Distribution of Heavy Metals in Marine Sediments of Palermo Gulf (Sicily, Italy)

Concentrations of Cr, Cu, Hg, Pb and Zn have been measured, by atomic absorption spectrophotometry, in the fine fraction (<63 μm) of surface sediments collected in 30 sites in the Palermo Gulf (Sicily, Italy) in order to assess the levels and the spatial distribution of these elements. Enrichment factors calculated with respect to clean areas have been considered to discriminate between levels due to background or to pollution contributions. The sampling stations, which form a grid inside these areas, are characterized by geographic proximity and by the presence of pollution sources. Ratio matching technique along with hierarchical clustering, minimum spanning tree and principal component analysis have been used for the statistical analysis of data, allowing to better describe the spatial distribution of metal levels. Our work allowed to assess the anthropogenic contribution to the pollution of the area under investigation through industrial and domestic wastes, presence of an harbour area and river inflow.     

Dating of a Sediment Core by 210Pbex Method and Pb Pollution Chronology in the Palermo Gulf (Italy)

In a few cases, atmospheric particulate matter characterization was taken into account together with aerobiological monitoring but never in an archive. The aim of this study was to estimate the air quality, by means of both chemical–physical and microbiological studies, at the Ca’ Granda Historical Archive (Milan, Italy) that houses an important collection of documents from the 12th century. Temperature and relative humidity were measured in the rooms. Particulate matter (PM2.5) concentrations were quantified and the chemical composition, in terms of ionic components, elements, and carbonaceous fraction (total, organic, and elemental carbon) determined. The gaseous pollutants NO₂, SO₂, and O₃ and indoor acidity were also measured. Aerobiological monitoring (aerobic heterotrophic bacteria and fungi) was performed as volumes stored in the Archive were composed of organic materials, a potential energy and carbon source. In this paper, we present our findings and propose some guidelines for a better preservation of the documents.     

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.     

Soil properties and metal accumulation by earthworms in the Siena urban area (Italy)

This paper reports the results of a study focused on the metal (Cd, Co, Cr, Cu, Ni, Pb, Sb, U and Zn) distribution in soils and uptake and accumulation by earthworms Nicodrilus caliginosus (Savigny) from urban, peri-urban, green-urban and non-urban zones of Siena municipality (central Italy). The main goal was to define the influence of soil properties and metal soil contents on the uptake of these contaminants by earthworms. Data indicated that Cd, Cu, Pb, Sb and Zn soil contents increased in the following order: non-urban < green-urban < peri-urban < urban soils, suggesting that vehicular traffic affects the distribution of these metals. Pb and Sb were the main soil contaminants and their highest enrichments were found in urban sites where stop-and-go traffic occurs. Concentrations of these traffic-related metals in earthworms showed a distribution pattern similar to that in soil, suggesting that soil contamination influenced the uptake of Cd, Cu, Pb, Sb and Zn by N. caliginosus. There were significant positive correlations between Cd, Pb and Sb earthworm concentrations and their soil contents. The lack of correlation for Cu and Zn could be due to the physiological regulation of these elements by earthworms. Statistical analysis pointed out that the uptake and accumulation of Cd, Cu, Pb, Sb and Zn by earthworms were affected by some soil physicochemical properties such as the organic carbon and carbonate contents that are able to rule the bioavailability of metals in soils.     

Characterization of the forest humus microbial community in a heavy metal polluted area

Various parameters of the soil microbial community may be used in soil quality evaluation and environmental risk assessment. The objectives of this study were to assess the effects of different environmental factors on the characteristics of forest humus microbial communities, and to test which environmental factors most affect the gross microbial indices and physiological profiles of these communities. Samples were taken at 71 plots located in a heavily polluted area of the Krakowsko-Cze¸stochowska upland in southern Poland. The samples were analyzed for pH in KCl (pH_KCl), organic C (C_org), total N (N_t) and S (S_t), and for total and soluble Zn, Pb and Cd concentrations. The considered microbial parameters included basal respiration (BAS), microbial biomass (C_mic), C_mic-to-C_org ratio, and community-level physiological profiles (CLPPs) studied using BIOLOG^® Ecoplates. Multiple regression analysis was used to estimate the effects of humus properties on the microbial parameters. It indicated that S_t and C_org-to-N_t ratio were the most important factors positively affecting C_mic (β=0.15 and 0.11, respectively) and BAS (β=0.13 and 0.08, respectively). The C_mic-to-C_org ratio was related positively to S_t (β=0.12) but negatively to N_t (β=−0.08). The effects of pH_KCl and heavy metals on the gross microbial indices were significant but less important. The most important effect on microbial activity on BIOLOG^® plates and CLPPs was from pH_KCl. The other significant variables included S_t, C_org-to-N_t and interactions of heavy metals with pH_KCl. It was concluded that C_mic, C_mic-to-C_org and BAS might be good indicators of the general status of soil microbial communities, but their use in studying heavy metal effects may entail difficulties in separating the effects of other factors. The sensitivity of the BIOLOG^® test to pH_KCl suggests that it may be useful for studying the effects of acidification or liming on soil microbial communities. The significant effect of the interactions between heavy metals and other variables on physiological profiles indicated that high heavy metal content affects the metabolic functions of soil microbial populations.     

Habitat selection by the Mediterranean horseshoe bat, Rhinolophus euryale (Chiroptera: Rhinolophidae) in a rural area of southern Italy and implications for conservation

We studied habitat selection by Rhinolophus euryale in a rural area of southern Italy in 1998-2000 by radio-tracking. Two comparisons were carried out, one between habitat occurrence within individual home ranges and within the study area, the other between time spent in each foraging habitat and habitat occurrence within the home range. The first analysis showed that olive groves and conifer plantations were, respectively, the most and the least important habitats. The second analysis highlighted the importance of woodland for R. euryale, while urban sites, open areas and conifer plantations were avoided. We recommend that clearing of continuous, large areas of woodland for tree harvesting should be avoided. Conifers should not be used for reforestation. Urbanisation should be limited in the areas of greatest importance for the species, and linear landscape elements such as tree lines and hedgerows should be maintained.     

The soils on the flysch area of Western Liguria (Italy)

The soils on the flysch area of Western Liguria (Italy) are described for the first time. Soils have developed in the alpine variant of the Mediterranean morphoclimatic system. The study area includes the higher part of the Arroscia and Tanarello catchment basins (province of Imperia). It is subdivided into three fundamental geological units which comprise part of the limestones of the outer margin in the paleoeuropean domain (Jurassic-Eocene) and part of the turbiditic sediments in the paleogeographic oceanic domain (Upper Cretaceous-Eocene). Twentythree profiles were described within morphological and vegetational units according to the different geolithological substrata. Lithology of the parent material, vegetation and morphology appear to be the main soil forming factors. The soils are shallow and can be severely limited in fertility. They are classified as Rendolls, Udorthents, Eutrochrepts, Haplumbrepts and Hapludalfs according to the U.S.D.A. Soil Taxonomy.     

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.     

基于GIS的黄淮海平原典型潮土区土壤重金属积累研究

以黄淮海平原典型潮土区——河南省封丘县为例,基于GIS数据统计分析方法和地统计学空间插值方法,其目的是为了:(1)明确土壤重金属Cr、Hg、As、Cu、Zn的当前含量水平及其历史变化趋势;(2)通过与潮土自然背景值(背景值)、国家土壤环境质量标准一级标准(一级标准)和绿色食品产地环境质量标准(绿色标准)的比较,阐明各重金属元素符合不同标准的土壤面积及其空间分布;(3)在上述研究基础上采用内梅罗综合指数法定量评价基于一级标准的土壤重金属综合环境质量及其县域分布.结果表明,5种重金属含量平均值除Hg与背景值相当外,其余均略高于背景值而远低于一级标准,除As外,土壤Cr、Hg、Cu、Zn含量均有随年限增加的趋势;占全县土壤总面积98％以上的Cr、As、Zn含量,100％的Hg含量,91％以上的Cu含量符合一级标准,超过99％以上的土壤符合绿色标准;基于一级标准的内梅罗综合指数进一步表明封丘地区土壤综合环境质量良好,仅有不足3％的土壤受到轻度污染.表明就重金属污染角度,当前状况下的封丘土壤适宜种植各类农作物,但个别超过绿色标准的地点应引起重视并及时采取防治措施.     

Soil quality in a Mediterranean area of Southern Italy as related to different land use types

The impact of different land use types on soil quality was evaluated by measuring several soil properties that are sensitive to stress or disturbance and by using two synthetic approaches, i.e. a numerical quality index and multivariate analysis. A Minimum Data Set of soil indicators was selected including physical (texture, bulk density and water holding capacity), chemical (pH, cation exchange capacity, electrical conductivity, organic carbon, total and mineral nitrogen, available K, Ca, Mg, P contents and total Cd, Cr, Cu, Pb and Zn contents) and biological (microbial biomass, fungal mycelium, soil potential respiration and potentially mineralizable nitrogen) parameters. These parameters were assayed on soil samples collected with seasonal frequency (except for physical parameters, determined only in autumn) in an area of Southern Italy under different land use types (i.e. permanent crops, grazing lands, shrublands, coniferous and mixed forests). Moreover, for most of the land use types, a further distinction on the basis of topographic position (hill, middle-hill and plain) was carried out. Annual means of the data (except for texture) were used to calculate a soil quality index (SQI) and elaborated by multivariate analyses (Cluster Analysis and Principal Component Analysis, PCA) in order to distinguish among different soil quality classes. Data indicated a clear difference in soil quality among the studied areas: low soil quality (SQI < 0.55) in almost all permanent crops; intermediate soil quality (0.55 < SQI < 0.70) in shrublands, grazing lands, coniferous forest and middle-hill olive grove (the only crop with an herb layer on the soil surface); high soil quality (SQI > 0.70) in mixed forests. Results suggested that the permanent crop management had generally a strong negative impact on soil quality, while the moderate grazing activity and the crop management that leaves an herb cover on the soil had a lower negative impact. Nevertheless, the abandonment of cultivated lands, with consequent development of shrublands, produced an improvement of soil quality suggesting a good recovery capacity in the studied soil.     

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.     

Impact of physico-chemical soil properties on erosion features in the Aliano area (Southern Italy)

This study has been carried out on three pairs of clayey-silt slopes, which are examples of typical badlands near Aliano (Southern Italy). These show features of erosion which are common to SE-exposed clayey-silt rocks outcropping in the same area. After mineralogical, geochemical and grain size analyses these slopes were compared with the SE-exposed adjacent ones, having however a different erosive action, and a partially-vegetated covering was found.     

Anomalous contents of heavy metals in soils and vegetation of a mine area in S.W. Sardinia,Italy

Samples of soils and vegetation from the mining area of South-West Sardinia (Italy) were analyzed for Pb, Zn, Cd, and Cu content. The area (more than 100 km²) is inhabited by many thousands of people; land utilization includes mainly grapes on some small plains and permanent sheep pasture on the hills. The levels of Pb, Zn, and Cd were found to be exceptionally high in most samples. Lead concentration was up to 71000 μg g^?1 in the soils and 4000 jig g^?1 in vegetation; Cd concentration was found up to 665 μg g^?1 in soils and 26.5 μg g^?1 in vegetation. The heavy metal content of some soil samples was highly variable. Data show that Pb is easily absorbed by plant roots and translocated to foliage. In spite of the high heavy metal level, no signs of toxicity were apparent in vegetation.     

Genesis of a polycyclic Terra Rossa (Chromic Cambisol on Rhodic Nitisol) at the Poggio del Comune in Central Italy

A polycyclic Terra Rossa (Chromic Cambisol on Rhodic Nitisol) was studied with the aim of characterizing pedogenetic processes and relating the most evolved term of a previously defined catena with its parent material. Results obtained by field, chemical, micromorphological, sedimentological and mineralogical techniques evidenced how the profile was lithologically and pedologically discontinuous. While the lower part of the profile was related to the underneath limestone, the upper part showed evidence of allochthonous aeolian addition. From a pedogenetic point of view, the existence of two different kinds of processes was revealed. The deepest horizons exhibited fully expressed nitic properties and a strong kaolinitization, whereas the upper horizons were less weathered, showing only rubefaction and slight lessivage, while the formation and hydroxy-interlayering of vermiculite was the dominant process in the clay minerals. The study revealed that Terra Rossa can differ not only in age and parent material, but also in evolutive process, so that quite different, and even contrasting, products of the pedogenesis can be present.     

Trace metal behaviour during summer in a stratified Mediterranean system: The Louros Estuary (Greece)

Trace metals (Al, Pb, Zn, Cr, Cu, Ni, Fe, Mn) were studied in waters (dissolved and particulate phases) and sediments of the Louros Estuary in the Amvrakikos Gulf, one of the most important European wetlands located at the NW coast of Greece. The study system is small, with a relatively narrow mixing zone, typical for Mediterranean estuaries. Particular emphasis was given to understanding the conditions prevailing in summer. During this season saline water intrudes the estuary along the river bed, despite the existing shallow sill, and forms a thin salt-wedge water mass, which occupies the near bottom layer with its thin end pointed upstream. Particulate metal concentrations within this saline bottom layer are considerably higher than in the riverine and marine sections of the estuary. Since the metal content of particles collected upstream is higher than that of the marine ones, there is a clear evidence that the salt-wedge acts as a ‘sink’ for most metals during the summer. Coexistance in the same zone of high dissolved metal concentrations indicate that loosely associated metals are desorbed from riverine particles, whereas newly formed suspended matter is deposited together with particles, transported by the river. The accumulation of metals in the near bottom layer affects directly their distribution in the sediments. The maximum concentrations of the metal fraction which is loosely held in sediments, are found primarily at the same site. The distribution of the ‘non-labile’ metal fraction of the sediments (particularly for Cu and Pb) is broadly constant throughout the estuary, confirming the absence of any significant natural or industrial point sources, at the lower part of the river. However, the analysis of sediment cores reveals an enrichment of this metal fraction at the top, near surface sections of the mouth area, indicating relatively recent pollution.     

“稻鸭共生”生态系统重金属镉的转化、迁移及循环特征

重金属镉(Cd)通过污染的饲料和化肥而影响农产品进而危害人体健康已经成为食品安全和生态环境关注的焦点。为完善"稻鸭共生"系统的肥料和饲料管理,建立合理的物质产投结构及降低重金属Cd的生态毒理风险,在湖南省长沙市望城区桐林坳社区开展了2年田间试验,以常规稻作为对照,采用投入产出法,研究分析"稻鸭共生"生态系统重金属Cd的转化、迁移及循环特征。结果表明,"稻鸭共生"生态系统Cd输入量为:肥料饲料秧苗雏鸭,其中肥料Cd输入主要是磷肥输入。"稻鸭共生"生态系统Cd输出主要是水稻籽粒Cd和成鸭Cd。"稻鸭共生"生态系统内循环的Cd主要是鸭粪Cd、杂草Cd、害虫Cd及归还给系统的水稻秸秆Cd和根系Cd。鸭所摄食的Cd主要来自鸭饲料,大鸭饲料Cd输入大于小鸭饲料Cd输入。在"稻鸭共生"生态系统中重金属Cd沿食物链的转化、迁移过程以鸭粪Cd形式放大,且鸭粪Cd高于鸭饲料Cd输入。稻田土壤Cd输出来看,"稻鸭共生"和常规稻作相比无显著差异(P0.05)。无论是常规稻作还是"稻鸭共生",水稻植株Cd含量次序为根秸秆籽粒。与常规稻作相比,"稻鸭共生"没有增加水稻植株Cd含量和Cd积累。糙米和鸭肉镉含量分别为0.033 mg·kg-1和0.008 mg·kg-1,短期来看,"稻鸭共生"能够提供安全无Cd污染的农产品(鸭和稻米)。     

Acid and alkaline deposition in precipitation on the Western coast of Sardinia,Central Mediterranean (40° N, 8° E)

The ionic composition of 53 precipitation samples collected at a coastal site in western Sardinia (Torregrande) was measured in order to determine concentrations and fluxes of the major ions. Precipitation events were sampled over a two year period, Oct'92/Oct'93 and Oct'93/Oct'94. Despite the proximity to the African continent and the detection of Saharan inputs reflected in high pH values and high_nssCa fluxes, there is evidence for acidic rain with over 54% of the events having pH values <5.6. This would suggest long-range transport of anthropogenic inputs, as there is no obvious local source. Within the study period, a marked decrease in median pH is recorded at Torregrande in '93/'94, decreasing from 5.94 to 5.18. This is coupled with an increase in total annual flux of NO₃ from 27 to 63 μg/cm², making the average flux of NO₃ in the two years comparable with that at Capo Carbonara (48 μg/cm²). Particulate fluxes at Torregrande show a marked inter- as well as intra-annual variability, from 70 to 200 μg/cm². Variations of pH seems to be partially due to the total particulate as well as_nssCa fluxes. A statistic of Saharan enriched rain episodes of the two sites showed a peak transport season in April–May and October which is two times greater at Capo Carbonara. Rainfall on the west coast, therefore, appears to be less affected by Saharan dust than rainfall on the southern coast and therefore shows greater signs of acidification due to anthropogenic inputs.     

Long-term cultivation impact on the heavy metal behavior in a reclaimed wetland,Northeast China

Purpose

Heavy metal fractionation varies according to land uses. To understand the behavior of heavy metals in wetland soils under long-term agricultural cultivation, we examined the distribution, source, and associated environmental risk of heavy metals in different types of wetland soils.

Materials and methods

Soils were collected in cultivated lands, artificial ditches, and riparian zones from a reclaimed wetland in the Sanjiang Plain, Northeast China. They were analyzed for total concentrations and chemical fractions of Pb, Cd, Cu, Zn, Cr, and Ni, as well as pH, soil organic matter, total phosphorus, and particle size distribution.

Results and discussion

Heavy metal concentrations were significantly lower in cultivated wetland than in ditch and riparian wetlands. Riparian wetland was found to exhibit the highest metal concentrations. When compared with other two wetland types, the cultivated wetland showed much higher partitioning levels of heavy metals in the acid-soluble fraction and lower partitioning levels in the oxidizable fraction. Although Cr, Cu, and Ni in ditch and riparian wetlands were identified as the metal pollutants of primary concern, they had a low or no risk of further dispersion to other environmental components. Weathering of parent materials was the main source of Cr and Cu, Pb, Cd, and Zn originated mainly from agricultural practices, and Ni emanated from a mixture of sources.

Conclusions

Long-term agricultural cultivation can lead to significant heavy metal loss in cultivated wetland but enrich heavy metal concentrations in ditch and riparian wetlands. Periodic ditch dredging is considered an effective measure for decreasing heavy metal input into the fluvial system and thereby reducing the dispersion to the regional water environment.     

奎河污灌区土壤重金属As变化系统动力学分析

污灌污染是一个亟待解决的土壤环境问题,研究污灌区土壤重金属污染状况及其动态对于土壤重金属污染修复具有现实意义。该文以奎河污灌区为例,通过文献资料搜集和现场监测获取相关数据,采用单因子污染指数法和内梅罗综合污染指数法评价了污灌区重金属污染状况,结果表明土壤As轻度污染,水田样点超标率达89.93%,旱地样点超标率达82.39%,水田综合污染指数为1.39,旱地综合污染指数为1.19。以As为例,采用系统动力学方法分析了As含量的变化。结果表明在当前种植制度下,土壤As的消除是一个漫长的过程,需要到2016年土壤As质量分数才会降低到30mg/kg以下,2024年后才会低于25mg/kg,达到当地土壤As背景值更需要到2073年。清除作物秸秆和根系对于消除土壤As污染有益,尤其是远期效果明显,而表层土壤的流失对于土壤As的清除作用显著。     

Silvicultural use of wood ashes — Effects on the nutrient and heavy metal balance in a pine (Pinus sylvestris,L) forest soil

In a sustainable forestry recirculation of nutrients through the application of ashes from forest residues can be an essential way to guarantee healthy and vital forests. Wood ashes can also be regarded as a measure against soil acidification. Wood ashes were applied at various rates to the soil in a 35 years old pine (Pinus sylvestris, L) stand at Ringamåla in Blekinge, South Sweden. The experiments started in 1984. The different treatments gave a clear effect on soil chemistry with decreased acidity and aluminum ion concentrations. The base saturation increased in both mor and upper mineral soil layers. Generally no significant increases were found in soil concentrations of heavy metals, except for Cu which increased significantly in the mor layer. Also the extractable Mn concentration increased, in spite of the increased pH in the soil after application of ashes. In order to achieve a biological circulation of nutrients through ash application without polluting the environment, it is of ultimate importance that the wood chips used in power plants and other furnaces have a low concentration of heavy metals and other pollutants.