483.9, 207.5, 13.35, 23.50, 312.1, 28.75, and 50.62 mg/kg, respectively. Among them, Zn, Pb, Cd, and As were the major heave metals with concentration exceeding Class 3 threshold value of Chinese national standard. The result also showed samples with high ecological risk were mainly located in the upstream of Xijiang River basin as Diaojiang River, Hongshui River, Jincheng River, and Dahuan River. Based on the pollution risk assessment, the area manifested composite pollution of heavy metals in the sediments, signifying As, Pb, and Cd as the dominant heavy metals, and there were high ecological risk in sediments for these metals. According to correlation matrix and factor analysis (FA), the seven heavy metals were divided into three types/classes, Cd, as and Zn attributed by anthropogenic sources, natural sources corresponds for Ni and Cr while both natural and anthropogenic sources were attributed to Cu.     

Environmental risk assessment of manganese and its associated heavy metals in a stream impacted by manganese mining in South China

In South China, high manganese content in the drinking water source influenced by upstream manganese mine drainage has become a major concern. To investigate the extent of metal pollution and environmental risk in upstream sediments and native aquatic macrophytes, a study was conducted on a manganese mining-impacted river named the Heishui River. The results indicated that streambed sediments collected were polluted by Mn and other metals with the highest contents of Mn 43349.4 mg kg^?1, Pb 128.6 mg kg^?1, Zn 502.9 mg kg^?1, and Cu 107.2 mg kg^?1. The level of Mn in all sediments was higher than the consensus-based Probable Effect Concentration, indicating that adverse effects on sediment-dwelling organisms were likely to occur frequently. Among the studied metals, Mn had the highest bioavailability and ecological risk, followed by Zn. Native aquatic macrophytes accumulate large amounts of the studied metals. A significantly positive correlation was found between exchangeable fractions of the studied metals in sediments and in aquatic macrophytes. The risk assessment code showed the following risk levels of metals in sediments in descending order: Mn > Zn > Cu > Pb. In conclusion, the river impacted by manganese mining drainage poses a high risk to both the local ecosystem and downstream drinking water.     

A comparison of NEWS and SPARROW models to understand sources of nitrogen delivered to US coastal areas

The relative contributions of different anthropogenic and natural sources of in-stream nitrogen (N) cannot be directly measured at whole-watershed scales. Hence, source attribution estimates beyond the scale of small catchments must rely on models. Although such estimates have been accomplished using individual models, there has not yet been a comparison of N source attribution predictions at large spatial scales. We compared results from two models applied to the continental US: Nutrient Export from WaterSheds (NEWS) and SPAtially Referenced Regressions On Watersheds (SPARROW). NEWS and SPARROW predictions for total N delivery to the US coastal zone were 373 and 429 kg N km^?2 year^?1, respectively, for the contemporary period. Despite differences in how inputs were represented and defined by the models, NEWS and SPARROW both identified the same single-largest N sources for 67 % of the surface area that drains to the US coastal zone. When only anthropogenic sources were considered, agreement increased to 78 % of surface area. Fertilizer and crop N-fixation were dominant in the Mississippi River Basin, where the bulk of agricultural lands are located. Sewage and population-related sources were most important in urban areas and natural N (primarily N-fixation on non-agricultural land) was most important in the Pacific Northwest. Attribution to fertilizer plus crop N-fixation, atmospheric deposition, and sewage and population-related sources was generally greater by SPARROW than NEWS, and the reverse was true for manure and natural sources. Nonetheless, both models agreed in attributing 62–81 % of N delivered to the coastal zone in the continental US to human activities.     

Sediment Contamination along Desert Wash Systems from Historic Mining Sites in a Hyperarid Region of Southern Nevada,USA

Abandoned mining sites in hyperarid environments are generally assumed to present an insignificant risk to water availability. This study investigated the impact abandoned mine sites in Southern Nevada can have on the wider environment. Southern Nevada is characterized with little precipitation and prolonged droughts. Precipitation in Southern Nevada is often in the form of short and intense events with the potential to mobilize and transport contaminated sediments down gradient. This work evaluated the movement of trace elements (Ag, As, Ba, Cd, Cr, Hg, Pb, and Se) and cyanide in surface sediments of three desert washes near the historic mining town of Nelson, a hyperarid region of Southern Nevada. Results indicate trace elements have been mobilized and transported down gradient from sources to areas not directly impacted by mining. Contaminants used in mining operations (Hg and CN^?) as well as those of geogenic nature migrated as far as 6000 m, providing evidence of their transport in hyperarid environments, contrary to the generally held belief. Although contaminants in this study are below levels that are environmentally significant, the findings show that transport is possible. This study demonstrates that large amounts of contaminant-laden sediments might be a significant threat in hyperarid environment and to areas down gradient from source materials.     

Metal Pollution Assessment in Sediments of the Southeastern Black Sea Coast of Turkey

The main objective of this investigation is to determine the concentration and accumulation of heavy metals in the coastal sediments of the Southeastern Black Sea of Turkey. The selected sampling area has mainly been affected by anthropogenic activities, such as agricultural, untreated domestic and treated industrial wastewater, and mining. Metal enrichment factor (EF), geo-accumulation index (I_geo), and metal pollution index (MPI) have been calculated and relative contamination levels evaluated at all stations. In this study, the maximum EF values calculated for nickel (Ni), cobalt (Co), cadmium (Cd), lead (Pb), chromium (Cr), arsenic (As), zinc (Zn), and copper (Cu) were 1.4, 3.1, 5.2, 7.8, 7.8, 20, 26, and 42, respectively. Metal pollution has decreased in recent years, but the enrichment of heavy metals has been observed to be relatively high, especially in the uppermost 3-6 cm of the core sample from the Sürmene sampling station, which has been polluted by mining activities. In addition, factor analysis revealed that the coastal sediments from the Eastern Black Sea were influenced by several sources, namely lithogenic and anthropogenic activities (mining, wastewater discharging, agriculture).     

Heavy metal contamination of sediments in the Upper Connecting Channels of the Great Lakes

In 1985, sampling at 250 stations throughout the St. Marys, St. Clair, and Detroit rivers and Lake St. Clair — the connecting channels of the upper Great Lakes — revealed widespread metal contamination of the sediments. Concentrations of cadmium, chromium, copper, lead, mercury, nickel, and zinc each exceeded U.S. Environmental Protection Agency sediment pollution guidelines at one or more stations throughout the study area. Sediments were polluted more frequently by copper, nickel, zinc, and lead than by cadmium, chromium, or mercury. Sediments with the highest concentrations of metals were found (in descending order) in the Detroit River, the St. Marys River, the St. Clair River, and Lake St. Clair. Although metal contamination of sediments was most common and sediment concentrations of metals were generally highest near industrial areas, substantial contamination of sediments by metals was present in sediment deposition areas up to 60 km from any known source of pollution.Contribution 735 of the National Fisheries Research Center-Great Lakes, U.S. Fish and Wildlife Service, 1451 Green Road, Ann Arbor, MI 48105.     

The National Distribution Pattern and Factors Affecting Heavy Metals in Sediments of Water Systems in China

Heavy metal discharge has become one of the most serious environmental problems due to extensive industrialization. Sixty eight sediment samples from four wetlands were collected to analyze the regional factors affecting metal deposition. Meanwhile, a national sediment data collection based on relevant publications was developed covering the period from 2000 to 2016 to study the metal distribution in China. Principal metals assessed in this study are Cr, Cd, Cu, Pb, Zn, As, and Ni. At regional scale, the accumulation of Pb and Cd is significantly higher in surface than in subsurface sediments. At the national scale, heavy metals tend to increase with the increase in precipitation from 600 to 1500 mm. Further, metal deposition in the main river basins in China shows an increase trend from northern to southern China, and follows the order of: Pearl River > Yangste River > Yellow River > Hai River and Liao River. Cluster analyses show that these river basins contribute a large proportion of heavy metals to coastal metal deposition, which follows the order of: South Sea > East Sea > Bohai Sea > Yellow Sea. In general, metal deposition in sediments of water systems increases from northern to southern China irrespective of in-land area or coastal seas.     

Application of microbial source tracking methods in a Gulf of Mexico field setting

Aims:  Microbial water quality and possible human sources of faecal pollution were assessed in a Florida estuary that serves shellfishing and recreational activities.
Methods and Results:  Indicator organisms (IO), including faecal coliforms, Escherichia coli and enterococci, were quantified from marine and river waters, sediments and oysters. Florida recreational water standards were infrequently exceeded (6–10% of samples); however, shellfishing standards were more frequently exceeded (28%). IO concentrations in oysters and overlaying waters were significantly correlated, but oyster and sediment IO concentrations were uncorrelated. The human-associated esp gene of Enterococcus faecium was detected in marine and fresh waters at sites with suspected human sewage contamination. Lagrangian drifters, used to determine the pathways of bacterial transport and deposition, suggested that sediment deposition from the Ochlockonee River contributes to frequent detection of esp at a Gulf of Mexico beach.
Conclusions:  These data indicate that human faecal pollution affects water quality in Wakulla County and that local topography and hydrology play a role in bacterial transport and deposition.
Significance and Impact of the Study:  A combination of IO enumeration, microbial source tracking methods and regional hydrological study can reliably inform regulatory agencies of IO sources, improving risk assessment and pollution mitigation in impaired waters.     

Proton-induced X-ray emission (PIXE) analysis of trace elements of total atmospheric deposit (TAD) around a smelting industry: Aerial pollution monitor

This study monitored total atmospheric deposit (TAD) around a smelting plant in Ile-Ife, Nigeria to assess the contributions of the industry to Nigeria's air-shed pollution. Samples were collected for 12 consecutive months using an Australian model gauge, harvested after 30 d of exposure, filtered and dried to constant weights using oven. Monthly deposition rates were determined and elemental characterizations of the TAD samples were done using proton-induced X-ray emission technique. Results revealed that the monthly deposition rates ranged from 0.69 to 4.62 gm^?3 and was more pronounced in Harmattan. Twenty-three elements were detected; their total elemental concentrations ranged from 1.23 to 13.63 mg m^?3 with Fe having the highest concentrations, while Na has the least. Pearson correlation indicated that some elements have common sources and/or similar chemical properties; enrichment factor showed that Fe, Zn, Pb, Mn were extremely enriched in the study area, modified degree of contamination (3.75) and pollution load intensity (1.21) showed that the neighborhoods could be exposed to high air pollution related impacts. Positive matrix factorization model revealed three distinct sources: Smelting emission (63%), biomass burning (17%), and suspended input material emissions (21%). The study concluded that the smelting activities posed a great hazard to receptors around the smelting industry.     

Lo Sviluppo Del Sistema Conduttore Nelle Plantule Di “Opuntia Vulgaris„ Mill.

Aquatic mosses and sediments were monitored along Topolnitsa River Basin (Bulgaria), copper-producing and mining region. Six mosses were applied as biomonitors: Bryum turbinatum, Fontinalis antipyretica, Leptodictyum riparium, Platyhypnidium riparioides, Rhizomnium punctatum and Sciuro-hypnum plumosum. Background levels were determined for both plants and fine fraction of sediments collected from an unpolluted site. Contamination factors (CFs) and metal pollution index at each site were presented. The highest sediment enrichment with toxic elements was found in Zlatishka River. Strong increase above background levels showed all 13 heavy metals and toxic elements in biomonitors from stations at Zlatishka and Pirdopska rivers. The two moss species adopted as biomonitors for the first time – Bryum turbinatum and Rhizomnium punctatum – showed high CFs for several heavy metals and contributed to chemical pollution pattern assessment. The parallel use of mosses and sediments in the monitoring study, as well as the applied statistical tools, led to the conclusion that mosses as higher plants revealed pollution patterns not detected by sediments. Results also showed that in a seriously contaminated aquatic environment, which requires rapid assessment, different moss species can be applied for water-monitoring purposes to present preliminary picture of pollution patterns and to direct further studies.     

南四湖典型入湖河流沉积物重金属污染特征与风险评价研究

以南四湖两条典型入湖河流为研究对象,分别对湖东的泗河及湖西的东鱼河沉积物中9种重金属(Cr、Ni、Zn、Cu、Pb、Hg、Cd、As、Mn)含量进行分析,最后采用多种方法解析重金属的来源并对其污染特征和生态风险进行评价。结果表明,两条河流沉积物中重金属均存在一定程度的富集,尤其是Hg、Zn、Cd富集最严重。泗河沉积物中大部分重金属在中游兖州段含量升高,尤其是Hg、Cd含量分别是山东省水系背景值的3.1、3.7倍,分析表明重金属主要来源为周边区域煤矿及其伴生产业产生的“工业三废”,同时说明了重金属高值区与煤矿分布密切相关。东鱼河沉积物中Hg、Cd含量在中游较高,其余重金属含量在上、下游较高,分析结果表明中游Hg、Cd含量较高主要与当地农业活动中农药及化肥的施用有关,上、下游重金属含量较高原因为引黄河水或南四湖水灌溉。     

Assessment of Trace Metals Contamination in the Suspended Matter and Sediments of a Semi-enclosed Mediterranean Gulf

This study investigates the distribution of heavy metals in the suspended particulate matter and the sediments of Kavala Gulf, located in Northern Greece. Particulate trace metals were determined in accordance to water column physicochemical parameters. Metals in sediments were related to the textural characteristics, the organic matter, and carbonate contents of surficial sediments. Results illustrated that the diverse human coastal activities influence the distribution of particulate and sediment metal concentrations, since lower trace metal levels were detected along the western (tourism) and eastern (aquaculture) coast, while increased values were observed at the central (urban and industrial). Overall, particulate metals show moderately low levels compared to other similar sites, with the exception of Ni and Cd depicting local peaks along the industrial coastal zone. Significantly increased levels for particulate lead (123.1 μg/g) and chromium (113.9 μg/g) were detected at the sites near the industrial zone. Direct effluents from a fertilizer plant appeared responsible for the increased Pb, Cr, and Cd levels, while the increased values in Zn, Cu, and Hg appear related to phosphogypsum leaching. Sediment contamination assessment indicated that the Kavala Gulf is characterized by clean to marginally polluted sediments, with moderately severe pollution levels along the urban coastline.     

Anthropogenic Metal Content and Natural Background of Overbank Sediments from the Mining District of Guanajuato,Mexico

In many mining districts, metal pollutants from mine tailings have historically been dumped into local streams. The purpose of this study was to determine the concentrations of Pb, Cu, Zn, Mo, Sb, Cs, Cr, Sc, Co, Ni, and Li in eight overbank-sediment profiles from the Guanajuato River, in the Guanajuato mining district and to establish geochemical background values using direct and indirect methods. The background levels calculated using the direct method in pristine overbank deposits were similar to or slightly higher than the upper crustal values for Sc, Cr, Co, Ni, Zn, and Mo (17.3, 108.7, 18.7, 44.4, 97.2, and 1.1 mg/kg, respectively). In contrast, levels of Cu, Cs, and Pb were up to two times higher than crustal values (93.1, 11.2, and 37.5 mg/kg, respectively), and the median concentration of Sb was 8.2 mg/kg, up to 20 times the crustal level. These natural anomalies can be explained by the presence of mineral deposits in the Guanajuato mining district. Ni and Cr were provided by the ultramafic rocks of the Sierra de Guanajuato. The geochemical backgrounds established with the indirect method of Sc, Cr, Co, Ni, and Mo were lower than those found in the natural background. Moreover, the geochemical backgrounds established with the indirect method of Cu, Zn, Sb, Cs, and Pb were higher than those found in the geochemical background established with the direct method. Contamination levels calculated by the geoaccumulation index (Igeo) indicated moderate to strong contamination for Cu, Zn, Sb, and Pb in more than half of the samples. This contamination may be attributable to historical discharges of mine tailings in the Guanajuato River and the use of Cu during the metallurgical process of amalgamation. Our results provide evidence that anthropogenic metals stored in the fluvial plain of the Guanajuato River represent a major potential source of pollutants to surface and groundwaters downstream from the study area in the Lerma-Santiago basin.     

Distribution characteristics,sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in sediments from Haizhou Bay,China

Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) were analyzed by gas chromatography–mass spectrometry. Twenty samples were collected from the surface sediments of Haizhou Bay in this survey. This research aimed to identify the PAHs' contamination level, composition pattern, pollution sources, and assess the ecological risk of PAHs. The results showed that the sum of PAH concentrations ranged from 116.6 ng g^?1 to 2414.9 ng g^?1 (mean: 662.42 ng g^?1), which is higher than the reported values for different wetlands worldwide. Three- and four-ring PAHs (accounts for more than 70% of the total PAH content) were predominant in the wetland sediment. The PAHs source distribution in the surface sediments were determined using diagnostic ratio and PCA/MLR. Consequently, multiple PAHs sources were found. Of the total PAH, 79.25% was derived from vehicular emission, 20.75% from coal combustion. The effect range low/effect range median (ERL/ERM) values indicated a low toxicity risk level. However, the fluoranthene concentrations exceeded the ERL level, and even the ERM level, in some stations. The mean effects range–median quotient (M-ERM-Q) suggests a low ecological risk for the PAHs in the sediments.