Variations In Heavy Metal Concentrations Research Articles

Concentrations of toxic heavy metals in ambient particulate matter in an industrial area of northeastern China

This paper investigates concentrations of various heavy metals in ambient particulate matter (PM) and provide evidence for prevention from air pollution. The concentrations of heavy metal components in the PM were determined by inductively coupled plasma/Mass spectrometry (ICP/MS) from September 2000 to August 2002 in a northeast industrial city in China. Concentrations of Cd, Mn, Pb, Ni, Cr and As in the PM were 9.3, 461.9, 588.7, 69.5, 205.7 and 57.4 ng/m3 in the industrial area, and 5.7, 245.5, 305.0, 31.4, 58.8 and 32.5 ng/m3 in the main road, respectively. Concentrations of these heavy metals except Cd were significantly higher in the industrial area and main road than those in the suburban area (P < 0.05 or P < 0.01). The change curves of the six heavy metal concentrations show their concentrations increased in the winter and spring, but decreased in the summer and autumn. The results indicate that concentrations of the metals in the PM are relatively high in the industrial area and main road.

Multivariate Analyses to Determine the Origin of Potentially Harmful Heavy Metals in Beach and Dune Sediments from Kizkalesi Coast (Mersin), Turkey

The aim of this study was to investigate variations in heavy metal concentrations and natural and artificial sources of heavy minerals in beach and dune sediments along Kizkalesi (Mersin) coast in Turkey. To this aim, sand sediment samples were collected from 20 locations throughout Kizkalesi coast and concentrations of Zn, Ni, Cu, Co, V, Mo, Ag, Sb, Sn, Cd, W, Hg, Pb, As, Si, Al, Fe, Ca, Mg, S, K, Na, Cl, Ti, Mn and Cr were determined. Simple analyses (frequency histogram), multivariate analyses (Coefficient correlation, Cluster Analysis), Principal Component Analysis, Model Summary and ANOVA were used to analyze the concentration values. Al, Fe, Mg, Cl, Ti, Mn, Cr and Ni were dominant heavy metals. Principal Component Analysis revealed six principal components. It was confirmed by Cluster Analysis. Based on the Hierarchical Cluster analyses, three different general groups were formed at a 50% arbitrary similarity of Q-type level. The frequency histogram indicated that W, Ag, Co, V, Cu, As, Sn, Ni, Zn, Pb, Cr, Cl and Mg concentrations originated from the nearby area, while Mn, Ti, Al and Fe Mg concentrations came from either the nearby area or moderately remote sources. Data from the study area showed that the Model Summary (based on R(2)=100%) was sufficient for the statistical data and that the Model ANOVA (variations of Pb) had a high explanatory power. The region lying on Miocene carbonate rocks of the Tauride belt were affected by the contaminants of anthropogenic origin that included coastal deposits, coastal erosion, the Kizkalesi settlement area, urban wastes, Mersin-Antalya road extending parallel to the shoreline and disposal sites of hotels.

The use of cypress tree bark as an environmental indicator of heavy metals deposition in Fuheis City, Jordan

The present study focused on the use of cypress tree bark as an environmental indicator of heavy metal deposition in Fuheis City, Jordan, and the evaluation of the impact of emissions from the cement industry in the adjacent environment. Tree bark samples were collected from four directions (north, south, east and west) in the vicinity of the cement factory. The samples were analysed for heavy metal content: Mn, Cu, Ni, Co, Pb, Cd, Zn, Cr, and Fe. The results showed variations in heavy metal concentrations between sites. The levels of heavy metal were divided into three groups: mean concentrations of Co and Cd ranged from 1 to 4 mg/kg; Mn, Cu, Ni, Pb, Zn and Cr ranged from 9 to 109 mg/kg; and finally, Fe ranged from 2238 to 3393 mg/kg.

Multivariate analysis of heavy metals concentrations in river estuary

Multivariate statistical techniques such as multivariate analysis of variance (MANOVA) and discriminant analysis (DA) were applied for analyzing the data obtained from two rivers in the Penang State of Malaysia for the concentration of heavy metal ions (As, Cr, Cd, Zn, Cu, Pb, and Hg) using a flame atomic absorption spectrometry (F-AAS) for Cr, Cd, Zn, Cu, Pb, As and cold vapor atomic absorption spectrometry (CV-AAS) for Hg. The two locations of interest with 20 sampling points of each location were Kuala Juru (Juru River) and Bukit Tambun (Jejawi River). MANOVA showed a strong significant difference between the two rivers in terms of heavy metal concentrations in water samples. DA gave the best result to identify the relative contribution for all parameters in discriminating (distinguishing) the two rivers. It provided an important data reduction as it used four parameters (Zn, Pb, Cd and Cr) affording 100% correct assignations. Results indicated that the two rivers were different in terms of heavy metals concentrations in water, and the major difference was due to the contribution of Zn. A negative correlation was found between discriminate functions (DF) and Cr and As, whereas positive correlation was exhibited with other heavy metals. Therefore, DA allowed a reduction in the dimensionality of the data set, delineating a few indicator parameters responsible for large variations in heavy metal concentrations. Correlation matrix between the parameters exhibited a strong evidence of mutual dependence of these metals.

Effects of heavy metal contamination from anthropogenic sources on Dasarahalli tank, India

AbstractThis study examines the concentrations of various heavy metals, and their distribution in a hyper‐eutrophic urban Dasarahalli tank system, which is being polluted from industrial, domestic and sewage effluents. The concentration of iron (Fe), zinc (Zn), copper (Cu), nickel (Ni), chromium (Cr), lead (Pb) and cadmium (Cd) in water, plant (Alternanthera philoxeroides) and sediment samples was determined. The water‐soluble (bioavailable) fractions of heavy metals correlated positively with their total concentration, exhibiting the following sequence of bioavailability: Zn &gt; Cd &gt; Ni &gt; Fe &gt; Cu &gt; Pb &gt; Cr. A. philoxeroides exhibited a maximum bioaccumulation factor for cadmium (3913). The mean values of all types of collected samples were correlated with the corresponding mean values in a control tank (Vasanthapura tank). The sequence of the order of the concentrations of the metals in water, plant and sediment samples exhibiting higher values than those observed in the control tank was as follows: Cr &gt; Ni &gt; Pb &gt; Cu &gt; Fe &gt; Zn, Cd &gt; Cr &gt; Fe ≈ Zn ≈ Cu ≈ Pb and Pb &gt; Cu ≈ Cr &gt; Zn ≈ Ni &gt; Fe, respectively. The geoaccumulation indices of the heavy metals revealed that the tank is moderately contaminated. As A. philoxeroides is extensively used for human consumption and also as cattle fodder, there is a growing health risk that these metals could find their way into the human food chain.

The relationship between WRB soil units and heavy metals content in soils of Catamarca (Argentina)

Trace element content in soils is mainly dependent on the nature of parent rocks from which the soil material is derived, as well as weathering and soil forming processes. Despite the close relationship between soil and rock, the soil forming processes modify the regolith and redistribute the content of heavy metals in the soil horizons. The World Reference Base (WRB) is a morphogenetic system of soil classification strongly based in soil genesis at the level of Reference Soil Groups (RSG). Present differences in trace elements content between different RSG may reflect the impact of pedogenic pathways of each RSG on the original trace element distribution. The natural variation of heavy metal content is a preliminary step in assessing heavy metal contamination in soils. Therefore, the term geochemical background became an important reference with increasing environmental awareness. The concentration and distribution of Cd, Cr, Cu, Ni, Pb, and Zn were investigated in thirty profiles of Catamarca in the municipal district of Fray Mamerto Esquiú, Argentina. The heavy metals content, except for Cd, is highly dependent on RSG according to WRB. Occasional or continuous contribution of sediments as in alluvial soils becomes the soil forming processes that acquires greater importance in the distribution of heavy metals. The organic matter content is the soil property that comes out as relevant at lower levels of Fluvisols when Humic or Mollihumic qualifiers apply. All studied soils show extremely high Pb in relation to the surrounding bedrock. This confirms that the infilling of the alluvial valley is not derived from the surrounding bedrock but it must come from a different source. The increase in the silt content of soils in the southern part of the alluvial valley are well reflected by Ni content. Therefore, pedogenic processes have had little influence in regional Ni distribution. The upper limit of the background, which allows distinguishing between natural element and anomalous concentrations are presented. The heavy metal showing the greatest number of samples with slight enrichment anomalies is Cd. Slight enrichment anomalies in Cd, Cr, Cu, Pb and Zn were detected in profile 29 confirming an anthropogenic pollution.

Antibiotic and heavy metal resistance in motile aeromonads and pseudomonads from rainbow trout ( Oncorhynchus mykiss) farms in Australia

A total of 129 Pseudomonas spp. and 90 Aeromonas spp. were isolated from nine rainbow trout ( Oncorhynchus mykiss) farms in Australia. All the isolates were tested for sensitivity to 15 antibiotics and the multiresistant strains were tested for sensitivity to seven heavy metals. Minimal inhibitory concentrations (MICs) were determined by the agar dilution method. In Pseudomonas spp., resistance to amoxicillin, cefalothin, ceftiofur, ticarcillin, chloramphenicol, florfenicol, streptomycin, nitrofurantoin and trimethoprim was widespread, whereas resistance to cefotaxime and oxolinic acid was less common and only single isolates were resistant to tetracycline and sulfamethoxazole; all isolates were sensitive to ciprofloxacin and gentamicin. In Aeromonas spp., resistance to amoxicillin and cefalothin was widespread, resistance to ticarcillin, tetracycline and streptomycin was common, whilst resistance to ceftiofur, florfenicol and sulfamethoxazole was less common. Single isolates were resistant to chloramphenicol, nitrofurantoin and trimethoprim, and all isolates were sensitive to cefotaxime, oxolinic acid, ciprofloxacin and gentamicin. Multiple resistance was also observed. Most isolates were tolerant to different concentrations of various heavy metals, as evidenced by their MICs ranging from 6.25 μg/mL to >3200 μg/mL. These results confirm our previous findings that bacteria resistant to antibiotics are present in fish and sediments from aquaculture in Australia. In addition, we have found resistance to heavy metals in fish and sediment isolates. Much of the antibiotic resistance detected is likely to be intrinsic, although resistance to oxytetracycline, streptomycin and sulfonamides suggests either contamination from run-off from farms or perhaps off-label use of antibiotics in a situation where no antibiotics are licensed for use in aquaculture.

In vitro effects of metals and pesticides on dehydrogenase activity in microbial community of cowpea (Vigna unguiculata) rhizoplane

Effects of heavy metals and pesticides on cowpea (Vigna unquiculata) rhizoplane microbial community were assessed in vitro via dehydrogenase activity. The microbial community was exposed to various concentrations of heavy metals and pesticides in a nutrient broth-glucose-2,3,5-triphenyl chloride (TTC) medium. At 0.2 mM, iron and cadmium stimulated the dehydrogenase activity of the microbial community. For all the metal ions, there was progressive inhibition with each successive increase in the concentration of metal ion, reaching near 100% at 0.6, 0.8, 1.2, 0.12 and 12 mM for cobalt, cadmium, iron, mercury and nickel, respectively. Between 0.2 and 0.4 mM, zinc sharply inhibited dehydrogenase activity and at concentration above 0.4 mm, inhibition of dehydrogenase activity became less pronounced. The order of toxicity is Hg2+ > Co2+ > Cd2+ > Zn2+ > Fe2+ > Ni2+. The herbicides Cotrazine (Atrazine 80W) and Northrin®10EC stimulated dehydrogenase activity of the microbial community at 0.2% and inhibited it at higher concentrations. The median inhibitory concentrations (IC50s) of Cotrazine (Atrazine 80W) and Northrin®10EC were 0.552 ± 0.028 and 0.593 ±0.051%, respectively. The dehydrogenase activity varied significantly (p < 0.05) with the type and concentrations of metals or pesticides. The result indicates that the heavy metals and pesticides are potentially toxic to V. unquiculata root surface microorganisms. In soil, this toxicity may affect nitrogen fixation processes and by extrapolation affect crop yield. Key words: Dehydrogenase activity, rhizosplane bacteria, atrazine, cypermethrin, heavy metals, cowpea.

Heavy metals in sediments as evidence for recent pollution and quasi-estuarine processes: an example from Lake Druzno, Poland

This article presents the results of a geochemical investigation of sediments from Lake Druzno (northern Poland), a reservoir fed by freshwater from the catchment, with periodic input of brackish water from Vistula Lagoon. This study analyzed the spatial variation in heavy metal content in surface sediments as well as the temporal changes in metal content in two sediment cores dated using the 210Pb method. In the surface sediments, the highest metal concentrations were recorded in the northern part of the lake, with lower concentrations in the central and southern parts. Absolute values of metal concentrations in the cores were low, but normalization with respect to Al showed an increase during the second half of the 20th century. Mean enrichment factors (EF) in sediments from the second half of the 20th century ranged from insignificant (1–1.2) for Fe to (1.55–3.3) for Cu, Cd, Pb and Zn. The sediments deposited before 1950 had lower EF values (>1.5) and had low variability. Results from both the surface sediments and the cores indicate that the main source of lake pollution is brackish water intrusion from the Vistula Lagoon via the contaminated River Elbląg.

In vitro effects of metals and pesticides on dehydrogenase activity in microbial community of cowpea (Vigna unguiculata) rhizoplane

Effects of heavy metals and pesticides on cowpea (Vigna unquiculata) rhizoplane microbial community were assessed in vitro via dehydrogenase activity. The microbial community was exposed to various concentrations of heavy metals and pesticides in a nutrient broth-glucose-2,3,5-triphenyl chloride (TTC) medium. At 0.2 mM, iron and cadmium stimulated the dehydrogenase activity of the microbial community. For all the metal ions, there was progressive inhibition with each successive increase in the concentration of metal ion, reaching near 100% at 0.6, 0.8, 1.2, 0.12 and 12 mM for cobalt, cadmium, iron, mercury and nickel, respectively. Between 0.2 and 0.4 mM, zinc sharply inhibited dehydrogenase activity and at concentration above 0.4 mm, inhibition of dehydrogenase activity became less pronounced. The order of toxicity is Hg2+ > Co2+ > Cd2+ > Zn2+ > Fe2+ > Ni2+. The herbicides Cotrazine (Atrazine 80W) and Northrin®10EC stimulated dehydrogenase activity of the microbial community at 0.2% and inhibited it at higher concentrations. The median inhibitory concentrations (IC50s) of Cotrazine (Atrazine 80W) and Northrin®10EC were 0.552 ± 0.028 and 0.593 ± 0.051%, respectively. The dehydrogenase activity varied significantly (p pesticides. The result indicates that the heavy metals and pesticides are potentially toxic to V. unquiculata root surface microorganisms. In soil, this toxicity may affect nitrogen fixation processes and by extrapolation affect crop yield.

Monitoring of Heavy Metal Pollution of Groundwater in a Phreatic Aquifer in Mersin-Turkey

In this study, heavy metal contents of groundwater from the Mersin aquifer were determined with photometric methods and used to determine the main factors controlling the pollution of groundwater in the area. Using MapInfo GIS software, spatial analysis and integration were carried out for mapping drinking water quality in the basin. From the photometric heavy metal analysis, it is inferred that the excess concentration of Fe, Ni, Mn, Mo and Cu at some locations is the cause of undesirable quality for drinking purposes. Similarly, the EC thematic map shows that considerable areas in the basin are having high salinity hazards. The reason for excess concentration of various heavy metals is the industrial activities and petroleum pipelines and salinity levels show the sea water intrusion.

Variation of heavy metal concentrations (Ag, Cd, Co, Cu, Fe, Pb, V, and Zn) during the life cycle of the common cuttlefish Sepia officinalis

The developmental changes in the concentration of 8 essential and non-essential heavy metals (Ag, Cd, Cu, Co, Fe, Pb, V, Zn) in the tissues (digestive gland, cuttlebone and whole animal) of the common cuttlefish Sepia officinalis collected in the bay of the river Seine were monitored from the end of the embryogenesis until the adult reproductive stage. Compared to embryos, juveniles after hatching displayed much higher concentrations of Ag, Cu, Fe and Zn, suggesting an efficient incorporation from seawater. Conversely, the amounts of Cd, Pb and V in hatchlings remained constant suggesting that these metals are barely bioavailable for juveniles. Once the juveniles start to feed, the digestive gland appears to play a major role in the storage of all metals. After only one month of benthic life, the digestive gland already contains up to 90% of the total metal body burden, indicating that it plays a major role in the storage and presumed detoxification of the selected metals. Metal concentrations in the digestive gland increase in a logarithmic fashion with age during the entire life of cuttlefish, except for Ag, which decreases as soon as cuttlefish migrate to open sea. This strongly suggests that (1) Ag is excreted from the digestive gland in relation to presumably lower exposure in less contaminated environments compared to coastal waters and (2) the digestive gland of cephalopods could be a very good indicator of Ag contamination in the marine environment.

The influence of heavy metals on the production of extracellular polymer substances in the processes of heavy metal ions elimination

Wastewaters from a chemical industry polluted by heavy metal ions represent a hazard for all living organisms. It can mean danger for ecosystems and human health. New methods are sought alternative to traditional chemical and physical processes. Active elimination process of heavy metals ions provided by living cells, their components and extracellular products represents a potential way of separating toxic heavy metals from industrial wastewaters. While the abilities of bacteria to remove metal ions in solution are extensively used, fungi have been recognized as a promising kind of low-cost adsorbents for removal of heavy-metal ions from aqueous waste sources. Yeasts and fungi differ from each other in their constitution and in their abilities to produce variety of extracellular polymeric substances (EPS) with different mechanisms of metal interactions. The accumulation of Cd(2+), Cr(6+), Pb(2+), Ni(2+) and Zn(2+) by yeasts and their EPS was screened at twelve different yeast species in microcultivation system Bioscreen C and in the shaking Erlenmayer's flasks. This results were compared with the production of yeast EPS and the composition of yeast cell walls. The EPS production was measured during the yeast growth and cell wall composition was studied during the cultivations in the shaking flasks. At the end of the process extracellular polymers and their chemical composition were isolated and amount of bound heavy metals was characterized. The variable composition and the amount of the EPS were found at various yeast strains. It was influenced by various compositions of growth medium and also by various concentrations of heavy metals. It is evident, that the amount of bound heavy metals was different. The work reviews the possibilities of usage of various yeast EPS and components of cell walls in the elimination processes of heavy metal ions. Further the structure and properties of yeasts cell wall and EPS were discussed. The finding of mechanisms mentioned above is necessary to identify the functional groups entered in the metals elimination processes.

Heavy metals distribution in mangrove sediments along the mobile coastline of French Guiana

The accumulation of nine heavy metals in fine-grained sediments from the mangrove fringed coast of French Guiana is evaluated. The dynamic features of the South American tropical coastline, from the Amazon to the Orinoco Rivers, result in mangrove sediments being alternately submitted to phases of erosion and net sedimentation a few tens of years long. This process influences the distribution of the heavy metals associated with these frequently re-mobilized deposits. Sedimentary cores and mangrove plant samples were collected, at different seasons, in various swamps characterized by different properties (content of sedimentary organic matter, distance from sea water and fresh water). The ranges of measured concentrations expressed in μmol g − 1 were the following: Cu (0.06 to 0.61), Co (0.12 to 0.68), Pb (0.08 to 0.18), Ni (0.32 to 0.76), Cr (0.61 to 1.40), Zn (1.25 to 5.94), Mn (4.36 to 45.4) and Fe (441 to 1128). No differences were found between sediments from mangroves developing upstream and downstream of urban areas, i.e. Cayenne and Kourou. This suggests that the content of mangrove sediments in heavy metals along the coastline of French Guiana is essentially the result of the continuous alternation of accumulation and transport phases occurring upstream after departing from the Amazon watershed. The sources of this heavy metals content are thus difficult to identify. However it is well known that the alluvium produced by the natural erosion of the Amazonian soils is naturally enriched in mercury. Also, the run-off from gold mining activities is known to contribute to mercury pollution. Ranges in total Hg were between 0.15 and 2.57 nmol g − 1, with mean values close to 0.41 nmol g − 1, and were clearly correlated with total organic carbon except for some outstanding high values, which may be a result of rapid geochemical changes. Heavy metal concentrations showed variations with depth. The redox conditions and the decay processes affecting the organic matter control the cycling of iron and manganese, which in turn control the concentrations and associations of heavy metals. These preliminary results suggest that the variations in heavy metal content with depth or between mangrove areas result largely from diagenetic processes rather than changes in metal input resulting from local human activities.

Seasonal variations of heavy metal concentrations in Qua Iboe River Estuary, Nigeria

Concentrations of six heavy metals namely Pb, Ni, V, Fe, C and Cd were determined in water samples from Qua Iboe river estuary and its associated creeks for six months (January to June, 1999). Results obtained indicate the following mean concentrations for the metals: Pb, 0.167mg/1 + 0.148; Ni, 0.112mg/1 + 0.089; V, 0.019mg/1 + 0.042; Fe, 0.118mg/1 + 0.077; Cu, 0.020mg/1 + 0.026 and Cd, 0.036mg/1 + 0.036. These concentrations were higher in the wet season than the dry season. On comparing these results with the WHO standard, it was observed that the mean concentrations of Pb and Ni were higher than the acceptable limit while the coefficient of variations of the metals were correspondingly high with the high degree of fluctuations in their concentrations from station to station and from season to season. The location of the river estuary correlated positively with its observed high metal concentrations. The environmental implications of these metals are discussed with reference to existing water quality of the river. KEY WORDS: Heavy metals, water sample, pollution, Qua Iboe River. Global Jnl of Pure and Applied Sciences Vol.10(4) 2004: 611-617

Spatial variations in heavy metals on tidal flats in the Yangtze Estuary, China

Surface samples are used to determine onshore-offshore variations in heavy metal concentrations on tidal flats on Chongming and Hengsha Islands in the Yangtze Estuary, China. The Mann-Whitney U-Test suggests that proximity to the estuarine turbidity maximum does not result in significantly higher metal concentrations on tidal flats. Principal Components Analysis shows that grain-size is the primary control on metal concentrations, reflecting the occurrence of salt marsh and mud and sand flats. Sediment quality is comparable to that of pristine estuaries because of dilution by high river sediment loads.

Seasonal and storm-scale variations in heavy metal concentrations of two mining-contaminated streams, Montana, U.S.A.

The impacts of spring runoff and short-term storm events on water quality are poorly documented. We used ultraclean methods to examine the filterable (<0.2μm) and total recoverable geochemistry of one small and one large mining-impacted stream in Montana, USA, over 2 years. At the small stream, filterable Fe, Mn, S, and Zn were higher during spring runoff than during the rest of the year. The highest concentrations of As, Cu, Fe, and Mn in both years occurred following a particularly large summer rainstorm. At the large stream, there were concentration spikes for Al, As, Cu, Fe, Mn, and Zn during an early snowmelt episode and on the rising limb of the main runoff discharge peak in 1999. In 2000 there were large increases in Al, As, Cu, Fe, Mn, P, and Ti concentrations after spring precipitation events. During the late summer rains in 2000, there were 3-8 fold increases in total recoverable Al, Cu, Fe, Mn, and Zn. We show that some of the strongest geochemical variations in mining-impacted streams can occur during spring runoff and summer rain events, both of which can be short-lived and easily missed in monitoring programs based on quarterly or monthly sampling designs.

A comparative study of bioassays based on enzyme biosynthesis in Escherichia coli and Bacillus subtilis exposed to heavy metals and organic pesticides

Two enzyme assays, namely β-galactosidase in Escherichia coli (E.C.3.2.1.23) and α-amylase in Bacillus subtilis (E.C.3.2.1.1), were compared following exposure to various concentrations of heavy metals and organic pesticides. It was shown that α-amylase biosynthesis in the Gram-positive bacteria was more sensitive to heavy metals, particularly to mercury as low as 0.1 ppm, compared to β-galactosidase in the Gram-negative bacteria. The results of organic pesticide treatment were more clear-cut, when comparing both assays. Alpha-amylase test system can detect the inhibition by the organometallic fungicides Maneb and Mancozeb at as low as 0.1 ppm, while no inhibition with β-galactosidase system up to as high as 100 ppm. The effect of organic insecticide endosulfan on α-amylase was also seen at very low concentrations (0.048 ppm). The electrophoretic analysis also revealed the inhibition of enzyme biosynthesis at the tested toxicant concentrations.

Metal concentrations in tissues of the Black Sea fish Mugil auratus from Sinop-Icliman, Turkey.

Levels of five heavy metals [copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and nickel (Ni)] were evaluated in liver and muscle tissues of fish (Mugil auratus) collected from the Black Sea at Sinop-Icliman, Turkey. Sampling and analysis methods are described. Variations of heavy metal concentrations with seasons are discussed. Cr and Ni concentrations were below the limits of detection (< 0.05 and 0.1 microg/g dry weight) in all tissues and seasons. Cu, Pb and Cd were detected within these limits, as microg/kg dry weight, in liver tissue: 0.49-1.30, 0.60-1.21 and 0.15-0.50, and in muscle tissue: 0.30-1.00, 0.57-1.12 and 0.10-0.40, respectively. Cu, Pb and Cd concentrations in these tissues were elevated and the highest heavy metal concentrations were found in the liver. While Cu, Pb and Cd concentrations were highest in fish tissues collected in August 2000, the lowest concentrations of these metals were observed in fish tissues collected in May 2000. Pb had the highest level observed in fish tissues. According to the Turkish Food Codex Regulation's residue limits, the cadmium level determined in fish tissues was high (0.1 microg/g) and the lead level, especially in liver tissue, was high in August (1 microg/g), while other metals (Cu, Cr and Ni) were within the maximum residue limits.

Heavy metal concentrations in growth bands of corals: a record of mine tailings input through time (Marinduque Island, Philippines)

The impact of copper mining along the western coast of Marinduque Island was investigated. Historic input of mine tailings in the coastal region was traced through variations in heavy metal concentrations in Porites growth bands. Five samples were collected from three reefs showing different modes and extent of exposure to mine tailings. Baseline metal concentrations in Porites were established using a coral from a reef that is least exposed to contamination. The lowest mean values of Cu (0.7 μg/g), Mn (0.8 μg/g), and Zn (1.0 μg/g) were calculated from annual skeletal bands representing five years of growth. Conversely, a sample from a reef adjacent to an old tailings stockpile displayed consistently elevated metal values in its growth bands. Mean Cu, Mn, and Zn values for this coral are 3.1, 1.0 and 1.8 μg/g, respectively. Corals from the Ihatub reef showed a distinct metal concentration peak in their 1996 growth ring. These peaks coincide with a documented release of mine tailings in the Ihatub area during that year. Other metal peaks observed in coral samples correlate with years of high precipitation which may have resulted in increased sediment transport in the region. The metals are presumed to be mostly bound to the aragonite lattice of the coral skeleton, however, contribution from incorporated detrital materials to the observed metal signal (mainly of Fe) could not be easily discounted.