Trace metals in fish from the Kuwait coast using the microwave acid digestion technique

The concentrations of chromium, iron, copper, nickel, lead, vanadium, and zinc in fish were determined to assess the impact of petroleum-refining activities and the 1991 Gulf War. Twenty-eight species of fish from the Kuwait coast were collected 50 m apart. Sample solutions prepared were analyzed using the atomic absorption spectrophotometry technique. Results show that fish samples contain 6.2 to 6.8 μg/g Cr, 4.2 to 96.2 μg/g Cu, 18.8 to 126.4 μg/g Fe, 0.5 to 20.4 μg/g Ni, 0.2 to 14.6 μg/g Pb, 0.02 to 15.6 μg/g V, and 7.6 to 81.3 μg/g Zn. Copper, nickel, and zinc in Station I, covering the Kuwait City area, were often greatly in excess of those present in Station II, covering the Al-Ahmadi area, while chromium, iron, lead, and vanadium were greater in Station II. Significant correlations were observed between some trace metals in fishes, indicating their common association.     

Aeolian contributions of trace metals to marine sediments of Kuwait

Concentrations of silver, cadmium, chromium, iron, manganese, nickel, lead, vanadium, and zinc were determined in dust fallout samples from eight inland locations in Kuwait. Results were used to calculate enrichment factors for metals relative to their abundance in the continental crust using Fe as the conservative element. Five metals (Cu, Cr, Mn, Ni, and V) showed enrichment factors that were approximately unity (1.3–4.7). Higher enrichment factors for the rest (24–421) suggested an anthropogenic contribution for Ag, Cd, Pb, and Zn. However, all metals in dust fallout (except Pb and Zn) showed a degree of enrichment relative to unpolluted marine sediments that was approximately unity, suggesting a substantial aeolian contribution to trace metals in marine surface sediments. Higher enrichments for Pb and Zn probably reflect a larger input from local pollution sources. This is particularly true for lead, the enrichment of which showed a stronger association with the distribution of urban population. Probable contributions of aeolian transport to a band of elevated lead concentrations in marine surface sediments are discussed.     

Biologically available trace metals in Mytilus edulis from the coast of Northeast England

The concentrations of Fe, Mn, Zn, Cr, Cu, Pb, Ni, Cd, and Ag were determined in soft tissue and shell material of mussel Mytilus edulis collected in the winter season from five coastal sites in the northeast of England. The trace metal levels observed were significantly high, particularly at locations affected by past coal mining activities (Blackhall) and present industrial sources (Middleton). The mussels from the chosen control site (Holy Island), a shellfish-designated area, were particularly enriched in Cu and Ag. The metal pollution index for the Bran Sands site, a heavily industrialised area on the Tees Estuary, was relatively low. At four sites out of five, the levels of Fe and Cu were negatively correlated with mussel size. No significant correlation with size was found for the other metals. With few exceptions, the elements Fe, Zn, and Mn accumulated preferentially in the soft tissue, whereas Pb, Cd, Cr, Ag, and Ni were more abundant in the hard part of the mussels. The Ag values in shell material were remarkably similar (about 6 mg kg⁻¹ – 7 mg kg⁻¹, dry wt) at all sites studied. In general, the data show that the mussels from the coastline studied accumulate metal concentrations comparable to or higher than the most contaminated sites reported in the literature.     

Biogeochemistry of Chinese estuarine and coastal waters: nutrients, trace metals and biomarkers

The dissolved and particulate trace metals in large and middle-sized Chinese rivers remain comparable with other less-disturbed world systems. Levels of nutrients in Chinese rivers are high due to erosion over the drainage area and the application of chemical fertilizers, which induces an N/P ratio up to 100–1,000. The concentrations of organic pollutants in Chinese rivers are ranked at the lower end of those of world systems; however, pollution has been identified in coastal waters from north to south of the country. In estuarine and coastal waters, dissolved trace metals illustrate a feature of remobilization, while non-conservative distribution is observed, with exceptions for iron and aluminum. Particulate trace metals demonstrate a fairly stable distribution along the salinity gradient, when the absolute concentration is normalized to reference materials. In high-turbidity estuaries, seaward nutrient flux can be increased by a factor of 5–10. Finally, the N/P ratio approaches 10–20 at the interior of the East China Sea, indicating that in coastal regions photosynthesis changes from P to N and Si limitations. Electronic Publication     

Removal of nutrients and heavy metals from anaerobic waste by aerobiological treatment

This study was conducted to investigate the effectiveness of aerobic biological treatment in removal of nitrogen, phosphorous, and heavy metals from a unique anaerobic liquid waste, produced at a solid waste-to-methane anaerobic digestion facility. Laboratory scale continuous flow activated sludge reactors were employed in this study. The liquid waste has moderate BOD/COD ratio with BOD concentration of 1300 mg/L and high concentration of essential nutrients, making the liquid waste biologically treatable. Results showed that aerobic biological treatment can remove nitrogen and phosphorous on the order of 85%. Metal removal efficiencies vary widely for 11 metals studied in this investigation.     

Toxic metals in imported fruits and vegetables marketed in Kuwait

The contentration of lead, cadmium, and mercury in 134 samples of imported fruits and vegetables marketed in Kuwait were determined using an atomic absorption spectrophotometer with a graphite furnace and the cold vapor technique. Results obtained showed that the concentration of these metal ions in most cases did not exceed the maximum permissible concentration of metals in fresh fruits and vegetables as restricted by some countries. Only a few samples of fruits and vegetables contained levels of mercury, cadmium, and lead which exceeded these maximum permissible levels.     

Impact of dredging in a shallow coastal lagoon: Microtox Basic Solid-Phase Test, trace metals and Corophium bioassay

The aim of this work was to measure survival of the amphipod Corophium insidiosum and luminescence inhibition in the marine bacterium Vibrio fisheri on surface sediment samples collected from a shallow coastal lagoon (Pialassa Baiona, northern Adriatic Italian coast) before execution of dredging operations to deepen the main inner channel of the lagoon and restore the water circulation. Trace metal (Cd, Cu, Cr, Hg, Ni, Pb) concentrations, grain size and organic carbon matter content as loss of ignition were also measured. Toxicity testing with V. fisheri was carried out according to the Microtox Basic Solid-Phase Test (BSPT) protocol. The preliminary outcomes of this work show that: (a) the investigated area can be categorised as moderately degraded; (b) there is no evident spatial pattern in sediment toxicity and trace metal concentrations; (c) Microtox responses are not biased by sediment characteristics such as silt, clay and organic matter content.     

Radionuclides and trace metals in eastern Mediterranean Sea algae

Three types of sea alga distributed along the Syrian coast have been collected and analyzed for radioactivity and trace elements. Results have shown that (137)Cs concentrations in all the analyzed sample were relatively low (less than 1.2 Bq kg(-1) dry weight) while the levels of naturally occurring radionuclides, such as (210)Po and (210)Pb, were found to be high in most samples; the highest observed value (27.43 Bq kg(-1) dry weight) for (210)Po being in the red Jania longifurca alga. In addition, most brown alga species were also found to accumulate (210)Po, which indicates their selectivity to this isotope. On the other hand, brown alga (Cystoseira and Sargassum Vulgare) have shown a clear selectivity for some trace metals such as Cr, As, Cu and Co, this selectivity may encourage their use as biomonitor for pollution by trace metals. Moreover, the red alga species were found to contain the highest levels of Mg while the brown alga species were found to concentrate Fe, Mn, Na and K and nonmetals such as Cl, I and Br.     

Bio-accumulation of some trace metals in the short-neck clam Paphia malabarica from Mandovi estuary, Goa

Monthly collections of the clam Paphia malabarica were made for period of 1 year from May 2002 to April 2003 from Verem, Mandovi estuary, Goa. Clams were categorised into two groups, 25-35 mm (small size) and 35-40 mm (big size). Significant difference was not observed in the accumulation of metals in the whole soft tissue between the two size groups. Irrespective of size, annual mean, metal content recorded as microg/g dry weight in the whole soft tissue was 3.8, 30.3, 13.5, 36.6 and 105.7, respectively, for Cd, Pb, Cu, Zn and Fe. Of the two toxic elements Cd and Pb, Cd content was almost uniform throughout the year except for a rise in September for the small size and October for the big size. Pb, on the other hand, was low from the beginning of the monsoon and exhibited distinct accumulation from December onwards up to April, May and, to some extent, June. The pattern was similar in both the size groups, the values being higher for the bigger size group. The three essential elements Cu, Fe and Zn exhibit trends similar to one another with peaks in September and December-January in both the size groups. Cadmium accumulation was highest in the mantle and adductor muscle, Lead, in foot, Copper, in digestive gland and gonad, and Zn and Fe, in gills. Correlation coefficient between different metal couplings as tested statistically revealed significant coupling for Zn-Fe (r 0.92) in the bigger size group, the same was observed between Cu-Fe (r 0.62) and Cd-Zn (r 0.94). Seasonal difference in Pb accumulation was highly significant.     

Heavy metals in four fish species from the French coast of the Eastern English Channel and Southern Bight of the North Sea

Shallow coastal waters act as nurseries for various fish species and have been recognized as essential fish habitat. We studied heavy metal concentrations in four fish species (plaice, dab, flounder and cod) as an indicator of large-scale habitat quality. The study took place along the French coasts between the Eastern English Channel and the Southern Bight of the North Sea. All species show different concentrations of measured metals (e.g., Cd, Cu, Mn and Pb) in liver but not in muscle. The highest concentrations are found for the flounder and the lowest for cod which is consistent with their habitat and diet. Although our results do not highlight levels of appreciable pollution within the study area, inter-site differences are mainly observed in the muscle tissues and are generally in agreement with the known environmental data (e.g., anthropogenic pressure). However, in the Bay of Seine, one of the most contaminated estuaries in Europe, metal concentrations are in the same range or even lower than those found in fish collected from areas distant from any anthropogenic pressures. At one site, the comparisons of the Cd, Cu and Pb concentrations between healthy and diseased dabs have been carried out on the muscle and liver tissues. The results of this preliminary study show a relationship between metal concentrations and the pathological status of the fish. The use of fish health as indicator of habitat quality is discussed.     

Transport of NOM and trace metals through macropores in the Lake Skjervatjern catchment

In the dystrophic Lake Skjervatjern, located at the west coast of Norway, periods with high precipitation coincide with an increase in the concentrations of natural organic matter (NOM) and several trace elements. The lake has no visual inlets, and, during high flow periods, a major part of the drainage follows macropores, entering the lake 10–40 cm below the surface. Water from the lake and the macropores were fractionated according to size by means of a hollow fiber ultra-filtration technique, during two periods with high precipitation. In the macropores, the high molecular weight form of NOM (nominal molecular cut off > 10 kDa) appears to be an important transporting agent for several trace elements that strongly interact with NOM (e.g., Fe, Al, Pb, Sm, La, Ce, and Eu). In contrast, anionic (V and As) and acid sensitive (Mn and Cs) elements were, generally, at a low molecular weight form (nominal molecular cut off < 3 kDa). The latter showed similar or lower concentrations in the macropores compared to the lake water, and NOM were apparently of small importance as a carrier for V, As, Mn, and Cs. Differences in concentration and size distribution of trace elements between the macropores and the lake basins indicate that parts of NOM and associated trace elements that enter the lake in a high molecular weight form, undergo aggregation and gravitational settling and thereby become a part of the lake sediments.     

Microbial binding of trace metals and radionuclides in sediments: Results from an in situ dialysis technique

The microbial oxidation of Mn and the microbial binding of ²⁴¹Am to a lacustrine sediment were five times greater than the binding effects of abiotic adsorption. In contrast, the microbial enhancement of Cu and ¹³⁷Cs binding were far less pronounced, resulting in only a doubling of the effects of adsorption. The microbial binding of trace metals or radionuclides could not be adequately expressed in terms of adsorption coefficients. Instead, binding rates were determined as a more accurate index of short-term processes at work in the sediment.     

Heavy metals in fish (Solea vulgaris, Anguilla anguilla and Liza aurata) from salt marshes on the southern Atlantic coast of Spain

Comparisons were made of metal concentrations in water and sediment with those in the muscle and livers of three species of fish caught in four seawater reservoirs (two in the Odiel estuary and two in the Bay of Cádiz). The concentrations of a large number of metals in the water, sediment and fish were higher in the Odiel reservoirs than in those in Cádiz. We found high metal-enrichment factors in the livers as compared to muscle (over 100 for Fe and Cu and around 5 for Zn, Ni, Cd and Pb). The three fish species showed differences in metal content. For example, eels accumulated more metals in muscle and grey mullet in the liver. The metal levels found in muscle in the three species were below the legal limits for human consumption, although Cu in the liver was above the limit in the three species taken from the Odiel reservoirs, and Zn levels in liver were over the maximum in eels from one of the Odiel marshes. Significant correlations (p<0.05) were obtained for the levels of numerous metals in water, sediment and fish.     

Essential and non-essential trace metals in scalp hair of men chronically exposed to volcanogenic metals in the Azores, Portugal

Volcanoes produce and release large amounts of toxicants, and the concentration of metals in hair can be used as a biomarker of exposure to trace metals. In order to investigate whether humans exposed to volcanic emissions demonstrate higher concentrations of essential and non-essential trace metals, scalp hair of men (3-89 years) living in two areas of the Azores, one exposed to volcanic emissions and the other not, was sampled, and their content in Cd, Cu, Pb, Rb, Se, and Zn was quantified by using High Resolution Inductively Coupled Plasma Mass Spectrometry. In average, men exposed to volcanic emissions presented higher concentrations of Cd (96.9 ppb), Cu (16.2 ppm), Pb (3417.6 ppb), Rb (216.3 ppb), and Zn (242.8 ppm), but not Se (469.6 ppb). Also, strong and significant correlations were found between Cd-Rb and Pb-Rb in the exposed men. In conclusion, humans living chronically exposed to volcanic emissions show high concentrations of essential and non-essential trace metals in scalp hair, and is suggested that this type of exposure may be as harmful as living close to industrial facilities.     

Distribution of some trace metals and their fluxes in the Genesee River,NY

Total and particulate metal concentrations, measured during intensive synoptic studies of the Genesee River, NY, correlated with suspended-sediment concentration and river discharge. Dissolved metal concentrations, on the other hand, showed little systematic variation over the length of the river. Metal and sediment fluxes for two elevated-discharged periods peaked at a midbasin sampling site. For most metals at most sampling sties particulate materials comprised over one-half of the total material. Comparison of particulate material metal concentrations, normalized to the measured suspended-sediment concentrations had with basinwide average values shows that sites having low suspended-sediment concentrations had high particulate material metal contents relative to the basin averages, while sites with high suspended-sediment concentration had low metal contents. These results are consistent with a metal transport mechanism in the Genesee River involving (1) a nearly constant dissolved component, (2) a fine acid-soluble component, and (3) a coarse component that is effectively a neutral diluent in the sediment. Chemical factors, such as sediment organic content, also appear to affect metal transport in the Genesee River.     

Partitioning of trace metals between soft tissues and shells of Patella aspera

This paper describes the partitioning of iron, manganese, zinc, copper, cadmium, cobalt, nickel and lead between the soft tissues and the shells of the gastropod mollusc Patella aspera. Specimens of the limpet P. aspera were collected from a clean coastal marine site (CMS) and from an estuarine contaminated site (ECS) on the south coast of Portugal. Fe and Zn concentrations were significantly lower on both populations and less variable in the shells than in the soft tissues. In contrast Mn concentrations were higher in the shells than in the soft tissues at ECS. The partitioning factor (PF), defined as the ratio between the mean metal concentrations in soft tissues and in the shells, was maximum for iron and minimum for manganese. Between the soft tissues and the shells, only manganese at ECS recorded a significant relationship between metal concentrations, suggesting that the mechanism that controls the accumulation of this essential metal in both tissues was different from the others. From the obtained data, in biomonitoring sewage contamination studies, shells of P. aspera can be considered as a good indicator for Mn while the soft tissues for Zn. As copper, cadmium, nickel and cobalt concentrations were much higher in the soft tissues than in the shells (< 0.1 microg g(-1)), this indicates that the shells were not a good indicator for these metals because they do not reflect the environmental bioavailability as do the soft tissues.     

Effects of moderate pollution on toxic and trace metal levels in calves from a polluted area of northern Spain

This study evaluated the contribution of anthropogenic pollution to toxic metal residues (Cd, Pb and As) in cattle in an industrialized area of Asturias (northern Spain), and investigated possible implications of toxic metal exposure for metabolism of essential metal elements (Cu, Zn, Fe, Mn). Samples of liver, kidney, muscle and blood from animals aged 9-12 months were obtained from an industrialized area (78 calves) and from a rural area (92 calves). Samples were acid-digested, and levels of metals determined by atomic absorption spectrophotometry. Cadmium and lead contents in the liver and kidney were moderately and significantly higher in calves from the industrialized area (Cd: liver 29.6, kidney 161; Pb: liver 38.1, kidney 38.3 microg/kg wet weight) than in calves from the rural area (Cd: liver 22.9, kidney 96.4; Pb: liver 20.7, kidney 15.9 microg/kg kg wet weight). Although these toxic metals were only moderately raised, our results suggest that they may nevertheless have interfered with trace element metabolism, as reported previously for severely polluted regions. Notably, copper levels in calves from the industrialized area were generally low, and nearly half of these animals showed tissue copper levels indicating risk of copper deficiency.     

Flux of heavy metal accumulation in various organs of the intertidal marine blue crab, Portunus pelagicus (L.) from the Kuwait coast after the Gulf War.

The metal levels of arsenic, chromium, copper, lead, magnesium, manganese, selenium, vanadium, and zinc concentrations were determined in various body organs, viz., hepatopancreas, gills, gonad, gastric stomach, and muscle of the blue crab, Portunus pelagicus (Crustacea: Decapoda) to assess the bioaccumulation of metals associated with petroleum input a decade after the 1991 Gulf War oil spillage. Sample solutions prepared were analyzed using an atomic absorption spectrophotometry. High concentrations of Zn and Cu in the muscle and hepatopancreas tissues were a strong indicative of high exposure of P. pelagicus to these metals. However, muscle tissue had been found to accumulate the highest values for all metal speciations analyzed. Copper, zinc, and chromium in samples collected from Station II covering the Kuwait City area were often in excess of those present in Station I and III. Arsenic, lead, magnesium, manganese, selenium, and vanadium were greater in individuals obtained from Station I. A significant correlation was found to exist between Se and V in crab muscle with a surge in Se metal concentration, which was found to be inversely proportional to that of V metal concentration irrespective of the sex of the crab. The difference in patterns of metal occurrence and the significant increase in the Cu and Zn concentrations in various organs of the crab were largely associated with the 1991 Gulf War oil spill. Such results could be used as a baseline for the monitoring of the level of metals in marine organisms of future studies.     

Speciations of trace metals in the Danube alluvial sediments within an oil refinery

A sequential extraction procedure was applied to identify forms of Ni, Zn, Pb and Cu with Fe- and Mn-oxides associated in alluvial sediments of the River Danube within Pancevo Oil Refinery (Serbia). The five steps of the sequential extraction procedure partitioned metals into: CH(3)COONH(4) extractable (S1); NH(2)OH.HCl carbonate extractable and easily reducible (S2); (NH(4))(2)C(2)O(2)/H(2)C(2)O(2) moderately reducible (S3); H(2)O(2)-HNO(3) organic extractable (S4); and HCl acid soluble residue (S5). Extracted concentrations of trace metals, analyzed after all five steps, were found to be (mg kg(-1)) for Mn: 656, Fe: 26734, Ni: 32.3, Zn: 72.8, Pb: 13.4 and Cu: 27.0. Most of the elements were found in acid soluble residue, characterizing stable compounds in sediments. Non-residual fractions of trace metals (sum of the first four fractions) were analyzed because they are more bioavailable than the residual amount. Correlation analysis and two multivariate analysis methods (principal component and cluster analysis) were used to understand and visualize the associations between the non-residual fractions of trace metals and certain forms, more or less crystalline of Fe- and Mn-oxides within the analyzed sediments, since Fe- and Mn-oxides play an important role in trace metal sorption within aquatic systems, especially within the Danube alluvium where the fluctuations of groundwater are very frequent and the level of groundwater could come close to surface.     

Impact of climate warming upon the fish assemblages of the Portuguese coast under different scenarios

Impact of sea-surface warming upon the fish assemblages of the Portuguese coast was assessed under two scenarios, the A2 and the B2 scenarios (Special Report on Emission Scenarios), which when coupled with a regional circulation model HadRM3 predict 1 and 2°C of sea-surface warming until the year 2100. Species richness increased in the Portuguese coast. In both scenarios, there was a latitudinal gradient in the amount of lost and gained species, increasing from north to south. An anomaly in the latitudinal gradient of species richness was detected in the southernmost area, which presented the lowest species richness of all areas, in the A2 scenario, and appears to be particularly vulnerable to climate change. Very few species were totally eliminated from Portuguese waters. For the Portuguese coast as a whole, there were more new than lost species, in both scenarios. Most of the new species were commercially important species, in the majority subtropical in the north and tropical in the south, mainly demersal and reef-associated. Reef-associated species also increased in relative importance. A commercial opportunity for fisheries may arise from climate warming, since most of the new species were commercial species and not many commercial species were lost. An increasing gradient from north to south was detected in the colonization of new species of herbivores, planktivores, and omnivores, as well as lower mean trophic level, which might have consequences for the future of trophic webs.