Investigations of some trace elements in the Bay of Lim

Sea water was collected at several stations in the Bay of Lim at a depth of one meter below the surface, and before analysis, was filtered with 0.45-μm Millipore filters. Shallow water sediments were collected at the same locations. Humic acids used in this work were separated from near-shore sediments taken from various saline waters of the Bay of Lim. The prepared humic acids were then analysed for their elementary composition and also for positions of their hydrolytic products to obtain more data on how and to which characteristic part, the trace elements were related. The hydrolysis of humic acids was done by chemical methods in order to obtain four main components: amino acids, sugars, phenols and condensed benzene core. Neutron activation analysis was used for trace element analysis in evaporated portions of filtered sea water, sediments, soil, living organisms, humic acids and their hydrolytic products. This work was undertaken to obtain more data on the organic matter present in sediments and in seagrass flats, and also to collect more data on trace elements that are associated with typical and representative samples for the Bay of Lim. Analyses of trace elements associated with either humic acids or their hydrolytic products were performed with the purpose of gaining evidence as to which part of humic acids metals are bound. Humic acids or their decomposition products play an important role in the distribution and availability of a number of essential or nonessential trace elements. Results of this work indicate that humic acids influence the process of redistribution of trace elements in the investigated local coastal area.     

Geochemical index of trace metals in the surficial sediments from the western continental shelf of India, Arabian Sea

The present study focuses on the determination and abundance of trace metals (viz. Cu, Ni, Zn, Cr, Co, Cd, Mn and Fe) in the surficial sediments of west coast of Arabian Sea along the Indian subcontinent. Sediment samples were collected from three transects along the western continental shelf of Arabian Sea. The enrichment of Fe and Mn in coastal oxic-sediments indicates the precipitation of these redox sensitive elements as Fe- and Mn-hydroxides and oxides, whereas the low Fe and Mn concentrations in the oxygen deficient sediments of deeper stations reflects the dissolution of their hydroxides and oxides. Concentrations of fairly redox insensitive trace metals like Cu, Ni, Zn, Cr and Cd (with the exceptions of Cr) showed higher values at nearshore sediments, then it decreased towards seaward and again showed a slight increase at oxygen minimum stations in all the three transects. This geochemical variability in their distributional characteristics is mainly associated with the extent to which the precipitation or dissolution of Fe- and Mn-oxides/hydroxides occur since the scavenging or releasing effects of Fe- and Mn-oxides/hydroxides act as significant ‘sinks’ or ‘sources’ of heavy metals. The change in wind pattern, coastal upwelling and increased productivity are also the reported factors which influence the biogeochemical cycling of trace metals in the surface sediments of west coast of India. Enrichment factor generally showed a high gradient accumulation from nearshore to shelf.     

The ecosystem of the bay of Mali Ston natural and anthropogenic influence

Chemical hydrography, nutrients and trace metals in water, sediments and marine organisms were studied in the Bay of Mali Ston and their role in terms of pollution discussed. Results show that the entire study area is very strongly affected by the adjacent land. The overall area is well aerated so that no dangerous accumulation of nutrients with oxygen content reduction was recorded.

Results of analyses of trace metals show that the water and sediments of the bay contain high levels of some metals significantly higher than those from the open sea. This may be attributed to the natural sedimentation processes and the Neretva River and submarine spring runoffs carrying constituents of ignous and limestone rocks.     

Sediment and porewater geochemistry in a metal contaminated estuary,Dulas Bay,Anglesey

Remobilisation of contaminant metals from sediments can occur by chemical, biological or physical changes. This in turn can lead to contaminant fluxes to the porewaters and ultimately the water column. The aim of the research presented here is to document post-depositional controls on metal mobility and fluxes in a heavily metal-contaminated estuary. This will allow for an improved understanding of the impact of contaminated sediments on water quality from both a short-term and long-term perspective. Dulas Bay is situated on the east coast of Anglesey, North Wales, and receives polluted waters from Parys Mountain. Metals within Dulas Bay sediments show surface enrichment and variations in mineralogical form. Diagenesis clearly plays a role in post-depositional behaviour of the metals, forming sulphides and potentially carbonates. The presence of a dominant exchangeable/carbonate fraction, and elevated porewater metals, in this sulphidic system is significant and could indicate the presence of freshwater diagenesis, or, reflect the high levels of metals in the sediment.     

Trace metal distribution in different chemical fractions of marine sediments along the eastern Aegean shelf

The major objective of this study was to carry out sequential chemical extraction for the partitioning of particulate trace metals in sediment samples, collected along the eastern Aegean shelf during cruises July‐August 1994, in the framework of a National Marine Measurement and Monitoring Programme for the Aegean Sea.

Five metals, Cd, Pb, Cu, Zn and Cr were examined in each of sediment samples. Three chemical fractions of the sediments were separated and concentrations of the trace metals were determined by AAS techniques. The three different leaches used were hydroxylamine hydrochloride‐acetic acid, hydrogen peroxide and nitric‐perchloric acids.

Metals were concentrated mainly in the fraction extracted by nitric‐perchloric acids. Lead in the first fraction were found in the sediments of Northern part of Aegean, where the concentration of organic material was high.

The total concentrations of Cd, Cu, Zn, Cr were higher in Izmir Bay than the other sampling points. The distribution of Pb concentrations was the highest in Edremit Bay and Izmir Bay.     

Historical trends of trace metals in a sediment core from a contaminated tidal salt marsh in San Francisco Bay

Sedimentation of metals preserves historical records of contaminant input from local and regional sources, and measurement of metals in sediment cores can provide information for reconstruction of historical changes in regional water and sediment quality. Sediment core was collected from Stege Marsh located in central San Francisco Bay (California, USA) to investigate the historical input of trace metals. Aluminum-normalized enrichment factors indicate that inputs from anthropogenic sources were predominant over natural input for Ag, Cu, Pb, and Zn. Among these, lead was the most anthropogenically impacted metal with enrichment factors ranging from 32 to 108. Depth profiles and coefficients of variation show that As, Cd, and Se were also influenced by anthropogenic input. The levels of these anthropogenically impacted metals decline gradually towards the surface due to regulation of the use of leaded gasoline, municipal and industrial wastewater discharge control, and closure of point sources on the upland of Stege Marsh. Although trace metal contamination is expected to be continuously declining, the rates of decline have slowed down. For lead, it is estimated to take 44, 82, and 153 years to decrease to probable effects level (112 μg/g), the San Francisco Bay ambient surface sediment level (43.2 μg/g), and the local baseline levels (5 μg/g), respectively. Some metals in surface sediments (0–6 cm) are still higher than sediment quality guidelines such as the probable effects level. To further facilitate the recovery of sediment quality, more efficient management plans need to be developed and implemented to control trace metals from non-point sources such as stormwater runoff.     

Heavy Metals in Sediments and Oysters From Bluefields Bay, Nicaragua

The distribution of trace metals (Co, Cu, Fe, Mn, Ni, Pb and Zn) was investigated during a year (1994-95) in surface and core sediment samples and in the oyster (Crassotrea rhizophorae) from Bluefields Bay, Nicaragua. the aim was to assess the arthropogenic impact of potential pollutant sources, mainly Bluefields City, since domestic waste waters are discharged directly or by infiltration to the bay. Lyophilised samples were submitted to different acid digestion methods and analysed by flame atomic absorption spectrophotometry. the results showed highest contents for copper, lead and zinc near Bluefields City, with an increase in the affected area in the rainy season that is generated by greater city run off. Metal contents in oysters do not show the same distribution pattern than in sediments and were similar to those from other areas without reflecting pollution levels.     

Physico-chemical characteristics of the peloid mud from Morinje Bay (eastern Adriatic coast, Croatia): suitability for use in balneotherapy

The study conducted in the Morinje Bay (Central Dalmatia, Croatia) included the investigation of the sedimentological, physico-chemical and geochemical properties of the Morinje Bay sediments in order to assess the suitability of the material for wellness-related purposes including medicinal use. The sedimentological characteristics of the Morinje mud are in accordance with the geological origin of the material; the sediment is fine grained, composed mostly of carbonates, quartz and clay minerals. The composition of the sediment determines the physico-chemical properties of the mud. The high content of carbonate minerals diminishes adsorbing the characteristics of the mud to some extent; however, they are still comparable to some commercial mud already successfully used for medicinal purposes. Geochemical analyses have shown that trace metals concentrations in the Morinje Bay samples were mostly in the range with similar material from unpolluted Adriatic environments. Only the concentrations of Cu, Pb, Zn and As were slightly higher than in the reference material, but still within acceptable limits.     

Seasonal variation and partition of trace metals (Fe, Zn, Cu, Mn, Cr, Cd and Pb) in surface sediments: relationship with physico-chemical variables of water from the Calabar River, South Eastern Nigeria

The seasonal variation and partition of trace metals (Fe, Cu, Zn, Mn, Cd, Cr and Pb) in the surface sediments of the Calabar River are reported. Chemical partition of the metals in the sediments reveals that 2–30% of the total metal load was contributed by the non-detrital (acid-soluble) fraction, while fine-grained host minerals/compounds are the main carriers of the detrital (acid-insoluble) fraction (70–98%). Using multivariate statistical analysis, the seasonal fluctuations in the distribution of some of the metals show significant influence by physio-chemical changes (dissolved oxygen, pH, salinity and conductivity) in the water column. Fe–Mn oxide grain coatings and sulphide materials have been identified as scavengers of some of the non-detrital and detrital trace metals in the sediments. On the basis of index of geoaccumulation (I-geo) and comparison with previous studies, the Calabar River surface sediments have been classified as unpolluted.     

Heavy Metal Pollution in Sediment from the Eastern Adriatic Coast,Croatia

Abstract

Sediment samples were collected from the Adriatic Sea in areas near large coastal towns along the eastern Adriatic coast (Zadar, [Ncirc]ibenik, Split, Plo?e and Dubrovnik).

Considerable quantities of untreated effluents are discharged via freshwater runoff and a variety of industrial waste waters, significantly affecting the quality of marine sediments.

Distribution of some trace metals (Pb, Cu, Ni, Cr, Zn, Mn, Cd, and Al) involved in problems related to metal pollution in Adriatic sediment were examined. Values are expressed as a total concentration of heavy metals of sediment dry weight.

Spatial distribution of some trace metal values in sediments and correlation of results for grain size effect were examined. the trace elements in marine sediments generally remain in the fine grained fraction, often in the silt-clay fraction. Higher values of heavy metals in some areas (Split, Sibenik) could be attributed to anthropogenic effects, i.e. to land-based activities. the main cause of higher values of some metals at open sea sites and in some coastal areas are probably caused naturally by sedimentation processes in those areas. Our results show that the sediments undoubtedly play a key role in determining the transport and ultimate fate of contaminants.     

莱州湾表层沉积物中重金属时空分布、污染来源及风险评价

运用污染风险评价标准和方法研究了2010年5月(春)、8月(夏)、10月(秋)和12月(冬)莱州湾表层沉积物中7种重金属污染物的时空分布特征、来源及生态风险。结果表明,表层沉积物中Cr、Zn和Pb含量均呈现春季低于其他季节特征,秋季Hg含量是其他季节的4倍,Cu、As和Pb含量无显著季节差异。表层沉积物中Cr、Cu、Zn、As和Cd最高值出现在莱州湾中部及小清河河口等西部水域,来源呈现受自然作用影响较大的特征;而Hg和Pb最高值出现在龙口和界河河口等东部水域,来源呈现受周边工业污染物的人为排放影响较大的特征。基于地理累积指数、生态效应浓度以及Hakanson潜在生态风险指数的综合评价表明,13%~29%的研究区域的表层沉积物受到轻微程度的Cd、Hg和Pb污染,Cd和Hg高值水域达到中等生态风险程度;Hg和As在65%~68%的研究区域的表层沉积物中达到可能对沉积物底质环境及生物群落产生不利生态影响水平。基于对重金属污染物的评价结果,莱州湾表层沉积物质量较好,局部区域存在Hg、Pb、Cd和As的潜在污染风险。     

Contamination of Surface Soils, River Water and Sediments by Trace Metals from Copper Processing Industry in the Churnet River Valley, Staffordshire, UK

The impacts of a functional and a demolished copper processing works on the aquatic and terrestrial environment in the vicinity of the works was investigated by determining the levels of selected trace metals in river water, river sediments, channel margin sediments and overbank soils. Samples were taken at five sites within an area of the Churnet Valley in Staffordshire, where the River Churnet flows through the two works. Analysis of river water samples by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) has shown that only copper is present above background levels considered to typify uncontaminated rivers. Analysis of river sediments, channel margin sediments and overbank soils by nitric-perchloric acid digestion and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) analysis has indicated contamination by arsenic, cadmium and copper in the vicinity of both works. Arsenic and copper are deposited primarily within the aquatic environment, although some contamination of the terrestrial environment by copper is also observed. Cadmium is deposited primarily within the terrestrial environment. The deposition of arsenic and copper in river and channel margin sediments respectively is also related to current and historical contamination.     

Geochemical distribution,bioavailability and potential toxicity of some trace metals in a complex micro-tidal estuary,Southwest India

The spatial and temporal variations of some trace metals in the surface sediments of Cochin Estuary were analyzed along with their geochemical associations to identify the possible sources, bioavailability and the health risks posed by them. The dominance of kaolinite and suggested that clay minerals distribution is influenced by sediment sorting. Total metal analysis revealed enrichment for Cd, Pb and Zn due to anthropogenic activities. The speciation analysis established that notwithstanding the large availability, carbonate as well as organic and sulfides bound fractions showed negligible associations with most of the metals. Hydrous Fe–Mn oxides appeared to play a major role in controlling the fate and transport of these metals in the sediments of Cochin Estuary. Lower contribution of the residual fractions for Cd (21%–26%), Pb (<60%) and Zn (24%–42%) indicated an obvious increase of other geochemical fractions. Risk assessment analysis revealed that regardless of total concentration, none of the analyzed metals were at safe levels in the estuary as appreciable percentages were found to be associated with mobile geochemical forms. The speciation study conspicuously established that the metals originating from non-geogenic sources are largely associated with the labile fractions and hence are more detrimental to the aquatic biota.     

Lysosomal,genetic and chromosomal damage in haemocytes of the freshwater bivalve (Unio pictorum) exposed to polluted sediments from the River Cecina (Italy)

The response to chemical disturbance of an Italian river (Cecina River) characterised by high levels of trace metals was assessed in the sentinel species freshwater painter’s mussel (Unio pictorum). We exposed U. pictorum in the laboratory to metal, metalloid and other trace element polluted river sediments in order to evaluate genetic and cellular biomarkers. Bivalves exposed to sediments taken from all the impacted sites of the river basin exhibited a significant impairment at the DNA, chromosomal and lysosomal levels. The lysosomal membrane stability of circulating haemocytes, assessed by the Neutral Red Retention Time, was found to be higher in specimens from Lake Maggiore and Berignone, while exhibited a significant decrease in specimens exposed to Ponteginori sediments. An increase of DNA migration in specimens exposed to the two contaminated sites in comparison with controls was found. Moreover, higher micronucleated haemocytes frequencies were observed in bivalves exposed to sediments collected at Possera 1 site. This study suggested that biomarkers evaluating cellular impairment, genetic and chromosomal damages, are highly sensitive and suitably applied to laboratory experiments. The painter’s mussel was confirmed to be an appropriate sentinel species for quality assessment in metal-contaminated freshwater environments.     

Heavy metal accumulation in water, sediments and fishes of Nallihan Bird Paradise, Turkey

The accumulation of some heavy metals such as Pb, Cd, Cu and Ni was determined in water sediment and fish samples (Albumus escherichii, Cyprinus carpio and Silurus glanis) collected from Nallihan Bird Paradise (NBP) and its vicinity (Sariyar Dam). The results showed that these metals are found widespread throughout the study area, but metal concentrations in the water samples are below the detection limits (BDL). Pb, Cd, Cu and Ni contamination were determined in sediments and in fish tissues (muscle and liver) and it was seen that they were accumulated and biologically magnified in lish tissues. Metal concentration levels in sediment samples were higher than that of water and fish tissues. The highest amount of metal concentrations in sediment samples among seven stations were determined in Usakbuku (Pb: 0.49 ppm), Sakarya River (Cu: 1.12 ppm) and Sariyar (Ni: 0.77 ppm). Unlikely to the other stations, no metal residues were determined in the sediment samples ofAladag Creek Station.     

Heavy metal pollution in Suva harbour sediments,Fiji

In Fiji, contamination of the coastal environment by heavy metals is proving to be a real concern. This work reports for the first time analyses carried out on an extensive basis, to ascertain the extent of anthropogenic contamination by heavy metals in the <0.063 mm surface sediments of Suva harbour. Sediment samples from 40 sites selected within the harbour were collected and analysed for five heavy metals. The levels of the metals range from 21.4 to 143.0 ± 0.1 mg/kg Cu, 1.40 to 4.87 ± 0.07 wt.% Fe, 22.1 to 93.5 ± 0.3 mg/kg Pb, 40.2 to 269.0 ± 0.3 mg/kg Zn and 1.1 to 2.6 ± 0.2 mg/kg Sn. With reference to the pristine area of the Great Astrolabe, in Kadavu, the acquired data from the harbour are indicative of heavy metal pollution. This could be attributed to the numerous industrial and commercial activities at Wailada and Walu Bay industrial areas, the municipal dump located at the Suva foreshore and the Suva wharf. The pollution is further compounded by the high population density in Suva city.     

AVS-SEM relationships and potential bioavailability of trace metals in sediments from the Southeastern Mediterranean sea,Egypt

In risk assessment of aquatic sediments, much attention is paid to the difference between acid volatile sulfide (AVS) and simultaneously extracted metals (SEM) as indicators of metal bioavailability. Distribution of AVS and SEM (Cd, Cu, Ni, Pb and Zn) were determined in 20 representative sampling sites collected along the Egyptian Mediterranean coast. Total SEM concentration [ΣSEM] ranged from 0.012 to 0.241 μmoleg^?1. AVS concentrations were much more variable, showing significant spatial variations. The values ranged from 0.015 to 31.326 μmoleg^?1. The different relationships between AVS and SEM to establish mechanical models such as the ratio of ΣSEM and AVS [ΣSEM/AVS], the difference between the ΣSEM and AVS [ΣSEM–AVS], or the organic carbon normalised difference between SEM and AVS [ΣSEM-AVS]/f_oc models were used as parameters to evaluate potential bioavailability. Considering SEM/AVS model, sediments at the Western Harbour, Eastern Harbour, Ras El-Burr, El-Gamil East, and Port Said stations are occasionally toxic, while according to SEM-AVS model, no indication of associated adverse toxic effect would occur at any of the sampling sites. Calculated [ΣSEM-AVS]/f_oc was<130 μmoleg^?1 in the sediments indicating that sediments should pose a low risk of adverse biological effects owing to cadmium, copper, lead, nickel and zinc. Association of adverse effects to aquatic organisms was determined, using the classification of the sediments according to the Sediment Quality Guidelines (SQGs). The marine Threshold Effect Levels (TEL) and Probable Effect Levels (PEL) were used in this work and in order to obtain a more realistic measure of predicted toxicity, mean PEL quotients (PELq) were calculated. The mean PELq calculated for the sampling sites was (0.11–1.5) and categorised as slightly toxic at all stations except Baghoush, Nobarreya and western harbour, which had PELq<0.1 and categorised as non-toxic. The obtained data concluded that the remobility and bioavailability of trace metals contained in surfacial sediments of the Egyptian Mediterranean coastal area are low.     

Heavy metal accumulation in certain marine animals along the East Coast of Chennai, Tamil Nadu, India

Heavy metals disposed through anthropogenic activities find their way into the oceans and seas through the rivers or through direct fall out from factory effluents. These heavy metals resuspend back into the water column along with the sediments and are known to affect the marine animals. Marine animals like fish, prawn, crab and mussel were collected along the East Coast (off Pulicat lake to Chennai Harbour) to evaluate trace metal concentrations in various tissues. The above specimens accumulated heavy metals such as Zn, Pb, Cu, Co, Cr, Ni and Cd. Fish, prawn, crab and mussel revealed higher concentration of heavy metals such as Zn, Pb, Cr Co, Cu and Ni and Cd in low levels. The results revealed that the heavy metal concentrations in the marine animals are below the threshold levels associated with the toxicological effects and the regulatory limits. The bioconcentration factors revealed that the animals have accumulated heavy metals along the food chain rather than from the water column and sediment.     

Water quality in a mediterranean marine protected area (North Sporades Islands,Greece)

Pollution in the marine protected area of North Sporades Islands was investigated in July 1997. Salinity, temperature, dissolved oxygen, dissolved inorganic nutrients, organic carbon, hydrocarbons as well as dissolved and particulate trace metals were determined at 15 offshore and coastal stations. Dissolved organic carbon and inorganic nutrient concentrations indicate the mesotrophic character of the investigated waters. The dissolved forms of nitrogen were slightly higher at coastal stations. Dissolved and particulate Cu, Zn and Ni, were higher in coastal stations, whereas concentrations of Pb were generally low and likely of atmospheric origin. Dissolved/Dispersed petroleum hydrocarbons (DDPH) were close to detection limits at all stations. Temperature and salinity vertical profiles, nutrient and trace metal concentrations revealed the presence of a slight influence of the Black Sea water coming from Dardanelles straits.     

The common mussel Mytilus edulis as an indicator of pollution by zinc,cadmium, lead and copper. II. Relationship of metals in the mussel to those discharged by industry

Concentrations of zinc, cadmium, lead and copper were determined in whole soft parts of the common mussel Mytilus edulis (L.) sampled in Port Phillip Bay and Western Port Bay, both in Victoria, Australia. The mussels were sampled according to procedures suggested by previous studies in order to eliminate the effects of natural environmental variables. Results of the analytical studies were compared to data on the quantities of trace metals known to be discharged by industry into the catchments of each Bay. This allowed an evaluation of the indicator ability of the mussel without the need for multiple analyses of water samples. The results suggest that the mussel is capable of acting as an efficient time-integrated indicator of zinc, cadmium and lead over a wide variety of environmental conditions. Although additional variables may remain to be investigated, the mussel is recommended as an alternative to the analysis of water and sediments. With further development this organism may also be useful for monitoring industrial effluent characteristics at the discharge site, allowing rapid, reliable and inexpensive control of water quality. In contrast, the mussel is of doubtful use as an indicator of copper; other indicator types such as macroalgae may be better-suited to the study of this element.