Background Concentrations Of Trace Elements Research Articles

Using iterative 2δ‐technique and 4δ‐outlier test for evaluating the geochemical background concentrations of trace elements in topsoil at Cao Bang province, Vietnam

AbstractThis study investigated the geochemical background values for seven trace elements in topsoil samples collected from highland areas within Cao Bang province, Vietnam. Total concentrations of these elements were determined, revealing the following order of mean concentration: Zn > Cr > Pb > Cu > As > Ni > Co. The background values were calculated using two different methods including iterative 2δ‐technique and 4δ‐outlier test. The 4δ‐outlier test yielded the following background concentrations (dry weight) for the seven elements: As (24.41 ± 12.42 mg kg−1), Co (15.64 ± 10.57 mg kg−1), Cr (49.31 ± 33.41 mg kg−1), Cu (29.77 ± 27.14 mg kg−1), Ni (22.52 ± 13.33 mg kg−1), Pb (38.06 ± 31.48 mg kg−1), Zn (71.79 61.09 mg kg−1). The 2δ‐technique, on the other hand, resulted in the following background concentrations (dry weight) for the same elements: As (8.41 ± 8.57 mg kg−1), Co (5.06 ± 4.31 mg kg−1), Cr (26.72 ± 26.20 mg kg−1), Cu (25.31 ± 24.81 mg kg−1), Ni (8.02 ± 7.83 mg kg−1), Pb (28.12 ± 27.58 mg kg−1), Zn (51.91 ± 49.44 mg kg−1). These results provide valuable baseline data for future environmental assessments and monitoring programs in the region. They also highlight the potential impact of human activities, such as mining, on the geochemical landscape of highland areas.

Choose Your Procedure Wisely: Removal of Outliers is Inappropriate for Estimating Background Concentrations of Trace Elements in Soil.

Background concentrations of trace elements in soil, i.e., the natural abundances of metals and metalloids in soil, have been the subject of much scientific discussion. This article attempts to clarify the concept, particularly from the perspective of environmental toxicology and chemistry. This article is protected by copyright. All rights reserved. Environ Toxicol Chem 2022;00:0-0. © 2022 SETAC.

The effect of rock lithology on the background concentrations of trace elements in alluvial soils: Implications for environmental regulation

To assess the extent of soil contamination with a potentially toxic element, it is important to determine the background concentration of that element in the soil. In this study we decided to investigate the relationship between trace element concentrations in soils and the lithology of their parent rocks. We collected 85 topsoils (0–20 cm) samples from the Petorca, La Ligua, Aconcagua, and Casablanca River basins (Valparaiso region, central Chile). For soil sampling, we chose 11 tributary watersheds free of anthropogenic influence. The areas that contributed to the formation of each alluvial soil were delineated and the parent lithologies were acquired from 1:250,000 geological maps. The results show that the total concentrations of arsenic (As), copper (Cu), lead (Pb), and zinc (Zn) in soil vary considerably among the four river basins studied. Soil concentrations of all elements under study are positively correlated with the presence of andesitic volcanic rocks. Furthermore, soils formed from marine sediments and felsic volcanic rocks had the highest concentrations of Pb and As. The carbonate-bearing marine sediments may have adsorbed As and Pb released by weathering of felsic volcanic rocks found upstream of the study area. In contrast, lithologies dominated by continental sedimentary and plutonic rocks showed negative correlations with the concentrations of As, Cu, Pb, and Zn in the soil. Thus, the differences in soil element concentrations in the watersheds under study were due to the different rock types present in the area. We argue that absolute “one-limit-fits-all” background trace element values may be inadequate to assess the extent of soil contamination. Therefore, it is important to determine background concentrations of soil elements in each river basin in the anthropogenically impacted areas. In contrast, erroneous conclusions can be drawn when background concentrations are determined in one region and then applied in another region that is lithologically different.

Background Concentrations of Trace Elements and Sediment Accumulation Rates for Tropical Pristine Environments

Background Concentrations of Trace Elements and Sediment Accumulation Rates for Tropical Pristine Environments

Development and validation of freshwater sediment quality assessment guidelines for trace elements in Korea

Sediment quality assessment guidelines(SQAGs) for seven trace elements were suggested to build an assessment system of freshwater sediment quality for a regulatory program in Korea. In this study, current one-step SQAGs were divided into three levels based on the probability of toxicity occurrence, namely, the threshold-effect-level(TEL), the probable-effect-level(PEL), and the apparent-effect-threshold(AET). A sediment toxicity database consisting of field-collected sediments and toxicity results from three different species were used to derive TEL, PEL, and AET. The ambient background concentrations of trace elements in freshwater sediments were used instead of the TEL values because TEL values were lower than the ambient background levels. To validate the reliability of the new SQAGs, a separate sediment toxicity database based on G. sobaegensis was used. When the mean quotient value for the PEL was 0.34, the reliability reached a maximum of 87% with a positive predictive value of 94% and a negative predictive value of 85%. These results showed the newly derived SQAGs were very useful for assessing and predicting the toxicity of field sediments in Korea. Finally, ambient background concentrations, a mean quotient of PEL of 0.34, and AETs were used to classify the quality of the field-collected sediments into four categories.

Assessment of trace element concentrations in sediment and vegetation of mesic and arid African savannahs as indicators of ecosystem health

The savannah biome supports unique biodiversity and provides a multitude of ecosystem services. Defining background concentrations for trace elements in the environment is beneficial for the determination of nutrient deficiencies/hotspots and for the management of pollution. Sediment and corresponding vegetation samples were collected around 48 surface water points in two savannah wildlife areas for assessment and comparison of 20 trace elements using ICP-MS. Site-specific and matrix-specific differences were evident for essential B, Co, Cu, Fe, Mn, Mo, Ni, Se and Zn, potentially toxic As, Cd, Cr, Hg, Pb and V and additional elements Al, Ba, Sb, Sn and Sr analysed. Sediment and vegetation from all sampled locations at both sites contained single or multiple potentially toxic elements at various concentrations. Although the presence of all elements can be linked to underlying geology and geochemistry specific to each site, evidence of anthropogenic cause was also evident at both sites. This paper covers the widest range of trace elements assessed in protected terrestrial wildlife reserves in the South African savannah biome to date and highlights the potential for deleterious consequences of trace element contamination of the environment.

Use of Background Concentrations of Heavy Metals for Regional Monitoring of Soil Contamination by the example of Rostov Oblast

In the monitoring of soils contaminated with heavy metals, the choice of the target indicators (background or threshold values) is a challenging task. The determination of the background concentrations is of practical importance, because the pollution of clean soils to the levels below the maximum permissible concentration (MPC) or the tentative permissible concentration (TPC) levels is not recorded and, hence, cannot be prosecuted. Background concentrations are rarely applied in pollution assessment, because they remain unknown in most cases. The study of the soils of specially protected natural areas in Rostov oblast has revealed the regional specificity of the soil cover—elevated concentrations of a number of heavy metals and other trace elements—related to their high concentrations in the parent materials. Therefore, it is impossible to apply current public health standards based on the total concentrations of elements, such as MPC and TPC, in the monitoring of soil contamination in Rostov oblast. The use of background values characterizing the soils of specially protected natural areas seems to be more promising for this purpose. For an adequate environmental monitoring, data on the background concentrations of trace elements in the virgin of slightly transformed soils of specially protected natural areas should be obtained with due account for the regional diversity of soils including their classification position, texture, and the character of parent materials.

Geochemical Investigation of Metals and Trace Elements around the Abandoned Cu-Ni Mine Site in Selibe Phikwe, Botswana

Metals and trace elements may occur naturally in rocks and soils, but elevated quantities of them are gradually released into the environment by anthropogenic activities such as mining. The current study aims at characterizing the spatial distribution of trace elements and evaluate site-specific geochemical background concentrations of trace elements in the mine soils and river sediments and also to discriminate between lithogenic and anthropogenic sources of enrichment around a copper-nickel mining town in Selibe-Phikwe, Botswana. A total of 43 soil, 30 river sediments, and 9 river water samples were collected from an area of 500 m2 within the precincts of the mine. The total concentration of Cu, Ni, Cr, As, Co and Zn in soils and sediments were determined using ED-XRF while river water samples were analyzed by ICP-AES. Geochemical pollution indices such as Geo-accumulation Index (Igeo), Enrichment Factor (EF) and Integrated Pollution Index (IPI) were employed for the assessment of metal and trace element contamination. The average metal concentration in soil of Cu, Ni, Cr, As, Co and Zn in the study area were 109.8, 107.1, 72.0, 2.3, 7.8 and 36.1 mg/kg, respectively. To calculate the geochemical baseline, Relative cumulative frequency curves and the 4 s -outlier test methods suggested by Matschullat et al. (2000) were incorporated. The estimated average baseline concentrations of Cr, Cu, Ni, Co, Zn and As are 53.8, 51.85, 53.95, 5.6, 32.36 and 4.27 mg?kg1, respectively. Soil leachate, sediment leachate and river water pH levels ranged from basic (9) to very acidic (3) in areas closer to the mine. There is high variation in heavy metal concentration, e.g. Cu, depicting regional natural background concentrations while others depict anthropogenic sources. The calculated Igeo values revealed moderate pollution level by the same metals. The result of integrated pollution indices suggested a generally deteriorating site quality. The results of chemical analysis also indicate that the trace elements in soils decreased with respect to distance from the mine; controlled mainly by water movement, wind direction, and topography.

Trace Elements in Benchmark Soils of Oklahoma

Natural background concentrations of trace elements in soils must be determined to establish baseline levels for soil remediation and to avoid the establishment of inaccurate or unrealistic guideline levels. The objectives of this study were to establish the background total trace element concentrations including As, Cd, Cr, Cu, Mn, Mo, Ni, Se, Pb, and Zn in 28 Oklahoma benchmark soils and to determine the relationship between soil properties and natural trace element concentrations. Soil samples were analyzed for total trace elements, pH, organic C, clay content, and oxalate‐extractable Al (Alox) and Fe (Feox). Both multiple regression and path analysis were used to examine the relationship between total trace elements and soil properties. The background concentrations of trace elements were (mg kg−1): As (0.75–33.6), Cd (0.13–0.80), Cr (4.30–69.7), Cu (1.94–32.7), Mn (27.4–2165), Mo (0.18–1.80), Ni (2.41–57.3), Pb (2.60–31.7), Se (below detection limit, i.e., <1.25), and Zn (15.3–142). Path analysis confirmed the relationships of the multiple regression but in some cases allowed us to more specifically identify the soil property most associated with the total trace element. In our study, total soil Cd, Cr, Cu, Ni, Pb, and Zn concentrations were dependent largely on clay content. Organic C content also significantly affected total soil Pb concentrations. Total soil As, Mn, and Mo concentrations were most dependent on Alox levels. Path analysis separated direct effects from indirect effects and proved to be an asset when determining which soil properties controlled total soil trace element concentrations.

Zoning and geochemical characterization of volcanic soils on Kamchatka

The paper presents the first data on the zoning of modern volcanic soils on the Kamchatka Peninsula according to the age and composition of volcanic ashes in which the surface organogenic horizons of the soils were formed. The following soil provinces are recognized: Northern, Central, Western, and Southeastern. Parameters of their regional geochemical background (concentrations of trace elements) are determined. The main factor controlling the background concentrations of trace elements in these soils is the composition of the ashes underlying the soils. The geochemical specifics of the surface organogenic horizons of volcanic soils on Kamchatka may be variably affected only by the concentrations of trace elements whose average contents in magmatic rocks are the highest: Cr, Cu, Mn, Sc, Zn, Co, V, and Ag. The maximum concentrations of excess elements were determined in the soils underlain by ashes of basic composition, and the minimum concentrations of these elements occur in the soils formed in silicic ashes. All soil provinces recognized on Kamchatka are characterized by pervasively elevated Cu concentrations. It is proposed to identify volcanic soils formed in the peninsula in ashes of various composition with the application of a multiplicative geochemical coefficient.

Local background concentrations of trace elements in soils: a case study in the Grand Duchy of Luxembourg

Background concentration values of trace elements were determined for soils in the southern part of the Grand Duchy of Luxembourg, which are developed on the Bituminous shale (BS), the so-called “Bifrons” shale, and the “Minette” (M) Fe-oolitic sandstone substrates. Sampling sites with minimal anthropogenic influence were selected, and soil profile samples were analysed for major and trace element contents. A clear distinction is seen between the trace element content of the soils developed on the Minette sandstone on the one hand and those developed on shales on the other hand. For the Minette soil samples, most elements are present in concentrations exceeding those reported in literature for soils developed upon sandstones, with, for example, values of up to 278 mg kg −1 As (median value 123 mg kg −1), 287 mg kg −1 Cr (median value 126 mg kg −1), and 95 mg kg −1 Co (median value 33 mg kg −1). In the shale soil samples, concentrations are generally lower except for Cu and Mo. These elements reach maxima of up to 66 mg kg −1 Cu (median value 41 mg kg −1) and 59 mg kg −1 Mo (median value 26 mg kg −1). The results confirm the importance of determining background concentrations locally. Bivariate analysis shows a linear relationship between Fe content and elements such as As, Co, and Ni for the Minette soils. No relationship is found between trace element concentrations and clay or organic carbon (OC) content, but this could be due to the limited variation of these factors among the studied soils. A reconnaissance study with regard to the availability of the trace elements in the Minette soil samples shows that these elements are quite immobile and hence of minimal threat to the ecosystem.

Trace Element Concentrations of Three Soils in Central Appalachia

Trace Element Concentrations of Three Soils in Central Appalachia

Mineralogy and geochemistry of sediments from Lakes Taupo and Waikaremoana, New Zealand

Abstract Sediments from Lakes Taupo and Waikaremoana, New Zealand, have been analysed to give background concentrations of trace elements in lakes relatively uninfluenced by anthropogenic contributions. Lake Waikaremoana sediments have higher contents of illite, chlorite, smectite, plagioclase, and quartz as well as higher contents of Al, Fe, Na, K, Mg, Ti, P, V, Cr, Co, Ni, Zn, Rb, Sr, Ba, Sc, U, Th, and Rare Earth Elements (REE), than Lake Taupo sediments. Diagenetic enrichment of Mn, Ni, Cu, Zn, P, As, and Fe was observed in surface sediments of certain cores from Lake Taupo where the surface sediment layer was preserved during coring.

Background aerosol composition in the namib desert, South West Africa (Namibia)

A remote site in the Namib Desert was selected for sampling background aerosols in southern Africa, as one of a wide network of stations spanning the Southern Hemisphere in a programme designed to measure the background concentrations of trace elements in the atmosphere. A series of samples was collected over a 6-month period using a single-orifice cascade impactor, which fractionated the particles into six size groups. Analysis was performed using particle-induced X-ray emission (PIXE), yielding results for S, Cl, K, Ca, Ti, Mn, Fe, Br and Sr, and occasionally also for V, Cr, Ni, Cu, Zn and Pb. No direct correlations with wind direction were observed excluding strong local or regional sources of particles. K, Ca, Ti, Mn and Fe can be identified with a dust dispersion source. Cl, large particle S and Br, and part of the K and Sr are derived from sea spray. Relative to the soil components small particle K is not enriched as it normally is in regions with less scarce vegetation. Cr, V, Ni, Cu, Zn and Pb concentrations and enrichments in the aerosol are lower than practically all values measured at any other location hitherto. The concentration of the small particle sulphur, 200 ng m −3, is believed to be related to anaerobic conditions and plankton blooms in the ocean upwelling zones off Namibia.

Some Evidence of Long-Distance Transport, Local Sources and Fractionation Between Air and Snow for Metallic Aerosols Deposited in Antarctic Snows Since the 1880s (Abstract only)

Using instrumental neutron activation analysis, we have determined the concentrations of Na, CI, Al, Sc, V, Cr, Mn, Co, Fe, Zn, As, Se, Br, Sb, and J in ultra-clean dated snow samples collected in central East Antarctica. These samples had been previously analysed by flameless atomic absorption spectrometry (Boutron 1980). For the elements determined by both techniques (Na, Al, Mn, Fe, and Zn) the results are in remarkable agreement. These new data confirm and extend the conclusion that background concentrations of trace elements observed at present in Antarctic snow are close to those observed about 100 a BP and thus that Antarctic aerosol is still little affected by global atmospheric pollution. These data also confirm that, for several metals, episodes of anomalously high concentrations are in phase with increased sulphate and acidity, which could result from volcanic fallout. However, during such episodes, a straightforward relationship between the rate of increase in trace metals and the rate of increase in sulphate and acidity is not observed. This also affects volatile elements such as Cl, Br, Se, and I. This is probably due to a combined effect of local versus long-range transport of volcanic aerosols together with a physico-chemical segregation between the various components of this aerosol.

Some Evidence of Long-Distance Transport, Local Sources and Fractionation Between Air and Snow for Metallic Aerosols Deposited in Antarctic Snows Since the 1880s (Abstract only)

Using instrumental neutron activation analysis, we have determined the concentrations of Na, CI, Al, Sc, V, Cr, Mn, Co, Fe, Zn, As, Se, Br, Sb, and J in ultra-clean dated snow samples collected in central East Antarctica. These samples had been previously analysed by flameless atomic absorption spectrometry (Boutron 1980). For the elements determined by both techniques (Na, Al, Mn, Fe, and Zn) the results are in remarkable agreement. These new data confirm and extend the conclusion that background concentrations of trace elements observed at present in Antarctic snow are close to those observed about 100 a BP and thus that Antarctic aerosol is still little affected by global atmospheric pollution. These data also confirm that, for several metals, episodes of anomalously high concentrations are in phase with increased sulphate and acidity, which could result from volcanic fallout. However, during such episodes, a straightforward relationship between the rate of increase in trace metals and the rate of increase in sulphate and acidity is not observed. This also affects volatile elements such as Cl, Br, Se, and I. This is probably due to a combined effect of local versus long-range transport of volcanic aerosols together with a physico-chemical segregation between the various components of this aerosol.