Geochemical Background Levels Research Articles

SOURCE RISK ASSESSMENT FOR HEAVY METALS IN SOIL ON THE SITE OF A HYDROCARBON POWER PLANT

The present study aims to assess the soil quality on a hydrocarbon power plant site in Arad, Romania. It investigates the evolution of heavy metal concentrations (Cu, Zn, Pb, Ni, Cd, and Cr) to establish source-related risks. For this purpose, the Global Pollution Index (GPI) was used, calculated for soil sampling points in the licensed area, and the database of monitored indicators was processed. Sampling was carried out annually between 2011 and 2020. An Individual Pollution Index (IPi) was calculated for each heavy metal and reference value, taking into account the Geochemical Background Level (Bi) specific to Romania. The correlation between these indices and the degree of pollution for each soil sample monitored was carried out to the legal provisions. Heavy metal concentrations (Cs, i) were evaluated in relation to the national legislation for less sensitive land use. Finally, the GPI was determined, and based on these values, the overall soil pollution status was assessed. Based on the determined CFi values and the corresponding Toxicity Factors (Ti) of heavy metals, the environmental impact was assessed by environmental risk analysis using the Risk Indices (ERi and R.I.) method. All the analyzed indicators were within the legal limits during the studied period, except Cd, where the alert threshold was exceeded in 2019 and 2020.

Background construction for tracing metal inputs in estuarine sediments of the Liaodong Bay (NE China): Linear-regression method

Intertidal sediments are a significant reservoir of trace metals originating from human activities and natural weathering. However, the absence of geochemical background levels and the heterogeneity of sediment components are challenging to quantify the extent of trace metal contamination. For distinguishing the contribution of natural and anthropogenic inputs, dynamic background functions were established by linear regressions of trace metals (i.e., Zn, Cr, Ni, Cu, Cd, and Pb) against normalizer Al in three cores of the Daliao River estuary. Lead-210 geochronology indicated that trace metals have accumulated rapidly in the sediments since 1985 CE. The calculation results of enrichment factors and excess fluxes confirmed that the increased contents of Zn and Cd were contaminated by human activities. Conversely, the increased contents of others (i.e., Cr, Ni, Cu, and Pb) were attributed to variations in geological background levels, driven by the combination of grain size and organic matter. Overall levels of trace metals were at medium-low ecological risks (MSQG-Q: 0.19–0.38), and Ni at high-medium ecological risks (PEL-QNi > 0.5) in recent decades. Interestingly, these Ni probably originated from natural weathering rather than anthropogenic inputs because sediment quality guidelines lacked consideration for the differences in regional background levels and grain size. This procedure could provide the fundamental framework for regional investigations of spatial and temporal contamination, applied to other similar intertidal zones of sediment quality management.

Toxic metal pollution of aquatic ecosystems of European Union nature protection areas in a region of intensive agriculture (Lake Gopło, Poland)

The paper presents the results of research into toxic metal concentrations in the surface layer of bottom sediments in Lake Gopło. The research objectives were to identify the levels and spatial variability of Cu, Pb, Cd, Zn, Ni, Cr, As and Hg concentrations, their potential sources and the determinants of pollution levels. Metal contamination of the sediments was assessed using the geoaccumulation index (Igeo), pollution load index (PLI) and ecological risk index (RI). Chemometric methods (Pearson correlation, principal component analysis (PCA) and cluster analysis (CA) were used to determine the relationship between sampling sites and concentrations of toxic metals, thereby identifying the sources of contamination. The research found that grain-size composition, carbonate content and organic matter content in the bottom surface sediments of Lake Gopło are all characterised by low diversity. Therefore, the lithological features of the sediments are not a major factor in the concentrations and spatial variability of the metals. It was found that the metal concentrations in the great majority of samples were above regional geochemical background levels. The geochemical indices (Igeo, PLI, RI) indicate that the degree of toxic metal pollution in the sediments is slight in the central and southern parts of the lake and high in the northern part. The chemical analysis results showed that the samples in the central and southern parts of the lake differ little in their shares and concentrations of individual metals. This provides evidence that, as well as geogenic sources, their presence in sediments can be associated with non-point sources related to agricultural activities and with atmospheric sources (mainly the products of fossil fuel combustion). The higher concentrations of metals (especially Ni, Cd, Cr and Hg) in the northern part of the lake are influenced by the supply of industrial and communal pollutants from the lakeside town of Kruszwica. A factor limiting the migration of pollutants from the northern part of the lake towards the south is the lake’s morphology of the lake, which hinders water exchange between the northern part and the rest of the lake.

Evaluation of Heavy Metals Contamination in Suspended Sediments of Dikrong River, Assam, India

This study is a comprehensive monitoring survey to assess the environmental pollution status of the river Dikrong -was carried out in 2020. Samples were taken at 10 different positions along the river from the foot hill of Arunachal Pradesh down to the Brahmaputra river. Besides other biological and chemical parameters, concentrations of Fe, Al, Ti, Pb, Zn, Cu, Ni, Co, Mn and Cr. Very high element concentrations were determined at only a few stations of the river Dikrong. The mean concentration exhibits positive correlations among Fe, Al, Ti, Mn, Zn, Pb, Ni, and Co. The relative distributions of the contamination are: Al > Fe > Ti > Mn > Cu > Cr > Zn > Pb > Ni > Co. An evaluation of the pollution status of the river was carried out by enrichment factors (EFs), contamination factors (CFs), geo-accumulation indexs (Igeo) and pollution load indexs (PLIs) calculated using adapted background concentrations of heavy metals in the sediments. The investigating factors suggest the significant contamination for Dikrong river sediments are Al and Fe. The mean concentrations of heavy metals in the sediments were found to be below the geochemical background level of world surface rock average. The elemental correlation is indicative to the metamorphosed pyrophanite (MnTiO3) deposition.

Human health risk exposure and ecological risk assessment of potentially toxic element pollution in agricultural soils in the district of Frydek Mistek, Czech Republic: a sample location approach

BackgroundHuman activities considerably contribute to polluting potentially toxic element (PTEs) levels in soils, especially agricultural soils. The consistent introduction of PTEs in the environment and the soil pose health-related risks to humans, flora and fauna. One hundred and fifteen samples were collected in the district of Frydek Mistek (Czech Republic) in a regular grid form. The soil samples were air-dried, and the concentrations of PTEs (i.e. lead, arsenic, chromium, nickel, manganese, cadmium, copper, and zinc) were determined by ICP-OES (inductively coupled plasma optical emission spectrometry). The purpose of this study is to create digitized soil maps that expose the human-related health risks posed by PTEs, estimate pollution indices, ascertain the spatially distributed patterns of PTEs, source apportionment and quantify carcinogenic and non-carcinogenic health risks using the sample location approach.ResultsThe results revealed that the pollution assessment of the soils in the study area using diverse pollution assessment indexes (pollution index, pollution load index, ecological risk and risk index), based on the application of the local background value and the European average value, displayed a range of pollution levels due to differences in the threshold limits from differing geochemical background levels. The principal components analysis and positive matrix factorization, respectively, identified the sources of pollution and the distribution of PTE sources. Mapping the health index and total carcinogenic risk highlighted hotspots of areas within the study area that require immediate remediation. The self-organizing map (SeOM) revealed a diversified colour pattern for the factor scores. A single neuron exhibited a high hotspot in all factor loadings on different blocks of neurons. Children’s CDItotal (Chronic Daily Intake total) values for non-carcinogenic risk and carcinogenic risk were found to be greater than adults’, as were their HQ (hazard quotients) and CR (carcinogenic risk) values. According to the health index of non-carcinogenic risk, 6.1% of the study area sampled posed a potential risk to children rather than adults. Corresponding to the sampled pointwise health risk assessment, 13.05% of the sampled locations are carcinogenic to children. The estimated health risk in the agricultural soil was high, with both carcinogenic and non-carcinogenic risks that could threaten persons living in the study area, particularly children.ConclusionIn general, the continuous application of agriculturally related inputs such as phosphate fertilizers and other anthropogenic activities (e.g., steel industry) can increase the level of PTEs in soils. The use of mean, maximum, and minimum values in health risk estimation does not provide a comprehensive picture of a research area’s health state. This study recommends using a sampled pointwise or location health risks assessment approach, which allows researchers to identify high-risk environments that exceeds the recommended threshold as well as areas on the verge of becoming high risk, allowing for rapid remedial action.

Multi-geochemical background comparison and the identification of the best normalizer for the estimation of PTE contamination in agricultural soil.

Identifying a suitable geochemical background level (GBL) and an appropriate normalizer is imperative for ensuring soil quality, health, and security. The objective of this study was to identify the appropriate normalizer and suitable GBL for determining PTE enrichment levels in agricultural soils and investigate if there are any statistical differences due to the GBL [World Average Value (WAV) European Average Value (EAV)] used. Forty-nine topsoil samples were obtained from seven agricultural communities in the Frdek-Mstek District (Czech Republic). Portable X-ray fluorescence was used to determine the total PTEs (Cr, Ni, Cu, Y, Ba, Th, As, Pb, and Zn) concentration levels in the soil. Correlation matrix analysis was used to determine the metallic relationship between the PTEs and the normalizers (Al, Fe, Ti, Zr, Sr and Rb). Pollution indices such as contamination factor (CF), geoaccumulation index (Igeo) and enrichment factor (EF) analysis were used to determine the most suitable GBL. Al, Fe, Sr, Ti and Rb strongly correlated with the CF, Igeo and EF, whereas WAV performed better than the other geochemical background (EAV). The results indicated that Rb was the suitable normalizer and WAV was the appropriate GBL for agricultural soil and provided a foundation for evaluating and surveilling soil quality and health in agricultural soil.

An in-depth human health risk assessment of potentially toxic elements in highly polluted riverine soils, Příbram (Czech Republic)

Environmental pollution by potentially toxic element (PTE) and the associated health risks in humans are increasingly becoming a global challenge. The current study is an in-depth assessment of PTEs including the often studied lead (Pb), manganese (Mn), zinc (Zn), arsenic (As) and the less-studied titanium (Ti), rubidium (Rb), strontium (Sr), zirconium (Zr), barium (Ba) and thorium (Th) in highly polluted floodplain topsoil samples from the Litavka River, Czech Republic. Soil chemical properties including carbon (Cox) and reaction (pH_H2O) together with iron (Fe) were assessed in the same soils. A portable X-ray fluorescence spectrometer (p-XRFS) (Delta Premium) was used to measure the PTEs and Fe contents of the soils. Soil organic carbon and reaction pH were determined following routine laboratory procedures. The concentration level of each PTE was compared against world average and crustal values, with the majority of elements exceeding the aforementioned geochemical background levels. Distributions of the PTEs were mapped. Two pollution assessment indices including enrichment factor (EF) and pollution index (PI) levels were calculated and their means for Zn (43.36, 55.54), As (33.23, 43.59) and Pb (81.08, 103.21) show that these elements were enriched. Zn, As and Pb accounted for the high pollution load index (PLI) levels observed in the study. The EF and PI distribution maps corresponded with the concentration distribution maps for each PTE. On health risk assessment, hazard quotients (HQ) in different human groups varied. Children had the highest HQs for all PTEs than adults (women and men). PTEs with high HQ levels in distinct human groups were As, Zr and Pb. Zirconium is a less likely element to pose a health risk in humans. Nonetheless, it should be kept in check despite its low pollution occurrence.

Heavy metal pollution characteristics and assessment of environmental quality and safety of facility agriculture soil in Shouguang

Taking Shouguang Facility agriculture in Weifang City as the research object, heavy metals and other pollutants in new and old facility agriculture soil were investigated and analyzed from 2017 to 2019. The content of heavy metals in soil was analyzed, and the environmental quality of heavy metals was evaluated by single-factor pollution index method and Nemerow index method. The correlation between heavy metal content in surface soil and cultivation years, vertical distribution of heavy metal content in soil, frequency distribution of heavy metal in surface soil, and correlation between heavy metals in surface soil and soil nutrients were analyzed. The results showed that the average contents of the eight heavy metals were Cd 0.23 mg•kg−1, Hg 0.05 mg•kg−1, As 8.09 mg•kg−1, Pb 23.31 mg•kg−1, Cr 70.81 mg•kg−1, Cu 38.54 mg•kg−1, Ni 25.87 mg•kg−1 and Zn 147.52 mg•kg−1. Aside from Pb and Ni, the average content of all other heavy metals in the surface soil of facility agriculture was higher than the average of the control and the geochemical background level of soil in Weifang. Compared with the Environmental Quality Evaluation Standard for Farmland of Greenhouse Vegetables Production (HJ333-2006) and the Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land (trial) (GB15618-2018), the average content of heavy metals met the standards, with Cd, Hg and Zn content in some samples exceeding the standards. Most surface soil environmental quality is clean or relatively clean, but there is also part of the soil has reached the level of mild or moderate pollution. The content of heavy metals in the soil of the old facility agriculture (cultivation years > 10) was higher than that of the new facility agriculture (cultivation years ≤ 10), and the content of heavy metals in the surface soil (0∼20cm) was higher than that in the deep soil. The quality distribution of heavy metals in the surface soil is affected by exogenous heavy metals, among which Hg and Cd have the largest skewness coefficient and are most affected by exogenous. There was significant positive correlation between heavy metals in surface soil and available phosphorus, hydrolytic nitrogen, available potassium and organic matter. The results indicated that the accumulation of heavy metals in soil was related to the application of organic fertilizer, phosphate fertilizer and compound fertilizer.

Quality of Peri-Urban Soil Developed from Ore-Bearing Carbonates: Heavy Metal Levels and Source Apportionment Assessed Using Pollution Indices

Pollution indices are used to assess the influence of the bedrock as a natural source of heavy-metal (HM), and anthropogenic pollution from ore mining in soils developed from ore-bearing carbonates. The research was conducted in two areas differing in geological setting and type of land use in the Upper Silesia Industrial Region, Southern Poland. Physical properties such as pH, total sulfur, total carbon and total organic carbon values, as well as total Zn, Pb, and Cd contents (ICP-OES) for 39 topsoil samples were measured. Contamination factor (Cf), degree of contamination (Cdeg), pollution load index (PLI) and geoaccumulation index (Igeo), were used to determine the deterioration of topsoil due to HM pollution. The HM content exceeded geochemical background levels by 2.5–18.1 times. Very high to moderate topsoil contamination was determined. In a shallow historical mining zone, the relative influence of particular HM was found to be in the order of Pb > Cd > Zn and, in a deep mining zone, Zn > Cd > Pb. In the topsoil developed over shallow ore bodies, the HM content was mainly (60%) due to naturally occurring HM. In the area of deeply buried ore bodies, 90% of the HM load was related to anthropogenic sources. Zn, Pb and Cd vertical distributions and the patterns of topsoil pollution differ in terms of types of mined ores, mining methods and times elapsed since mining ceased. Pollution indices are an efficient tool for distinguishing soil anthropogenic pollution and geogenic contamination.

Comparison of Pollution Indicies in Assessing the Heavy Metal(loid)s Pollution of Arable Soils Adjacent to Industrial Complex in Gyenggi-do

Soils adjacent to the industrial complexes are known to be vulnerable to pollution with the diverse pollutant sources. This research assessed pollution level in the arable soils located nearby industrial complexes using different pollution indices. Both surface (0 - 15 cm) and subsurface (15 - 30 cm) soil samples were taken from 150 agricultural fields located nearby 15 industrial complexes. Total concentrations of As, Cd, Cu, Ni, Pb, Zn, and Hg in soils were determined after extracting with aqua regia and mostly were lower than the pollution threshold criteria for the agricultural soil designated by the Korean Soil Environment Conservation Act. The calculated PI values for As indicated the unpolluted status but those for all other metals were in the ranges of low to moderately polluted. The Igeo values for Cd and Zn indicated soils were in the unpolluted to moderately polluted ranges, but those for other metals were unpolluted. The Igeo evaluated the pollution level lower than PI due to the geochemical correction factor. The average PINemerow values for surface soil and subsurface soils were 1.26 and 0.73, respectively, indicating a higher pollution in surface soil than subsurface soil. Ranges of PINemerow values showed a wide spectrum of pollution level from clean to heavy pollution, depending on soil sampling sites. All pollution indices indicate that levels of pollution for Cd were higher than other metals. Also four pollution indices exhibited different levels of pollution, even though they are equally based on the total concentrations of heavy metals in soil. This discrepancy might be derived from the fact whether a pollution index considers the geochemical background level, an individual metal or overall metals. The results suggest that a suitable pollution index for the pollution assessment cannot be specified based on the total concentrations of metal in the arable soil. Pollution assessments of the arable soils using (A) single pollution index and (B) geoaccumulation index for each heavy metals, and (C) Nemerow pollution index for the integrated heavy metals in each industrial complex.

Urban Soils and Road Dust—Civilization Effects and Metal Pollution—A Review

Urban soils have been changed much by human impacts in terms of structure, composition and use. This review paper gives a general introduction into changes from compaction, mixing, water retention, nutrient inputs, sealing, gardening, and pollution. Because pollutions in particular have caused concerns in the past, metal pollutions and platinum group metal inputs have been treated in more detail. Though it is not possible to cover the entire literature done on this field, it has been tried to give examples from all continents, regarding geochemical background levels. Urban metal soil pollution depends on the age of the settlement, current emissions from traffic and industry, and washout. It seems that in regions of high precipitation, pollutants are swept away to the watershed, leaving the soils less polluted than in Europe. Health hazards, however, are caused by ingestion and inhalation, which are higher in 3rd world countries, and not by concentrations met in urban soils as such; these are not treated within this paper in detail. With respect to pollutants, this paper is focused on metals. Contrary to many reviews of the past, which mix all data into one column, like sampling depth, sieved grain sizes, digestion and determination methods, these have been considered, because this might lead to considerable interpretation changes. Because many datasets are not Gaussian distributed, medians and concentration ranges are given, wherever possible. Urban dust contains about two to three fold the hazardous metal concentrations met in urban soils. Some data about metal mobilities obtained from selective and sequential leaching procedures, are also added. Soil compaction, pollution, sealings and run-offs cause stress situations for green plants growing at roadside locations, which is discussed in the Section 5. Environmental protection measures have led to decrease metal pollutions within the last decade in many places.

Sources of anthropogenic contamination of soil in the Upper Silesian Agglomeration (southern Poland)

This assessment of the environmental degradation by toxic chemical elements within the Upper Silesian Industrial Agglomeration of Poland encompasses the impact of mining for base metals and coal and non-ferrous metallurgy, as well as the discharge of industrial and municipal sewage causing strong degradation of the natural environment in the area over the years. The content of the following elements: Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, P, Pb, S, Sn, Sr, Ti, V and Zn has been assessed both in the topsoil (0.0–0.3 m) and the subsoil (0.8–1.0 m) of the study area. Concentrations of the elements in the <2 mm soil fraction were analysed using the ICP-OES method after Aqua regia extraction. The soil contamination was assessed based on the enrichment factor ( EF ) and geo-accumulation index ( I geo ). The tests revealed elevated contents of several metals, arsenic and sulphur, exceeding the regional geochemical background levels. Unusually high concentrations of the following elements: As (up to 5,300 mg/kg), Cd (up to 388.8 mg/kg), Cr (up to 1,638 mg/kg), Cu (up to 13,230 mg/kg), Hg (up to 23.44 mg/kg), Mo (up to 93.7 mg/kg), Pb (up to 54,940 mg/kg), Sn (up to 701 mg/kg) and Zn (up to 88,120 mg/kg) were recorded. The highest concentrations of these elements were found in the proximity of smelters and residential areas. The spatial distribution of metals is shown as interpolated data on maps and compared with the locations of mining and industrial sites.

Contamination features and ecological risks of heavy metals in the farmland along shoreline of Caohai plateau wetland, China

Spatial distribution characteristics of heavy metal (Cd, Pb, Cr, Cu, Zn, and Hg) contents and their ecological risks in the farmland along the shoreline of the Caohai wetland were investigated. Incubation experiments were also conducted to characterize the emission of heavy metals across soil-water interface if the farmland was reclaimed to wetland. The results showed that spatial distribution characteristics of these heavy metal contents were significantly different. Concentrations of Cd, Zn, and Hg were higher than the corresponding geochemical background levels. Ecological risk assessment suggested that the farmland along the shoreline of Caohai wetland were characterized by non-pollution or slight pollution of Pb, Cr, and Cu, moderate pollution of Cd, slight to moderate pollution of Hg, and slight pollution of Zn. Emission rates of Cd, Zn, and Hg across soil/sediment-water interface first increased, then decreased and finally reached equilibrium after the farmland soil was submersed. The contribution-rates of Cd, Zn, and Hg transferring from sediment to overlying water were calculated to be 12.7%, 14.8%, and 10.4%, respectively. We conclude that environmental issues caused by heavy metals, especially by Cd, Zn, and Hg, in the farmland along the shoreline of the Caohai wetland should be paid great attention.

Evaluation of the environmental and human health risk related to metallic contamination in agricultural soils in the Mediterranean semi-arid area (Saiss plain, Morocco)

In the plain of Saiss, the most agricultural region of Morocco, the studies concerning the assessment of environmental and human risks related to metal contamination of agricultural soils are severely missing. To overcome the lack of such studies, trace-element analyses were carried out on six sampling sites of agricultural surface soils (66 sampling points), irrigated by superficial watercourses with high heavy metal contents. The average trace-element contents were 78, 55, 33, and 119 (mg kg−1), respectively, for Cr, Cu, Ni, and Zn. These values are above average worldwide soil and geochemical background levels. Multivariate statistical analyses, principal component, and cluster analyses suggest that soil contamination by Cr, Cu, and Zn is mainly due to wastewater irrigation, with the exception of Ni, which is probably of pedo-lithogenic origin. To provide further information on contamination transmission, the bioavailability and distribution of the four heavy metals in the soils were studied by sequential and single extractions. The results indicate that Cu and Zn are potentially available and can constitute a potential risk to the environment. The risk assessment of soil contamination was also carried out using risk assessment code, enrichment factor, contamination factor, degree of contamination, pollution lead index, geoaccumulation index, and potential ecological risk factors. The health risk evaluation by the Hazard Index was used to derive a combined risk of soil ingestion, dermal contact, and inhalation for adults and children. According to these indices, the soils present a moderate-to-high contamination for Cu and Zn elements, respectively. Hazard Index values indicate the relative absence of health risks associated to heavy metals for both adults and children.

Assessment of Metallic Content, Pollution, and Sources of Road Dust in the City of Białystok (Poland)

ABSTRACT This study used flame atomic absorption spectrometry (FAAS) to determine the metallic content in 69 samples of street dust collected in various environments (viz., streets with heavy traffic, streets in residential neighborhoods, and streets near green areas and parks) of Bialystok, Poland, during 2018. In descending order of average concentration, the measured metals were Fe (2,335 mg kg−1), Zn (68.99 mg kg−1), Mn (68.62 mg kg−1), Cu (16.37 mg kg−1), Pb (11.42 mg kg−1), Cr (9.12 mg kg−1), and Ni (5.20 mg kg−1). Only Zn and Cu exhibited concentrations exceeding the geochemical background levels for Polish soil. We mapped the metallic concentrations in the samples to evaluate the spatial distribution of these elements and identified proximity to main road junctions with high traffic as a major factor. Multivariate statistical analysis (Pearson correlation, cluster analysis, and analysis of major components) revealed an association between vehicle operation, and Zn, Ni, Cu, and Cr, as these elements were found in the most traffic-congested areas. By contrast, Fe and Mn, which were detected in potentially unpolluted areas, displayed concentrations that were similar to natural ones.

Assessment of Selected Heavy Metals Content in Soil of Agricultural Activity

A representative sample of agricultural soil was studied for assessing the level of toxic heavy metals that could be passed on to crops; this can be the first step towards determining the possibility of its further use, especially in areas where strong industrialization progress is visible. The soil texture, pH, and bulk density along with the total amount of lead (Pb), cadmium (Cd), and nickel (Ni) were analyzed for characterizing the status of the soil at two depths: TOP (a composite sample from 0–30 cm deep) and BOTTOM (a composite sample from 30–60 cm deep). The sampling scheme was a square grid with 16 regularly spaced points. The heavy metals concentration values were below legal limits but higher than the regional geochemical background level, suggesting an anthropogenic origin. The pollution load index (PLI) was implemented as a tool for computing the generalized heavy metal pollution status. A geostatistical analysis of the data shows a spatial variation on a detailed scale, both in the horizontal and vertical dimensions, with the TOP soil showing higher average Pb and Cd concentrations.

HEAVY METALS BIOCONCENTRATION AND TRANSLOCATION IN PLANTS: THE INFLUENCE OF A THERMAL POWER SITE

Soil and plant samples were collected from agricultural areas under the influence of thermal power plant and ash samples were collected from ash storage area. In samples, As, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, V, Zn, Al, Ca, Fe, K, Na and S were analyzed using ICP-MS. The aim of the study is to determine the set of elements mainly emitted from the components of the thermal power plant, as well as the major sources influencing the plant elemental levels. In the ash samples, significant enrichments of S, Mo, As, Ca, Cd and Cr were determined. Sugar beet leaves were considered to be a potential Na hyperaccumulator due to the translocation factor (TF) of 13525 calculated in its leaves. As a result of the Principal Component Analysis applied to the bioconcentration factors (BCFs) determined in plant parts, the main source of Co , Pb , Ni , Cr , Fe , Al, V, As, Mn and Cd was determined as geochemical background level of soil. Cu, Zn, and Mo enrichment in plant parts were found linked with agrochemicals used on the site, while another source of Cd was detected as phosphate fertilizers. Mo and S are identified as the main elements sourced from thermal power plant units.

A multi-method approach for the assessment of natural background levels in groundwater

The assessment of geochemical Natural Background Levels (NBLs) in groundwater, aims at distinguishing the naturally high levels of geogenic compounds from anthropogenic pollution. This is a fundamental issue in groundwater management, in particular when the concentration of inorganic compounds exceeds the threshold values set for the evaluation of the groundwater chemical status, as requested by environmental regulations.In this paper, we describe a new procedure that integrates the pre-selection method and statistical techniques, using the example of two case studies.The pre-selection aims to identify suitable groundwater samples for the NBLs assessment. The nitrate concentration threshold, for the removal of the groundwater samples affected by human activities, is established locally through different graphical and statistical approaches. Then, the statistical distribution of each compound is analyzed and the outliers are identified. Normality tests on the datasets allow one to select the most appropriate value, e.g. one percentile, to be adopted as NBL within the data distribution.In the selected case studies, we have defined the NBLs for As, F, Mn, Fe and SO4. The two sites are part of a volcanic-sedimentary aquifer in central Italy, where the geochemical background is frequently well above the standards for human consumption.The results of the simple and easily reproducible pre-selection method are strengthened by integration with statistical techniques, notably in selecting the appropriate percentile. New criteria are suggested for the choice of the nitrate threshold to be used for the pre-selection of uncontaminated samples.

Environmental indicators for evaluation of chromium content in soils on the example of an inoperative tanning plant

The main goal of this article was to assess the environmental impact of pollutants from anthropogenic sources (tanning plant) using environmental indicators (Igeo – geoaccumulation index, CF – contamination factor). The assessment was carried out based on the results of total chromium content in soil samples collected in the area of an inoperative tanning plant. Based on the obtained results of total content, significant chromium concentrations were found in the discussed area. All obtained chromium concentrations in the analyzed soil samples exceeded the geochemical background level and the specification limit for group II of soils, i.e. protected areas, defined by a Decree of the Minister of Natural Environment (2016). Based on the obtained results of Igeo and CF, the soils in the analyzed area should be considered highly polluted with chromium.

Copper prospectivity in Tibet, China: Based on the identification of geochemical anomalies

The Qinghai–Tibet Plateau is an important mineral-rich region and is well known for its copper resources. This study investigates stream-sediment geochemistry in assessing the potential for Cu resources in the region. A spectrum–area model is used to process large volumes of data with multifractal and power-spectrum analysis. The model can be used to separate geochemical anomalies from geochemical background levels thus eliminating the influence of different geomorphological landscapes. It is recognised from this study that geochemical anomalies are closely related to deep-seated faults forming terrane boundaries that are multiply deformed and intruded by granites. Second order structures related to these tectonic zones are commonly mineralised and are considered highly prospective for mineral resources. The results of this study indicate that geochemical anomalies are useful for identifying potential Cu mineral resources.