Metal Levels In Sediments Research Articles

Cobre, cadmio y plomo en el pez Cyprinodon dearborni , sedimentos y agua en dos lagunas de Venezuela

The concentration of copper, cadmium and lead in superficial sediment, water and the fish Cyprinodon dearborni was determined in two coastal lagoons of Sucre State, Venezuela. Chacopata lagoon is hyper saline while Los Patas lagoon is hypo saline and receives significant wastewater from Cumana city. Water, sediment and fish samples were collected in February 1998. In the laboratory, samples underwent acid digestion and were analyzed by atomic absorption spectophotometry. The mean values of the metals in C dearborni from the Chacopa­ta lagoon were: 159.26 ± 210.68 μg/g for Cu, 44.71 ± 45.58 μg/g for Cd; and 9.31 ± 23.34 μg/g for Pb, while for Los Patos lagoon the mean values were: 64.88 ± 16.30, 19.48 ± 5.81 lUllI 22.85 ± 20.00; respectively. In the water column, the metal concentration ranges were; 2.3-11.6, 3.9-5.4 and 21-32 mg/l for copper, cadmium and lead, respectively. These results suggest that metal levels in sediment, water column and organisms in both lagoons do not differ, except for lead, even though only Los Patos receives waste water.

Regional-scale monitoring of coastal contamination. Nutrients and heavy metals in estuarine sediments and organisms on the coast of Galicia (northwest Spain)

We determined background levels of heavy metals in sediments and biota of estuarine environments and nutrient reference levels in sediments of the Galician coast. This region is characterised by having ria-type estuaries. The determination of these levels, which were affected by the geological heterogeneity of the area, was the basis that let us evaluate the contamination status of this coast. The contamination factors calculated for different metals evidenced few sites with severe contamination. The potential ecological risk approach, used to evaluate the overall degree of pollution based on the metal levels in the sediments, agreed with this conclusion.

Spatial variability in characteristics and trace metal levels in sediments from watercourses

Assessing sediment quality requires sampling designs which address variability. Often however, only one sample or composited sample is collected at a sample site. Existing studies on sediment variability or sampling strategies primarily concern lake or marine sediments. Two rivers and one canal were sampled to assess sediment variability. Further, it was determined if sediment contamination in running water could be predicted by using visual criteria and/or knowledge of the presence of depositional and erosion areas. Metal concentrations and sediment characteristics were measured in different visually distinct areas of the river. At all sample sites the coefficient of variance was relatively high for most sediment characteristics (1.4‐ > 100%) and metal levels (15.3–63.6%). In one river the majority of sediment characteristics variation was between two sediment types and detected by visually distinct differences. Significant differences in cadmium and zinc concentrations were also detected. Contrary to what was expected, cadmium, and zinc levels were highest in the coarse fraction. No differences were found in the second river. In the canal a greater concentration of fine grained sediments and metals were found in the deep areas. It was not possible to predict sediment areas with the highest levels of metal contamination using visual criteria or knowledge of the erosion and sedimentation pattern of the river.

Metal pollution in coastal areas of Mexico.

Metals are natural constituents of the earth core and can be widespread in all environments, forming part of sediments, rocks, animal and plant tissues, crude oil, hemoglobin, pigments, proteins, and enzymes. However, some of these metals, such as lead, chromium, and mercury, have been widely used in industrial and human activities, thus provoking an alteration in their geochemical balance and causing high concentrations, frequently three to four orders of magnitude higher than their natural concentrations. The aggressive industrialization and urbanization of coastal areas in Mexico have given rise to singular pollution problems in which such metals play an important role. Thus, this review identifies the main sources and quantifies the concentration levels of metals in the water, sediments, and organisms of coastal ecosystems (rivers, estuaries, coastal lagoons, Continental Shelf) in the Gulf of Mexico as well as the Mexican Pacific. The results show high concentrations of lead, chromium, and nickel in sediments and animal tissues from coastal states (Tamaulipas, Veracruz, Tabasco, and Campeche) in the Gulf of Mexico, especially in areas close to industrialized towns such as Tampico, Veracruz City, and Villahermosa. On the other hand, studies conducted on Mexican Pacific coasts indicate low levels of metals in sediments and organisms, an indication that the metal pollution here is closely tied to human, industrial, and oil activities.

Trace Metals in Sediments and Molluscs from an Estuary Receiving Pig Farms Effluent

Pig farming in Malaysia has become more active over the years as it yields high annual turnover of estimated 2 billion Malaysian Ringgit. The increase in pig farming activities has brought about changes in environmental qualities in the forms of organic matter pollution and trace metals pollution. Many earlier studies have indicated the presence of high levels of trace metals in sediment from estuarine receiving effluent from pig farming. This study shows that there are high concentrations of copper, zinc and lead in sediment and gastropods sampled close to the pig farm but this reduced about 100 fold towards the river mouth. The ranges of trace metals in sediment studied are 4–670 µg g−1 for Cu, 4–550 µg g1 for Zn, 3.4–46.5 µg g−1 for Pb and 0.1–2.1 µg g−1 for Cd. While in molluscs, the levels range from 6–15 µg g−1 for Cu, 18–47 µg g−1 for Zn, 7–17 µg g−1 for Pb and 0.1–2.5 µg g−1 for Cd. The results also show that 60 to 70 percent of the Cu, Zn and Pb concentration in the sediments are from anthrophogenic activities.

Nacreous shell of Mytilus galloprovincialis as a biomonitor of heavy metal pollution in Galiza (NW Spain)

The rock mussel (Mytilus galloprovincialis Lam.) was used as a biomonitor species for metal pollution on the coast of Galiza, NW Spain. The measured concentrations in the soft tissues and in the nacreous shell were contrasted with those from the HCl and HNO3 leached fractions of sediment samples collected from the mussels' environment. The nickel and lead concentrations in the nacreous shell and the zinc and lead concentrations in the soft tissues were correlated with the sediment metal levels. The results suggest that Mytilus galloprovincialis can be used as a particularly appropriate biomonitor for lead pollution, with the nacreous shell seemingly producing better results than the tissue.

Variability of cadmium, copper and zinc levels in molluscs and associated sediments from Chile

The concentrations of cadmium, copper and zinc in mussel and sediment samples collected together from eight different geographical coastal areas of Chile were determined. The mussels studied were ‘Chorito Maico’, ‘Almejas’ and ‘Navajuelas Chilenas’ ( Perumytilus purpuratus, Semelle solida and Tagellus dombeii, respectively). Sampling was carried out in July and September 1992 and January and April 1993 (winter, spring, summer and autumn seasons in Chile, respectively). The metal levels in these mussels varied among species; there were several sites where the metal concentrations in molluscs approached or exceeded the criteria levels for Cd, Cu and Zn in shellfish products: 1, 10 and 50 ppm ww respectively, which are regarded as safe levels for human consumption. The results of metal levels in sediments showed two areas clearly polluted with Cu. Strong relationships between Cu concentrations in the three molluscs and sediments were found; weak correlations were observed for Zn in S. solida

Background heavy metal levels in estuarine sediments and organisms in Galicia (northwest Spain) as determined by modal analysis

We investigated metal (Al, Fe, Mn, Co, Cr, Cu, Ni, Zn and Pb) concentrations in surface sediments (107 samples) and intertidal organisms (424 samples of macroalgae, phanerogams, molluscs and polychaetes) from 44 estuarine areas in Galicia (northwest Spain). Three acid extraction procedures (HCl, HNO3 and HNO3 + HF) were used. Following analysis of the effect of sediment particle size distribution on metal contents, Al content was selected as a normalization element. For most species and most metals, there was only minor contamination of the organism samples by particulate matter, confirming the efficiency of the washing and depuration procedures used and thus obviating the need to correct for such contamination on the basis of Fe contents. Background metal levels in the sediments and organisms were estimated by modal analysis. To the best of our knowledge, this is the first time that this method has been used for this purpose.

Cadmium and Copper in Bivalves Mussels and Associated bottom Sediments and Waters from Corral Bay-Chile

Samples of bivalves mussels Tagelus dombeii and Semelle solida (Navajuelas and Almejas Chilenas respectively) were collected at Corral Bay-Chile. Simultaneously, samples of water and sediments from the same site were collected. Seven sampling were carried out between July 1990 and July 1993. The total metals concentration in whole tissue of molluscs, sediment and the dissolved metals in water were determined. For Tagelus dombeii, the Cd concentrations ranged between 2.9 to 6.4 µg g−1 and for Cu between 2.2 to 3.6 µg g−1. For Almejas Cd concentrations ranged between 0.6 – 1.2 µg g−1 d.w. while Cu levels ranged from 4.8 to 11 µg g−1. The Cd/Cu ratio Tagelus dombeii was around 5, while for Semelle solida it was always lower than 1. The results show that Tagelus dombeii is a more effective bioaccumulator of Cd than Semelle solida. A comparison between the metal levels in sediment and water samples taken in Pacific coastal areas, from four rivers surrounding the Corral Bay sampling site shows that the partitio...

Heavy Metal Pollution in Sediments and Waters of the Penang River, Malaysia

Abstract The concentrations of zinc, copper, lead and nickel in the Penang River and its tributaries were determined to assess the extent of heavy metal pollution, and to evaluate which compartment provides a better indicator for heavy metal pollution. The results indicate that the concentrations of total and non-residual heavy metals in sediments increase significantly towards the estuary of the river. This trend is, however, not obvious for heavy metals in the river water. The data indicate that assessment of heavy metal pollution in rivers could be made by using the data of heavy metal levels in river sediments. It is suggested that non-residual heavy metal levels in sediments give the best indication of anthropogenic input of heavy metals to river systems.

Comparison of metal concentrations in the fore and hindguts of the crayfish Cambarus bartoni and Orconectes virilis and implications regarding metal absorption efficiencies

The anthropogenic perturbation of trace metal cycle has resulted in increased emission of trace metals into the atmosphere. This has resulted in the elevation of trace metals in recently deposited sediments of lakes far removed from the original source. Benthic invertebrates, such as crayfish, live and feed directly on recently deposited sediments and are in direct contact with metals both of natural and anthropogenic origin. Crayfish may be good indicators of sediment-metal levels as they appear to retain tissue-metal concentrations that are correlated to environmental levels (e.g., for Cu, Zn and Fe). However, it is suggested that as crayfish homeostatically control tissue elemental concentrations they, in fact, cannot be used as indicators of environmental metal level. One aspect often missing is a comparison of how efficiently crayfish can absorb the element from its food under different environmental conditions. Differences in the ability of the crayfish to absorb elements from food will in turn influence ultimate tissue concentrations. One possible way to assess the importance of food as a source of elemental contamination is through gut content analysis. For essential elements not in excess (i.e., uncontaminated sites), foregut concentrations should either be equal to or greater than hindgut concentrations. Alternatively, essentialmore » elements in excess (i.e., from contaminated sites) or non-essential elements such as Cd, foregut elemental concentrations should be less than hindgut. This study aims at determining the importance of food as a source of essential (Zn, Cu, Mn, Fe, Mg and Ca) and non-essential elements (Al, Cd) in crayfish sampled from two metal and acid stressed-sites versus two non-contaminated reference sites. 22 refs., 1 fig., 2 tabs.« less

Petroleum hydrocarbons and trace metals in nearshore Gulf sediments and biota before and after the 1991 war: An assessment of temporal and spatial trends

Immediately following the 1991 Gulf War, a survey was organized to determine the extent and degree of contamination by petroleum hydrocarbons and trace metals that entered the Gulf from the massive oil spill and oil field fires in Kuwait. Between June–October 1991 samples of nearshore sediments, bivalves and fish were collected from Kuwait, Saudi Arabia, Bahrain, UAE and Oman. Analyses revealed that the highest levels of contamination were along the heavily-impacted coast of Saudi Arabia between Ras Al Khafji and Ras Al Ghar, where concentrations of total petroleum hydrocarbons (expressed as Kuwait crude oil equivalents) ranged from 62–1400 μg g −1 dry wt in surface sediments, 570–2600 μg g −1 dry wt in clams and 9.6–31 μg g −1 dry wt in fish muscle. Gas chromatographic analyses indicated that much of the oil in the intertidal zone had substantially degraded within a few months of the spill. Concentrations of the oil-related metals Ni and V were slightly elevated in oil-contaminated sediments from Saudi Arabia but elsewhere in the Gulf were similar to levels measured in earlier years at those sites. This initial regional survey demonstrated that hydrocarbon contamination originating from the war-related pollution events was restricted to approximately 400 km from the source, that levels of combustion derived PAHs in the marine environment at that time (e.g. 1–450 ng g −1 dry wt for pyrene in sediments) were of the same order as those which have been measured in several coastal areas of the eastern United States and northern Europe, and that outside the immediate area of impact, petroleum hydrocarbon and trace metal levels in sediment and bivalves were generally as low as, or lower than, those concentrations measured at the same sites before the war.

Assessment of elemental contamination in estuarine and coastal environments based on geochemical and statistical modeling of sediments

Sediment of variable mineralogical, textural and metal contaminant composition was collected from 38 estuaries along the Atlantic and Gulf of Mexico coasts of the United States and analyzed for total Al, Ag, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Si, Sn, Tl and Zn concentrations. Based on observed covariation of elements at 15 estuaries remote from contaminant inputs, linear regressions of metals on Al were used to model the metal content in baseline sediments. A geochemical model for the covariation was developed, verified and used to guide the statistical modelling approach. Comparison of metal concentrations predicted by the models with those occurring in uncontaminated geological materials suggests that baseline relationships are valid for the entire region sampled. Using these baseline relationships, sediment metal concentrations can be partitioned into natural and anthropogenic fractions. Models improve the comparability of metal levels in sediments by correcting for variable background concentrations that, if left uncorrected, only serve to increase total data variability and reduce detection of spatial and temporal differences. Examples of the application of baseline models to pollution studies are provided. A continuing decline in Pb concentrations in Mississippi River delta sediments is observed consistent with the declining use of Pb additives in gasoline since 1970. Major spatial trends in contaminant metals in sediments along the Atlantic and Gulf of Mexico coasts are noted.

Heavy Metals and Toxic Organic Contaminants in Effluents, Water, and Sediments of the Bay of Quinte, Lake Ontario

In 1988, water and sediment samples were collected from 10 point sources, 4 tributaries and 15 in-bay locations in the Bay of Quinte, Lake Ontario. These were analyzed for trace contaminants (inorganic and organic). Point source sampling showed that Domtar Wood Preserving at Trenton was a major contributor of chlorinated phenols; several sewage treatment plants were significant sources of heavy metals, but tributary metal loadings were generally higher than sewage treatment plant loadings. In the Bay of Quinte water, Provincial Water Quality Objectives (PWQO) were exceeded only on a small portion of samples for copper, cadmium, iron, zinc, and phenols; indeed, most samples showed undetectable amounts of arsenic, cadmium, mercury, nickel, and lead. Metal levels in Bay of Quinte water were, however, greater than those in open Lake Ontario. While the levels of heavy metals in sediments were generally found to exceed the low effect level of Ministry sediment quality guidelines, they were toward the low end of the range of values observed in Lake Ontario depositional zones, and less than those in Hamilton Harbour. Detectable levels of many PAHs were found in the sediments, with the highest concentrations at the mouth of the Trent and Moira rivers. Other organic contaminants were seldom, if ever, found in the sediments. Levels of PAHs were lower than those in Hamilton Harbour and the Detroit River.

Heavy Metals in Sediments of Matanzas Bay, Cuba

Abstract Different granulometric fractions of surface sediment samples and dissected sediment cores taken from Matanzas Bay and from three inflowing rivers were investigated for the content of metals (Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn) and organic matter. the data on 'total' and easily extractable metal fractions were normalized and statistically treated with the aim of finding procedures applicable for assessment of the sources and levels of contamination. the results show clearly that the investigated area is not much contaminated with respect to those determinands. However, sewage effluents, urban runoff and industrial discharges from Matanzas City draining to the bay via two rivers cause elevated heavy metal levels in sediments of the rivers and of the adjacent coastal areas. in addition, a tannery discharge was revealed as a contamination ‘hot spot’ for chromium.

Effects of gut sediment contents on measurements of metal levels in benthic invertebrates--a cautionary note.

Studies of heavy metal levels in benthic organisms typically do not correct for gut sediment metal levels other than by allowing a period of depuration in clean water. The effectiveness of depuration has recently been questioned in British Columbia in the particular case of the marine clam Yoldia. In light of this controversy, it appears appropriate to present data from a study of heavy metal levels in sediments and benthic organisms in the Lower Fraser River, BC, regarding the effects of gut sediment contents.

Application of Ultraclean Sampling and Analytical Techniques to an Investigation of the Impact of Power-Plant Derived Heavy Metals on Groundwater, Riverwater, Bottom Sediments and Benthic Organisms

As utility companies refit their oil-fired power stations for use with coal, they are attracting the attention of a concerned public. It becomes especially important, when operating under such close scrutiny, to conduct thoughtful environmental investigations with accurate analytic techniques. In one case, at a Massachusetts, U.S.A., power station, the routine trace metal analyses provided by private water-quality laboratories gave the impression that metal levels in stream and groundwaters adjacent to the plant were alarmingly high. This data, released by the utility company itself, resulted in extensive public criticism and costly effort for the utility and State of Massachusetts regulatory agencies. The problem, however, was more perceived than real, as the present study, conducted later, showed. This investigation brought together ultra-clean sampling and handling techniques (borrowed from geochemical oceanographic practices) and interpretive concepts from aquatic geochemistry. Levels of metal enrichment in stream waters were revealed to be in fact much lower (eg. Cu, 2 µg/l) than implied by the evidently investigator-contaminated samples (eg. Cu, 20 µg/l) from previous work, underlining the importance of employing difficult but uncompromising procedures when dealing with metals in the aquatic environment. Furthermore, with accurate analyses at hand, the geochemist's “mixing diagram” concept allowed interpretation of the fate of the power-plant derived excess metals in the cooling-water discharge; excess dissolved copper, for instance, disappeared not due to reactions with particles, but rather due to simple and rapid dilution in the effluent-river mixing zone. Examination of the relationships between various trace metal concentrations and parameters reflecting major processes controlling metal distributions (sediment grain size, labile iron and manganese concentrations) for bottom sediments from the adjacent Connecticut River revealed that natural processes largely explained the distribution of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn associated with the acid leachable fraction of the sediments in all locations. While no anomalous metal concentrations were recognized amongst sediments, oligochaete worms living in the sediments beneath the cooling-water plume appeared to have accumulated more metal than those elsewhere. Because tissue metal levels were unrelated to sediment metal levels, it seems that the worms may respond more to the dissolved metal load than to the sediment burden. Tight correlations are evident between metal concentrations determined by the author's techniques and a measure of the redox poise (COD) in groundwaters near fly ash settling ponds. Relationships between parameters determined by the routine water-qua1ity laboratories on duplicate samples, on the other hand, are characterized by the lack of correlations, suggesting that in the latter case sample handling methods were inappropriate, leading to unrepresentative concentration estimates. The correlations that appeared with the author's data, however, indicate that metal levels in the groundwater are controlled more by spatial variations in the redox poise than by pollutant (leachate) source strength.

The occurrence of copper, iron and zinc in the hard shell clam, Mercenaria mercenaria, and sediments of Southampton Water

The concentration of copper, iron and zinc has been measured in hard shell clams, Mercenaria mercenaria, collected from several localities in Southampton Water to provide the background data necessary for the accurate assessment of the significance of observed fluctuations. The studies reveal considerable seasonal, age and geographical fluctuations in tissue metal concentrations. All metal concentrations in clam tissue are lower at the seaward end of the estuary, but although sediment metal levels generally follow a similar trend, tissue and sediment values appear to correlate with each other only for iron. There appears little evidence of any significant effect on metal uptake which could be attributable to the operation of Marchwood Power Station.

Immediate industrial effects on sediment metals in a clean coastal environment

A programme to determine the immediate impact of a new nickel refinery on sediment metal levels in Halifax Bay, North Queensland was begun in May, 1975. The results indicate that within three weeks of the initiation of continuous refinery discharge to the Bay, area levels of at least one element (cobalt) had been significantly increased. In addition, samples taken from nearshore river mouth stations located near the plant also showed relatively high levels of nickel which may not be attributable to the plant's effluent discharge. The field data together with laboratory experiments suggest that future levels of cobalt, nickel and iron may be expected to increase significantly in Halifax Bay as a direct result of the refinery.

Trace metal concentrations in sediments from Long Island Sound

It is important to determine trace metal concentrations in marine sediments because these could be important sources of contamination of marine organisms that reside there. In this study we measured the concentrations of thirteen metals in sediments obtained from Long Island Sound. We found great variations in metal levels for various geographic areas in the Sound; but, generally the highest concentrations found were in the extreme western end of the Sound. Comparison is made between metal levels in sediments from the Sound to seven other areas located in the U.S. and U.K.