Multiproxy investigation of a Holocene sedimentary sequence near Ferrara (Italy): clues on the physiographic evolution of the eastern Padanian Plain

Purpose

This paper investigates soils and sediments from the eastern Padanian Plain (northern Italy) in order to delineate the physiographic evolution of the area.

Materials and methods

We present new geochemical, mineralogical and textural analyses of alluvial sediments collected from a 13-m-deep section located a few kilometres south of Ferrara. The chronology of the related depositional events is provided from ¹⁴C dating of tree trunks buried at depths of ca. 9 m and organic matter from the underlying horizons.

Results and discussion

The data indicate that (1) the upper part of the sequence (down to depths of 9 m) includes sediments characterized by low nickel–chromium (Ni–Cr) concentrations ascribed to the alluvial deposits of the river Reno, deposited in the last 400 years; (2) buried soils (depths of 9–10.5 m) developed on Ni–Cr-rich sediments related to the river Po; and (3) the deeper facies (depths of 10.5–13 m) are CaCO₃-free and characterized by higher amounts of organic carbon, sulphur and arsenic, reflecting episodic lacustrine/marsh environments. These wetlands probably developed in the area during the Iron and Roman ages, persisting up to the Middle Ages.

Conclusions

The data provide a contribution to the understanding of the evolution of the river network during the last 3,000 years and provide insights on the related paleohydrological framework that can be useful for geographical and historical reconstructions of the area. Results highlight the importance of investigating alluvial sediments to elucidate (1) fluctuations of environmental conditions and (2) anthropogenic impacts on the natural landscape.     

Heavy metals in the lichen Ramalina duriaei transplanted in biomonitoring stations

The amounts of six heavy metals, Cu, Cr, Cd, Pb, Zn, and Ni in the transplanted fruticose lichen Ramalina duriaei, have been determined. The contents of these metals in the material exposed for 1 yr at the site which served as a source for the transplantation were found to be much lower than in the lichen transplanted close to busy roads and to places with other intensive human activities. Correlation coefficients between some pairs of the heavy metals found in the transplanted R. duriaei are closer to those previously found in Caloplaca aurantia from rural and suburban sites than to those from industrial sites in Tel-Aviv. All these heavy metals are expected in the emission from a coal-fired electric generating station to be located at the sea shore in the near future. We recommend that a program of monitoring for a power station at the proposed coastal site include routine determination of (a) the amounts of these metals in transplanted lichens, (b) the correlation between the amounts and the distance from the sea, and (c) the correlation between pairs of these metals at various locations.     

Heavy metals in the slope deposits of loess areas of the Lublin Upland (E Poland)

The concentration of heavy metals (Cd, Cu, Pb, Zn) has been analyzed in Holocene slope deposits of the loess agricultural area in the Eastern Poland. Five profiles were examined. In general, low concentrations of the examined metals were determined, on average 50% of the samples exceeded the designated regional, geochemical background. The average concentrations were: cadmium < 0.5 ppm, copper up to 15, and lead up to 20 and zinc up to 70 ppm, showing a vertical diversity in the profile. Higher heavy metal concentrations in Holocene deposits are related to soil formation or accumulation of organic matter. The direct influence of human factors was most visible in recent deposits. It includes the modification of the development conditions of soil-forming processes as well as the influence on the character of the colluvial deposits. Taking into account the ¹⁴C datings as well as the archeological and historical data the age and rate of sedimentation of deposits have been calculated. The average rate of the colluvia deposition varied from 1.3 to 7.3 mm/year depending on their age and the character of sedimentation.     

Heavy Metal Contents and Distribution in Coastal Sediments of the Gulf of Trieste (Northern Adriatic Sea, Italy)

A set of ten heavy metals (Al, As, Cd, Cr, Cu, Hg, Ni, Pb, V, and Zn) was investigated in surface sediments (0–5 cm) collected in 21 sites of the Gulf of Trieste, Northern Adriatic Sea (Italy). The aim of this work was to obtain a preliminary assessment about the levels and spatial distribution of these selected elements. Ancillary parameters such as grain size, total organic carbon, and total nitrogen were also determined. The enrichment factor was calculated to discriminate if a natural condition or a status of anthropogenic contamination occurs. In addition, a set of sediment quality guidelines, mean effect low range and effect medium range quotients, was also applied in order to predict the probability of adverse biological effects on the benthic community.     

Dark gray soils on two-layered deposits in the north of Tambov Plain: Agroecology, properties, and diagnostics

Dark gray soils in the Tambov Plain are developed from the light-textured glaciofluvial deposits underlain by the calcareous loam. Their morphology, water regime, and productivity are determined by the depth of the slightly permeable calcareous loamy layer, relief, and the degree of gleyzation. The light texture of the upper layer is responsible for its weak structure, high density, the low content of productive moisture, and the low water-holding capacity. If the calcareous loam is at a depth of 100?C130 cm, dark gray soils are formed; if it lies at a depth of 40?C70 cm, temporary perched water appears in the profile, and dark gray contact-gleyed soils are formed. Their characteristic pedofeatures are skeletans in the upper layers, calcareous nodules in the loamy clay layer, and iron nodules in the podzolized humus and podzolic horizons. The appearance of Fe-Mn concretions is related to gleyzation. The high yield of winter cereals is shown to be produced on the dark gray soils; the yields of spring crops are less stable. Spring cereals should not be grown on the contact-gleyed dark gray soils.     

Heavy metals (copper,lead, nickel,and cadmium) in the organic part of gray forest soils in the Buryat Republic

The levels of the accumulation of copper, lead, nickel, and cadmium in the parent material-soil-plants-soil organic matter system are given for gray forest soils in the Buryat Republic. The concentrations of copper, lead, and nickel in the parent materials do not exceed the corresponding clarkes, and cadmium is present in trace amounts. The concentrations of copper and nickel in the humus horizon are lower than those in the parent material; an opposite situation is observed for lead. The concentrations of copper, lead, and nickel in the soil organic matter and in the herbaceous plants correspond to their contents in the soil and do not exceed the background (clarke) values. Cadmium was not detected in the aboveground part of the plants, though it was found in the root mass and in the organic soil horizon. In the humus of gray forest soils, these heavy metals are mainly present in the acid filtrate remaining after the precipitation of humic acids.     

Heavy metal contamination of soils in Northern Slovakia

Environmental damages like forest decline in Northern Slovakia could be a result of long-distance transport of pollutants with the dominating north-west winds. On 10 sites, primarily in the northbound upper slopes of west-east oriented mountain ranges in Northern Slovakia, the extent of the heavy metal contamination in soils along a north-south transect was examined. Oi, Oe, Oa, A, and B horizons were sampled and the total concentrations of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined. The ranges of heavy metal concentrations in the forest floor were higher than reported for comparable samples from Bavarian soils except for Zn (Cd: 0.65–1.77; Cr: 12–40; Cu: 19–41; Ni: 8–24; Pb: 70–187; Zn: 31–92 mg kg^?1), in the mineral soil the concentrations were lower. The depth distribution of the metal concentrations indicated a contamination with Cd, Cr, Cu, Ni, Pb, and Zn. The concentration differences between forest floor and mineral soil tended to be higher at the northern than at the southern sites for Cu, Ni, Pb, and Zn, indicating a long-distance transport from the north. Correlation and principal component analyses of the total metal concentrations revealed three groups: Cu, Pb, and Zn inputs mainly seemed to result from long-distance transport from the north, Cr and Ni inputs additionally from local sources. Cd probably had its origin mainly in local sources. This result was further confirmed by the grouping of the sites when clustered.     

Lichen biomonitoring of trace elements in a geothermal area (central Italy)

The epiphytic lichen Parmelia caperata was used systematically to biomonitor trace elements in the Travale-Radicondoli geothermal field (central Italy). The results showed a very low occurrence of potentially toxic heavy metals such as Cd, Hg and Pb, and relatively high values for As, B, Mo and elements associated with soil dust (Al, Co, Cr, Fe, Mn and Ni). Boron was the principal element of geothermal origin. Arsenic seems to originate both from power plants and adjacent thermal springs. It is concluded that trace element pollution in the area is low.     

Heavy metals in European soils: A geostatistical analysis of the FOREGS Geochemical database

This paper presents the results of modeling the distribution of eight critical heavy metals (arsenic, cadmium, chromium, copper, mercury, nickel, lead and zinc) in topsoils using 1588 georeferenced samples from the Forum of European Geological Surveys Geochemical database (26 European countries). The concentrations were mapped using regression-kriging (RK) and accuracy of predictions evaluated using the leave-one-out cross validation method. A large number of auxiliary raster maps (topographic indexes, land cover, geology, vegetation indexes, night lights images and earth quake magnitudes) were used to improve the predictions. These were first converted to 36 principal components and then used to explain spatial distribution of heavy metals. The study revealed that this database is suitable for geostatistical analyses: the predictors explained from 21% (Cr) to 35% (Pb) of variability; the residuals showed spatial autocorrelation. The Principal Component Analysis of the mapped heavy metals revealed that the administrative units (NUTS level3) with highest overall concentrations are: (1) Liege (Arrondissement) (BE), Attiki (GR), Darlington (UK), Coventry (UK), Sunderland (UK), Kozani (GR), Grevena (GR), Hartlepool & Stockton (UK), Huy (BE), Aachen (DE) (As, Cd, Hg and Pb) and (2) central Greece and Liguria region in Italy (Cr, Cu and Ni). The evaluation of the mapping accuracy showed that the RK models for As, Ni and Pb can be considered satisfactory (prediction accuracy 45-52% of total variance), marginally satisfactory for Cr, Cu, Hg and Zn (36-41%), while the model for Cd is unsatisfactorily accurate (30%). The critical elements limiting the mapping accuracy are: (a) the problem of sporadic high values (hot-spots); and (b) relatively coarse resolution of the input maps. Automation of the geostatistical mapping and use of auxiliary spatial layers opens a possibility to develop mapping systems that can automatically update outputs by including new field observations and higher quality auxiliary maps. This approach also demonstrates the benefits of organizing standardized joint European monitoring projects, in comparison to the merging of several national monitoring projects.     

Chemical composition of water-soluble fraction in soils on glaciolacustrine deposits of the Russian Plain

The behavior of some chemical elements was studied in soils and their liquid phase. Two reference soil profiles on glaciolacustrine clays (soddy-eluvial-metamorphic soil) and sands (soddy podzol) were investigated on the Russian Plain. A colloidal fraction (particles <1 μm) was isolated with deionized hot water from a soil sample of 30 g at the soil: water ratio of 1: 10. The suspension was mixed for 6 h, settled for 24 h, and filtrated using a membrane filter (<1 μm). The soil sample and its water-soluble fraction (WSF) were analyzed by mass spectrometry with inductively coupled plasma. The chemical characteristics of the extracted liquid phase of the soil reflect its water-soluble component properties. The comparison of the data obtained with the results of the analysis for the whole soil allows assessment of a share of easily mobile and difficultly mobile forms of chemical compounds. This is the necessary basis for the development of a model describing the transport of metals in soil.     

杭州市城市土壤中重金属、磷和其它元素的特征

Health implications of inhaling and/or ingesting dust particles with high concentrations of heavy metals from urban soils are a subject of intense concern. Understanding the geochemistry of these metals is key to their effective management. Total concentrations of heavy metals, phosphorus (P) and 8 other elements from topsoil samples collected at 82 locations in Hangzhou City were measured to: a) assess their distribution in urban environments; and b) understand their differentiation as related to land use. Metal mobility was also studied using a three-step sequential chemical fractionation procedure. About 8.5%, 1.2%, 3.6%, 11.0% and 30.3% of the soil samples had Cd, Cr, Cu, Pb, and Zn concentrations, respectively, above their allowable limits for public and private green areas and residential use. However, in commercial and industrial areas, most samples had metal concentrations below their allowable limits. Statistical analyses revealed that the 16 measured elements in urban soils could be divided into four groups based on natural or anthropic sources using a hierarchical cluster analysis. Additionally, Cu, Pb, and P showed similar spatial distributions with significant pollution in commercial zones, suggesting vehicle traffic or commercial activities as dominant pollutant sources. Also, Cd, Co, Cr, Ni, Zn, Mn and Fe had the highest concentrations in industrial locations, signifying that industrial activities were the main sources of these seven metals. Moreover, the data highlighted land-use as a major influence on heavy metal concentrations and forms found in topsoils with large proportions of soil Cd, Co, Cr, and Ni found in residual fractions and soil Cu, Pb and Zn mainly as extractable fractions.     

Geomorphic features of a badland (biancane) area (Central Italy): characterisation, distribution and quantitative spatial analysis

The biancana landscapes, rather common in several Italian areas, have a very complex morphology. Different geomorphic features often occur along the same hillslope. From a morphological survey of an experimental site in southern Tuscany, the forms were classified, and their distribution analysed. Spatial analysis of the biancane provided insights into the range of forces responsible for their formation and evolution. The results confirm an evolutionary trend from an original gently sloping surface to a complex biancana landform, emphasising a trend from the taller bean forms to the terminal soufflé-like and cone forms. The presence of scarp and sliding forms in the most sloping areas and along the residual surfaces supports the hypothesis of a process influenced by base level, acting initially by small mass movements. Spatial analysis did not reveal any systematic trend in the variability of the erosional features along the slopes. Variographic analysis showed that selected morphological attributes are spatially auto-correlated over a short range, suggesting that the erosive processes responsible for morphogenic evolution of biancane act mostly on a local scale. The strong geometric anisotropy detected in directions parallel to the main jointing systems also indicated a broader scale tectonic control of biancane evolution, probably in an early stage of their formation.     

松嫩平原北部土壤重金属背景值及累积特征研究

以松嫩平原北部作为研究区,以多目标区域地球化学调查成果作为数据基础,采用多元统计与地统计相结合的方法,对土壤重金属背景值及累计特征进行研究。结果表明:(1)松嫩平原北部土壤重金属背景值与1986年测得的背景值相比,As、Cr、Cd、Cu、Ni、Pb、Zn均升高;在不同地貌单元条件下,背景值差异显著;(2)分别以全区域和地貌单元条件下的背景值作为参考标准,表层重金属Hg、Cd、Cr均产生了累积;较全区域背景值而言,不同地貌条件下的背景值更能反映重金属累积状况;(3)松嫩平原北部重金属空间分布含量较高的区域主要集中在中东部,而在西南部相对较低。     

松嫩平原北部土壤重金属空间分异特征及生态安全评价

以松嫩平原北部8.15万km2的范围为研究区域,以20 701个表层土壤样品的As,Cd,Cr,Pb,Hg,Cu,Zn,Ni共8种重金属元素含量为基础数据,利用地统计方法分析研究区内表层土壤重金属的空间分异特征.利用主成分分析法进行土壤生态安全质量评价.评价结果显示:松嫩平原北部表层土壤中重金属元素含量普遍低于世界土壤和中国土壤重金属平均含量;研究区内松花江、嫩江对表层土壤中重金属的水平迁移影响显著,表层土壤重金属含量由低及高呈现沿松花江嫩江的主要干支流向周围梯级过渡的趋势.表层土壤中重金属元素的空间分布主要受自然因素影响,其中Pb,As元素的空间分布受到一定程度的人为因素干扰.松嫩高平原区域土壤生态安全质量相对较低,松嫩低平原区域土壤生态安全质量相对较高.     

Changes in surface structure (crusting) after application of sewage sludge and pig slurry to cultivated agricultural soils in Northern Italy

The first results of a cooperative research project on changes in cultivated agricultural topsoils after treatment with sewage sludge and pig slurry are discussed for a silty clay soil (Vertic Xerochrept) and a sandy loam soil (Typic Psammaquent). Such changes are expressed in the surface structure, including crusts, of the soils and have a direct effect on their fertility. To measure these changes, special attention was paid to porosity characteristics; especially increases in porosity after application of organic manures to agricultural soils with crusting problems. Light microscopy, SEM-EDXRA (scanning electron microscopy — energy dispersive X-ray analysis) and Quantimet (electro-optical image analysis) were applied and allowed quantitation and visualisation of pores. Initial results clearly demonstrate that the porosity of the topsoil increased after treatment with urban refuse or pig slurry and that crusting decreased.     

Heavy metals in urban soils of Bristol (UK). Initial screening for contaminated land

Purpose  

UK local authorities are required by environmental regulations to keep a public register of contaminated land. In many towns and cities, there is growing concern of allotment holders about the quality of their allotment soils. Limited information on soil chemistry is available for the southwest of England. This work was carried out to assess whether any allotment and park soil in Bristol could be defined as “contaminated”.     

黑龙江省海伦市农田土壤重金属分布特征及污染评价

海伦市是以农业为主导产业的黑龙江省县级市,为了解该市土壤重金属时空分布特征及其污染现状,对农田耕层及亚耕层土壤中Cd、Cr、Cu、Ni、Pb、Zn、Hg和As等重金属全量进行了分析,并采用单因子污染指数法和Nemerow综合污染指数法分别对土壤的重金属污染状况进行了评价。结果表明,该地区土壤重金属含量较低,总体表现为西南和西北含量较高、西部含量高于东部的空间分布特征。以松嫩平原土壤元素背景值为标准进行评价,已出现一定程度的污染。以GB15618-1995土壤环境质量标准二级标准进行评价,综合污染指数为0.504,所有样点土壤重金属均未达到污染水平。与耕层土壤相比,亚耕层土壤Hg和Cd含量显著下降,其他元素含量及分布特征则与耕层相似。从1980年到2008年,随着时间的变化,该区域土壤重金属含量增加趋势不明显,近期土壤出现重金属污染风险较小。     

Bulk Atmospheric Deposition in the Southern Po Valley (Northern Italy)

A study on pH and chemical composition of precipitation was carried out in two Italian sites, one urban (site 1) and one rural (site 2), located approximately 30 km far from Bologna, during a 3-year period. No significative site variation was found. In both locations, bulk deposition pH ranged from slightly acid to slightly alkaline, despite the volume weighted mean concentration of acidic species, NO ₃ ^? and SO ₄ ^2? (67.4 and 118.4 μeq l^?1 in site 1 and 88.7 and 103.8 μeq l^?1 in site 2), that were similar to those of typical acidic rainfall region. This might be ascribed to the neutralization reaction of the Ca²⁺, attributed to the calcareous soil and the frequent dusty air mass intrusion from the Sahara. The pair correlation matrix and the analysis of the main components suggested also ammonium and other crustal elements as neutralization agents. The depositional rate of SO ₄ ^2? and NO ₃ ^? , chemical elements of agricultural interest, amounted to 38 and 28 and 32 and 35 kg ha^?1 for site 1 and site 2, respectively. These supplies of nutrient were not negligible and had to be considered on cultivated lands. NH ₄ ⁺ deposition rate on site 2 was 7 kg ha^?1, 23% over site 1, probably due to nitrogen fertilization in the fields around the monitoring station. In site 1, SO ₄ ^2? presented a seasonal trend, indicating that its principal source was the residential heating. Results emphasized that the entity of the bulk deposition acidification is linked not only to the ions local emission sources (fossil fuel combustions, heating, and fertilizers) but also to the surrounding territory and the prevalent wind that transports through kilometers air masses which may contain acidic and alkaline species.     

Heavy metals in soils and plants of the don river estuary and the Taganrog Bay coast

Natural and anthropogenic factors determining the distribution and accumulation features of Pb, Cu, Zn, Cr, Ni, Cd, Mn, and As in the soil–plant system of the Don River estuary and the northern and southern Russian coasts of Taganrog Bay estuary have been studied. High mobility of Cu, Zn, Pb, and Cd has been revealed in alluvial soils. This is confirmed by the significant bioavailability of Cu, Zn, and, to a lesser degree, Cd and the technophily of Pb, which are accumulated in tissues of macrophytic plants. Statistically significant positive correlations have been found between the mobile forms of Cu, Zn, Cd, and Mn in the soil and the accumulation of metals in plants. Impact zones with increased metal contents in aquatic ecosystems can be revealed by bioindication from the morphofunctional parameters of macrophytic plants (with Typha L. as an example).     

PCBs and Organochlorine Pesticides in Lake Orta (Northern Italy) Sediments

PCB congeners and organochlorine pesticides (DDT, lindane and HCB) distribution were studied in Lake Orta sediments. The results indicated a contaminated area in the nor-them part of the sub-basin. The observed high levels of organochlorine compounds (OCs) may he explained by the focusing phenomenon, ie. the preferential transport of lighter and smaller particles from the emission sources to this area. The PCBs and DDT values were correlated with the organic carbon content and the heavy metal contamination. The toxicity of the sediment samples was related also to PCB content. PCBs and OCs pollution of Lake Orta was of the same order of magnitude as in Lake Como, which is the most contamined lake in Northern Italy.