Elements In Surface Soils Research Articles

Quantitative source apportionment and health risk assessment of trace elements in surface soils around the Shazand chemical industrial district, northwestern of Iran

A comprehensive study aimed at measuring trace elements pollution in the Shazand chemical industrial district, located in northwestern Iran, was conducted. Employing principal component analysis (PCA) and positive matrix factorization (PMF), we identified sources of trace elements and assessed associated health risks for inhabitants. The results showed that the mean concentrations of Pb, Cd, Ni, Zn, and As of 190 topsoil samples exceeded the background values, except for Cu. The total noncancer risk values for adults and children were 0.72 and 7.95, respectively, and the total carcinogenic risks were 8.46 E – 05 and 2.69 E – 04, respectively. The noncarcinogenic risk for children was above the threshold level, but low for adults. The total potential carcinogenic health risks for children exceeded the threshold of 1 E – 04 indicating a high carcinogenic risk for them, whereas the risk for adults was considered acceptable. Furthermore, As was the primary hazardous metal to human health, followed by Cd and Ni. According to the results of the PMF model, four factors were extracted for trace elements, including natural source, transportation sources, industrial sources, and agricultural sources, which contributed about 27.9%, 17.51%, 29.15%, and 25.44% to pollution of the area, respectively. Anthropogenic sources contributed far more to the potential health risks posed to inhabitants of the study area. These findings can assist governmental agencies in implementing targeted control strategies to prevent the contamination of heavy metals.

Risk Assessment of Toxic Elements in Surface Soils Collected Near and Far from a Deactivated Lead Smelter in Bahia, Brazil

Twenty-eight surface soil samples were collected in Santo Amaro, Brazil, to evaluate the current environmental impact caused by a lead smelter that operated in this city from 1960 to 1993. The smelter was deactivated after causing deaths and irreversible adverse effects on the health of the population due to contamination by lead and other elements. In this context, lead, cadmium, arsenic, chromium, copper, and zinc, six of the seven elements recommended by Hakanson in 1980 for ecological risk assessment, were determined using inductively coupled plasma – optical emission spectrometry (ICP OES). The contamination factor (CF), ecological risk index (Er), pollution load index (PLI), degree of contamination (mCdeg), and potential ecological risk index (PERI) were used to investigate the level of contamination and the ecological risk of the samples. The CF index demonstrated that the samples collected inside the smelter showed high contamination for lead, cadmium, and zinc, low contamination for chromium, and low to moderate contamination for arsenic and copper. In addition, the integrated PLI index demonstrated that all samples collected inside the foundry showed high pollution; however, of the other twenty-two samples investigated, only two showed pollution. The ecological risk index showed that the soil samples collected inside residences near the foundry denoted ecological risk due to cadmium contamination. The PERI demonstrated that samples collected on the city’s access road and samples collected on streets close to the foundry denoted low ecological risk. The results obtained by applying the principal component analysis (PCA) and hierarchical cluster analysis (HCA) to data relating to the levels of chemical elements in the soil samples fully corroborate the results found using toxicological assessment indices.

Fractionation and risk assessment of potentially toxic elements in surface soil from northeast China mountains

Fractionation and risk assessment of potentially toxic elements in surface soil from northeast China mountains

Potential Sources, Pollution, and Ecological Risk Assessment of Potentially Toxic Elements in Surface Soils on the North-Eastern Margin of the Tibetan Plateau.

Due to increased levels of human activity, various pollutants are frequently detected on the Tibetan Plateau, where the environment is extremely fragile and sensitive. Therefore, this study investigated the sources, pollution, and ecological risks of soil potentially toxic elements (PTEs) in different landscape areas within the Qaidam Basin in the northeastern part of the Qinghai–Tibet Plateau. The contents of seven PTEs (Cd, Cu, Pb, Zn, As, Cr, and Ni) in 32 topsoil samples (0–2 cm) were analyzed in different regions of the Qaidam Basin. The concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn were 10.4–29.9 mg/kg, 0.08–4.45 mg/kg, 19–66 mg/kg, 8.2–40 mg/kg, 11.7–30.8 mg/kg, 11.1–31.2 mg/kg, and 32–213 mg/kg, respectively. The correlation between Pb and Cd in unpopulated areas was 0.896 (p < 0.01). The correlations among Pb, Cd, and Zn in agricultural areas, among As, Cd, Cr, and Zn in saline lake areas, and among As, Cd, Cr, Cu, Ni, Pb, and Zn in residential areas were all greater than 0.65 (p < 0.05). The principal component analysis results showed that Pb and Cd in unpopulated areas, Pb, Cd, and Zn in agricultural areas, As, Cd, Cr, Zn, and Pb in saline lake areas, and As, Cd, Cr, Cu, Ni, Pb, and Zn in residential areas were affected by human activities (significant factor >0.70). Based on the geological accumulation index and single-factor pollution index results, the maximum Cd values were found to be 4.93 and 45.88, respectively; Cd was thus the most serious PTE pollutant. The comprehensive pollution index of Nemero showed that moderately and severely polluted areas accounted for 18.89% and 18.46% of the total area, respectively. The results of the potential risk index showed that very strong and strong ecological risk points together accounted for 18.8% of the total points. The spatial variations in PTE pollution and the potential ecological risk index had similar patterns; both increased from the unpopulated areas in the northeastern Qaidam Basin to Golmud city in the south-western Qaidam Basin. These results indicate that human activities negatively impacted the soil ecological environment in the Qaidam Basin during the rapid development of the economy and urbanization and that these negative impacts tended to spread to unpopulated areas. Therefore, it is necessary to emphasize the significant impacts of human activities on environmental quality and formulate preventive measures to reduce PTE pollution in the Qinghai–Tibet Plateau.

Spatial variability and source analysis of typical soil trace elements at permafrost section along national highway 214 in the eastern Qinghai-Tibet Plateau.

This paper attempts to reveal the enrichment status, spatial characteristics and material sources of typical soil trace elements at permafrost section along National Highway 214 on the Qinghai-Tibet Plateau. Therefore, the samples of typical trace elements in surface soil, being located at the northern slope of Bayan Kara Mountains, were collected and tested. The concentrations of typical trace elements in soil were analysed by mathematical statistics, spatial analysis and ecological assessment. The results show that: (1) the concentrations of As, Cd and Hg in the soil are higher than the local background values, and their degrees of variation were high. There was a certain degree of accumulation. Soil As and Hg elements constitute "slight pollution", indicating there is a none-to-slight ecological hazard. (2) The distributions of soil As, Cd, Pb and Zn concentrations are lower near the highway and increase with distance from it and then become relatively low further away. The distributions of Cr, Cu, Hg and Ni concentrations show no obvious trends in any direction. (3) The spatial heterogeneity of typical trace elements in soil is affected by soil organic matter (SOM), cation exchange capacity (CEC), pH, slope curvature and aspect. At the local scale, soil texture and topography were the main affecting factors. Concentrations of Cd, Cr, Cu, Ni, Pb and Zn were mainly affected by natural factors, while those of As and Hg were affected by both natural and human factors.

Evaluating a Sampling Regime for Estimating the Levels of Contamination and the Sources of Elements in Soils Collected from a Rapidly Industrialized Town in Guangdong Province, China.

Gaogang Town, a typical urban center within the Pearl River Delta region of China, suffers contamination of soils with metals/metalloids due to rapid development of industrial activities and agriculture. Few studies have been conducted to systematically describe the main sources, influencing factors, and ecological risks of metals/metalloids in soils in China. In this study, 312 surface soil samples were collected, and 15 elements were detected by plasma emission spectroscopy, atomic fluorescence spectroscopy, and atomic emission spectrometry. Element content features were analyzed by index of geo-accumulation (Igeo), pollution load index (PLI), potential ecological risk index(RI), positive matrix factorization model (PMF), and geostatistical analysis. The PLI value is between 0 and 1, indicating that the whole study area is lightly polluted. Combining PMF model and geostatistical analysis, soil elements in surface soils of Gaogang town were quantitatively apportioned into four sources: parent material and basic substances (23.5%), natural sources (32.2%), agricultural activities and industrial pollution (22.9%), and transportation (21.4%). The comprehensive analysis results show that polluted areas are mainly distributed on roads, rivers, and industrial and human activity areas. The main sources of ecological risks are factory pollution and human activity. Finally, we found that a quarter of the sampling density was the best sample size for this study.

Migration Characteristics and Potential Ecological Environment Evaluation of Metal Elements in Surface Soil

In view of the excessive heavy metals in soil will affect the quality of crops and the personal safety of local residents, in order to analyze and evaluate the migration characteristics and potential ecological risks of heavy metals in soil in the study area, the heavy metal content, pH, regional distribution, correlation, migration characteristics, enrichment state and potential risk in 0–1 m soil depth were tested and analyzed. The results show that the distribution of most metal elements is closely related to pH in the soil. The contents of elements As, Cr and Hg in the soil of the study area change in an “L” shape along with the buried depth, that is, the contents of As, Cr and Hg increase generally along with the buried depth of the soil, and the contents of elements Cd and Pb decrease along with the buried depth. By analyzing the enrichment degree of heavy metals and evaluating the ecological risk degree, it can be concluded that only element Hg is moderately enriched in the soil layer of 0–0.4 m and Cd is the main ecological risk factor, and the potential ecological risk degree of Yuyao is between slight and moderate ecological risks.

Divergent Patterns and Spatial Heterogeneity of Soil Nutrients in a Complex and Dynamic Savanna Landscape

AbstractMany grassy ecosystems around the world are experiencing woody encroachment. These woody encroachers often cause nutrient enrichment in the plant‐soil environment, potentially facilitating their growth and reproduction. However, studies of encroachment effects on nutrient distributions have been confined to a few major elements (e.g.,N, and P) and limited in spatial extent. We analyzed 19 elements in dominant plants and in georeferenced soils across a subtropical savanna landscape experiencing woody encroachment to quantify their spatial patterns and elucidate drivers responsible for these patterns. We found divergent patterns of spatial heterogeneity of these elements in surface soils across this complex landscape. Nutrient accumulation and redistribution underneath woody canopies occurred in a subset of elements (i.e., N, P, S, Ca, Cu, and Sr). Though some of these elements are not necessarily growth‐limiting, they do occur in higher concentrations in woody compared to herbaceous plants. Distributions of the other elements were closely related to spatial variation in soil pH, clay content, and slope rather than to woody encroachment. Our nuanced spatial sampling approach and analysis reveal significant variation in nutrient distributions in response to woody encroachment, and illustrate the role of landscape patterns in mediating ecosystem processes. These changes in the concentrations and distributions of key essential nutrients broaden our understanding of the biogeochemical consequences of woody encroachment, and provide new insights regarding the significance of long‐term vegetation dynamics in dryland ecosystems.

Potentially toxic elements in surface soils of the Lower Don floodplain and the Taganrog Bay coast: sources, spatial distribution and pollution assessment.

The pollution of floodplain, deltaic and adjacent coastal soils in large fluvial systems, considered an urgent environmental problem, as well as potentially toxic elements in such environments, can negatively affect aquatic ecosystems, as well as pose significant risks to human health. This paper is devoted to the geochemistry of potentially toxic elements in soils of the Lower Don basin, which is one of the largest and most anthropogenically transformed water bodies in Southern Russia, as well as the adjacent areas of the Taganrog Bay coast. The median element concentrations in the soils of the study area were consistent with the world soil average and the contents of elements in background soils. Comparative assessment of the spatial distributions as well as the results of Pearson's correlations, cluster analysis and principal component analysis showed that Cr, Ni, Cu and Zn are predominantly of natural origin; Mn and As are of mixed sources; and Cd and Pb are predominantly of anthropogenic origin. The geochemical anomalies of elements were associated with the impact of local anthropogenic sources. Geochemical background values for Cr, Mn, Ni, Cu, Zn, As, Cd and Pb in the soils of the Lower Don and the Taganrog Bay coast determined using the 'median + 2 median absolute deviations' approach are presented. The highest values of the integrated pollution indices were observed in floodplain soils of small rivers.

Concentration and Spatial Distribution of Potentially Toxic Elements in Surface Soil of a Peak-Cluster Depression, Babao Town, Yunnan Province, China.

Potentially toxic elements (PTEs) in Chinese agricultural soils, including those in some heritage protection zones, are serious and threaten food safety. Many scientists think that these PTEs may come from parent rock. Hence, at a karst rice-growing agricultural heritage area, Babao town, Guangnan County, Yunnan Province, China, the concentrations of eight PTEs (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) were determined in 148 surface soil, 25 rock, and 52 rice grain samples. A principal component analysis (PCA) and hierarchical cluster analysis were used to divide the surface soil into groups, and inverse distance weighting (IDW) was used to analyze the spatial distribution of PTEs. Soil pollution was assessed with the geoaccumulation index (Igeo). The results show that Cd, Hg, Zn, and Cr were polluting the soil (average Igeo > 0). The highest concentration of PTEs was distributed in the southwest of Babao town in the carbonate rock area, which had the highest pH and soil total organic carbon (Corg), Mn, and TFe2O3 contents. PCA biplots of soil samples showed that the carbonate rock area was associated with the most species of PTEs in the study area including Pb, Cd, Hg, As, and Zn. The clastic rock area was associated with Cu and Ni, and the lime and cement plants were associated with CaO, pH, Corg, TC, and aggravated PTE pollution around factories. In high-level PTE areas, rice was planted. Two out of 52 rice grain samples contained Cd and 4 out of 52 rice grain samples had Cr concentrations above the Chinese food safety standard pollutant limit (Cd 0.2 mg/kg; Cr 1 mg/kg). Therefore, the PTEs from parent rocks are already threatening rice safety. The government should therefore plan rice cultivation areas accordingly.

Potentially Toxic Elements (PTEs) in Surface Soils of Gemstones and Lead Mining Communities: Differential Mineral Phases and Exposure Risks

Proper human health risk assessments are rarely conducted for mining communities, consequently when there is need for remediation to be conducted and compensation to be paid to impacted population they are typically done, assuming equal exposure risks from varying mining activities. This study was conducted to compare the distribution of potentially toxic elements in surfaces soils of gemstone and lead mining towns in Nigeria, and their anticipated exposure risks. To achieve this thirty-two surface soil samples were collected from Eggon, a gemstone mining town in Nasarawa State and Enyigba, a lead mining town in Ebonyi State. The samples were air dried, disaggregated and sieved through a 2000 μm mesh with the <2000 fraction retained for aqua regia digestion. Potentially toxic elements bound in the samples were quantified with Agilent Technologies 4210 (MP-AES). Mineral phases were identified and quantified using using a inXitu’s portable transmission XRD/XRF instrument (Terra) with a miniature X-ray tube and a CCD detector for collection both XRD signatures. The PTEs, As, Cd, Mn, Pb and Zn were higher in surface soils of lead mining town. At the gemstone mining town most the PTEs indicated similar concentrations at both mine site and residential areas, while at the lead mining town of the PTEs indicated higher concentrations at mine sites and mine road. At the lead mining town the estimated daily exposure doses for Pb were above threshold values irrespective of the exposure scenario. Mineralogy data indicated most of the PTEs in mineralized phases.

Ecological and health risk assessment of trace elements in surface soil in an arid region of Xin Jiang, China

Trace element pollution in soil has become an increasingly common issue and potentially harms the environment and human health. In this study, the contamination levels and ecological and health risk indices of trace elements in surface soils in Bai Cheng, Xin Jiang, were investigated in order to examine if the land usage changed from pasture to agriculture has influenced the behaviours of these trace elements. In this study, descriptive analysis, normality test, the Tukey-HSD method and non-parametric methods were used to investigate the characteristics of trace elements. The geo-accumulation pollution and ecological risk indices were used to analyse the degree of contamination by trace elements. Correlation and principle analyses were used to identify the sources of trace elements and a health risk assessment was used to analyse human exposure to trace elements of the soil. Cadmium was the main pollutant in the 0–5 cm soil layer in both agricultural and pastoral areas. Thus, it contributed most to the Geo-Accumulation Index (Igeo) and the comprehensive potential ecological risk index (RI) of the surface soils. The levels of RI for the topsoil layer of agricultural areas fell into moderate to high (II-III) ecological risk categories, and those of pastoral areas belonged to low to moderate risk categories (I-II). Both values of Igeo and RI of the surface soils in agricultural areas were higher than in pastoral areas. The carcinogenic risk of Cr through hand-to-mouth intake and the total risk of trace elements in soils for humans were higher than the safety reference level. Chromium was the greatest contributor to total carcinogenic risk. Trace element concentration levels in surface soils in pastoral areas were relevant to geochemical characteristics and atmospheric deposition, whereas trace element concentration levels in surface soils in agricultural areas were derived not only from geochemical characteristics but also from human activities. The change in land use from pasture to agriculture increased the trace element concentration level in surface soils. There were both ecological risks and human health implications for residents exposed to such contaminants of soils in the studied region.

Concentrations of selected trace elements in surface soils near crossroads in the city of Bratislava (the Slovak Republic).

It is well known that road transport emits various trace elements into the environment, which are deposited in soils in the vicinity of roads, so-called roadside soils, and thus contributes to the deterioration of their chemical state. The aim of this work was to determine concentrations of some metals and metalloids (arsenic (As), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), vanadium (V), and zinc (Zn)) in soils from crossroads with traffic signals, which are characterized by deceleration of vehicles and increased emissions of elements related mainly to brake and tyre wear. The results confirmed a moderate enrichment of soils with Cu, Pb, and Zn (enrichment factor (EF) values > 2) and significant enrichment for Sb (EF > 5), while the other elements showed no or minimal enrichment. The age of crossroads proved to have a positive influence on the accumulation of some elements in soils with the largest differences for Cu, Fe, Pb, Sb, and Zn (p < 0.001). Traffic volumes expressed as the average daily traffic intensity (ADTI) also positively influenced soil concentrations of Cr, Cu, Pb, Sb, and Zn, while distance to the crossroad had a significant negative effect on the soil concentration of Cu, Sb, and Zn (p < 0.001). The stable isotopic ratios of Pb, 206Pb/207Pb and 208Pb/206Pb, ranging from 1.1414 to 1.2046 and from 2.0375 to 2.1246, respectively,pointed to the mixed natural-anthropic origin of Pb in the soils of crossroads with a visible contribution of traffic-related sources. Based on the above findings combined with covariance among the studied elements using statistical methods applied to compositionally transformed data, it was possible to show that Cu, Pb, Sb, and Zn clearly originated from road traffic.

A regional soil and river sediment geochemical study in Baoshan area, Yunnan province, southwest China

This study aims to better understand, at a regional scale, the concentration and distribution of selected chemical elements in surface environments and the influence of natural factors (geological background, geomorphology) and anthropogenic factors (mining activities, land-use, agricultural fertilization) on their distribution in the Baoshan area, Yunnan province, southwest China. Mineral resources (such as copper, lead, zinc, mercury, gold, silver) and carbonate and basalt parent materials in this area often lead to elevated potentially toxic metals (PTMs), which are widely distributed where mining activities have rapidly developed since last 20–30 years. This study makes use of 1574 surface soil data and 425 deep soil data from the National Geochemistry Survey of Land Quality project (NGSLQ), and 1585 archived river sediment data which were collected and analyzed for the Regional Geochemistry-National Reconnaissance program (RGNR). These data, once log-ratio (clr) transformed have been studied by compositional data analysis (CoDA), principle components analysis (PCA) and spatial analysis. In the Baoshan area, the concentration of elements As, B, (Br), Co, Cr, Cu, Hg, (I), Mn, (N), Ni, Sb, (Sc), (Se), V, Fe2O3Total and (COrgonic) are enriched compared to the China Soil Geochemical Baselines program (CGB) and RGNR data sets; while elements Sr and Na2O are depleted compared to CGB and RGNR data sets. Influencing factors on surface soil, deep soil and river sediment composition of the study area are revealed. The distribution of most elements in surface soil, deep soil and river sediment are influenced by natural factors such that: Co, Cr, Cu, Ni, Sc, Ti, V, Fe2O3Total and MgO are controlled by the distribution of basic igneous rocks; Ca, Mg, Sr and pH are controlled by the distribution of carbonate rocks and basic igneous rocks; As, Hg, Sb, (Ag), Cd, Pb and Zn are controlled by mineralization; and other elements normally controlled by the distribution of clastic rocks and acid-intermediate rocks; while the organic matter such as Br, N, (P), S, COrgonic and CTotal in soil data set are controlled by geomorphic (altitude and temperature). Anthropogenic factors are also recognized in the soil data set. For example: high pH values in paddy land and grassland, and low pH values in forested land, garden plot and dry cultivated land; in agricultural area fertilization has caused enrichment of the nutrient elements (COrgonic, CTotal, N, P, etc.,) in surface soil; while in areas of mining, surface soils are contaminated by PTMs (incl. Hg, As, Sb, Cu, Pb, Zn and Cd).

Determination of local background and baseline values of elements within the soils of the Birimian Terrain of the Wassa Area of Southwest Ghana

ABSTRACT This study establishes the local background and baseline values of elements in surface soils in Wassa area underlain by Birimian rocks using probability Q–Q plots. In this study, a total of 2868 soil samples were collected. The chemical elements in these samples were analysed by XRF technique. The results from the analysis were processed following Papastergios and Karim methods that normalized and transformed the data after which a best of fit is estimated to determine the background and baseline values. The method excludes the outliers at the extremities from the transformed data until the distribution follows a straight line. The method yielded the following background values in this study: 6.41 mg/kg for As, 52.55 mg.kg for Cr, 9.89 mg/kg for Pb, 10.21 mg/kg for Co and 17.18 mg/kg for Ni. The calculated baseline values were also 13.2 mg/kg, 80.7 mg/kg, 6.7 mg/kg, 6.4 mg/kg and 8.7 mg/kg for As, Cr, Pb, Co and Ni, respectively. The departure between the locally calculated background and baseline values of elements relative to worldwide accepted background and baseline values suggests the relevance to conduct such studies for the various geological provinces in the country as a vital step to properly and effectively manage and sustain the environment against environmental health diseases.

Spatial Distribution and Health Risk Assessment of Potentially Toxic Elements in Surface Soils of Bosten Lake Basin, Central Asia.

A geographically weighted regression and classical linear model were applied to quantitatively reveal the factors influencing the spatial distribution of potentially toxic elements of forty-eight surface soils from Bosten Lake basin in Central Asia. At the basin scale, the spatial distribution of the majority of potentially toxic elements, including: cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), thallium (Tl), vanadium (V), and zinc (Zn), had been significantly influenced by the geochemical characteristics of the soil parent material. However, the arsenic (As), cadmium (Cd), antimony (Sb), and mercury (Hg) have been influenced by the total organic matter in soils. Compared with the results of the classical linear model, the geographically weighted regression can significantly increase the level of simulation at the basin spatial scale. The fitting coefficients of the predicted values and the actual measured values significantly increased from the classical linear model (Hg: r2 = 0.31; Sb: r2 = 0.64; Cd: r2 = 0.81; and As: r2 = 0.68) to the geographically weighted regression (Hg: r2 = 0.56; Sb: r2 = 0.74; Cd: r2 = 0.89; and As: r2 = 0.85). Based on the results of the geographically weighted regression, the average values of the total organic matter for As (28.7%), Cd (39.2%), Hg (46.5%), and Sb (26.6%) were higher than those for the other potentially toxic elements: Cr (0.1%), Co (4.0%), Ni (5.3%), V (0.7%), Cu (18.0%), Pb (7.8%), Tl (14.4%), and Zn (21.4%). There were no significant non-carcinogenic risks to human health, however, the results suggested that the spatial distribution of potentially toxic elements had significant differences.

Potential effects of exploiting the Yunfu pyrite mine (southern China) on soil: evidence from analyzing trace elements in surface soil.

Trace element contamination caused by mining is a serious environmental problem. The potential effects of exploiting the Yunfu pyrite mine (southern China) on soil were investigated by determining trace elements in 56 surface soil samples from the vicinity of the Yunfu pyrite mine. The samples were acid dissolved and measured by an inductively coupled plasma mass spectrometry (ICP-MS). Principal component analysis and hierarchical cluster analysis were used to identify factors influencing the trace element contents and possible sources of the trace elements. The degree of trace element pollution was determined using the geological accumulation index Igeo. Monte Carlo simulations were used to assess the health risks posed. The results show that (1) six factors (parent material, mining activities, ore composition, rainfall, terrain, and other inputs) strongly affected the trace element contents of the soil samples. (2) There were three groups of trace elements, according to their possible sources. One group (Cs, Ga, Ge, Hf, Nb, Rb, Ta, Th, Ti, U, and Zr) mainly originated in parent rocks. Another group (Cr, Ni, Sr, and V) was mainly supplied by industrial plants and traffic emissions. The third group (Ba, Co, Cu, Mn, Pb, and Zn) was mainly supplied through pyrite ore exploitation processes. (3) Some samples were slightly to moderately polluted with Cs, Ga, Ge, Nb, Rb, Ta, and Ti. Most samples were moderately to highly polluted with Ba, Co, Cu, Mn, Pb, and Zn. (4) Trace elements in soil pose strong non-carcinogenic and carcinogenic health risks to people (particularly children) living near the Yunfu pyrite mine.

Topsoil pollution in highway medians in the State of São Paulo (Brazil): determination of potentially toxic elements using synchrotron radiation total reflection X-ray fluorescence.

The presence of metals in vehicle emissions is due to several factors, such as the composition of fuels and lubricating oils, the wear of engine components, and their use in catalytic converters. It is known that the soil near highways is greatly affected by heavy vehicle traffic, since the use of highways is of fundamental importance for the flow of goods and public transport, especially in Brazil, street transport being the main form of transport in the country. Considering the scenario described, the main objective of this study was to monitor the concentration of potentially toxic elements in surface soils located on the medians of the main access highways in the city of Campinas (SP-Brazil) and classify the soils through geoaccumulation index. Using SR-TXRF it was possible to detect and determine the concentrations of 5 elements of toxic-environmental interest (Cr, Ni, Cu, Zn, and Pb) and 11 natural soil composition elements (Al, Si, S, Cl, K, Ca, Ti, Mn, Fe, Rb, and Sr). To evaluate the influence of highway distance on elementary concentrations, ANOVA and Tukey statistical tests were applied. Nickel, Cu, and Zn showed a decrease in their concentrations moving away from the highway, indicating their relation with vehicular emissions. Applying principal components analysis (PCA), it was possible to identify four groups of the quantified elements: those mainly related to the soil itself, those produced by traffic of automotive vehicles, and those emitted by industrial activities.

Calculation of Pollution Indicators and Health Hazards of Heavy Elements in Surface Soils in Samarra City

The current study focuses on the assessment of pollution indicators and health risks of heavy elements in the surface soil of Samarra City. Twelve soil sample collected from different sites in Samarra City, analysis of soil sample to find the heavy metals concentrations which As, Br, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sn, V, Zn, Zr, U, B, Cd, Hg, Th, Ce, La, Th, B, Ba .The results are compared with limit of world standard (12). The higher values which refer to pollution in heavy metal are Cr, Cu, Ni, Zn, Zr, Cd due to industry activity and Hg higher concentration because of Pharmaceutical Industries and Medical Waste . The high concentration in V, Br, Mo, Se, As because of agriculture activity. The enrichment factor calculated for the purpose of calculating saturation coefficient and treatment, analysis and conversion of the values of raw concentrations and the creation of the local background of Iraq. The most of the results are less than five ,but few value are greater than five indicating the anthropogenic input of these elements in soil in Samarra City which are Co, Mo, U in S2 because of agriculture activity and using fertilizer. Mo , Sn in S2 because of highly building activity. Cu, Mo, Zn in S5 Because industrial and motor oil spill. Uranium in S2, S4 and S11 because military activity. Contamination factor (CF) and the value of the pollutant load index are less than 4 that’s mean sites are polluted medium to high. After applying the health risk assessment model, the risk value for each non-carcinogenic heavy element is found to be less than 4 and for all three exposure methods (ingestion, skin contact and inhalation), in terms of carcinogenic components, the average daily dose (LADD) ) And compared to slope coefficient (SF) collected from previous studies. Equations are applied to find less than 0.0001 which is indicative of the occurrence of cariogenic diseases that may affect people exposed to soil. The risk of soil or dust ingestion is more insecure in the area of ​​activity in the effect of cobalt and manganese than on adults, and chromium has an effect on adults at a high level. HI value of inhalation that’s effect on adults and children revel the most hazardous heavy elements is Mn, Cr, Co for adults and children. HI value of dermal absorption the most hazard element Cr, Hg , Ce for adults and children which exposed to the soil. Swallow soil effect on children and adults. Especially chromium and mercury, which in turn affect the health exposed to the ingestion of polluted soil.

Assessment of trace element contamination of urban surface soil at informal industrial sites in a low-income country.

Trace elements released by human activity are ubiquitously detected in surface soil. The trace element contamination statuses of 20 sampling stations at two busy informal industrial sites of Harare city, Zimbabwe, were evaluated using geochemical indices. Spectrophotometric determinations of concentrations of trace elements in surface soil indicated generally higher values than the reference site and the average upper earth's crust. High contamination factors were observed for trace elements across sampling stations at Gazaland and Siyaso informal industrial sites. Concentrations exhibited heterogeneous distribution of trace elements in surface soil varying with the nature of activity at a sampling station. The pollution load index and degree of contamination suggested highly contaminated surface soil with Cd, Cu and Pb particularly where the following activities were done: (1) welding, (2) automobile maintenance and (3) waste dumping. These results may be very important to reduce soil contamination. Paving surfaces may help to reduce dispersal of trace elements deposited on surface soil to other stations and minimise human exposure via inhalation and contact.