Heavy metal distribution in the surface layer of bottom sediments of the Kara Sea

This paper addresses the distribution of heavy metals (Co, Ni, Cu, Zn, Cd, Sn, Sb, Pb, and Bi) as well as Si, Al, Fe, and Mn in the surface (0–2 cm) layer of bottom sediments of the Kara Sea. The contents of these elements are determined in each of the previously distinguished facies-genetic types of terrigenous sediments: fluvial, glacial, estuarine, shallow water–marine, “background” marine, and relict sediments. It is shown that these types reflect the modern conditions of accumulation of river discharge material, which forms fans of two greatest Siberian rivers, Ob and Yenisei. The main stages are distinguished in heavy metal accumulation. The first stage is related to the avalanche sedimentation of terrigenous sediments in the estuary and characterized by the elevated contents of Co, Ni, Cu, Zn, Cd, Sb, and Bi. The second stage reflects the mechanical differentiation of sedimentary material by waves and bottom currents in a shallow-water sea part adjacent to the estuarine zone, with accumulation of Pb- and Sn-bearing “heavy” ore minerals. The deepwater background terrigenous–marine sediments accumulate mainly Ni, Zn, and Cd, as well as Mn. The relict sediments differ in the high contents of Si, Mn, and Sn.     

南极普里兹湾表层沉积物微量元素分布特征及其物源指示意义

利用电感耦合等离子体质谱仪测定了中国南极科考21~27航次期间获取的普里兹湾表层沉积物中Cu、Pb、Zn、Cd、Cr、Co、Al、Fe、Mn的含量,分析了普里兹湾微量元素的分布特征,结合沉积物粒度分布、生物硅含量,并利用富集系数和主成分分析的方法,探讨了微量元素的物源指示意义。研究结果表明:普里兹湾沉积物中的微量元素含量与南大洋其他海域具有很好的可比性。Cu、Zn、Cr、Co、Fe、Mn含量在陆坡深海区明显高于冰架边缘区和陆架区;Al、Pb含量在冰架边缘区较高;而Cd含量在陆架区相对较高。人类活动对普里兹湾沉积物中的微量元素没有明显的影响,南极大陆岩石风化产物和海洋生物源性沉降是其主要来源。冰架边缘区及陆架破折处P2-9站位的微量元素主要为岩源性输入。陆架区、陆坡深海区的微量元素Cu、Zn、Cr、Co、Fe、Mn明显受到生源性物质输入的影响。而普里兹湾沉积物中Cd则主要来源于硅藻的吸收利用及硅质软泥的富集。     

New constraints on elemental and Pb and Nd isotope compositions of South American and Southern African aerosol sources to the South Atlantic Ocean

Improving the geochemical database available for characterising potential natural and anthropogenic aerosol sources from South America and Southern Africa is a critical precondition for studies aimed at understanding trace metal controls on the marine biogeochemical cycles of the South Atlantic Ocean. We here present new elemental and isotopic data for a wide range of sample types from South America and Southern Africa that are potentially important aerosol sources. This includes road dust from Buenos Aires and lichen samples from Johannesburg, soil dust from Patagonia, volcanic ash from the Andean volcanic belt, and aerosol samples from São Paulo. All samples were investigated for major (Al, Ca, Fe, Mg, Na, K, Mn) and trace element (Cd, Co, Cr, Cu, Ni, Pb, REE, Sc, Th, Y, V, Zn) concentrations and Nd and Pb isotopic compositions. We show that diagrams of ²⁰⁸Pb/²⁰⁷Pb vs. ε_Nd, ²⁰⁸Pb/²⁰⁷Pb vs. Pb/Al, 1/[Pb], Zn/Al, Cd/Al, Cu/Al, and ε_Nd vs. Pb/Al, and 1/[Nd] are best suited to separate South American and South African source regions as well as natural and anthropogenic sources. A subset of samples from Patagonia and the Andes was additionally subjected to separation of a fine (<5?μm) fraction and compared to the composition of the bulk sample. We show that differences in the geochemical signature of bulk samples between individual regions and source types are significantly larger than between grain sizes. Jointly, these findings present an important step forward towards a quantitative assessment of aeolian trace metal inputs to the South Atlantic Ocean.     

石家庄市大气降尘重金属元素来源分析

本文对石家庄市大气降尘重金属含量水平进行了研究,从2007年11月起连续收集一年的大气降尘样品,分析了As、Cd、Hg、Pb、Cr、Cu、Zn、Ni、Mo、Mn、Al2O3、K2O等12项。结果表明,与土壤背景值相比,石家庄市大气降尘中除Al2O3外的重金属含量总体明显升高。采用相关分析和主成分分析,对降尘重金属元素来源进行解析,认为有3种主要来源:一是Pb、Cr、As、Hg、Mo、Cd、Mn与燃煤活动、道路交通有关;二是Ni、Cu、Zn除与燃煤活动有关外,还与工矿企业废气排放有关;三是Al2O3主要与土壤颗粒物有关(自然来源)。以Al作为参考元素计算重金属的富集因子表明,受工业活动影响的Cd、Hg、Zn具有较大的富集因子,大气降尘中的重金属含量高值区与工业区域的分布相吻合。     

南京市大气降尘重金属含量特征及来源研究

文中对南京市大气降尘重金属含量水平进行了研究,从2006年12月起连续收集一年的大气降尘样品,分析了As、Cd、Cr、Cu、Hg、Mn、Mo、Ni、Pb、Se、Zn等11个元素。结果表明,与土壤背景值相比,南京市大气降尘中除Cr、Fe、Mn外的重金属含量总体明显升高。采用相关分析和主成分分析,对降尘重金属元素来源进行解析,认为有三种主要来源:一是As、Cu、Hg、Pb、Se与燃煤活动、汽车尾气排放有关。二是Cd、Ni、Zn、Mo可能与化学工业有关,但Mo还受工业活动、土壤颗粒物的影响。分析还表明,在化工业园附近的样点,这些元素含量普遍较高。三是Mn、Cr主要与土壤颗粒物有关(自然来源)。以Fe作为参考元素计算重金属的富集因子表明,自然来源的Cr、Mn具有较小的富集因子,而受工业活动影响的Cd、Pb、Se、Zn具有较大的富集因子。     

Distribution and immobilization of heavy metals in Pliocene aquifer sediments in Wadi El Natrun depression, Western Desert

The Pliocene aquifer receives inflow of Miocene and Pleistocene aquifer waters in Wadi El Natrun depression. The aquifer also receives inflow from the agricultural activity and septic tanks. Nine sediment samples were collected from the Pliocene aquifer in Wadi E1 Natrun. Heavy metal (Cu, Sr, Zn, Mn, Fe, Al, Ba, Cr, Ni, V, Cd, Co, Mo, and Pb) concentrations of Pliocene aquifer sediments were investigated in bulk, sand, and mud fractions. The determination of extractable trace metals (Cu, Zn, Fe, Mn, and Pb) in Pliocene aquifer sediments using sequential extraction procedure (four steps) has been performed in order to study environmental pathways (e.g., mobility of metals, bounding states). These employ a series of successively stronger chemical leaching reagents which nominally target the different compositional fractions. By analyzing the liquid leachates and the residual solid components, it is possible to determine not only the type and concentration of metals retained in each phase but also their potential ecological significance. Cu, Sr, Zn, Mn, Fe, and Al concentrations are higher in finer sediments than in coarser sediments, while Ba, Cr, Ni, V, Cd, Co, Mo, and Pb are enriched in the coarser fraction. The differences in relative concentrations are attributed to intense anthropogenic inputs from different sources. Heavy metal concentrations are higher than global average concentrations in sandstone, USEPA guidelines, and other local and international aquifer sediments. The order of trace elements in the bulk Pliocene aquifer sediments, from high to low concentrations, is Fe?>?Al?>?Mn?>?Cr?>?Zn?>?Cu?>?Ni?>?V?>?Sr?>?Ba?>?Pb?>?Mo?>?Cd?>?Co. The Pliocene aquifer sediments are highly contaminated for most toxic metals, except Pb and Co which have moderate contamination. The active soluble (F0) and exchangeable (F1) phases are represented by high concentrations of Cu, Zn, Fe, and Mn and relatively higher concentrations of Pb and Cd. This may be due to the increase of silt and clay fractions (mud) in sediments, which act as an adsorbent, retaining metals through ion exchange and other processes. The order of mobility of heavy metals in this phase is found to be Pb?>?Cd?>?Zn?>?Cu?>?Fe?>?Mn. The values of the active phase of most heavy metals are relatively high, indicating that Pliocene sediments are potentially a major sink for heavy metals characterized by high mobility and bioavailability. Fe–Mn oxyhydroxide phase is the most important fraction among labile fractions and represents 22% for Cd, 20% for Fe, 11% for Zn, 8% for Cu, 5% for Pb, and 3% for Mn. The organic matter-bound fraction contains 80% of Mn, 72% of Cu, 68% of Zn, 60% of Fe, 35% of Pb, and 30% of Cd (as mean). Summarizing the sequential extraction, a very good immobilization of the heavy metals by the organic matter-bound fraction is followed by the carbonate-exchangeable-bound fraction. The mobility of the Cd metal in the active and Fe–Mn oxyhydroxide phases is the highest, while the Mn metal had the lowest mobility.     

攀枝花市大气降尘的地球化学特征

运用ICP-MS和ICP-OES分析了攀枝花市不同时段不同地点大气降尘中重金属元素含量,并对大气降尘中重金属的地球化学特征进行了分析,得出以下结论:①攀枝花市大气尘中As、Co、Mn、Pb、Ti、V的含量,与四川省其他城市相比均偏高,Zn的含量相对较低;②Cd、Mn、Pb主要分布在冶炼区和石灰石矿区,Co、Cu、Ti主要分布在石灰石矿区,Cr和V主要分布在冶炼区,As在仁和河富集较为富集,Zn集中在排土场附近,Fe集中在冶炼区和煤矿区;③除Pb外,其余十种元素旱季含量基本都高于雨季,而雨季Pb的含量却明显高于旱季。通过主成份分析,得出了在攀枝花市大气降尘中,重金属元素的来源主要为矿山污染和开采过程中产生的废水、废气。     

Speciation of some heavy metals in bottom sediments of the Ob and Yenisei estuarine zones

The speciation of Fe, Mn, Zn, Cu, Co, Ni, Cr, Pb, and Cd was studied in 52 samples of bottom sediments collected during Cruise 49 of the R/V Dmitrii Mendeleev in estuaries of the Ob and Yenisei rivers in the southwestern Kara Sea. Immediately after sampling, the samples were subjected to on-board consecutive extraction to separate metal species according to their modes of occurrence in the sediments: (1) adsorbed, (2) amorphous Fe-Mn hydroxides and related metals, (3) organic + sulfide, and (4) residual, or lithogenic. The atomic absorption spectroscopy of the extracts was carried out at a stationary laboratory. The distribution of Fe, Zn, Cu, Co, Ni, Cr, Pb, and Cd species is characterized by the predominance of lithogenic or geochemically inert modes (70–95% of the bulk content), in which the metals are bound in terrigenous and clastic mineral particles and organic detritus. About half of the total Mn amount and 15–30% Zn and Cu is contained in geochemically mobile modes. The spatiotemporal variations in the proportions of metal species in the surface layer of sediments along the nearly meridional sections and through the vertical sections of bottom sediments cores testify that Mn and, to a lesser extent, Cu are the most sensitive to changes in the sedimentation environment. The role of their geochemically mobile species notably increases under reducing conditions.     

Assessment of geochemical and sedimentological characteristics of atmospheric dust in Shiraz,southwest Iran

Geogenic dust is commonly believed to be one of the most important environmental problems in the Middle East.The present study investigated the geochemical characteristics of atmospheric dust particles in Shiraz City(south of Iran).Atmospheric dust samples were collected through a dry collector method by using glass trays at 10 location sites in May 2018.Elemental composition was analysed through inductively coupled plasma optical emission spectrometry.Meteorological data showed that the dustiest days were usually in spring and summer,particularly in April.X-ray diffraction analysis of atmospheric dust samples indicated that the mineralogical composition of atmospheric dust was calcite+dolomite(24%)palygorskite(18%)quartz(14%)muscovite(13%)albite(11%)kaolinite(7%)gypsum(7%)zircon=anatase(3%).The high occurrence of palygorskite(16%-23%) could serve as a tracer of the source areas of dust storms from the desert of Iraq and Saudi Arabia to the South of Iran.Scanning electron microscopy indicated that the sizes of the collected dust varied from 50 μm to0.8 μm,but 10 μm was the predominant size.The atmospheric dust collected had prismatic trigonal-rhombohedral crystals and semi-rounded irregular shapes.Moreover,diatoms were detected in several samples,suggesting that emissions from dry-bed lakes,such as Hoor Al-Azim Wetland(located in the southwest of Iran),also contributed to the dust load.Backward trajectory simulations were performed at the date of sampling by using the NOAA HYSPLIT model.Results showed that the sources of atmospheric dust in the study area were the eastern area of Iraq,eastern desert of Saudi Arabia,Kuwait and Khuzestan Province.The Ca/Al ratio of the collected samples(1.14) was different from the upper continental crust(UCC) value(UCC=0.37),whereas Mg/A1(0.29),K/Al(0.22) and Ti/Al(0.07) ratios were close to the UCC value(0.04).This condition favours desert calcisols as the main mineral dust sources.Analysis of the crustal enrichment factor(EF_(crustal)) revealed geogenic sources for V,Mo,Pb,Sr,Cu and Zn(2),whereas anthropogenic sources affected As,Cd,Cr and Ni.     

Heavy metals in mangrove sediments of the central Arabian Gulf shoreline,Saudi Arabia

To assess heavy metals in mangrove swamps of Sehat and Tarut coastal areas along the Arabian Gulf, 18 sediment samples were collected for Al, V, Cr, Mn, Cu, Zn, Cd, Pb, Hg, Sr, As, Fe, Co, and Ni analysis. The results indicated that the distribution of some metals was largely controlled by anthropogenic inputs, while others were of terrigenous origin and most strongly associated with distribution of aluminum and total organic carbon in sediments. Mangrove sediments were extremely severe enriched with Sr (EF?=?67.59) and very severe enriched with V, Hg, Cd, Cu, As (EF?=?44.28, 37.45, 35.77, 25.97, and 11.53, respectively). Average values of Sr, V, Hg, Cd, Cu, Ni, As, and Cr were mostly higher than the ones recorded from the Mediterranean Sea, the Red Sea, the Gulf of Aqaba, the Caspian Sea, the Arabian and Oman gulfs, coast of Tanzania, sediment quality guidelines, and the background shale and the earth crust. Landfilling due to coastal infrastructure development around mangrove forests, oil spills and petrochemical and desalination effluents from Al-Jubail industrial city to the north were the anthropogenic activities that further enhanced heavy metals in the studied mangrove sediments.     

Distribution and partitioning of major and trace elements in pyrite-bearing sediments of a Mediterranean coastal lagoon

The formation of iron sulphide minerals exerts significant control on the behaviour of trace elements in sediments. In this study, three short sediment cores, retrieved from the remote Antinioti lagoon (N. Kerkyra Island, NW Greece), are investigated concerning the solid phase composition, distribution, and partitioning of major (Al, Fe) and trace elements (Cd, Cu, Mn, Pb, and Zn). According to ²¹⁰Pb, the sediments sampled correspond to depositions of the last 120 years. The high amounts of organic carbon (4.1–27.5%) result in the formation of Fe sulphides, predominantly pyrite, already at the surface sediment layers. Pyrite morphologies include monocrystals, polyframboids, and complex FeS–FeS₂ aggregates. According to synchrotron-generated micro X-ray fluorescence and X-ray absorption near-edge structure spectra, authigenically formed, Mn-containing, Fe(III) oxyhydroxides (goethite type) co-exist with pyrite in the sediments studied. Microscopic techniques evidence the formation of galena, sphalerite and CuS, whereas sequential extractions show that carbonates are important hosts for Mn, Cd, and Zn. However, significant percentages of non-lattice held elements are bound to Fe/Mn oxyhydroxides that resist reductive dissolution (on average 60% of Pb, 46% of Cd, 43% of Zn and 9% of Cu). The partitioning pattern changes drastically in the deeper part of the core that is influenced by freshwater inputs. In these sediments, the post-depositional pyritization mechanism, illustrated by overgrowths of Fe monosulphides on pre-existing pyrite grains, results in relatively high degree of pyritization that reaches 49% for Cd, 66% for Cu, 32% for Zn and 7% for Pb.     

Endmember analysis of heavy-metal pollution in surficial sediments from the Gulf of Gdansk and the southern Baltic Sea off Poland

Thirty one bulk (<2 mm) samples of surficial sediments from the Gulf of Gdansk and the Southern Baltic Sea off Poland were analyzed for 20 elements and the resulting compositional dataset was subjected to endmember analysis. The compositions of 4 endmember estimates were constructed and the abundances of these endmembers were calculated for each sample. Copper, Zn and Ag appear on one endmember and Cd and Pb on another. This suggests that Cu, Zn and Ag are introduced into the Gulf of Gdansk principally from the Vistula River whereas Cd and Pb are introduced as a result of atmospheric and riverine transport of these elements. The dual source of Cd and Pb into the Gulf of Gdansk may explain the complex interelement relationships displayoed by these elements in the sediments from this region.     

Impact of sewage and mining activities on distribution of heavy metals in the water-soil-vegetation system

Several samples of groundwater and soils and plants have been collected from Sohar (Batina region, NE Oman), which is affected by various activities such as mining, agriculture, and sewage. To characterize quality of groundwater, As and Cu concentrations have been investigated in waters collected from different wells. Comparison of data with local and international standard values revealed that groundwater in Sohar region is characterized by lower concentrations in Cu and As compared with standards. In soils collected from the same area, concentrations of heavy metals have been measured in different fractions in order to investigate the mobility of such elements and risk of vulnerability in this area. A sequential extraction procedure has been applied to surface sediments to determine the partitioning of Zn, Cu, Co, Mn, Fe, Pb, Cr, Cd and Ni among (1) exchangeable and acid-soluble phases, (2) Fe–Mn oxides, (3) organic matter and sulphides and (4) resistant phases. The results showed that the mobile fraction in the sewage area accounts only for 10 % of the total concentration in sediments while in the Cu mining area, the contribution of the mobile fraction may exceed 10 %, especially for Pb, Mn, Cd, Cu and Co. Investigation of concentrations in As and Cu in plants collected from mining and sewage areas revealed an important accumulation of these elements in leaves and may explain enrichment of As in shallow groundwater relative to deep groundwater. This investigation also showed that Cu is more available in sewage area than in mining zone, as opposed to As.     

Geochemical characteristics of elements in suspended sediments in the Huanghe (Yellow) River

Eighteen suspended sediment samples were collected along the Huanghe River main stem from upper reaches on the Qinghai-Tibet Plateau (Tibet Plateau) to the entrance at the Bo Hai Bay and at confluences of its tributaries, during the first summer flood in 1980. Major elements such as Si, Al, Fe, Ca, Mg, K, Na, and trace elements such as As, Ba, Cd, Ce, Co, Cr, Cu, Ga, Hg, Li, Mn, Mo, Ni, P, Pb, Se, Sn, Sr, Ti, V, Zn and humus were examined. Variations in composition of suspended sediments also were studied. Three major types of sediment composition were observed. The controlling factor for the variation is parent rocks, though climate and vegetation played an active role. Correlation coefficients, cluster analysis, and enrichment factors were calculated to study the geochemical characteristics of the sediments. Mg, Na and Fe were the only ones subject to considerable leaching, whereas Se, Cd, Zn were significantly accumulated, indicating a low intensity of weathering.     

Environmental geochemistry of El Temsah Lake sediments, Suez Canal district, Egypt

The heavy metal contents of Mn, Ni, Cu, Zn, Cr, Co, Pb, Cd, Fe, and V in the surface sediments from five selected sites of El Temsah Lake was determined by graphite furnace atomic absorption spectrophotometer. Geochemical forms of elements were investigated using four-step sequential chemical extraction procedure in order to identify and evaluate the mobility and the availability of trace metals on lake sediments, in comparison with the total element content. The operationally defined host fractions were: (1) exchangeable/bound to carbonate, (2) bound to Fe/Mn oxide, (3) bound to organic matter/sulfides, and (4) acid-soluble residue. The speciation data reveals that metals Zn, Cd, Pb, Ni, Mn, Cu, Cr, Fe, and V are sink primarily in organic and Fe–Mn oxyhydroxides phases. Co is mainly concentrated in the active phase. This is alarming because the element is enriched in Al Sayadin Lagoon which is still the main site of open fishing in Ismailia. Average concentration of the elements is mostly above the geochemical background and pristine values of the present study. There is a difference on the elemental composition of the sediment collected at the western lagoon (Al Sayadin Lagoon), junction, the shoreline shipyard workshops, and eastern beach of the lake. Depending upon the nature of elements and local pollution source, high concentration of Zn, Pb, and Cu are emitted by industrial wastewater flow (shoreline workshops), while sanitary and agricultural wastewater (El Bahtini and El Mahsama Drains) emit Co and Cd in Al Sayadin Lagoon. On the other hand, there is a marked decrease in potentially toxic heavy metal concentrations in the sediments at the most eastern side of the lake, probably due to the successive sediment dredging and improvements in water purification systems for navigation objective. These result show that El Temsah receives concentrations in anthropogenic metals that risk provoking more or less important disruptions, which are harmful and irreversible on the fauna and flora of this lake and on the whole ecobiological equilibrium.     

Geochemistry of surface sediments in the southwestern East/Japan Sea

We analyzed 77 surface sediment samples collected in the southwestern East/Japan Sea from the Korea Strait through the Ulleung Basin and the Korea Plateau for grain size, calcium carbonate, organic carbon, and major (Na, Mg, Al, Fe, K, Ca, and Ti) and trace elements (P, Mn, Sr, Li, Sc, V, Cr, Co, Ni, Zn, Cu, and Pb).The chemical composition of the surface sediments was found to be highly variable spatially. Cluster analysis of surface sediment chemical compositions indicated five major geochemical sedimentary environments: basin, lower slope, coast and upper slope, inner shelf, and outer shelf. Continental-shelf sediments were rich in shell fragments and had relict and coarse-grained characteristics. Recent fine-grained sediments were only distributed in coastal, slope, and basin areas. Concentrations of Al, K, Ca, Ti, Cr, and Sc were highest in the coastal and upper slope areas and decreased with water depth. Elemental ratios using major and trace elements indicated that coastal and upper slope detrital sediments were mixtures of sediments derived from the Changjiang (Yangtze) and Nakdong Rivers. Although the concentrations of organic carbon, P, Mn, V, Co, Ni, Cu, and Pb increased with water depth, their distribution patterns indicated authigenic (V, Cu, and Pb) and diagenetic (Fe, P, Mn, Co, and Ni) origins. The distribution pattern with water depth suggested that the chemical composition of surface sediment was determined by sedimentologic and geochemical processes, such as the supply of detrital and biogenic materials, and authigenic and post-depositional diagenetic processes in sediments.     

The environmental impact of Aguilar mine on the heavy metal concentrations of the Yacoraite River,Jujuy Province,NW Argentina

The Yacoraite River and its tributaries run down the eastern slope of the Aguilar Range. It is one of the tributaries of the Rio Grande, located in Quebrada de Humahuaca, a UNESCO World Heritage site. The Aguilar underground mine (Pb–Ag–Zn) is located in the upper reaches of the Yacoraite River drainage basin. The aim of this work is to characterize the presence of heavy metals in water and sediments of the Yacoraite River and to identify their sources. The analysis shows the seasonal variation of heavy metals concentration in water and their relation with the World Health Organization (WHO) limits established for human consumption. The Yacoraite basin is naturally anomalous in some metals and some elements, such as As which is controlled by the chemical composition of regional lithology. During the wet season, Al, Co, Mo and Pb concentrations in water samples are higher than during the dry season; in addition, these metals are also higher than WHO limit values. High enrichment factors for Ba, Mo, Pb, Zn and Cd were found in Casa Grande stream, indicating the direct influence of the mining activities. Cd, Pb and Zn are present in the Aguilar ore minerals, such as sphalerite and galena. Sediments collected during the dry season show a drastic increase in the concentration of As, Pb, Ba, Zn, Cd and Mn. The Müller geo-accumulation index in Casa Grande indicates that it is a highly polluted stream. The concentrations of As, Pb, Ba, Zn, Cd are also high in Yacoraite River: Security Quality Guidelines indicates toxicity. A decrease in enrichment factors and geo-accumulation indices observed in sediments indicates the occurrence of precipitation/adsorption processes in the river to restore the equilibrium composition. Strict environmental controls in Aguilar Mine are necessary to avoid the uncontrolled input of toxic metals in Casa Grande stream and Yacoraite River.     

Application of multivariate geostatistics in the investigation of heavy metal contamination of roadside dusts from selected highways of the Greater Toronto Area, Canada

A good understanding of roadside soil contamination and the location of pollution sources is important for addressing many environmental problems. The results are reported here of an analysis of the content of metals in roadside dust samples of four major highways in the Greater Toronto area (GTA) in Ontario, Canada. The metals analyzed are Pb, Zn, Cd, Ni, Cr, Cu, Mn, and Fe. Multivariate geostatistical analysis [correlation analysis (CA), principal component analysis (PCA), and hierarchical cluster analysis (HCA)] were used to estimate soil chemical content variability. The correlation coefficient shows a positive correlation between Cr–Cd, Mn–Fe, and Fe–Cu, while negatively between Zn–Cd, Mn–Cd, Zn-Cr, Pb–Zn, and Ni–Zn. PCA shows that the three eigenvalues are less than one, and suggests that the contamination sources are processing industries and traffic. HCA classifies heavy metals in two major groups. The cluster has two larger subgroups: the first contains only the variables Fe, Mn, Cu, Cr, Ni, and Pb, and the second includes Cd and Zn. The geostatistical analysis allows geological and anthropogenic causes of variations in the contents of roadside dust heavy metals to be separated and common pollution sources to be identified. The study shows that the high concentration of traffic flows, the parent material mineralogical and chemical composition, and land use are the main sources for the heavy metal concentration in the analyzed samples.     

济南市大气降尘地球化学特征及污染端元研究

在济南市城区对大气降尘及不同污染端元样品进行采集,系统分析了大气降尘和污染端元元素含量特征,并对大气降尘空间分布及污染来源进行研究。结果表明:不同污染端元中元素含量差别明显,燃煤尘中As、Cd、F、Pb是汽车尾气尘的3倍以上,是交通尘、冶炼尘、建筑尘等其他端元尘的1.26~2.35倍,对环境影响较大;汽车尾气尘中Cr、Ni、S、Zn含量最高,冶炼尘中Co、Ni、Pb、F含量偏高,而建筑尘中多数元素含量为所有端元尘中最低。与土壤背景值相比,济南市大气降尘中Cr、Cu、Pb、Zn、Cd、F、S富集程度较高,受到不同程度人为污染;相关分析和因子分析结果表明,Cd、Cu、Hg、Pb、As主要来源于企业燃煤,大气降尘中这些元素高含量区与热电厂、冶炼厂、化工厂等燃煤污染源空间分布相一致;F、S可能与汽车尾气排放有关,而As、Cr主源于交通污染,这3种污染源是济南市大气降尘污染的主要来源,对降尘的贡献约占60.42%。研究表明,工业燃煤排放已逐渐代替汽车尾气成为大气降尘中Pb元素的主要来源。     

Plankton: Its chemical composition and its significance as a source of pelagic sediments

The absolute concentrations of minor and trace elements vary considerably in plankton. However, normalization of elemental abundances versus the minor elements Fe, Al and Zn (instead of the commonly used normalization versus seawater concentrations) demonstrates that these elements show remarkably constant proportions vis à vis each other. Thus, Ti, Fe, Al, Mn, V, and Zr occur in marine lower organisms in the same proportions as in the average shale, whereas Ba, Cr, Cu, Ni, Cd, Pb, Zn and B are enriched relative to the shale abundances, as are also Ca, Mg, Na, K, and Sr. These patterns appear to suggest that marine plankton are rich in lithogenic matter, but this is probably not the normal case.Contrary to the uniformity of plankton, sediments from the Pacific vary considerably in composition. Under the Equatorial high-productivity region the sediments show striking similarities with a mixture of average shale and average plankton mass, as could be expected, whereas sediments from the East Pacific Rise differ considerably from such mixtures. An iron—manganese phase (of deep-seated origin?), mixed with biological matter, on the other hand, yields model sediments with remarkable similarities to the East Pacific Rise deposits. It is therefore likely that biological processes account for a considerable fraction of some elements such as Cu, Ni, Zn and Ba also in the East Pacific Rise metalliferous sediments.