Heavy Metals In Topsoil Research Articles

Spatial pattern and distribution regularity of soil environmental quality in East China

Random numbers of heavy metal (Cd, As, and Pb) concentrations were created by Monte Carlo simulation of 16 representative sites in five soil zones from published papers for subsequent research. Ordinary kriging and significant analyses were used in a dataset of the 16 areas. Concentration of heavy metals in topsoil was found to be mainly influenced by zonality, non-zonality, and anthropogenic inputs. Nevertheless, human-induced correlations among heavy metals could not be detected on a regional spatial scale. Soil zone and landform were found to be representations of zonality and non-zonality, respectively. It was found that in east China, heavy metals accumulated in the south, especially the southwest, and were not uniform in each soil zone, indicating that zonality was not the unique influencing factor of soil environment quality. Both soil zone and landform may be responsible for heavy metal concentrations. An analysis of variance, coefficients of divergence analysis, was applied to assess the effects of soil zone and landforms on the variation of heavy metal concentrations in the study region. The influence of soil zone and landform was relatively homogeneous in areas of the north; while in the south, landform played a dominating role. Therefore, soil environment quality formed mainly under the effect of landform. This was mainly due to the fact that landform in fluences other natural environment elements including climate, further impacting the division of soil zone.

基于小流域尺度的土壤重金属分布与土地利用相关性研究——以厦门市坂头水库流域为例

基于小流域尺度的土壤重金属分布与土地利用相关性研究——以厦门市坂头水库流域为例

Identifying the origins and spatial distributions of heavy metals in soils of Ju country (Eastern China) using multivariate and geostatistical approach

Identifying the sources of heavy metals in soils is a crucial issue for soil remediation and management. Most regions in China have been undergoing a rapid industrialization and urbanization since the last three decades. However, there is little information available on the spatial distribution of heavy metals in soils experiencing a rapid transition from agricultural-based to industrial-based economy. To resolve this problem and to provide references on similar regions, we carried out an investigation on heavy metals in soils in Ju country to identify potential sources and to map their spatial distributions. A total of 646 samples including 511 samples in topsoils (0–20 cm, regular grid of 2 × 2 km2) and 135 samples in subsoils (150–200 cm, regular grid of 4 × 4 km2) were collected in Ju country, and the total contents of Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn were determined. Enrichment factor method and multivariate analyses (correlation analysis, principal component analysis, and cluster analysis) were applied to identify the sources of ten heavy metals in topsoils. Additionally, ordinary kriging was used to map the spatial distributions of heavy metals concentration in topsoils. The overall levels of all heavy metals did not show high values, but the enrichment factor results suggested that Hg, Cd, Cu, Pb, and Zn in topsoils showed significant accumulation. Ten heavy metals can be grouped into three groups. Co, Cr, Mn, Ni, and V were associated with parent material and seemed to originate from a natural source. Cd, Cu, Pb, and Zn seemed to be related to the combination of parent material and anthropic inputs. Hg as an isolated element was dominated by atmospheric deposition inputs related to various human activities. Distribution maps derived by ordinary kriging suggested that Cd, Cu, Hg, Pb, and Zn were linked to the western part, corresponding well to the surroundings of urban areas located in the western part of Ju country. Hg, Cd, Cu, Pb, and Zn were the main metals affected by human inputs in Ju country, and the high risk resulting from human influence was mainly shown around urban areas, consistent with the spatial distribution of industrial and traffic sites. Agricultural practices did not have significant influence on the spatial distribution of metals. The combination of multivariate analysis and geostatistics was found to be an effective approach to identify the origins and spatial distribution of heavy metals in soils.

Contamination and spatial distribution of heavy metals in topsoil surrounding a mega cement factory

This study assessed the level of contamination of the topsoil by Pb, Cu, Cr, Cd and Zn and the spatial distribution of these heavy metals around a cement factory. Thirty–eight composite soil samples were collected around the cement factory and subjected to nitric–perchloric acid digestion. Total metal contents of the soil were determined by flame atomic absorption spectrophotometry (FAAS) and the data generated were analyzed statistically. Spatial mapping of the distribution of heavy metals was done through the use of Inverse Distance Weighted technique (IDW) of ArcGIS 10. The results showed that the contamination domain of Cd was in the extreme domain while Pb and Cu levels in the soil were in the severe and moderate contamination domains. Zn and Cr posed no potential environmental hazard because of their low level in the soil. The spatial mapping of the heavy metals indicated Pb and Cu enrichment of the soil not only to come from cement production activities but also from vehicular activities while Cd enrichment of the soil was mainly from the cement production. Mapping of Zn and Cr distribution showed that their enrichments in the soil were from cement production activities. From these findings, it is highly recommended that environmental auditing of the cement production line be carried out to reduce the release of pollutants. It is also important that remediation activities be carried out on the soil to reduce the levels of Cd, Pb and Cu to avert potential ecological disasters.

Magnetic properties of urban soils from typical oasis cities and their environmental implications

This study is a systematic analysis on the environmental magnetic properties, soil texture and distribution of heavy metals content in topsoil sampled from typical oasis cities in desert like Wuhai, Shizuishan and Yinchuan. The results indicated that the topsoil in Wuhai and Shizuishan is typical sandy soil, while that in Yinchuan is sandy loam. Magnetic properties of topsoil samples are all predominated by ferrimagnetic magnetic mineral (magnetite) of coarse pseudo single domain (PSD)-multi domain (MD) particles with magnetic susceptibility of 152 X 10(-8), 104X10(-8), and 117x10(-8)m(3).kg(-1) respectively for the three cities. The magnetic mineral content and magnetic particles size in topsoil samples of Wuhai are significantly higher than that of Shizuishan and Yinchuan. Pollution Load Index (PLI) of heavy metals (Cr, Cu, Pb, Zn, Fe) showed that there is slight pollution in the three cities. Dotted distribution of high values of magnetic susceptibility and Pollution Load Index is shown in nonindustrial area, whilst planar distribution with high value is shown in industrial area. The correlation coefficient between magnetic parameters and heavy metals of topsoil in Wuhai is significantly higher than that in Shizuishan and Yinchuan, which suggests that magnetic parameters are more advantageous for evaluation on pollution degree in regions with single pollution source. There is an increase by the same degree in magnetic susceptibility in parallel with the increase of Pollution Load Index, despite of the significant difference of magnetic properties among three cities. Therefore, magnetic susceptibility can be used as the unified and effective substitute indicator to evaluate the pollution degree of heavy metals in topsoil of Ningxia plain.

Fractionation, Mobility, and Sources of Selected Heavy Metals in Topsoils from the Middle Black Sea Region of Turkey

An investigation into spatial distribution, pollution sources, and mobility of heavy metals was conducted on 19 topsoil samples from the Samsun, Sinop, Merzifon, and Ilgaz Provinces of the Middle Black Sea Region, Turkey. Metal concentration, chemical fractionation, enrichment, and mobility factors were determined for Zn, Cu, Pb, and Cd. Concentrations varied from 29 to 328 mg kg−1 for Zn, 3.35 to 130.80 mg kg−1 for Cu, 3.45 to 217.70 mg kg−1 for Pb, and 0 to 5.8 mg kg−1 for Cd. Enrichment factors decreased in the order Cu > Zn > Pb > Cd. Significant enrichments were found for some Samsun and Sinop soils. Sequential extraction revealed that Zn is associated with Fe/Mn oxide and organic fractions, Cu with residual and organic fractions and Pb with residual fraction. The abundances of heavy metals in the mobile phases were evaluated with a mobility factor, which increased with metal concentration. Generally, the mobility of Zn poses a higher risk, but the most mobile metal varied between soils.

Spatial extraction model for soil environmental quality of anomalous areas in a geographic scale

An approach to establish a soil environmental assessment model was proposed to evaluate the soil environmental quality level. The kriging technique and a self-organizing map (SOM) were integrated to investigate the soil environmental quality in a geographic information system (GIS). In this study, SOM was applied to categorize the data set of nine heavy metals in topsoil. A total of 261 topsoil samples were collected to determine the concentrations of Cu, Pb, Zn, Cd, Ni, Cr, Hg, As, and Mn. The samples were clustered into three classes by SOM and visualized by GIS. The results show that different environmental quality categories are significantly different and that the soil environmental quality assessment model is effective.

Source identification and ecological risk assessment of heavy metals in topsoil using environmental geochemical mapping: Typical urban renewal area in Beijing, China

Environmental geochemical mapping with high-density soil sampling was conducted to determine the spatial distribution, possible sources and potential ecological risk of heavy metals at a former chemical industry area in Beijing. A total of 550 surface soil samples were collected and the concentrations of heavy metals, such as Ni, Cr, V, As, Cu, Pb, Cd, Zn and Hg, were analyzed. The spatial distribution characteristics of these metals were demonstrated by environmental geochemical mapping. Enrichment factors show that the soil concentrations of Cu, Pb, Cd, Zn and especially Hg were higher than the background values. Multivariate geostatistical analyses suggested that Cu, Pb, Cd, Zn and Hg in the topsoil were strongly influenced by anthropogenic or chemical industry activities while Ni, As, V and Cr mainly originated from the natural parent materials of the soils. The potential ecological risk was quantitatively estimated for each site and the risk map was plotted for assessment. Among the metals, Cd and Hg showed a higher potential ecological risk than the others.

The Dublin SURGE Project: geochemical baseline for heavy metals in topsoils and spatial correlation with historical industry in Dublin, Ireland

The Dublin SURGE (Soil Urban Geochemistry) Project is Dublin’s first baseline survey of heavy metals and persistent organic pollutants in topsoils and is part of a Europe-wide initiative to map urban geochemical baselines in ten cities. 1,058 samples were collected as part of a stratified random sampling programme in the greater Dublin area to give an overview of baseline conditions in the city. Samples were analysed for 31 inorganic elements including heavy metals. Analysis of results indicates that the concentrations of lead, copper, zinc and mercury are strongly influenced by human activities, with elevated concentrations in the city docklands, inner city and heavy industry areas. Sources of heavy metals in these areas may include historical industry, coal burning, re-use of contaminated soil, modern traffic and leaded paint and petrol. Concentrations of other inorganic elements in topsoil show patterns which are strongly related to regional bedrock parent material. The spatial distributions of heavy metals, in particular Pb and As, are explored in detail with respect to regional geology and the influence of historical industry on soil quality. Exploratory data, geostatistical and correlation analyses suggest that the concentrations of heavy metals tend to increase as the intensity of historical industrial activity increases. In particular, drinks production, power generation, oil/gas/coal, metals and textile historical industries appear to be the contamination source for several heavy metals. The data provide a geochemical baseline relevant to the protection of human health, compliance with environmental legislation, land use planning and urban regeneration.

Environmental geochemical mapping and multivariate geostatistical analysis of heavy metals in topsoils of a closed steel smelter: Capital Iron & Steel Factory, Beijing, China

A high-density survey was conducted in this study to determine the spatial distribution and possible sources of heavy metals at the former Capital Iron & Steel Factory, Beijing, China. A total of 400 surface soil samples were collected at a density of 16 samples per km2, and the concentrations of heavy metals, such as Ni, Cr, V, As, Cu, Pb, Cd, Zn and Hg, were analyzed. The spatial distribution characteristics of these metals were demonstrated by environmental geochemical mapping. The mean concentrations of Ni, Cr, V and As are close to the background values. Enrichment factors show that the soil concentrations of Cu, Pb, Cd, Zn and Hg were higher than the background values, especially Hg. Multivariate geostatistical analysis suggests that Cu, Pb, Cd and Zn have similar properties and their presence was mainly from steel-smelting activities. However, the Hg contamination was more weakly related to the steel smelting activities, partially due to other anthropogenic activities, such as the combustion of coal for heating.

Sources identification of heavy metals in urban topsoil from inside the Xi'an Second Ringroad, NW China using multivariate statistical methods

Abstract The concentrations of Co, Cr, Cu, Mn, Ni, Pb, Zn, and V in urban topsoil samples collected from inside the Xi'an Second Ringroad, northwestern China were measured by X-ray fluorescence spectroscopy. Correlation coefficient analysis, factor analysis and cluster analysis were used to analyze the data and to identify the possible sources of these heavy metals. The results show that the mean concentrations of Co, Cr, Cu, Mn, Ni, Pb, Zn, and V in urban topsoil from Xi'an are 19.3, 81.1, 54.3, 671.5, 34.5, 59.7, 186.2, and 85.2 mg kg− 1 respectively, which are higher than the background values of Shaanxi soil. The mean concentrations of heavy metals in topsoil divided by the corresponding background values of Shaanxi soil increase in the order of Ni

Concentration, Distribution and Comparison of Total and Bioavailable Heavy Metals in Top Soils of Bonab District in Zanjan Province

Heavy metal contamination of soils is a widespread problem in Zanjan province located in North West Iran due to natural pedo geochemical background and anthropogenic sources. The province is highly polluted by some heavy metals due to the presence of mineral resources notably Lead and Zinc, their improper utilization, and also the development of a number of related industries. Bonab district was selected for detail study and the objectives of the study were set to evaluate the total as well as bioavailable fraction of heavy metals in surficial soils within the studied area. 72 soil samples were collected and analyzed for heavy metal contamination by Atomic Absorption Spectrometry (AAS). The obtained results when compared with WHO and USEPA standards show a very high concentration of some toxic metals. Soils were basically polluted by Pb, Zn, Cu, and Cd. Bioavailable fraction of studied metals were also measured with formation of metal complex with Diethylene tri amine penta acetic acid (DTPA) agent. To find the share of the anthropogenic sources in the contamination of soils, the Enrichment factor (EF) and Geological Accumulation Index were measured and the distribution maps were drawn using Arc GIS (9.3). Highest concentrations of some toxic metals were found as isolated patches around the Bonab Industrial Town as well as within and around the most populated areas of the district notably Zanjan city indicating its anthropogenic origin.

Distribution of Heavy Metals, Chemical Fractions and Ecological Risks around a Molybdenum Mine in Liaoning Province, China

The total contents of lead, arsenic, mercury, chromium, cadmium, zinc, copper, molybdenum and nickel were determined in soils collected from mining and agricultural areas around the molybdenum mine in Liaoning Province, China. The distribution, chemical fractions and ecological risks of heavy metals in soils were investigated and assessed. It was found that: the degrees of warning for all soils, both mining industry areas and agricultural areas, were serious warning. The results meant that all soils were contaminated seriously by heavy metals. The observed scheme of chemical fractions for heavy metals in soils of different sites was as follows commonly: residual>oxidable> reducible>acid soluble. The sources of heavy metals in top soils around the mine were as follows: dust fall, residue in the open air, higher background in soil-forming process, accompaniment element, automobile exhaust, wear of tires and brakes, release of heavy metals from ore tailing, the application of pesticides and irrigation with wastewater.

Monitoring and assessing heavy metals in topsoils as potential diffuse pollutants in the Pyeongchang River Basin, Korea

Topsoils, mainly from crop fields, orchards, forests, and barns around the Pyeongchang River, were collected to investigate their heavy metal concentrations. Pollution load index, ecological risk index, and enrichment factor were applied to assess levels of heavy metal contamination for topsoils. The concentrations of cadmium (Cd) (1.7 mg/kg) and chromium (Cr) (4.1 mg/kg) exceeded the troublesome level in one site, whereas zinc (Zn) (396.7 to 711.1 mg/kg) and nickel (Ni) (40.1 to 95.3 mg/kg) in several topsoils exceeded the troublesome to countermeasure levels, according to soil contamination standards for the study areas. A significant risk of contamination was observed for mercury (Hg) by all indices, although the concentration in most of the topsoils was below the guideline. As expected, a positive linear correlation was observed for the values of pollution load index and ecological risk index, demonstrating lower heavy metal contamination in upstream areas compared to those downstream. High to extremely high ecological risk was observed in several samples for Zn and Ni, while all of the soils were unpolluted to slightly polluted, according to the pollution load index. A baseline study was not performed earlier for these sites, so these assessed values of heavy metals should be used as reference values for further assessment.

Heavy metals in 3300‐year‐old agricultural soils used to assess present soil contamination

For evaluating present concentrations of heavy metals in soils, it is important to be able to determine natural or background soil concentrations. Here, we compare the content of 7 m HNO3‐extractable and 0.2 m Na‐EDTA‐extractable fractions of cadmium (Cd), zinc (Zn), lead (Pb) and copper (Cu) in present day cultivated A horizons (Ap) under different land uses and 19 buried A horizons (Apb) that have been covered by 3300‐year‐old burial mounds. The buried A horizons represent a unique opportunity to evaluate background concentrations of heavy metals in top soil. Variations in background concentrations were mainly related to clay content. Using the grain size distribution of present‐day topsoils (cultivated and forest/natural A horizons), the background concentrations were calculated and subtracted from observed concentrations prior to an evaluation of soil‐type‐ and land‐use‐specific metal accumulation. All cultivated soils were significantly enriched with respect to Cd, Pb, Zn and Cu over the last 3300 years and all forest soils were enriched with Pb. The study highlights the importance of using appropriate reference material for assessing present‐day metal concentrations and stocks.

Using Multivariate Statistical and Geostatistical Methods to Identify Spatial Variability of Trace Elements in Agricultural Soils in Dongguan City, Guangdong, China

Dongguan City, located in the Pearl River Delta, South China, is famous for its rapid industrialization in the past 30 years. A total of 90 topsoil samples have been collected from agricultural fields, including vegetable and orchard soils in the city, and eight heavy metals (As, Cu, Cd, Cr, Hg, Ni, Pb, and Zn) and other items (pH values and organic matter) have been analyzed, to evaluate the influence of anthropic activities on the environmental quality of agricultural soils and to identify the spatial distribution of trace elements and possible sources of trace elements. The elements Hg, Pb, and Cd have accumulated remarkably here, incomparison with the soil background content of elements in Guangdong Province. Pollution is more serious in the western plain and the central region, which are heavily distributed with industries and rivers. Multivariate and geostatistical methods have been applied to differentiate the influences of natural processes and human activities on the pollution of heavy metals in topsoils in the study area. The results of cluster analysis (CA) and factor analysis (FA) show that Ni, Cr, Cu, Zn, and As are grouped in factor F1, Pb in F2, and Cd and Hg in F3, respectively. The spatial pattern of the three factors may be well demonstrated by geostatistical analysis. It is shown that the first factor could be considered as a natural source controlled by parent rocks. The second factor could be referred to as “industrial and traffic pollution sources”. The source of the third factor is mainly controlled by long-term anthropic activities, as a consequence of agricultural activities, fossil fuel consumption, and atmospheric deposition.

Multivariate geostatistical analysis of heavy metals in topsoils from Beijing, China

Background. Regional soil environmental quality is a hotspot and difficulty in the environmental sciences for the spatial variability of pollutants and the relationship between them. Beijing, the capital of China, has been undergoing a rapid economical development during the past three decades, and thus might encounter the same issues as the developed countries. However, there is little information about the soil environmental quality of Beijing, especially at the regional scale. The real soil environmental situation of heavy metals remains unknown, even less the sources of possible pollutants. Objectives. The main objectives were to identify the spatial variability and main sources of heavy metals in Beijing soils by conducting multivariate statistical analyses, including geostatistical analysis assisted with GIS tools. These results will contribute to the establishment of the soil quality baseline and the management of regional environment. Materials and Methods. Seven hundred and seventy-three samples of topsoils (0–20 cm) were collected from all over Beijing, China. The samples were digested with HNO3 and H2O2. The concentrations of Cr, Cu, Ni, Pb and Zn were analyzed with a FL-AAS and those of Cd with a GF-AAS. The concentrations of As were determined with AFS-2202. Principal component analysis (PCA) and partial correlation analysis (CA) were used and geostatistics was conducted for the data processing. Results. Concentrations of topsoil As, Cd, Cr, Cu, Ni, Pb and Zn in the Beijing area were measured and contour maps were constructed to describe the metals' spatial distribution. Except for the background effect of the soils, anthropogenic factors made the soil heavy metal concentrations increase, especially in the center of the city. Combined with the PCA results, it was found that vehicle exhaust and smelters were the main sources of soil heavy metals. Pedogenic factors were also controlling the spatial features of metals. Discussion. Combined with the results of PCA, 7 heavy metals could be divided into 4 factors. F1 was the metals, i.e., Cu, Pb, Zn, mainly controlled by the human activities. Cr and Ni was in F2, Cd in F3 and As in F4. These 3 factors might be con

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

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

Monitoring of heavy metals in topsoils, atmospheric particles and plant leaves to identify possible contamination sources

The research reveals results of metal pollution on urban topsoil in relation to the metal content in leaves of two plant species and atmospheric particles. The content of pollutants (Ba, Cd, Cu, Fe, Mn, Ni, Pb, V and Ti) was determined by ICP-OES. Twenty-two samples of soil were collected over a six-month period from two different urban sites and one from a rural zone. Regarding the pollution level, the studied soils were found to be low. Results for enrichment (EF) and concentration (CF) factors showed that soils were enriched in Pb, Ba, Cu and Ni. However, both species of plants showed a common behavior for all elements acting as excluders. ANOVA and different multivariate statistical analyses confirmed that the main pollution source of soil was traffic and fertilizers. Cd, Fe, Mn, Ti and V elements were attributed to natural sources. Also, it was suggested that N. oleander leaf is useful as a bio-monitors of soil pollution by Cu. Similarly, a direct relationship was found between the content of Cu in soils with the Cu level in PM 10 atmospheric particles. The origin was attributed to dry and wet atmospheric deposition processes.

Parameterization of Freundlich adsorption isotherms for heavy metals in soils from an area with intensive livestock production

Adsorption coefficients are valuable tools used to estimate the environmental relevance of heavy metal contamination. However, their determination with batch experiments is laborious. Thus, attempts have been made to deduce these coefficients from soil parameters. However, the application of the resulting parameterized equations to different sets of samples has often yielded poor results. Hence, the objectives of the present study were (1) to deduce basic soil properties governing the coefficients of Freundlich adsorption isotherms for Cd, Cu, Ni, Pb, and Zn, and (2) to derive parameterized isotherms and examine their accuracy. For this purpose, 30 topsoil and nine subsoil samples were investigated which represented one Podzol-Cambisol-Gleysol soilscape in an area with intensive livestock production in Lower Saxony, Germany. Total background concentrations (aqua regia digestion) of heavy metals in topsoils ranged from 0.290 (Cd) to 19.2 mg kg -1 (Zn) and exhibited elevated mobilizable proportions (NH 4 EDTA pH 4.6 extract) of 17 (Ni) - 66 % (Zn) from the total concentration. Background concentrations were higher in topsoils than in subsoils by factors of 1.7 (Ni) - 28 (Zn). These differences were assigned to the special situation of heavy metal input mostly originating from animal excrements. The isotherms obtained by batch experiments showed larger coefficients K F for partition among soil solid phase and soil solution in topsoils than in subsoils by a factor of 3.5. The coefficients of the isotherms were significantly correlated with routinely determined soil properties such as cation exchange capacity and pH (R = 0.36-0.89). Parameterized isotherms were calculated for each metal by inserting the relevant parameters in multiple linear regression equations. Among these parameters were the soil pH, cation exchange capacity, total metal concentration, and the concentrations of organic carbon, clay, fine silt, and various pedogenic oxides. The K F values, separately calculated for topsoils and subsoils, agreed well with those determined by batch experiments (R = 0.63-0.97). Therefore, parameterized isotherms are valuable tools for the prediction of heavy metal partition in soils from one soilscape and for a risk assessment in the investigated, densely stocked area and similar areas.