Water and sediment quality of dry season pools in a dryland river system: the upper Leichhardt River, Queensland, Australia

This article presents the geochemical characteristics and physicochemical properties of water and sediment from twelve semi-permanent, dryland pools in the upper Leichhardt River catchment, north-west Queensland, Australia. The pools were examined to better understand the quality of sediments and temporary waters in a dryland system with a well-established metal contamination problem. Water and sediment sampling was conducted at the beginning of the hydroperiod in May and September 2007. Water samples were analyzed for major solute compositions (Ca, Na, K, Mg, Cl, SO(4), HCO(3)) and water-soluble (operationally defined as the <0.45 μm fraction) metals (Cd, Cu, Pb, Zn). Sediment samples were analyzed for total extractable and bioaccessible metals (As, Cd, Cu, Pb, Zn), elemental composition and grain morphology. At the time of sampling a number of pools contained water and sediment with elevated concentrations, compared to Australian regulatory guidelines, of Cu (maximum: water 28 μg L(-1); sediment 770 mg kg(-1)), Pb (maximum: water 3.4 μg L(-1); sediment 630 mg kg(-1)) and Zn (maximum: water 150 μg L(-1); sediment 780 mg kg(-1)). Concentrations of Cd and As in pools were relatively low and generally within Australian regulatory guideline values. Localized factors, such as the interaction of waters with anthropogenic contaminants from modern and historic mine wastes (i.e. residual smelter and slag materials), exert influence on the quality of pool waters. Although the pools of the upper Leichhardt River catchment are contaminated, they do not appear to be the primary repository of water and sediment associated metals when compared to materials in the remainder channel and floodplain. Nevertheless, a precautionary approach should be adopted to mitigating human exposure to contaminated environments, which might include the installation of appropriate warning signs by local health and environmental authorities.     

Enhanced anthropogenic heavy metal dispersal from tidal disturbance in the Jiaozhou Bay, North China

Heavy metal contamination in surface sediments of the Jiaozhou Bay was investigated in this study. Sediment sample was collected from the Jiaozhou Bay and its rivers. Heavy metal concentration was determined by inductively coupled plasma atomic emission spectroscopy and graphite furnace atomic absorption spectrometry. The result shows that river sediment in the east coast of the Jiaozhou Bay was heavily polluted especially for the Cu, Pb, Cd, and Zn. A slightly increase of heavy metal concentration was observed at stations near the east coast in the Jiaozhou Bay; however, contaminated sediment from polluted river was constrained mostly near shore within 3–4 km. Downstream decrease of heavy metals in river mouth suggested dilution from strong tidal current. Rapid seaward decline in the east coast and alongshore band dispersal pattern of heavy metals in surface sediment indicated mixing and remobilizing enhanced by large tidal range that regulated dispersal of sediments and anthropogenic heavy metals in the Jiaozhou Bay area.     

Gold Concentrations in Abiotic Materials, Plants, and Animals: A Synoptic Review

Gold (Au) is ubiquitous in the environment and mined commercially at numerous locations worldwide. It is also an allergen that induces dermatitis in sensitive individuals. Gold concentrations were comparatively elevated in samples collected near gold mining and processing facilities, although no data were found for birds and non-human mammals. Maximum gold concentrations reported in abiotic materials were 0.001 microg L(-1) in rainwater; 0.0015 microg L(-1) in seawater near hydrothermal vents vs. < 0.00004-0.0007 microg L(-1) elsewhere; 5.0 microg kg(-1) dry weight (DW) in the Earth's crust; 19.0 microg L(-1) in a freshwater stream near a gold mining site; 440 microg kg(-1) DW in atmospheric dust near a high traffic road; 843 microg kg(-1) DW in alluvial soil near a Nevada gold mine vs. < 29 microg kg(-1) DW premining; 2.53 mg kg(-1) DW in snow near a Russian smelter vs. < 0.35 mg kg(-1) DW at a reference site; 4.5 mg kg(-1) DW in sewage sludge; 28.7 mg kg(-1) DW in polymetallic sulfides from the ocean floor; and 256.0 mg kg(-1) DW in freshwater sediments near a gold mine tailings pile vs. < 5 microg kg(-1) DW prior to mining. In plants, elevated concentrations of 19 microg Au kg(-1) DW were reported in terrestrial vegetation near gold mining operations vs. < 4 microg kg(-1) DW at a reference site; 37 microg kg(-1) DW in aquatic bryophytes downstream from a gold mine; 150 microg Au kg(-1) DW in leaves of beans grown in soil containing 170 microg kg(-1) DW; up to 1.06 mg kg(-1) DW in algal mats of rivers receiving gold mine wastes; and 0.1-100 mg kg(-1) DW in selected gold accumulator plants. Fish and aquatic invertebrates contained 0.1-38.0 microg Au kg(-1) DW. In humans, gold concentrations up to 1.1 microg L(-1) were documented in urine of dental technicians vs. 0.002-0.85 microg L(-1) in reference populations; 2.1 microg L(-1) in breast milk, attributed to gold dental fillings and jewelry of mothers; 1.4 mg kg(-1) DW in hair of goldsmiths vs. a normal range of 6-880 microg kg(-1) DW; 2.39 mg L(-1) in whole blood of rheumatoid arthritis patients receiving gold thiol drugs to reduce inflammation (chrysotherapy) vs. a normal range of 0.2-2.0 microg L(-1); and 60.0 to 233.0 mg kg(-1) fresh weight (FW) in kidneys of rheumatoid arthritis patients undergoing active chrysotherapy vs. < 42.0 mg kg(-1) FW kidney 140 months posttreatment.     

Source identification and assessment of sediment contamination of trace metals in Kogarah Bay,NSW, Australia

The distribution of trace metals (spatial and temporal) and sedimentary fractions were investigated to identify the concentrations and sources of trace metals within Kogarah Bay, NSW, Australia. A total of 59 surface sediments and six subsurface samples from core of the sediment were collected. The contamination factor and pollution load index indices used to evaluate environmental effects of trace metals. The study area was found to be uncontaminated with Cr and Ni, moderately contaminated with As and considerably contaminated with Cu, Zn and Pb. The concentrations of Cr and Ni were below both effect range low and effect range median, while As, Cu, Zn and Pb were slightly above effect range low. The highest concentrations of these trace metals such as Cu, Zn and Pb were found in the north, northwest and southeast of the bay, close to discharge points, stormwater outlets and around boatyards and watercrafts. The spatial distributions of metals were strongly related to muddy particles and organic matter. The temporal sediments of metals declined with increased sediment depth, which reflects accumulation of trace metals since European settlement in this area. Furthermore, the source of the trace metals was found to be stormwater outlets, gasoline fumes, boatyards and other human activities.     

Characterization of heavy metals in water and sediments in Taihu Lake, China

To explore a comprehensive status of heavy metals in the Taihu Lake, which is one of the most important waters in China, water and sediment samples were taken throughout the lake during April to May of 2010, and metal elements (Cu, Cd, Cr, Ni, Pb, Sn, Sb, Zn, Mn) were analyzed in the water column, interstitial water and sediment. Relevant standards were used to assess the sediment and water quality. Results show that, in the lake water column, the average concentration of all metals ranged from 0.047 μg/l (Cd) to 8.778 μg/l (Zn). The concentration in the river water was usually higher than in the lake water for many metals. In the interstitial water Mn was significantly higher than that in water column, and other metals had no significant difference between the two media. In the surface sediment, average metal content ranged from 1.325 mg/kg (Cd) to 798.2 mg/kg (Mn). Spatially, contents of many metals were higher in Zhushan Bay than in other lake areas, and there existed a clear content gradient from the river to the lake for both water and sediment. On the sediment profiles, many metals presented an increasing trend from the depth of 15-20 cm to the top, which is indicative of the impact of increasingly intensive human activities from that period. Quality assessment indicates that metals in water phase are generally safe compared with USEPA "National Recommended Water Quality Criteria," with the exception of Mn in the interstitial water and Sb in the river water. Whereas the sediment is widely contaminated with metals to some extent compared with the "Consensus-Based Sediment Quality Guidelines," and Cu, Cr, and Ni are more likely to raise ecological risks. This work could be a basis for the ongoing China's criteria strategy.     

Biomonitoring of contaminated mine tailings through age accumulation of trace metals in the bank vole (Clethrionomys glareolus)

Lead, zinc and cadmium were determined in a range of tissues from laboratory-bred bank voles (Clethrionomys glareolus) exposed to elevated levels of dietary zinc (124 micrograms g-1). The pelletised diet was derived from vegetation harvested from the surface of a revegetated tailings dam at a modern Zn-Pb mine. Exposure regimes to the contaminated diet were 16, 32, 64, 128 or 256 days. Elevated levels of dietary zinc were not reflected in the individual tissue or total body concentrations. Marginal age accumulation of lead and cadmium was evident in the liver (Pb) and kidney (Pb and Cd). Tissue residues did not attain toxicologically significant concentrations. Animals inhabiting the grassland are considered to be at low ecotoxicological risk with respect to trace metals.     

Trace metal concentrations in suspended particles, sediments and clams (Ruditapes philippinarum) from Jiaozhou Bay of China

Suspended particulate matter (SPM), sediments and clams were collected at three sites in Jiaozhou Bay to assess the magnitude of trace metal pollution in the area. Metal concentrations in SPM (Cu: 40.11-203; Zn: 118-447; Pb: 50.1-132; Cd: 0.55-4.39; Cr: 147.6-288; Mn: 762-1670 microg/g), sediments (Cu: 17.64-34.26; Zn: 80.79-110; Pb: 24.57-49.59; Cd: 0.099-0.324; Cr: 41.6-88.1; Mn: 343-520 microg/g) and bivalves (Cu: 6.41-19.76; Zn: 35.5-85.5; Pb: 0.31-1.01; Cd: 0.51-0.67; Mn: 27.45-67.6 microg/g) are comparable to those reported for other moderately polluted world environments. SPM showed a less clear pattern. Metal concentrations in sediments displayed a clear geographical trend with values increasing with proximity to major urban centers. The clams (on dry weight) showed a complex pattern due to the variability introduced by age-related factors. Cd showed an apparent reverse industrial trend with higher concentrations in clams collected at distant stations. Zn, Pb and Mn showed no clear geographical pattern, whereas Cu increased in the clams collected in the most industrialized area. In addition, the bioaccumulation factors (BAF) were calculated. The result indicated that the studied Ruditapes philippinarum in Jiaozhou Bay possessed different bioaccumulation capacities for Cd, Zn, Cu, Pb and Mn, and Cd, Zn had a relatively high assimilation of those metals from sediment particles. A significant relationship with clam age was observed for Zn (positive) and Cu (negative) suggesting different physiological requirements for both metals with age. Trace metal concentrations measured in the tissue of the investigated clam were in the range considered safe by the WHO for human use.     

Spatial, temporal, and speciation variations of heavy metals in sediments of Nan'ao Island, a representative mariculture base in Guangdong coast, China

Heavy metals in sediments from Baisha Bay, Nan'ao Island, one of Guangdong Province's largest mariculture bases in Southern China, were investigated. The results display that the concentrations of 6 heavy metals from surface sediments were 0.040-0.220 (Cd), 24.22-39.61 (Pb), 25.30-42.66 (Cr), 10.83-19.54 (Ni), 15.06-39.24 (Cu) and 55.12-141.73 mg kg(-1) (Zn), respectively. The highest concentrations and the greatest increasing rates of heavy metals were found in a sediment core in a fish cage culture area due to receiving sewage discharge, uneaten fish bait, and boat gasoline combustion. Cd was preferentially associated with the acid-soluble fraction and Pb mainly with the reducible fraction in surface sediments. Meanwhile, Cd and Pb displayed greatest labile fractions, indicating anthropogenic origin. A principal component analysis (PCA) revealed three groupings (Cd; Cr, Ni and Cu; Pb and Zn) that mainly result from different distributions of the metals in the various fractions. The ecological risk of the polluted sediments stemmed mainly from Cd, and from Pb and Cu to a lesser degree. It is suggested that the density of fish-stocking be controlled, periodic movement of rafts (cages) be introduced, and the total numbers of net-cages and human activities in the mariculture zones be restricted. in order to facilitate the recovery of the polluted sediment.     

Variation of Metals in Bed Sediments of Qaraaoun Reservoir, Lebanon

The Qaraaoun Reservoir (impoundment of the River Litani) is the only artificial surface water body in the country, Lebanon. Earlier study on the water quality of the Qaraaoun Reservoir identified three water quality zoning with a central distinct zone suitable for multipurpose water usage. The objective of this study was to extend the earlier work by considering the total metal content of reservoir bed sediments and hence to evaluate factors that control metal deposition or capture. Water samples were collected from 15 sampling sites and sediment samples were simultaneously collected from 9 sites. Water parameters analyzed were pH, Eh, DO and temperature. Sediment samples were dried and sieved and sediment < 75 μ m was retained for analysis. Sediments were subjected to a stepwise heating process with aqua regia to extract the metals, and their content in sediments determined by ICP-MS. The sediment data revealed higher metal contents where the river entered the reservoir which matched higher concentrations of water parameters at the influx site. Regression analysis of total metals in sediments with distance from the river Litani influx point to the dam revealed a log trend for Fe, Cr and Ni, whereas, the concentrations of Cu, Zn, Cd, Pb were better described by a polynomial regression. Three sediment zones were identified: entrance, oxidation (central) and reducing (near dam) zones. Sediment contents of Zn, Cu and Pb correlated with organic content, whereas sediment Cr and Ni were associated with iron. It was concluded that sediments act as a sink for metals and the deposition of metals is primarily related to sediment organic content and the level of dissolved oxygen in water.     

Near-shore distribution of heavy metals in the Albanian part of Lake Ohrid

The heavy metal contamination in Lake Ohrid, a lake shared between Albania and Macedonia, was studied. Lake Ohrid is believed to be one of the oldest lakes in the world, with a large variety of endemic species. Different anthropogenic pressures, especially heavy metal influxes from mining activities, might have influenced the fragile equilibrium of the lake ecosystem. Heavy metal concentrations in water, sediment, emergent vegetation, and fish were investigated at selected sites of the lake and a study of the heavy metals in five tributaries was conducted. The lake surface water was found to have low levels of heavy metals, but sediments contained very high levels mostly near river mouths and mineral dump areas with concentrations reaching 1,501 mg/kg for Ni, 576 mg/kg for Cr, 116.8 mg/kg for Co and 64.8 g/kg for Fe. Sequential extraction of metals demonstrates that heavy metals in the sediment are mainly present in the residual fraction varying from 75% to 95% in different sites. High heavy metal levels (400 mg/kg Ni, 89 mg/kg Cr, and 39 mg/kg Co) were found in plants (stem of Phragmites australis), but heavy metals could not be detected in fish tissue (gill, muscle, and liver of Salmo letnica and Salmothymus ohridanus).     

Ecotoxicological impact assessment of some heavy metals and their distribution in some fractions of mangrove sediments from Red Sea, Egypt

The total and fraction concentrations of heavy metals (Mn, Cu, Ni, Pb, Co, and Cd) were analyzed in some sediment fractions (Φ2, Φ3, Φ4, Φ5) of selected mangrove ecosystems collected from the Egyptian Red Sea shoreline. The results revealed that manganese had the highest mean value (133?±?97 mg/kg) followed by copper (49.9?±?46.0 mg/kg), nickel (28.1?±?11.8 mg/kg), lead (19?±?13 mg/kg), cobalt (6.7?±?4.0 mg/kg), and cadmium (3.327?±?1.280 mg/kg). The concentrations of heavy metals in the different sediment fractions showed that there was a preferential accumulation of Cu, Co, Mn, and to a lesser degree Cd in the silt and clay fractions rather than in the sand-sized. The sediment quality was performed by using some sediment quality guidelines. Additionally, the contamination and the risk assessment of these heavy metals were achieved by different methods including, potential ecological risk index, contamination factor, pollution load index, and geoaccumulation index. According to the Sediment Quality Guidelines comparisons, the concentrations of Mn and Pb were low and showed no possibility of detrimental effects on the local environment. The levels of Cu and Ni were high, however, could not be considered to present serious threat to the mangrove ecosystem. The data showed that the mangrove ecosystems were affected by the Cd risk.     

Trace metal concentrations in tidal flat coastal sediments, Yamaguchi Prefecture, southwest Japan

Geochemical investigations of tidal flat coastal sediments at Ogori, Ozuki, and Kasado in Yamaguchi Bay of southwest Japan were conducted to determine their metal concentrations and to assess contamination levels, compared with sediment quality guidelines (SQG) and several pollutant indicators. Selected major oxides, trace elements, and total sulfur (TS) were determined by X-ray fluorescence. pH values of most samples were alkaline, indicating anoxic conditions. Average abundances of As, Pb, Zn, Cu, Ni, and Cr in Ozuki sediments were 11, 27, 109, 21, 19, and 52 mg/kg, respectively, compared to 9, 29, 80, 16, 18, and 42 mg/kg at Ogori and 12, 27, 151, 34, 30 and 80 mg/kg at Kasado, respectively. Average concentrations of As, Zn, and Cu in all samples and TiO(2), Fe(2)O(3), and P(2)O(5) at Kasado were greater than those of the upper continental crust. Contamination levels were assessed based on SQG, contamination factors (CF), pollution load index (PLI), enrichment factor (EF), and index of geoaccumulation (Igeo). According to the SQG of the US EPA, the sediments were heavily polluted with respect to As, whereas Zn, Cu, Ni, and Cr were classed as moderately polluted. The elevated CF values of As, Pb, and Zn identify moderate to considerable contamination, indicating that these metals are potentially toxic in the study area. Based on PLI and EF, the study sites are moderate to moderately severe polluted with As and Pb, moderately polluted with Zn, and weakly contaminated to noncontaminated with Cu, Ni, and Cr. The highest Igeo values for As, Pb, and Zn in the surface and core sediments reflected the tendency of metal contamination that seems to be related to their fine-grained nature, organic matter-rich sediments, and anthropogenic point sources. Trace metal contents were strongly correlated with Fe(2)O(3) and TiO(2), suggesting that Fe oxyhydroxides and detrital clastic load play a role in controlling abundances in the study area.     

Trace metal concentrations in suspended particles, sediments and clams (Ruditapes philippinarum) from Jiaozhou Bay of China

Suspended particulate matter (SPM), sediments and clams were collected at three sites in Jiaozhou Bay to assess the magnitude of trace metal pollution in the area. Metal concentrations in SPM (Cu: 40.11–203; Zn: 118–447; Pb: 50.1–132; Cd: 0.55–4.39; Cr: 147.6–288; Mn: 762−1670 μg/g), sediments (Cu: 17.64–34.26; Zn: 80.79–110; Pb: 24.57–49.59; Cd: 0.099–0.324; Cr: 41.6–88.1; Mn: 343−520μg/g) and bivalves (Cu: 6.41–19.76; Zn: 35.5–85.5; Pb: 0.31–1.01; Cd: 0.51–0.67; Mn: 27.45−67.6 μg/g) are comparable to those reported for other moderately polluted world environments. SPM showed a less clear pattern. Metal concentrations in sediments displayed a clear geographical trend with values increasing with proximity to major urban centers. The clams (on dry weight) showed a complex pattern due to the variability introduced by age-related factors. Cd showed an apparent reverse industrial trend with higher concentrations in clams collected at distant stations. Zn, Pb and Mn showed no clear geographical pattern, whereas Cu increased in the clams collected in the most industrialized area. In addition, the bioaccumulation factors (BAF) were calculated. The result indicated that the studied Ruditapes philippinarum in Jiaozhou Bay possessed different bioaccumulation capacities for Cd, Zn, Cu, Pb and Mn, and Cd, Zn had a relatively high assimilation of those metals from sediment particles. A significant relationship with clam age was observed for Zn (positive) and Cu (negative) suggesting different physiological requirements for both metals with age. Trace metal concentrations measured in the tissue of the investigated clam were in the range considered safe by the WHO for human use.     

Application of geoaccumulation index and enrichment factor for assessing metal contamination in the sediments of Kafrain Dam, Jordan

An investigation is reported of the degree of metal pollution in the sediments of Kafrain Dam and the origin of these metals. Fourteen sampling sites located at Kafrain Dam were chosen for collecting the surface, cutbank, and dam bank sediment samples. The sediment samples have been subjected to a total digestion technique and analyzed by atomic absorption spectrometer for metals including Pb, Zn, Cd, Ni, Co, Cr, Cu, Mn, and Fe. XRD analyses indicate that the sediments of Kafrain Dam are mainly composed of calcite, dolomite, quartz, orthoclase, microcline, kaolinite, and illite reflecting the geology of the study area. The enrichment factor (EF) and geoaccumulation index (I _geo) have been calculated and the relative contamination levels assessed in the study area. The calculations of I _geo are found to be more reliable than of those of EF. The enrichment of metals in the study area has been observed to be relatively high. I _geo results reveal that the study area is not contaminated with respect to Ni, Co, Cr, Cu, and Mn; moderately to strongly contaminated with Pb; and strongly to extremely contaminated with Cd and Zn. The high contents of Pb, Cd, and Zn in the study area result from anthropogenic activities in the catchment area of the dam site. These sources mainly include the agricultural activities, sewage discharging from various sources within the study area (effluent of wastewater treatment plants, treated and untreated wastewaters, and irrigation return water), and the several industries located in the area. Degrees of correlations among the various metals in the study area are suggested by the results and the intermetallic relationship.     

Distribution and contamination assessment of heavy metals in sediment of the Second Songhua River, China

The Second Songhua River was subjected to a large amount of raw or primary effluent from chemical industries in Jilin city in 1960s to 1970s, resulting in serious mercury pollution. However, an understanding of other trace metal pollution has remained unclear. The objective of this study was to investigate trace metal contamination in the sediment of the river. Bottom sediment samples were taken in the river between Jilin city and Haerbin city in 2005. An uncontaminated sediment profile was taken in the Nen River at the same time. Total concentrations of Al, Fe, Mg, Ca, K, Na, Ti, Mn, V, Sc, Co, Cu, Cr, Ni, Pb and Zn in the sediment samples were measured by ICP-MS or ICP-OES, following digestion with various acids. Concentrations of Co, Cu, Cr, Ni, Pb and Zn in the surface sediments were 5.1–14.7, 18.5–78.9, 2.4–75.4, 7.2–29.0, 13.5–124.4, and 21.8–403.1 mg/kg, respectively, generally decreasing along the course of the river from Jilin city to Haerbin city. Background concentrations of trace metals were reconstructed by geochemical normalization to a conservative element scandium. Results showed that concentrations of Co, Cr, and Ni in the sediment were generally only slightly higher than or equal to their background values, while concentrations of Cu, Pb, and Zn in the some sediment samples were significantly higher than their background values. In detail, the sediment at Jilin city was moderately contaminated by Cu, and the sediment of the Second Songhua River was moderately contaminated by Pb and Zn. The top layer (0–10 cm depth) and bottom layers (30–46 cm depth) of one sediment profile at Wukeshu town were generally moderately polluted by Pb and Zn. Synthetically, the surface sediment in the studied river section was classified as natural sediment without ecological risk by the sediment pollution index (SPI) of Cu, Cr, Ni, Pb and Zn. Only the 30–45 cm depth of the sediment profile at Wukeshu town was classified as low polluted sediment by the SPI of these metals, recording a historical contamination of the river in the 1960s to 1970s. This buried contamination of trace metals might pose a potential risk to water column under disturbance of sediment. Foundation item: The National Basic Research Priorities Program of China (2004CB418502)     

Assessment of dam removal from geochemical examination of Kuma River sediment,Kyushu, Japan

The aim of this study was to determine if Arase dam gate removal and flushing elevated concentrations of any trace elements in Kuma River and Yatsushiro Bay sediments or caused riverine environmental change. The Arase dam gate on the Kuma River was opened in April 2010. Surface and bottom sediments were compared using 10-cm-long cores (2011) and two grain size fractions. Surface sediment data from 2002, 2012, and 2013 from the Kuma River and Yatsushiro Bay were also compared. The sediments were analyzed using XRF for 23 elements, and the grain size analysis was done. The short core surface and bottom sediments do not show major chemical changes, and therefore, may not represent post-and pre-dam sediments. Results based on 2011 samples show that the removal of the Arase dam gates in 2010 has been geoenvironmentally beneficial due to the decrease of environmentally related trace elements Pb and Zn in 2013. However, a slight increase in the levels of Cr, Cu, Zr, and Nb in 2013 indicates that periodic flushing in winter leads to elevation in these elements due to an increase in the fine fraction. Metal enrichment factors (EF) in 2002 are higher and these have decreased by 2013. Some elements exceed environmental guidelines, but this is due to natural background values, and there is no anthropogenic contamination. Thus, the environment of the river and bay has been significantly improved due to the dam opening. This result suggests that assessment and environmental monitoring studies are very important for dam management and future decision making.     

Effect of heavy metals (Cu, Pb, and As) on the ultrastructure of Sargassum pallidum in Daya Bay, China

Concentrations of Cu, Pb, and As were determined in seawater, surface sediment, Sargassum pallidum collected from the Daya Bay, China. The influence of metal contamination on the marine alga was investigated at chemical and ultrastructural level. Mean concentrations of Cu (19.44 mg kg^?1) and Pb (33.99 mg kg^?1) were found to be high in sediment, whereas concentration of As (122.29 mg kg^?1) in S. pallidum was higher than that in water and sediment. The ultrastructure of S. pallidum cells was anomalous and aberrant. Energy-dispersive x-ray spectroscopic analysis revealed that the nanometal particles in the form of comparatively high-electron density substance diffused in the cell structures constituted by Cu, Pb, As, etc. There is a remarkable similarity or correspondence in the anomalous elements between the geochemistry and the botanic cell, and the heavy metals have potential hazardous effect on the ocean ecology system in Daya Bay.     

Investigation of heavy metals in sediments and Manila clams Ruditapes philippinarum from Jiaozhou Bay, China

Manila clams (Ruditapes philippinarum) and sediments were collected bimonthly during 2007 at five locations in Jiaozhou Bay near Qingdao, China, to determine heavy metal concentrations and to assess the validation of R. philippinarum as a metal biomonitor. Concentrations of heavy metals in clam soft tissues ranged between 0.75 and 3.31, 0.89 and 15.20, 5.70 and 26.03, 52.12 and 110.33, 10.30 and 72.34, 9.64 and 28.60, and 3.15 and 52.75 μg g^???1 dry weight for Cd, Pb, Cu, Zn, Mn, Cr, and Ni, respectively. Most of the highest values occurred at the northeast bay and the lowest values occurred at the western part. Regarding seasonal variation, relatively high tissue metal concentrations were observed during October or December. A similar pattern was also found in habitat sediments. There was a strong correlation between the concentrations of Cd, Pb, Zn, Mn, Cr, and Ni in soft tissues and surrounding sediments. It is indicated that R. philippinarum could be used as a biomonitor for heavy metal contamination in Jiaozhou Bay.     

Heavy Metal Contents of the Karasu Creek Sediments, Nigde, Turkey

Heavy metal contamination in sediments of the Karasu spring was investigated in the presented study. In this respect, sediment samples were collected from contaminant sites along the spring starting from the spring water manifestation site, base of the Akkaya dam to the dam exit site. Heavy metal concentrations were determined by X-ray Fluorescence Spectrometer. Cobalt, copper, arsenic, tin, nickel, zinc, cadmium, lead, aluminum, iron, titan, chromium and manganese contents of the Karasu creek sediments are found as 18.30–69.00, 12.40–595.0 5.50–345.3, 5.80–15.1, 10.9–64.1, 28.90–103,300, 4.1–356.2, 7.70–37,840, 13,460–109,400, 11,740–62,900, 22.18–59.04, 41.70–369 and 12.09–3,480 mg/kg, respectively. Results indicate the presence of a contamination in the Karasu creek. All the metal concentrations were found to be exceeding their acceptable limit values. Eutrophication is developed in the Karasu creek and the Akkaya dam. It is thought that heavy metal accumulation in the creek is originated from discharge from mine quarries, industrial and domestic wastes. Protection zones should be defined and all necessary measures must be taken along the Karasu creek.     

杨家幛子钼矿区土壤中重金属污染状况的评价

对杨家幛子钼矿区土壤重金属污染的情况进行了详细研究。选择土壤样本80个,采用HNO3-HF-HClO4混酸对土壤样品进行处理,运用等离子体发射光谱仪(ICP-AES)测定土壤样品中Pb、As、Hg、Cr、Cd、Zn、Cu、Ni、Mo的含量,全面系统地评价土壤重金属污染现状。结果表明,该矿区土壤重金属As、Cd和Hg污染较为严重,平均含量分别达154.13、74.92和3.06mg/kg。不同片区间存在明显差异,污染强度以矿山山沿污染最高,其次是运输区、选矿厂及矿区附近山地,内梅罗综合指数分别为59.98、59.33、52.14、42.44。