Total Trace Element Concentrations Research Articles

Remobilization of trace metals during laboratory resuspension of contaminated sediments from a dam reservoir

Dam reservoirs sometimes need to be fully drawn down, an operation that induces sediment resuspension. In the case of contaminated sediments, such resuspension may promote the remobilization of trace metals from the solid to the dissolved phase, threatening the water quality. The objective of this study is to evaluate the kinetic release and removal processes of trace metals during the resuspension of polluted sediments from a dam reservoir. Total contents of trace elements were analyzed in the surface sediments collected in the dam. Ascorbate and sequential extractions were used to assess the trace metal fractionation. Aliquots of wet sediments were resuspended during a week using a 3-L glass reactor. Three solid/solution ratios (2.7, 5.0, and 9.4 g L−1) were tested. The pH, Eh, dissolved oxygen, and temperature were continuously measured, and water samples were collected through a small pipe inserted into the reactor. Evolution of dissolved organic carbon, alkalinity, major ions, and trace element concentrations were measured in the water over the resuspension experiments. Another resuspension experiment was carried out to determine the quantity of elements that could be adsorbed onto the glass wall of the reactor. High levels of As, Cd, Pb, and Zn were measured in the reservoir sediments, compared to the quality guidelines. The temporal evolutions of the dissolved elements were similar during the resuspension experiments, regardless of the mass of sediment used. Depending on the elements, different trends can be highlighted: (1) Cd, Cr, Cu, Ni, V, and Zn were not remobilized; (2) Al, Mo, As, Ba, and Sr continuously increased during the experiments; and (3) Mn, Co, Fe, and Pb increased at the beginning of the experiments and then were removed from the dissolved phase. Co was likely adsorbed onto Mn oxyhydroxides, whereas Pb appeared to be regulated by the Fe oxyhydroxides. The results from sequential extractions did not allow to relate these groups to specific distributions in the solid phase. The greater risk of water quality degradation for this reservoir would be posed by the remobilization of As, which showed the greatest and the most prolonged release during resuspension, because it could not be removed onto particles due to its speciation. Dissolved As reached a maximum of 30 μg L−1 at the conclusion of the experiments, a concentration above the drinking water standard but well below the acute toxicity levels reported in the literature for fishes.

Trace Elements in Soils and Selected Agricultural Plants in the Tongling Mining Area of China.

The quality and safety of agricultural products from metal mining areas are of wide concern. In order to investigate the contents and health risks of trace elements in fruit vegetables planted in metal mining areas, 440 samples of fruit vegetables from 117 vegetable plots were collected from Tongling mining area. Trace element contents in fruit vegetables and soil were measured. The results indicated that the total concentration of trace elements in some of the soil samples exceeded the Grade II national standard in China. Transfer factor (TF) of Cd was the highest (8.360), followed by Zn, Cu, As, and Pb. Estimated daily intake (EDI) of the trace elements, except Cd, were generally below the maximum tolerable daily intake (MTDI). The target hazard quotient (THQ) of Zn for children was more than 1 in some vegetables, suggesting potential health hazards for child population. Total target hazard quotient (TTHQ) of Cu and Zn were also more than 1 through consumption of all vegetables, indicating significant health risks. For both adults and children, hazard index (HI) was more than 1 for the consumption of vegetables. The findings reveal the health risks associated with the consumption of trace elements through the intake of selected vegetables in the population of Tongling.

Trace element phytoextraction from contaminated soil: a case study under Mediterranean climate.

The current field study aims to assess the suitability of four different plant species (i.e. poplar, willow, hemp and alfalfa) to be used for trace element (TE) (i.e. Cd, Cu, Ni, Pb and Zn) phytoextraction under hot-arid Mediterranean climate conditions. Plants were grown for two consecutive years on a moderate TE contaminated soil, supplied with water and mineral nutrients. The growth and physiological parameters were assessed throughout the trial to compare the response of plants to the environmental pollution, and TE uptake rates were measured for aboveground plant tissues. The phytoextraction rate for each species was expressed as a function of aboveground biomass yield and the TE uptake and translocation within the plant. Alfalfa played a significant role in reducing extractable Ni (60.6%) and Zn (46%) in the soil, whereas hemp reduced 32% of extractable Cd and 46% of extractable Pb; poplar decreased extractable Cd (37%), Ni (49%), Pb (46%) and Zn (63%); and willow reduced the extractable Zn (73%) compared to the beginning of the trial. No change in total TE content was observed; however, poplar and willow were able to extract and accumulate the highest amount of Zn (3200 and 5200gha-1year-1 respectively) and Cu (182 and 116gha-1year-1), whereas hemp, with 36gha-1year-1, showed the best phytoextraction potential for Pb. Overall, we found a positive correlation between the phytoextraction rate and biomass yield, extractable TE concentration and translocation factor (TF) and a negative relationship with Ca concentration in the soil.

Elemental Composition and Health Risk Assessment of PM10 and PM2.5 in the Roadside Microenvironment in Tianjin, China

ABSTRACT To determine the elemental composition and health risk of particles in the roadside microenvironment, particulate matter samples (PM10 and PM2.5) were collected at the side of four roads in winter, spring, and summer of 2015. The total concentrations of crustal and trace elements and the average concentrations of most single elements followed the sequence of spring, winter, and summer. Crustal elements accounted for 18.9%, 13.2%, and 9.3% of the PM10 and 15.1%, 11.2%, and 18.8% of the PM2.5 in the three seasons, respectively. On average, Zn contributed the largest share, accounting for 34.0%, 32.2%, and 34.2% of the total trace elements in PM10 and for 35.2%, 28.3%, and 35.6% in the PM2.5 for winter, spring, and summer, respectively. The enrichment factor results showed that Mn, K, Na, Co, and Si originated in crustal sources; V, Ca, Mg, Mo, Cr, Fe, Ti, and Ba were derived from both anthropogenic and crustal sources; and Cd, Sb, Zn, Cu, Pb, As, and Ni were largely derived from anthropogenic sources. The results of principal component analysis explained 72.64% of the total variance for PM10 and 78.76% of the variance for PM2.5. Possible sources include resuspended road dust, vehicular exhaust, fugitive dust (road dust and soil dust), and tire/brake wear. The respective ratios of Fe/Al, Mn/V, Cu/Sb, Cu/Zn, Zn/Pb, V/Ni, and Cu/Pb in this study were 0.58, 2.87, 11.07, 0.28, 1.23, 1.34, and 4.45 for PM10 and 1.07, 0.83, 23.07, 0.44, 1.83, 1.60, and 4.18 for PM2.5. Accumulative non-cancerous toxic elements in winter and spring may pose risks to roadside workers via inhalation. The integrated cancer risks (CR) of As, Co, Cd, Cr, Ni, and Pb in PM2.5 and PM10 ranged from 1.58E-05 to 4.95E-05 CR.

Concentration of trace and major elements in natural grasslands of Bosnia and Herzegovina in relation to soil properties and plant species

ABSTRACTDeficient trace elements concentration in soils, forages, and animals have been reported in several areas of Balkan region. Main challenge in overcoming low productivity of forage and animal production in this region is the lack of data on the nutritional status of the pastures and soils. This study examined the nutrient and pseudo total concentration of trace elements in soil and herbage plants, and the potential deficiency or excess with regards to crop and livestock production. Soil and plant samples from 100 sampling points were collected in the mountainous grasslands of Manjača (between longitudes 16°56′ and 17°8′ east; and latitudes 44°33′ and 44°42′ north) and Vlašić (between longitudes 17°14′ and 17°29′ east; and latitudes 44°25′ and 44°37′ north). Soil samples were analysed for soil texture, pseudo total concentration (5 ml HNO3) of trace elements (TE), pH, soil organic carbon (SOC), while plant samples were analysed for TE. The soil pH varied from strongly acidic to moderately alkaline. The concentration of SOC varied from 0.5% to 12.3%. Most of the soil samples were finer-textured soils high in silt content. The average concentrations of Na, P, Zn, Se, Cu, Co, and B were low in both soil and herbage plants. Plant K, Ca, Mg, Mo, and Mn concentrations were sufficiently high to meet the requirements of grazing animals, while Fe concentrations was elevated in certain areas. High levels of Mo were found in both soil and plants. The results suggest that imbalances observed in natural pastures of Manjača and Vlašić area, caused by low soil TE concentration and other soil and plant properties, could contribute to poor animal nutrition.

Spatial Distribution and Fuzzy Health Risk Assessment of Trace Elements in Surface Water from Honghu Lake.

Previous studies revealed that Honghu Lake was polluted by trace elements due to anthropogenic activities. This study investigated the spatial distribution of trace elements in Honghu Lake, and identified the major pollutants and control areas based on the fuzzy health risk assessment at screening level. The mean total content of trace elements in surface water decreased in the order of Zn (18.04 μg/L) > Pb (3.42 μg/L) > Cu (3.09 μg/L) > Cr (1.63 μg/L) > As (0.99 μg/L) > Cd (0.14 μg/L), within limits of Drinking Water Guidelines. The results of fuzzy health risk assessment indicated that there was no obvious non-carcinogenic risk to human health, while carcinogenic risk was observed in descending order of As > Cr > Cd > Pb. As was regarded to have the highest carcinogenic risk among selected trace elements because it generally accounted for 64% of integrated carcinogenic risk. Potential carcinogenic risk of trace elements in each sampling site was approximately at medium risk level (10−5 to 10−4). The areas in the south (S4, S13, and S16) and northeast (S8, S18, and S19) of Honghu Lake were regarded as the risk priority control areas. However, the corresponding maximum memberships of integrated carcinogenic risk in S1, S3, S10–S13, S15, and S18 were of relatively low credibility (50–60%), and may mislead the decision-makers in identifying the risk priority areas. Results of fuzzy assessment presented the subordinate grade and corresponding reliability of risk, and provided more full-scale results for decision-makers, which made up for the deficiency of certainty assessment to a certain extent.

Effect of neutralising substances on the total content of trace elements in soil contaminated with zinc

Effect of neutralising substances on the total content of trace elements in soil contaminated with zinc

Open-water and under-ice seasonal variations in trace element content and physicochemical associations in fluvial bed sediment.

Across the circumpolar world, intensive anthropogenic activities in the southern reaches of many large, northward-flowing rivers can cause sediment contamination in the downstream depositional environment. The influence of ice cover on concentrations of inorganic contaminants in bed sediment (i.e., sediment quality) is unknown in these rivers, where winter is the dominant season. A geomorphic response unit approach was used to select hydraulically diverse sampling sites across a northern test-case system, the Slave River and delta (Northwest Territories, Canada). Surface sediment samples (top 1 cm) were collected from 6 predefined geomorphic response units (12 sites) to assess the relationships between bed sediment physicochemistry (particle size distribution and total organic carbon content) and trace element content (mercury and 18 other trace elements) during open-water conditions. A subset of sites was resampled under-ice to assess the influence of season on these relationships and on total trace element content. Concentrations of the majority of trace elements were strongly correlated with percent fines and proxies for grain size (aluminum and iron), with similar trace element grain size/grain size proxy relationships between seasons. However, finer materials were deposited under ice with associated increases in sediment total organic carbon content and the concentrations of most trace elements investigated. The geomorphic response unit approach was effective at identifying diverse hydrological environments for sampling prior to field operations. Our data demonstrate the need for under-ice sampling to confirm year-round consistency in trace element-geochemical relationships in fluvial systems and to define the upper extremes of these relationships. Whether contaminated or not, under-ice bed sediment can represent a "worst-case" scenario in terms of trace element concentrations and exposure for sediment-associated organisms in northern fluvial systems. Environ Toxicol Chem 2017;36:2916-2924. © 2017 SETAC.

Total and Leachable Concentration of Trace Elements in Soil towards Human Health Risk, Related with Coal Mine in Jorong, South Kalimantan, Indonesia

Total and Leachable Concentration of Trace Elements in Soil towards Human Health Risk, Related with Coal Mine in Jorong, South Kalimantan, Indonesia

Evaluation of Metals Bioavailability in Agricultural Soil Treated with Wood Ash

In the present work, we aimed to study the effect of quantitative changes of micronutrients (Cu, Zn, Mn) in soil and plants caused by wood ash applied into the soil in increasing doses. A pot experiment with medium textured soil, white mustard as a test plant and six amendment treatments (doses of wood ash: 0, 1, 5, 10, 20, 30 Mg·ha-1) was performed. Total contents of Cu, Zn and Mn were determined in soil and plant samples. Single (DTPA and HCl) and sequential (BCR) extractions were used to evaluate the available amounts of metals and their distribution in fractions. A plant’s ability to accumulate metals from soils was estimated using the bioconcentration factor (BCF), which is defined as the ratio of metal concentration in the plants to that in soil. The increasing doses of wood ash increased total and available contents of trace elements, especially Cu and Mn. The distribution of metals among particular fractions depended mainly on their geochemical character. The highest content of Cu was found in the reducible and oxidisable fractions, whereas, the greatest amounts of Zn and Mn were in the exchangeable and reducible fractions, and the lowest in the oxidisable fraction. Despite small wood ash influence on metal distribution in the individual soil fractions, increasing doses of wood ash increased the amounts of Cu, Zn, Mn in easily soluble fractions, which are potentially available to plants. As a result of wood ash increasing doses application, the higher amounts of Cu, Zn and Mn in plant tissues were found. However, only in the case of Zn, the value of BCF indicated on such accumulation in the plants.

Trace element levels in an area impacted by old mining operations and their relationship with beehive products

The environmental status of an area impacted by Roman mining activities was assessed in order to establish the current risks posed by such old mine emplacements. For this purpose, soil samples were collected throughout the mining area and analysed for their total, mobile and mobilizable trace element (As, Cd, Mo, Sb and Zn) contents. Additionally, beehive products (honey and pollen) were also sampled and evaluated for their use as environmental indicators of the area. The results obtained were compared with those from a control non-polluted area. The mine soils presented slightly increased levels of Cd and Sb (about 2- to -3-fold their normal soil concentrations), whereas the enrichment of As reached considerable levels, with concentrations almost ten-fold of those considered the threshold for causing toxicity. Leachable As contents exhibited very high values (1.2–21.9mgkg−1), indicating the need for risk attenuation measures. All trace elements were mainly partitioned in the soil residual fraction, especially Mo (76–99%) and Sb (61–91%). Significant partitioning levels were also found in the reducible fraction of As (up to 35%) and Cd (up to 38%), and in the oxidizable fraction of Mo (up to 23%). The reducible pool of As was particularly relevant due to the eventual mobilization of this element under reducing conditions. Among the beehive products tested, honey proved not to be useful as an environmental indicator, whereas pollen showed great potential as an indicator when the contamination levels were moderate to high.

Chemical characteristics and source apportionment of PM2.5 using PCA/APCS, UNMIX, and PMF at an urban site of Delhi, India.

The present study investigated the comprehensive chemical composition [organic carbon (OC), elemental carbon (EC), water-soluble inorganic ionic components (WSICs), and major & trace elements] of particulate matter (PM2.5) and scrutinized their emission sources for urban region of Delhi. The 135 PM2.5 samples were collected from January 2013 to December 2014 and analyzed for chemical constituents for source apportionment study. The average concentration of PM2.5 was recorded as 121.9±93.2μgm-3 (range 25.1-429.8μgm-3), whereas the total concentration of trace elements (Na, Ca, Mg, Al, S, Cl, K, Cr, Si, Ti, As, Br, Pb, Fe, Zn, and Mn) was accounted for ∼17% of PM2.5. Strong seasonal variation was observed in PM2.5 mass concentration and its chemical composition with maxima during winter and minima during monsoon seasons. The chemical composition of the PM2.5 was reconstructed using IMPROVE equation, which was observed to be in good agreement with the gravimetric mass. Source apportionment of PM2.5 was carried out using the following three different receptor models: principal component analysis with absolute principal component scores (PCA/APCS), which identified five major sources; UNMIX which identified four major sources; and positive matrix factorization (PMF), which explored seven major sources. The applied models were able to identify the major sources contributing to the PM2.5 and re-confirmed that secondary aerosols (SAs), soil/road dust (SD), vehicular emissions (VEs), biomass burning (BB), fossil fuel combustion (FFC), and industrial emission (IE) were dominant contributors to PM2.5 in Delhi. The influences of local and regional sources were also explored using 5-day backward air mass trajectory analysis, cluster analysis, and potential source contribution function (PSCF). Cluster and PSCF results indicated that local as well as long-transported PM2.5 from the north-west India and Pakistan were mostly pertinent.

Mineral chemistry and genesis of the Permian Cihai and Cinan magnetite deposits, Beishan, NW China

Cihai and Cinan are Permian magnetite deposits related to mafic-ultramafic intrusions in the Beishan region, Xinjiang, NW China. The Cihai mafic intrusion is dominantly composed of dolerite, gabbro and fine-grained massive magnetite ore, while gabbro, pyrrhotite+pyrite-bearing clinopyroxenite and magnetite ore comprise the major units in Cinan. Clinopyroxene occurs in both deposits as 0.1–2mm in diameter subhedral to anhedral grains in dolerite, gabbro and clinopyroxenite. High FeO contents (11.7–28.9wt%), low SiO2 (43.6–54.3wt%) and Al2O3 contents (0.15–6.08wt%), and low total REE and trace element contents of clinopyroxene in the Cinan clinopyroxenite imply crystallization early, at high pressure. This clinopyroxene is FeO-rich and Si and Ti-poor, consistent with the clinopyroxene component of large-scale Cu-Ni sulfide deposits in the Eastern Tianshan and Panxi ares, as well as Tarim mafic intrusion and basalt, implying the Cinan mafic intrusion and sulfide is related to tectonic activity in the Tarim LIP. The similar mineral chemistry of clinopyroxene, apatite and magnetite in the Cihai and Cinan gabbros (e.g., depleted LREE, negative Zr, Hf, Nb and Ta anomalies in clinopyroxene, lack of Eu anomaly in apatite and similarity of oxygen fugacity as indicated by V in magnetite), indicate similar parental magmatic characteristics. Mineral compositions suggest a crystallization sequence of clinopyroxenite/with a small amount of sulfide – gabbro – magnetite ore in the Cinan deposit, and magnetite ore – gabbro – dolerite in Cihai. The basaltic magma was emplaced at depth, with magnetite segregation (and formation of the Cinan magnetite ores) occurring in relatively low fO2 conditions, after clinopyroxenite and gabbro fractional crystallization. The evolved Fe-rich basaltic magma rapidly rose to intermediate or shallow depths, forming an immiscible Fe-Ti oxide magma as fO2 increased and leaving a Fe-poor residual magma in the chamber. The residual magmas was emplaced at different levels in the crust, forming the Cihai gabbro and dolerite, respectively. Finally, the immiscible Fe-Ti oxide magma was emplaced into the earlier formed dolerite because of late magma pulse uplift, resulting in a distinct boundary between the magnetite ores and dolerite.

Sources of trace elements in wet deposition in Pamukkale, Denizli, western Turkey

ABSTRACTForty-two rainwater samples were collected during December 2011 and November 2012 in Pamukkale, Denizli, Turkey to investigate the characteristics of trace elements in wet deposition. The samples were analyzed by inductively coupled plasma optical emission spectrometry. Zn, Al, and Fe concentrations contributed 50.4% to the total element concentration. The trace element concentrations in rainwater samples showed seasonal variations, with high and low values in spring and summer, respectively. The daily total trace element concentrations of rainwater samples decreased exponentially with increasing precipitation rates. The wet deposition fluxes of trace elements were more affected by precipitation heights than concentrations. Enrichment factor analysis showed that Cr, Ni, Mn, Cd, Zn, Pb, Cu, Li, Sr, Co, and Ba indicate anthropogenic enrichment, while Al, Fe, and Ti were considered to be of crustal origin. As a result of principal component analysis, a three-component system of precipitation consisted of a mixed component (crustal and anthropogenic), a local pollution component, and an anthropogenic component, which explains 86.5% of the total variance. A significant fraction of the measured anthropogenic pollutants was transported to the sampling area from source regions in the North Atlantic Ocean, northern Europe, and the Balkans based on back-trajectory analysis. The acidic rain events, high concentrations, and fluxes of trace elements obtained in this study show that wet deposition in Pamukkale may be crucial for impacts on the local travertine. Trace elements that reach travertine by wet deposition may be viewed as a risk because of the anthropogenic origins of air pollutants.

Use of BCR sequential extraction procedures for soils and plant metal transfer predictions in contaminated mine tailings in Sardinia

PurposeThe total concentration of trace elements in soils does not always represent the fraction available for organisms and/or plants because they accumulate in several geochemical forms. The bioavailable concentration of Zn and Pb in mine tailing soils and its relation to the concentration in the leaves of plants growing there are analysed. Materials and methodsThe three-step sequential extraction BCR method was used to analyse samples from mine tailing and uncontaminated soils. The correlations of the Zn and Pb contents in the three BCR steps with the total concentrations of both trace elements in soils and plants and with the soil characteristics were determined. Three plant species were analysed: Dittrichia viscosa, Euphorbia pithyusa subsp. cupanii, Cistus salviifolius. The study area was situated in the Sulcis-Iglesiente biogeographic sector (SW Sardinia, Italy). Results and discussionThe soils with the highest total concentration of trace elements also presented the greatest metal availability. In general, the ratios of Pb and Zn concentrations in the BCR steps and the respective total concentrations in the soils were similar. The mine tailing soils registered high values for total Zn and Pb and also showed the highest percentages of these trace elements in the first two BCR fractions. However, the uncontaminated soils gave the highest percentages in the residual fraction. The total Pb concentration in the soils correlated with the concentrations found in the first two BCR steps (BCR1 and BCR2) and in the residue. For Zn, positive correlations were found with the three BCR steps. The correlations between the element extractions in the BCR steps and the soils characteristics depended on the particular soil type. Plant characteristics determined the correlations between the Pb and Zn concentration in leaves and soils. Specifically, none of the plants studied showed significant correlations between the Pb concentration and that found in the BCR steps. The opposite occurred for Zn whose concentration in plants appeared to be positively correlated with the concentrations found in the three BCR steps. ConclusionsThe Pb concentrations in plants and in the BCR steps were not indicative of the bioavailability of this element in the soil. On the contrary, the Zn concentration in the leaves showed the bioavailability of this element in the soil and the constituents to which it was related. The BCR method proved to be appropriate in case of Zn showing the existing correlations with the soil constituents and the plant contents.

TOTAL AND PLANT AVAILABLE TOXIC TRACE ELEMENTS (Cd, Cr, Co AND Pb) AT FARMS OF EASTERN CROATIA

UDK 631.453(497.5)
 It is well known that soil properties, metal speciation and plant species, especially soil- plant interactions, determine the availability of metals in soils. Therefore, various one- step extraction methods such as EDTA and DTPA have been used to represent the available fraction. In present study we observed the total (aqua regia) and available fraction (EDTA and DTPA) of toxic trace elements (Co, Cd, Cr and Pb) from soil on two farms (Berak and Vinogradci) in eastern Croatia that have different soil properties. The study included 106 soil samples from soil depth 0-30 cm that were collected during 2013- 2014. Samples were analyzed for standard soil properties (pH, organic matter, AL-P, AL- K) as well as for total and available fractions of toxic trace elements. Analyses of main soil properties show vide variety of soils. Soil pH (in H2O) was in range 4.4-8.6 (avg: 6.5), thus sampling sites included range from very acid to alkaline soils. Farm in Berak (average pH was 7.2) had more alkaline soils while farm in Vinogradci was acidic (average pH was 5.9). Organic matter varied from 1.1-2.8% (avg: 1.9), average phosphorous was 17.4 mg/100g and potassium 20.9 mg/100g. Total concentration of trace elements extracted by aqua regia show satisfactory results as not one sample had elevated levels of toxic trace elements (Co, Cd, Cr and Pb). In that regard all sites satisfy Croatian regulation on pollutants in agricultural fields. However, EDTA and DTPA extractions show higher availability of Cr, Co and Pb for both extractions (EDTA and DTPA) at farm in Vinogradci where soils are more acidic compared to farm Berak. Only available Cd was shown to be higher in Berak than in Vinogradci.

THE TOTAL AND AVAILABLE CONCENTRATIONS OF ESSENTIAL TRACE ELEMENTS IN AGRICULTURAL SOILS OF EASTERN CROATIA

UDK 631.41:546.4(497.6)
 The research objective was to determine the influence of basic soil chemical properties on total concentration and available fractions of essential trace elements in the soil. Agrochemical soil analysis were conducted at two localities of different soil properties Berak and Vinogradci in eastern Croatia. The soil at the site Berak was eutric cambisol of neutral reaction (pH average (H2O) 7.20), while the soil in Vinogradci was luvisol of slightly acid reaction (average pH (H2O) 5.87). Both soils were poor in organic matter and well supplied with phosphorus and potassium. As expected, at both analyzed sites the highest average concentrations were determined for total Fe, Mn and Zn followed, and the lowest concentrations were for total Cu. Higher total concentrations of analyzed microelements were recorded at the Berak site. The total concentrations of Zn and Cu in all analyzed soil samples were below the maximum permissible concentrations. The highest average concentration of available microelements fraction by EDTA Extraction, were at the Berak site determined for Mn (50.52 mg/kg), then Fe (21.77 mg/kg), Cu (4.78 mg/kg), and the lowest for Zn (1.47 mg/kg). At the Vinogradci site average concentrations of available fraction of microelements determined by EDTA extraction were the highest for Fe (77.09 mg/kg), then Mn (30.75 mg/kg), Cu (4.36 mg/kg), and the lowest for Zn (1.76 mg/kg). Identical order of average concentrations at both sites was also recorded for extraction with DTPA solution. Comparing available fraction of microelements by localities, higher average concentrations of Mn and Cu were found at the site Berak, while on site Vinogradci higher average concentrations were of Fe and Zn. At both sites the DTPA method extracted more of Fe and Mn, an average of 51.06% and 6.39% more than the EDTA method, but the method EDTA extracted more Zn and Cu, an average of 127.10% and 100.40% than DTPA method. The smallest share of the available fraction of the total concentration was recorded for Fe (0.06% by EDTA -0.09% by DTPA ), followed by Zn (1.20% by DTPA - 2.74% by EDTA) and Mn (5.93% by EDTA – 6.31% by DTPA), while the largest share was observed for Cu (10.92% by DTPA and 21.84% by EDTA).

Assessment of Trace Element Accumulation by Earthworms in an Orchard Soil Remediation Study Using Soil Amendments

This study assessed potential bioaccumulation of various trace elements in grasses and earthworms as a consequence of soil incorporation of organic amendments for in situ remediation of an orchard field soil contaminated with organochlorine and Pb pesticide residues. In this experiment, four organic amendments of differing total organic carbon content and quality (two types of composted manure, composted biosolids, and biochar) were added to a contaminated orchard field soil, planted with two types of grasses, and tested for their ability to reduce bioaccumulation of organochlorine pesticides and metals in earthworms. The experiment was carried out in 4-L soil microcosms in a controlled environment for 90 days. After 45 days of orchardgrass or perennial ryegrass growth, Lumbricus terrestris L. were introduced to the microcosms and exposed to the experimental soils for 45 days before the experiment was ended. Total trace element concentrations in the added organic amendments were below recommended safe levels and their phytoavailablity and earthworm availability remained low during a 90-day bioremediation study. At the end of the experiment, total tissue concentrations of Cu, Cd, Mn, Pb, and Zn in earthworms and grasses were below recommended safe levels. Total concentrations of Pb in test soil were similar to maximum background levels of Pb recorded in soils in the Eastern USA (100 mg kg−1 d.w.) because of previous application of orchard pesticides. Addition of aged dairy manure compost and presence of grasses was effective in reducing the accumulation of soil-derived Pb in earthworms, thus reducing the risk of soil Pb entry into wildlife food chains.

Geochemistry of Elements in the Coal Seams of the Xishanyao Formation from Gashunwusan Mine, Xinjiang, Northwest China

The samples from Xishanyao Formation in Gashunwusan Mine were analysed by inductively coupled plasma mass-spectrometry (ICP-MS), X-Ray fluorimetry (XRF) and other techniques. Through the use of the above techniques, we researched characteristics and modes of occurrence of the trace elements. According to content and ratios of trace elements, we discussed coal-forming environments of the research area. The results show that Co, Ga, Sr, and Ba were slightly enriched in different coal seams in Xishanyao Formation in Gashunwusan Mine and total contents of trace elements were lower than the average values of Chinese and world coal. The common elements mainly contain CaO, SiO2, Al2O3 and Fe2O3. The contents of above elements were low. Contents of CaO and MgO were higher than those in Chinese coal and US coal, while other elements were relatively depleted. There was a positive correlation between most of the trace elements and ash content. Modes of occurrence of most of trace elements were connected with inorganic mineral, which were effected considerably by terrestrial material. The values of Sr/Ba, V/Ni, and V/Zn revealed that the sedimentary type of Jurassic coal seam in Gashunwusan Mine was the typical interior phase of lakes. The value Ni/Co revealed that the redox environment of coal-forming swamp was relatively weak.

Apatite Trace Element Compositions: A Robust New Tool for Mineral Exploration

Apatites from the major types of mainly magmatic-hydrothermal mineral deposits (30 localities, mostly in British Columbia, Canada) together with apatites from carbonatites (29 intrusive complexes) and unmineralized rocks (11 localities) have been analyzed by electron microprobe and laser ablation-inductively coupled plasma mass spectrometry. Discriminant analysis using Mg, V, Mn, Sr, Y, La, Ce, Eu, Dy, Yb, Pb, Th, and U reveals that apatites from mineral deposits can be distinguished from apatites in carbonatites and unmineralized rocks. Apatites from mineral deposits are characterized by higher Ca and correspondingly lower total contents of trace elements that partition onto the Ca sites (rare earth elements (REEs), Y, Mn, Sr, Pb, Th, and U) than apatites from unmineralized rocks and carbonatites. Apatites from the different deposit types also have distinct trace element compositions that are readily discriminated by the discriminant functions. Apatites from worldwide carbonatites have the most fractionated REE distributions with light REE enrichment (Ce/Yb CN = 35–872), high V (1.6–1,466 ppm), Sr (1,840–22,498 ppm), Ba (1.8–275 ppm), and Nb (0.4–19 ppm) contents, the lowest W contents (0.05–0.55 ppm), and no significant Eu anomalies (Eu/Eu* = 0.9–1.2). Apatites from alkalic porphyry Cu-Au deposits in the North American Cordillera possess high V contents (2.5–337 ppm), whereas apatites from calc-alkaline porphyry Cu-Au and Cu-Mo deposits have high Mn contents (334–10,934 ppm) and typically large negative Eu anomalies (Eu/Eu* = 0.2–1.1). Apatites from iron oxide Cu-Au (IOCG) and related Kiruna-type iron oxide-apatite (IOA) deposits in Canada, China, and Mexico typically have large negative Eu anomalies (Eu/Eu* = 0.2–1.5) and low Mn contents (40–5,753 ppm). Apatites from orogenic Ni-Cu, porphyryrelated Cu-Au breccia, Au-Co skarn, Pb-Zn skarn, and Cu skarn deposits have relatively low abundances of impurity cations. This study demonstrates that detrital apatite grains collected during regional geochemical surveys are effective in identifying specific types of buried mineral deposits in glaciated terranes.