Baseline levels of heavy metals in the waters and sediments of Baffin Bay

Baseline levels of a number of trace metals have been determined in samples of water and sediment from Baffin Bay. Concentrations of Cr, Mn, Fe, Ni, Cu and Cd in the waters of Baffin Bay are generally lower than those observed in eastern Canadian coastal waters, levels being close to reported open ocean concentrations. Nearshore sediment samples, analysed for Cr, V, Mn, Ni, Co, Cu, Zn, Hg and Pb, display comparable concentrations to unpolluted muds in eastern Canadian coastal regions. Concentrations of these elements in the deep sediments of central Baffin Bay closely resemble levels in Atlantic Ocean deep-sea clays.     

Trace element accumulation in fishes collected from coastal waters of the Caspian Sea

Concentrations of 13 trace elements (V, Mn, Cr, Co, Cu, Zn, Se, Mo, Ag, Cd, Hg, Tl and Pb) were determined in muscle of bony fishes collected from coastal areas of the Caspian Sea (Kazakhstan, Azerbaijan, Turkmenistan and Iran). In all the fishes, Zn concentration was highest, followed by Cu, Se, Mn and Co, while levels of toxic elements (Ag, Cd, Cd, Tl and Pb) were relatively low. Concentrations of several elements were significantly varied between the species in each sampling area. For most of the trace elements examined, the concentrations decreased significantly with body weight of fishes. In contrast, a positive correlation with body weight was found for Co, Se and Pb concentrations in one fish species, and Hg in 2 fish species. Geographical difference in the concentrations of trace elements was examined using the Caspian roach collected from five stations of Iranian coastal waters. The concentrations of Co, Mo, Ag, Cd and Tl were higher in fishes from western stations than those from eastern stations, whereas the opposite trend was observed for Hg, indicating that local sources of trace metal pollution may be present in the Iranian coastal areas of the Caspian Sea. Levels of trace elements in Caspian fishes were relatively low in comparison to those of other regions, but Zn and Hg levels in some specimens exceeded the guideline values for food.     

Temporal distribution of heavy metal concentrations in oysters Crassostrea rhizophorae from the central Venezuelan coast

The oyster Crassostrea rhizophorae is a bivalve abundant in Venezuelan estuaries and consumed by local populations. No known values have been reported on trace metals in oysters from the central Venezuelan coast. We report the concentrations of Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V and Zn in the soft parts of C. rhizophorae, which were collected bimonthly between March 2008 and March 2009, at two sampling areas from the Central Venezuelan Coast: Buche estuary and Mochima estuary. Our results show that for each metal there is a similar temporal variation pattern. The concentrations of the heavy metals reported in this work are useful as reliable baselines and can be used for comparison in future environment studies. Concentrations in C. rhizophorae from the Buche estuary can be interpreted to be high on a global scale for Cd, Cu, Ni and Mn, indicating atypically raised bioavailabilities.     

Sponges and sediments as monitoring tools of metal contamination in the eastern coast of the Red Sea, Saudi Arabia

Sediments and sponges were collected from various locations along the eastern coast of the Red Sea, the Kingdom of Saudi Arabia. Total concentrations of Cd, Zn, Ag, Cu, Pb, As and Hg in the sediments were measured. Metal contamination was not significant in most of the studied sites and only one site was moderately polluted by Zn, Cu, and Pb. Sponges accumulated specific metals readily even though the metal exposure was low in the ambient environment. Contrasting interspecies differences in metal accumulation patterns were observed among the nine collected species of sponges. Significant positive correlations were found between the metal concentrations in the two species of sponges collected from the same sites. The strong ability to accumulate specific metals and the diversity of sponges that live in the Red Sea coastal areas make them a promising biomonitor of metal contamination in the areas.     

Trace metal fluxes to nearshore Long Island Sound sediments

Sediments are very important as trace metal ‘sinks’ in coastal areas. In this paper we present data on the concentrations and calculated fluxes of the trace metals, Fe, Mn, Cu, Pb, Zn, Cd and Ag at nearshore sites in Long Island Sound. In both areas a percentage of the metal accumulation can be ascribed to local human activities with the highest anthropogenic metal fluxes occurring closest to their source.     

Dissolved and particulate trace metals in meltwater from the Rhône glacier

Glacial meltwater and sediment at the source of the River Rhône have been analyzed to determine: 1. the partitioning of Al, Cd, Co, Cu, Cr. Fe, Mn, Ni, Pb and Zn between the water and particulate phase. 2. the particle size ranges which affect the dissolved trace metal ion composition of the meltwater and 3. the availability (potential release) of the ten trace metal ions from the sediment. Greater than 80% of the total Cd, Cu, Mn, Ni and Zn were found to be in operationally-defined (0.4 μm) dissolved forms. Fe and Al in the meltwater are primarily associated with particles in the size range 0.4–8 μm, while Cd. Cu, Mn, Ni and Zn occur with particles smaller than 0.1 μm. For the sediment, Cu, Ni and Pb were significantly present as exchangeable forms; only Cu, Ni, Pb and Zn were determined as organicallybound forms.     

Metals in sediments of Rhodes Harbour, Greece

Metal concentrations (Cd, Cr, Cu, Fe, Mn, Pb and Zn) were determined in the 0.5 HCl extractable fraction of surface sediments collected in Rhodes Harbour, Rhodes Island, Greece. The metals related to human activities (Cu, Pb and Zn) were found in relatively higher concentrations in the harbour sediments and in some cases showed important enrichment compared to the nonpolluted coastal sediments. The highest metal enhancement was found in the fine sediments of the Mandraki Harbour, which is located in the vicinity of the main sewage outfall of a densely populated area.     

The degree of trace metal pyritization in subtidal sediments of a mariculture area: application to the assessment of toxic risk

Four 2–3 m sediment cores were taken at the sites on the periphery of mussel raft concentrations in the subtidal zone of the inner Ría de Vigo (Galicia, NW Spain) with a view to evaluate the potential risk to mariculture from sediment-borne trace elements (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn). The distribution of each of these elements in reactive, organic, pyrite and silicate-bound fractions was determined at 64 samples, and these data were used to calculate the degree of trace metal pyritization (DTMP) of each metal/metalloid. In the top 10–20 cm, relatively oxic conditions led to As, Cd, Cu, Pb and Zn having large reactive fractions due to their association with Fe and Mn oxyhydroxides. At lower levels, anoxic conditions favoured by intense diagenesis led to the precipitation of trace metals and metalloids as sulphides, with or without association with pyrite. Particularly large pyrite fractions in the 20–100 cm layer are attributed to the organic matter of this layer being more marine in origin than that of deeper sediments. DTMP was greatest for Cu and As, and least for Pb, Zn and Cr. The risk of trace element toxicity in the event of disturbances instituting oxic conditions in these sediments is discussed.     

Interelement relationships and age-related variation of trace element concentrations in liver of striped dolphins (Stenella coeruleoalba) from Japanese coastal waters

Concentrations of 19 trace elements (V, Cr, Mn, Fe, Co, Cu, Zn, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, Hg, and Pb) were determined in the liver of the striped dolphins (Stenella coeruleoalba) collected around Japan during 1977–1982 to examine the sex difference, age dependence, and interrelationships among trace elements. Tissue distribution of trace elements was also investigated in one adult and one fetus specimens. Generally, concentrations of Se, Sr, Ag, Cd, Cs, Ba, Hg, and Pb were higher in the tissues of adult than those of fetus, whereas the opposite trend was observed for Cr and Tl. There were no significant sex differences in the trace element levels in the liver. Significant positive correlations between age (0–26.5 years) and hepatic concentrations were found for Ag, Se, Hg, V, Fe, Pb, and Sr, suggesting their age-dependent accumulation in the liver. In contrast, hepatic concentrations of Mn and Zn decreased with age. Significant positive relationships were observed between Se, and Hg, Ag, V, Fe, and Sr in the liver.     

Mediterranean Talitrus saltator (Crustacea, Amphipoda) as a biomonitor of heavy metals contamination

The use of sandhoppers and beachfleas as biomonitors of heavy metals contamination is relatively recent. Using adult individuals of Talitrus saltator from nine localities on the northern Mediterranean Sea, we studied the concentrations of eight trace elements: Al, Cd, Cr, Fe, Hg, Pb, Cu, Zn, both in the substratum and in the individuals. We also carried out a preliminary investigation of the correspondence between the sandhoppers' genetic variability and heavy metal contamination at the sampling sites. T. saltator accumulated Cd, Cu, Zn and Hg (at higher concentrations than in the sand) and also Al and Fe (at lower concentrations than in the sand). It seems that Mediterranean sandhoppers do not accumulate Pb and Cr. An intraspecific comparison between northern European (Baltic) and Mediterranean populations of T. saltator was made. Finally, we observed a tendency to a positive correlation between the sandhoppers' genetic variability and heavy metals contamination.     

Association of metals with plastic production pellets in the marine environment

Plastic production pellets sampled from four beaches along a stretch of coastline (south Devon, SW England) and accompanying, loosely adhered and entrapped material removed ultrasonically have been analysed for major metals (Al, Fe, Mn) and trace metals (Cu, Zn, Pb, Ag, Cd, Co, Cr, Mo, Sb, Sn, U) following acid digestion. In most cases, metal concentrations in composite pellet samples from each site were less than but within an order of magnitude of corresponding concentrations in the pooled extraneous materials. However, normalisation of data with respect to Al revealed enrichment of Cd and Pb in plastic pellets at two sites. These observations are not wholly due to the association of pellets with fine material that is resistant to ultrasonication since new polyethylene pellets suspended in a harbour for 8 weeks accumulated metals from sea water through adsorption and precipitation. The environmental implications and potential applications of these findings are discussed.     

Trace element content of seagrasses in the Leschenault Estuary,Western Australia

Estuarine environments are particularly vulnerable to human impacts. In this study, trace elements in Ruppia megacarpa, Halophila ovalis, sediment and porewater were analysed to assess the potential contamination of the Leschenault Estuary, Western Australia, from a primarily agricultural drain. Sediment concentrations of Cd, Cu, Mn, and Ni and were highest nearest the drain while Al, As, Cr, Fe and Zn and were highest further from the drain. H. ovalis showed greater accumulation of Fe, Al, and As than R. megacarpa. Concentrations of Fe, Al, As, and Ni were generally higher in below-ground plant parts than above, suggesting uptake of these trace elements via the sediment-route pathway. This study suggested that the drain was a source of Cu and Mn, with these elements entering the estuary through water inflows. As and Fe, were highest furthest from the drain suggesting input of trace elements from sources other than the drain under study.     

Bioaccumulation of trace metals in the submarine hydrothermal vent crab Xenograpsus testudinatus off Kueishan Island,Taiwan

The concentrations of ten trace metals were determined in the gills, muscles, hepatopancreas, and exoskeleton tissues of Xenograpsus testudinatus that lives around shallow and acidic hydrothermal vents off Kueishan Island, northeastern Taiwan. The analytical results demonstrate that the metal concentrations vary significantly with the type of crab tissue. The concentrations of Al, Cd, Co, Cu, Fe, Ni, and Zn are highest in the gills, whereas the concentration of Mn is highest in the exoskeleton. Cr and Pb concentrations are similar across the different tissues. The enhanced accumulation of most metals in the gills suggests the metal accumulation via the respiration pathway rather than the uptake of food. The results also reveal that the distribution patterns of metals in tissues are similar in the hepatopancreas and muscles, but very different in both the gills and the exoskeleton, perhaps because of the different pathways of metal utilization in the different crab tissues.     

Dissolved and particulate trace metal fluxes through the central English Channel, and the influence of coastal gyres

Measurements of dissolved Cd, Co, Cu, Mn, Ni, Pb, and Zn have been made on a seasonal basis at five stations on a north–south transect across the central English Channel between Cherbourg and the Isle of Wight. Vertical and horizontal distributions of dissolved Cd, Pb, Cu and Zn are relatively uniform except for sampling sites near the English coast. Dissolved Mn and Co show increased concentrations in the English coastal waters, and for Mn the seasonal trend in concentration follows the pattern seen in the Strait of Dover with higher values in the late summer. Ni and Cu are higher in concentration on the English side, which reflects mainly riverine sources. Measurements were also made of particulate forms of the metals above plus particulate Al, Ca, Fe, Mg, Sr and Ti. Water column concentrations of particulate metals broadly follow the distribution of suspended particulate matter, with highest concentrations near the UK coast. Trace metal concentrations have been integrated with modelled data on fluxes of water to provide estimates of fluxes for these elements into the eastern Channel, and an initial comparison is made with data for fluxes of metals through the Strait of Dover obtained during an earlier study. A major influence on the fluxes of particulate metals through the Isle of Wight-Cherbourg transect is the gyre system to the South east to the Isle of Wight, which has important east to west as well as west to east transport components. For those elements where the dissolved form of the metal dominates, the large flow of water in the central Channel waters leads to major fluxes of the metals towards the east and the Strait of Dover. However, the high suspended particulate matter loadings in the coastal waters and impact of the gyre system lead to net east to west fluxes of particulate Al, Fe, Mn and Ti. Comparison of these fluxes with data on the net west to east transport of these materials through the Strait of Dover infers that there must be a significant supply of these particulate metals to the eastern Channel.     

Evaluation of metal contamination in coastal sediments of the Bay of Bengal, India: geochemical and statistical approaches

Surface sediment samples collected from the inner shelf region of the Bay of Bengal, were analysed for the major elements and total and acetic acid available trace elements (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Si, Zn) to evaluate geochemical processes influencing their distribution. Major elemental analysis showed that the sediments had high concentrations of Si and relatively low concentrations of Al and Fe. Both major elemental and trace metal concentrations indicated that the sediments represent weathered products of granite and charnockite. Normalization of metals to Al indicated relatively high enrichment factors for Pb, Cd, Zn and Cr. The higher proportions of nondetrital Pb (66%), Cd (41%) and Co (28%) reveal metal contamination due to anthropogenic inputs. Factor analysis (FA) identified six possible types of sedimentological and geochemical associations. The dominant factor accounting for 26.9% of the total variance identifies an anthropogenic input and accumulation of nondetrital Cd, Co, Cr, Ni and Pb. Association of these metals with CaCO3 reveals that shell fragments in the surface sediments are likely act as a carrier phase for nondetrital metals. The results are discussed in the context of the sources and pathways of elements in the Bay of Bengal.     

The Apure River: geochemistry of major and selected trace elements in an Orinoco River tributary coming from the Andes,Venezuela

The analysis of physicochemical variables and selected dissolved elements was performed on the Apure River waters for 15 months. The variables pH, alkalinity, dissolved O₂, conductivity and Na, Ca, Mg and Cd concentrations showed maximum values during low water, whereas K, Si, Fe, Al, Mn, Zn, Cu, Cr and dissolved organic carbon (DOC) showed maximum concentrations during rising and high water. Five important factors were found to control the amount and temporal variability of the dissolved elements: lithology, hydrology, vegetation–floodplain processes, redox conditions and organic complexation. Weathering of silicates, carbonates and evaporites in the Andes provides most of the proportion of Na, Ca, Mg and HCO₃^? to waters. The temporal variability of these ions is controlled by a dilution process. Although Si can be taken up by the biomass, Si and K can be leached from the floodplain by weathering of clays. Microbial decay of the submerged plants in the floodplain during the inundation periods provides DOC and K to river waters and changes the redox conditions in water. The changing redox conditions control the solubility of Mn, Zn and Fe. Dissolved Mn is a function of pH‐dependent redox process, whereas Zn solubility is controlled by scavenging of Zn during the oxidation of Mn²⁺ to MnO₂. Positive relationships between Al, Fe, Cu, Cr and DOC suggest that these elements are complexed by organic colloids generated in the floodplain. Moreover, the binding capacity of Fe with DOC increases under reducing conditions. Although Cd seems to be provided by weathering in the Andes, several processes can affect the mobility of Cd during transport. Copyright © 2010 John Wiley & Sons, Ltd.     

Interelement relationships and age-related variation of trace element concentrations in liver of striped dolphins (Stenella coeruleoalba) from Japanese coastal waters

Concentrations of 19 trace elements (V, Cr, Mn, Fe, Co, Cu, Zn, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, Hg, and Pb) were determined in the liver of the striped dolphins (Stenella coeruleoalba) collected around Japan during 1977–1982 to examine the sex difference, age dependence, and interrelationships among trace elements. Tissue distribution of trace elements was also investigated in one adult and one fetus specimens. Generally, concentrations of Se, Sr, Ag, Cd, Cs, Ba, Hg, and Pb were higher in the tissues of adult than those of fetus, whereas the opposite trend was observed for Cr and Tl. There were no significant sex differences in the trace element levels in the liver. Significant positive correlations between age (0–26.5 years) and hepatic concentrations were found for Ag, Se, Hg, V, Fe, Pb, and Sr, suggesting their age-dependent accumulation in the liver. In contrast, hepatic concentrations of Mn and Zn decreased with age. Significant positive relationships were observed between Se, and Hg, Ag, V, Fe, and Sr in the liver.     

Assessment of Urban Source Metal Levels in Influent,Effluent, and Sludge of Two Municipal Biological Nutrient Removal Wastewater Treatment Plants of Bursa,an Industrial City in Turkey

Removal of Al, As, Cd, total Cr (Tot. Cr), Cu, Total Fe (Tot. Fe), Mn, Ni, Pb, Sb, Sn, and Zn from urban effluent by wastewater treatment plants (WWTPs) operated under five‐stage Bardenpho® process were investigated and water soluble metals in the dewatered sludge were quantified. Samples were collected from two WWTPs on a weekly basis over an approximately 2.5‐year time span. Tot. Fe and Al were the most abundant, As, Pb, Ni, Cu, and Cd were the least abundant metals in the influents of both WWTPs. Removal efficiencies above 75% were achieved for Tot. Cr, Tot. Fe, Al, and Cu, whereas, no significant removal was observed for As, Cd, Pb, Sb, and Sn. Removal of Tot. Cr, Cu, Tot. Fe, Zn, Al, Mn, and Ni were influenced by influent suspended solids concentrations, and of Tot. Cr, Zn, and Cd were influenced by their initial content in the influent. Zn removal efficiency of biological nutrient removal (BNR) system in this study was higher and Cd removal efficiency was lower than that of conventional activated sludge reported in the literature. No remarkable difference for metals such as Cu, Mn, Ni, and Pb was observed between the removal efficiencies of conventional system and BNR system.     

Bioaccumulation of Sediment-Bound Heavy Metals in Grey Mullet, Liza macrolepis

Two groups of grey mullet, Liza macrolepis, a filter and a detritus-mud feeder, were chosen as the subjects of a sediment exposure experiment for evaluating the bioaccumulation of toxic metals associated with the Kaohsiung-harbour sedimental contamination. After 180 days of sediment exposure, the sediment treated group showed significantly elevated Cu, Mn, Fe, Zn and Cd concentrations in whole fish at 3-, 1.5-, 3-, 2-, and 2-times, respectively, higher than the control group. The Ni concentrations were not significantly different between the two groups. The metal levels (Cu, Mn, Fe, Zn, and Cd) in various parts of the fish showed that all metals in muscle and gill, Cu in liver, and Zn in intestine and liver of the sediment-treated group were significantly higher than those of the control group. The bioaccumulation factors (BAFs) in whole fish ranked as Cd > Zn > Cu > Mn > Ni > Fe. The results of significant bioaccumulation suggest that L. macrolepis can be used as a good bio-indicator of metal pollution in coastal area.     

A new sentinel organism for vanadium and titanium

Using X-ray Energy Spectroscopy trace metal concentrations (Ti, V, Mn, Fe, Ni, Cu, Zn, As, Pb) were measured in specimens of Eudistylia vancouveri (feather duster tube worms) collected from floating wharves near and far from a storm water outfall in a metropolitan area. As for the well-studied bio-accumulator Mytilus edulis (mussels), higher metal concentrations were noted in specimens near the pollution source. In particular the worms accumulated certain metals, namely vanadium and titanium, not picked up by the mussels, signaling that a new sentinel organism could be available.