Distribution Patterns Of Trace Metals Research Articles

Insights on trace metal enrichments in tourists beaches of Santa Elena Province, Ecuador

Metal concentrations in beaches of major coastal cities is directly identified based on the enrichment pattern of bioavailable metals in sediments. The main objective of the study is to know the present level of metal enrichments in beach sediments of Santa Elena Province in Ecuador. Sediment beach quality was assessed in five tourist beach zones (n = 52) by analyzing the bioavailable trace metal concentration. Distribution pattern of trace metals indicates Cd, Co, Pb is on higher side exceeding the UCC. Geochemical indices calculations (Geoaccumulation index, Enrichment factor, Degree of contamination) and ecological risk indices (Hazard quotient, potential risk index, pollution load index) indicates that Cd has the high degree of enrichment level (Cd ≥ 32) followed by Co, Pb and As posing adverse ecological risk (RI > 600). Sediment quality assessment results reveals that the sediments were very unsafe in nature with a probability level of 11–21% being toxic. Statistical correlation suggests that carbonates vs Cu, Ni, Co, Pb, Cd (r2 = 0.51–0.98) were the main controlling factor for the metal behavior in sediments. Overall results reveals that the toxic elements were derived locally accompanied by anthropogenic influences enriching the geochemical elements affecting the beach quality in the Santa Elena coast region and for future coastal management programs.

Spatial and Temporal Redox Heterogeneity Controlled by a Fe(II), Anoxic Upwelling System in the Early Mesoproterozoic Ocean

AbstractThe availability of oxygen and nutrients during the Mesoproterozoic (1.6–1.0 Ga) is thought to influence the rate of eukaryote evolution. The cause of the transition from low productivity in the upper Wumishan Formation to organic‐rich sediments in the Hongshuizhuang Formation remains unknown. We report FeHR/FeT, Fepy/FeHR, MoEF, UEF, VEF, and [Ce/Ce*]SN in one core of the Yanliao Basin to study the redox evolution and compare it with other sections in different depths of the Yanliao Basin to get clues of the spatial and temporal redox heterogeneity. Mo‐U covariation, low Co × Mn and CoEF × MnEF, and distribution patterns of trace metals indicate the upwelling events. An upwelling system could fuel nutrients to promote productivity levels in surface water and contribute to anoxic deep waters. The uniformly positive δ15N values are interpreted as sufficient NO3− reduction via denitrification and dissimilatory nitrate reduction to ammonium in a ferruginous upwelling condition.

Distribution and assessment of trace metals in modern bottom sediments in the southwestern Chukchi Sea

Sediment samples from 53 stations of the southwestern Chukchi sea were investigated to the spatial distributions and assess the state of trace metals contamination using ecological indices. The mean concentrations (mg kg−1) in sediments were: Cr (70.5), Ni (41.0), Cu (16.5), Zn (82.7), As (15.90), Cd (0.27), Pb (15.96), Hg (32.0 μg kg−1). The spatial distribution pattern of trace metals was similar with maximum values in the northern of the Chukchi Sea in the outer shelf sediments, while the high values of Cd were noted at stations located in the southern part of the sea where a strong influence of the Pacific waters penetrating through the Bering Strait. The ecological indices indicated no signs of anthropogenic pollution in the study sediments of the Chukchi Sea. Received data are of value for detecting and tracking future chemical changes in the sediments of the Chukchi sea, particularly in light of environmental changes.

Distribution, Risk Assessment, and Sources of Trace Metals in Surface Sediments from the Sea Area of Macao, South China.

Due to rapid economic development in the Pearl River Delta, South China, trace metals pose a significant threat to the coastal ecosystems. In this study, we investigated the spatial distribution, contamination status, ecological risk, and possible sources of trace metals in 150 surface sediment samples from the Macao sea area. The results showed that concentrations of Ag, Pb, Cu, Zn, and Cd were highest in the Inner Harbour, whereas Cr, Co, As, and Ni were mainly accumulated in the downstream area of the Maliuzhou Waterway and the eastern area of Macao International Airport. Sediment grain composition, organic matter, total phosphorus, and hydrological regime were key factors influencing the spatial distribution patterns of trace metals. According to the environmental contamination indices of the enrichment factor, geo-accumulation index, and contamination factor, moderate contamination of trace metals occurs in the study area, while Ag and Pb contribute significantly to the contamination. Based on the potential ecological risk index, trace metals in surface sediments pose a low ecological risk. Correlation analysis and principal component analysis indicated that Cr, Co, Ni, and As were mainly derived from natural sources, whereas Ag, Pb, Cu, Zn, and Cd were mainly associated with anthropogenic sources.

Distribution pattern of trace metals in selected surface soils of Palakkad district, South India

This study focussed on the extent of contamination caused by metals (Cd, Co, Pb, Cu, Zn, Mn, and Mg) in selected sites of Palakkad district, a major agrarian zone in Kerala, India. Soils sampled during summer and monsoon were processed for metal analysis using standard protocol and AAS. The metal data was compared with the threshold values proposed by the European Commission (EC), Indian Standard (IS), Lindsay Standard (LS) and the United States Environmental Protection Agency (USEPA). The extent of pollution caused by these metal contaminants was deduced using enrichment factor (EF), contamination factor (CF), geoaccumulation index (Igeo) and pollution load index (PLI). Details regarding sources and their interaction with soil parameters were effectively deduced by Pearson’s correlation and principal component analysis (PCA). The intensity and extend of monsoon play a prominent role in the distribution of trace metals in the study area which is evident from the distribution pattern during summer and monsoon. Even though most metals were found within the threshold limit, Cd (range: 0.25 to 3.00 mg Kg−1), and Co (range: ND to 22.56 mg Kg−1) was above the permissible limit. Spatial adsorption pattern along with the anthropogenic sources, specifically, agrochemicals, metals leaching and emitting from geological matrix and automobiles prevailing in these zones play a prominent role in regulating the levels of contamination caused by trace metals.

Benthic trace metal fluxes in a heavily contaminated bay in China: Does the sediment become a source of metals to the water column?

Over three different seasons, seawater, porewater and sediment samples were collected from Jinzhou Bay, a previously heavily contaminated bay, to quantitatively assess the benthic flux of trace metals after a reduction in fluvial/sewage discharge for almost three decades. The spatial distribution patterns of trace metals in seawater, surface sediment, as well as the vertical distribution patterns of metals in porewater and solid phases in short sediment cores were reported. Metal concentrations in seawater and sediment all showed much higher Cd and Zn concentrations inside the Jinzhou Bay compared to the rest of Bohai Sea area. Zn, Ni, Pb and Co all had average benthic fluxes coming out of the sediments to the water column, contributing about 0.5%, 0.3%, 1.4% and 14% to their current standing stock in Jinzhou Bay. Seasonal difference was also identified in seawater and porewater, as well as in the benthic fluxes. In general, benthic fluxes and porewater concentrations all tended to be higher in summer, implying a close relationship between benthic flux and the temperature-dependent organic matter degradation process at the sediment-water interface.Currently, there are clearly still other sources, possibly fluvial/sewage discharge, as the main source of trace metals in Jinzhou Bay waters. For Cd and Cu, concentrations in the water column remain high on an annual basis indicating that sediment still acts as a sink. Conversely, for Pb, Zn, Co, and Ni, the sediment is beginning to act as a source to the water column. Although this may not yet be significant, it will become more and more important with time, and can last for hundreds to thousands of years.

Distribution patterns of trace metals in soils of Gbonganorileowu Area, southwestern Nigeria

One hundred and eighty six (186) in situ soil samples of the B - horizon were collected around Gbongan- Orileowu area of Osun State, Southwestern Nigeria for a reconnaissance geochemical soil survey. The objective was to determine the distribution pattern of some trace metals in the area with a view to discovering anyindication of metallic mineralization and possible correlation with the underlying bedrock. The samples were air-dried and sieved to obtain the minus 230 micron fractions which were split into two portions for hot aqua regia acid digestion and pH determinations. The solutions obtained from the digestion were analyzed for Ag, As, Au, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sn, and Zn using Atomic Absorption Spectrometric methods. The resulting data were used in preparing distribution maps of the elements in the study area, employing the location point symbol method. Simple statistical treatment was also carried out on the data to determine the mean and standard deviation for each element. With these, the spatial distributions of the trace elements in the area were discussed. The pH of the soils range from 4.70 to 7.59 and this reflects the geochemical distribution patterns of trace metals in the area. The spatial distribution maps of the elements showed similarity in the distributions of Co, Cr, Fe, Ni, Mn and Pb. This suggests close associations between these elements none of which showed any significant anomaly. The association might be due to the scavenging actions of Fe-Mn oxides on the other elements. Ag, Au and Sn on one hand and Zn on the other hand showed significant anomalies, which were thought to be due to mineralization and anthropogenic activities respectively. As, Co, Cu, Fe, Ni and Pb probably occur as sulphides within reported underlying ultramafic rocks or Au bearing quartz veins or both. It is probable that Au and Ag occur as disseminations within the ultramafic rocks, aside from their occurrence in the veins, while Sn is most probably from the pegmatites. The very high Zn in the area is probably due to contamination.Keywords: Significant anomalies, Ultramafic, Anthropogenic, Mineralization

Heavy metal concentrations in sediments and in mussels from Argentinean coastal environments, South America

Among environmental contaminants, heavy metals are currently considered to be some of the most toxic ones present worldwide due to their harmful effects on organisms and ability to bioaccumulate in aquatic systems. In this work, the concentration of heavy metals (Cd, Cu, Pb, Zn, Ni and Cr) in Brachidontes rodriguezii and in the fine sediments of several coastal sites at the southwest of Buenos Aires Province, Argentina is analyzed. The Bahia Blanca Estuary and Pehuen-Co beach are located in a highly complex oceanographic and ecological regional system, which creates the basis of one of the most valuable Argentinean habitats for fishing commercial species. An assessment, which involved analyzing distribution pattern of trace metals, comparative studies with sediment and ecological quality guidelines; and a sequential and integrated index analyses approach (containing Metal Pollution Index, Biosediment Accumulation Factor, Geo-accumulation Index (Igeo), Pollution Load Index and the mean Probable Effect Level quotients), was followed to estimate enrichment and risks of heavy metals in the sediments and in the mussels from these study areas. The results showed higher concentrations of some heavy metals (e.g., Cd, Cr and Ni) in mussels collected at Pehuen-Co, while no spatial differences in sediments were observed. According to the international environmental regulations, mean values of trace metals in mussels allowed to place both sites between “unpolluted and moderately polluted” and between the “low and medium category” of pollution. Furthermore, the mean concentrations found were within the detected ranges in other coastal sites worldwide.

Level, pattern, and risk assessment of the selected soil trace metals in the calcareous-cultivated Vertisols

Dynamics and distribution pattern of trace metals in agricultural lands are an increasing concern due to potential risks to the environment and human health. To ascertain more knowledge of this aspect, the fractions of total and available Fe, Mn, Zn, Cu, and Cd belonging to Vertisols under intensive cultivation and adjoining uncultivated soils were investigated. The order of abundance of metals in both cultivated and uncultivated soils was Fe > Mn > Cu > Zn > Cd and Fe > Mn > Zn > Cu > Cd for both available and total fraction, respectively. A relative enrichment was observed in the value of diethylene-triamine pentaacetic acid-extractable Fe (1.2–201%), Mn (2–31%), Cu (1–40%), and Cd (21–45%) as well as total fraction of Zn (3–17%), Cu (12–32%), and Cd (42–108%) after intensive cropping, which can be contributed to repeated application of agrochemical inputs and manure over long time. The values of RI (potential ecological risk) showed that cultivation caused a low potential ecological risk (33.3% of the soil samples) to moderate potential ecological risk (66.7% of the soil samples) in the study region and that cadmium made up 88%, on average, of the RI value.

Distribution and Pollution Assessment of Trace Metals in the Surface Sediments around Farming Area of Jinhae Bay

Trace metals(As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb and Zn) concentrations in surface sediments of Jinhae bay in August of 2013 were measured to investigate the characteristics of trace metals distribution and to evaluate the metal pollution. Assessment for metal pollution was carried out using the sediment quality guidelines(SQGs) such as threshold effects level(TEL) and probable effects level(PEL) proposed by the ministry of onceans and fisheries(MOF) in Korea and geochemical assessment techniques(enrichment factor(EF) and geoaccumulation index ()). The mean concentration of trace metals in the sediments are as follows: 11.1 mg/kg for As, 0.52 mg/kg for Cd, 14.1 mg/kg for Co, 69.8 mg/kg for Cr, 57.2 mg/kg for Cu, 3.7 % for Fe, 0.064 mg/kg for Hg, 600 mg/kg for Mn, 40.1 mg/kg for Pb, 167.2 mg/kg for Zn. The spatial distributions of As, Co, Cr and Fe were not distinguished clearly in whole area. However, Cd, Hg, Pb and Zn were high in northern area of bay, and Cu and Mn were high in southeastern and eastern area of bay, respectively. The distribution pattern of trace metals, correlation matrix and R-mode factor analyses results revealed that the distribution of trace metals were mainly effected by the sediment grain size(Co, Cr and Fe), redox condition of sediments(Mn) and anthropogenic factors(As, Cd, Cu, Hg, Pb and Zn). Comparing the concentrations of several trace metals(As, Cd, Cr, Hg and Pb) with SQGs from Korea(TEL and PEL), the concentrations of Hg, Cd and Pb in sediment of northern area of bay were higher than TEL. EF and values of As, Cd, Cu, Hg, Mn, Pb and Zn showed that these metals in sediments are enriched by anthropogenic activities in some areas, and pollution status for Cd, Hg and Pb in northern area and Cu in southeastern area of bay were concerned about current level, although those for As, Mn and Zn were not.

Overview of the 20th century impact of trace metal contamination in the estuaries of Todos os Santos Bay: Past, present and future scenarios

This paper discusses the distribution patterns of trace metals in sediments and suspended particulate matter (SPM) in the three main estuaries of the Todos os Santos Bay (BTS), Brazil, during dry and rainy seasons. Data available up to 2012 was also reviewed to assess the status of contamination. For most elements, metal concentrations in sediments decreased from the tidal limits to the lower estuary. Metals in SPM presented more complex distributions along the salinity gradient. Metal variability between rainy and dry conditions was only significant for SPM data. Of the BTS estuaries, the levels of Cd, Zn, Pb and Cu are highest in the Subaé estuary, and they seem to be promoting harmful biological effects in macrofauna, and also may pose potential human health risks. Despite the evidence of important localized contamination, much of the data compiled indicates that the bay and its estuaries are still relatively preserved.

Distribution Patterns of Trace Metals and of Lipid Peroxidation in Plasma and Erythrocytes of Rat Exposed to Aluminum

Significant decreases of the hematocrit, hemoglobin, and plasma iron levels were observed in rats receiving daily intraperitoneal injections of aluminum at a dose of 27 mg Al/kg body wt for 3 wk, as compared to untreated controls. The activity of alkaline phosphatase was also significantly lower in the treated animals as a result of the accumulation of aluminum in the liver (p<0.05). Following aluminum administration, the plasma concentrations of aluminum and copper were also significantly increased, whereas the plasma zinc levels and oxidative stress measured through thiobarbituric acid reaction products showed nonsignificant differences between the two groups (p>0.05). The erythrocyte concentrations of aluminum, copper, zinc, and iron and of superoxide dismutase activity were found to be significantly higher in the study group as compared to controls. The treated animals also showed evidence of higher oxidative stress in comparison to controls. These results suggest that erythrocyte aluminum accumulation could result in abnormal trace element homeostasis and increasing oxidative stress, which might be a mechanism of aluminum-induced anemia.

Mechanisms Influencing the Spatial Distribution of Trace Metals in Surficial Sediments off the South-Western Taiwan

Surficial sediments collected from the south-western coast off Taiwan were determined for the grain size, organic carbon contents (OC), carbonate and leachable trace metals (Co, Cu, Fe, Mn, Ni, Pb and Zn). The sediments in the study area were mostly the very fine sands (0.125–0.0625 mm, φ =3–4). However, muds (0.0625–0.0156 mm, φ =4–6) were observed in the trough area located in the south of the Waisanding Barrier Island. Concentration ranges of organic carbon, carbonate and leachable trace metals in the sediments were: OC, 0.06–0.49% (mean, 0.2%); carbonate, 1.48.6–3.68% (2.23%); Fe, 0.41–1.52% (0.85%); Co, 4.6–18.2 mg/kg (8.9 mg/kg); Cu, 0.4–16.7 mg/kg (4.39 mg/kg); Mn, 186–625 mg/kg (338 mg/kg); Ni, 2.1–10.2 mg/kg; Pb, 0.73–21.8 mg/kg (6.8 mg/kg) and Zn, 3.6–56.4 mg/kg (22.1 mg/kg). Normalization technique and comparison with the results obtained in other marine environment around Taiwan are used to assess the contaminated status of the study area. The results suggest that the sediment of the south-western coast off Taiwan has not been contaminated by trace metals. The distribution patterns of trace metals and OC are fairly similar, and oppositely correlated with that of sediment mean grain-size. That is the finer the sediment, the higher the concentrations of trace metals and OC. Moreover, higher concentrations of trace metals and OC were found in the trough located in the south of the Waisanding Barrier Island while lower values were in the near-shore area. The sediment grain size is probably the most crucial parameter which controls the spatial distribution of trace metals, except Mn, in the south-western coast off Taiwan. Although, the maximum contour of Mn also occurs in the trough, the concentration of Mn does not correlate well with the sediment grain size. In contrast, concentration of Mn significantly correlates with the carbonate, which may suggest that Mn is adsorbed or co-precipitated with the calcium carbonate and forms rhodochrosite-calcite (MnCO 3–CaCO 3) in the water column.

Choice of Extraction Technique for Soil Reducible Trace Metals Determines the Subsequent Oxidisable Metal Fraction in Sequential Extraction Schemes

Ten agricultural soils were treated with sewage sludge and subjected to two contrasting operationally-defined sequential extraction schemes to extract three trace metal fractions: HOAc-soluble, NH2OH.HCl-reducible and H2O2/NH4OAc-oxidisable. One scheme used 0.10M NH2OH.HCl at pH 2.0 and the other used 0.04M NH2OH.HCl in 25% (v/v) HOAc at 96 ± 3°C to extract the reducible fraction. The latter solution dissolved much more Fe and Mn than did the former, and the higher concentrations of Fe and Mn were accompanied by increased concentrations of Cu and Zn in the reducible fraction. Dissolution of the moderately reducible Fe-Mn oxides also increased the subsequent oxidisable metal fraction. The results demonstrate that reducing reagents with different capacities to extract reducible Fe-Mn oxides produced different distribution patterns of trace metals in sludge-amended and control soils. We conclude that the latter solution is a more useful extractant for dissolution of reducible trace metals in soils.

Trace metals in sediments of a Mediterranean estuary affected by human activities (Acheloos river estuary, Greece)

Trace metals were studied in the sediments of the ecologically, economically and scientifically important estuary of the Acheloos river, in western Greece. Human activities (dams, agriculture, traffic, etc.) influence the estuarine system of Acheloos and in combination with the hydrological, mineralogical and morphological characteristics of the estuary affect the chemical behaviour and the distribution patterns of trace metals in its sediments. The large scale disturbance of the system is imminent in the near future as it is planned to divert ∼50% of the river water. A study of the distribution patterns of trace metals revealed that in the estuary there are zones with different metal levels. The concentrations of most metals (Al, Fe, Cu, Ni, Zn) are elevated in three of these zones (upstream, sill, seawards). A different behaviour was observed for Mn due to its association with carbonates that were observed in significant concentrations throughout the estuarine zone. A sequential extraction procedure, applied to the sediments, indicated low percentages of easily exchangeable metals, increased mobility of Cu and Zn and increased association of Ni, Cr and Fe with the aluminosilicate lattice. Although the river is not considered to be heavily polluted, some metals have shown an enrichment in the surface sediments as a result of general anthropogenic activities not derived from point sources.

Trace metal concentration, distribution and correlation in water, sediment and fish from the Ravi River, Pakistan

Fourteen commercial fish species, along with relevant water and sediment samples, from polluted and non-polluted sites of the Ravi River were analysed for 11 trace metals (Ag, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn and Hg) and four major cations (Na +, K +, Ca 2+ and Mg 2+) using flame/flameless atomic absorption spectrophotometry. The distribution pattern of trace metals in water, fish and sediment revealed that industrial and domestic effluents were responsible for the enrichment of metals in water at specific sites along the river. A linear correlation study incorporating paired variables (water-sediment, water-fish and fish-fish) showed a strong correlation ( r≥0.900 at P=0.01), indicating a common metal pollution source at various sites.

Changes in the distribution patterns of trace metals in sediments of the mersey estuary in the last decade (1974–1983)

A survey of the trace metal distribution in the sediments of Liverpool Bay, and the Dee and Mersey estuaries in 1972–1974 has been followed by a series of regular monitoring surveys in the Mersey estuary during the last 10 years. Over 15 000 individual observations have been recorded, including measurements of the trace metal content (cadmium, chromium, cobalt, copper, lead, manganese, mercury, nickel and zinc), organic carbon content and particle size distribution. In parallel with the physical and chemical measurements, a limited biological sampling programme has also been carried out. These results are discussed in relation to the spatial and temporal variability detected, and in relation to the potential biological effect of the sedimentary trace metals.