Elevated Levels Of Cu Research Articles

SENSITIVITY OF ERICOID MYCORRHIZAL FUNGI AND MYCORRHIZAL CALLUNA VULGARIS TO COPPER MINE SPOIL FROM AVOCA, COUNTY WICKLOW

Ericoid mycorrhizal fungi were isolated from roots of Calluna vulgaris collected from mine spoil at abandoned copper mines at Avoca, County Wicklow, Ireland, and Parys Mountain, Anglesey, Wales. Two isolates were morphologically identical to Hymenoscyphus ericae and formed typical ericoid mycorrhizal associations. Four fungal isolates— the two mine-site isolates and two H. ericae isolates (obtained from uncontaminated sites) were grown in liquid media containing elevated levels of Cu and Zn. All isolates were determined to have a low sensitivity to these metals, with EC₅₀ values (concentration of metal causing 50% reduction in mycelial dry mass) in the range 0.3-0.9mM Cu and 1.2-5.5mM Zn, but there were differences in metal sensitivity between isolates. There was a significant decline in the tolerance of each isolate to increasing concentrations of mine spoil (up to 10% in the agar medium). Mycorrhizal amelioration of heavy-metal toxicity was determined by growing mycorrhizal (M) and non-mycorrhizal (NM) rooted cuttings of C. vulgaris on mine spoil. Rooted cuttings obtained from an uncontaminated site showed no response to mycorrhizal colonisation. However, C. vulgaris obtained from the Avoca site and inoculated with H. ericae performed better than NM plants. The improved growth of these plants was associated with a reduction in Cu within the host's shoot. Inoculation of C. vulgaris with an ericoid mycorrhizal fungus isolated from the Avoca mine site also reduced Cu accumulation within shoots but there was no change in the growth and Zn accumulation of C. vulgaris on mine spoil. Results are discussed in relation to the potential benefit of the ericoid mycorrhizal association to C. vulgaris at metal contaminated sites.

Sensitivity of Ericoid Mycorrhizal Fungi and Mycorrhizal <i>Calluna vulgaris</i> to Copper Mine Spoil from Avoca, County Wicklow

Ericoid mycorrhizal fungi were isolated from roots of Calluna vulgaris collected from mine spoil at abandoned copper mines at Avoca, County Wicklow, Ireland, and Parys Mountain, Anglesey, Wales. Two isolates were morphologically identical to Hymenoscyphus ericae and formed typical ericoid mycorrhizal associations. Four fungal isolates? the two mine-site isolates and two H. ericae isolates (obtained from uncontaminated sites) were grown in liquid media containing elevated levels of Cu and Zn. All isolates were determined to have a low sensitivity to these metals, with EC50 values (concentration of metal causing 50% reduction in mycelial dry mass) in the range 0.3-0.9mM Cu and 1.2-5.5mM Zn, but there were differences in metal sensitivity between isolates. There was a significant decline in the tolerance of each isolate to increasing concentrations of mine spoil (up to 10% in the agar medium). Mycorrhizal amelioration of heavy-metal toxicity was determined by growing mycorrhizal (M) and non-mycorrhizal (NM) rooted cuttings of C. vulgaris on mine spoil. Rooted cuttings obtained from an uncontaminated site showed no response to mycorrhizal colonisation. However, C. vulgaris obtained from the Avoca site and inoculated with H. ericae performed better than NM plants. The improved growth of these plants was associated with a reduction in Cu within the host's shoot. Inoculation of C. vulgaris with an ericoid mycorrhizal fungus isolated from the Avoca mine site also reduced Cu accumulation within shoots but there was no change in the growth and Zn accumulation of C. vulgaris on mine spoil. Results are discussed in relation to the potential benefit of the ericoid mycorrhizal association to C. vulgaris at metal contaminated sites. Brian R. Gibson, Division of Food Sciences, School of Biosciences,

Phosphatases of ericoid mycorrhizal fungi: kinetic properties and the effect of copper on activity

Ericoid endomycorrhizal fungi (two isolates of Hymenoscyphus ericae obtained from unpolluted heathlands and two H. ericae-type endophytes isolated from Calluna vulgaris growing on Cu-contaminated mine spoil) were grown for 14 d on 10% Rorison's solution containing sodium phytate as the sole P source and either trace (0.16 microM) or elevated (0.25 mM) concentrations of Cu. The elevated levels of Cu in the medium had no effect on the growth of the two H. ericae-type endophytes from mine spoil sites but caused a significant reduction in growth of the two H. ericae isolates from unpolluted sites. Wall, cytoplasmic and extracellular fractions were assayed for phosphomonoesterase (PMEase) and phosphodiesterase (PDEase) activity. K(m) and V(max) values varied between the different endophytes and both were highest in the wall fractions. Wall-bound phosphatase activity, excluding PDEase of one H. ericae-type endophyte, was generally unaffected after the isolates had been grown on medium containing 0.25 mM Cu. Extracellular PDEase of the two H. ericae-type endophytes from mine spoil sites was stimulated by 0.25 mM Cu in the growth medium. Cu concentrations up to 5.0 mM in the assay medium did not inhibit wall-bound phosphatase activity whereas three of the isolates showed a stimulation of extracellular activity with increasing Cu. The results are discussed in relation to phosphatase activity of ericoid endophytes on Cu-contaminated substrates.

Recovery of uptake and assimilation of nitrate in Scenedesmus sp. previously exposed to elevated levels of Cu 2+ and Zn 2+

A study of the effects of elevated levels of Cu2+ and Zn2+ on NO3- uptake and nitrate reductase (NR) activity in Scenedesmus sp. was carried out. The two metals inhibited NR and NO3- uptake in a concentration-dependent manner, with the latter process being inhibited more strongly than the former. After withdrawal of metal stress, NR activity and NO3- uptake recovered in a metal ion concentration-dependent manner. Dark pretreatment of the alga enhanced the toxic effects of the metal ions on NR activity and NO3- uptake. The recovery from metal stress was slower in the dark-pretreated cells in comparison to the light-pretreated cells. No recovery of NR and NO3- uptake occurred in the presence of the photosynthetic inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), suggesting that photosynthesis was required for the recovery from metal stress. Cycloheximide blocked the recovery of NR activity in metal-treated alga, suggesting that new enzyme synthesis was required for the recovery from metal stress.

Aquaculture-related trace metals in sediments and lobsters and relevance to environmental monitoring program ratings for near-field effects

The study was undertaken to assess the marine environmental effects from feed and waste associated with aquaculture activities. Metal compositions of sediment, lobster, and feed were used to evaluate the extent of detectable effects at 0 m (under the cage) and 50 m distance. Sediments that were collected under the cages and were characterised as hypoxic or anoxic, showed elevated levels of Cu, Zn, organic carbon, and % <63 μm particles, and low Mn and Fe. At 50 m there was a major reduction in waste chemical impact. Using lobster, a bioindicator species, as a tool for detecting near-field impacts, showed accumulations of high Cu associated with active aquaculture sites. Chemical compositions and metal ratios normalised with organic carbon, were used to assess the sediment conditions associated with environmental monitoring program ratings (EMP––normal, hypoxic, and anoxic). Principal component analysis (PCA) was used to explore chemical data at all sites for differentiating normal, hypoxic and anoxic sediment conditions. Selected variables (Cu, Zn, Fe, Mn, organic carbon, and particles <63 μm) were sufficient for the PCA approach with >90% explainable variance of first two components. The groupings based on PCA and cluster analysis were similar to EMP classifications with some exceptions of mis-identification by EMP. The sediment chemistry components were valid indicators for evaluating marine environmental conditions and for assessing aquaculture operating sites. The developed techniques, using chemical variables in combination with EMP and the statistical approach should be useful to predict the effects of aquaculture practices and the suitability of aquaculture operations.

Analysis of trace metal humic acid interactions using counterion condensation theory.

Recent extensions of counterion condensation theory, originally developed for well-defined linear polyelectrolytes, enable us to analyze the interaction of trace metals with humic acid. In the present model, the heterogeneity of the macromolecule is taken into account as well as the chemical binding of the considered metal ions to the humic material. Experimentally, potentiometric titrations have been performed for humic acid in solution in the presence of different environmentally important (heavy) metals (Ca, Cd, Cu, Ni, and Pb) at various metal concentrations by titrating with potassium hydroxide without additional salt. From proton release data obtained for the initial point in the titration, it was estimated that the interaction of the different metals with the humic acid in terms of binding strength increased in the order Ca < Cd approximately = Ni < Pb approximately = Cu. These results were confirmed by model analysis. Experimentally obtained apparent dissociation constants were in good agreement for the humic acid systems containing Ca, Cd, and Ni at concentrations ranging from 0 up to 0.75 x 10(-3) mol L(-1) and polymer dissociation degree from about 0.1 up to approximately 0.8. Also for the Cu/humic acid and Pb/humic acid systems, the agreement between experimental data and calculated data was satisfactory atthe lowest metal concentrations over the complete titration curve. For elevated levels of Cu and Pb, the agreement between experimental data and theoretical calculations becomes less satisfactory at low degrees of dissociation of the humic acid. This distortion of the potentiometric curves is probably due to changes in the intrinsic pK of the functional groups due to metal binding. This complex process is not included in present polyelectrolytic models.

Effect of storm drain discharge on the soft shore ecology of Porirua Inlet, New Zealand

The effect of storm drain discharge on the ecology of the soft shore community near the Semple Street outfall in Porirua Inlet, New Zealand, was investigated from December 1998 to April 1999. Biological community structure, sedimentary properties, and heavy metal concentrations of surficial sediments were examined at increasing distance (5, 90, 140 m) from the storm drain at two (upper and lower) shore heights (total of six sites). Concentrations of copper (Cu), lead (Pb), and zinc (Zn) at nine sites from the storm drain to the mouth of the inlet were estimated in April 1999. Typically, mean numbers of individuals decreased, whereas mean numbers of taxa, and the Shannon‐Wiener diversity index increased with increasing distance from the storm drain. Analysis of variance revealed that the 5, 90, and 140 m sites at both tidal heights exhibited small but significant differences in community structure which were attributable to differences in species abundance, rather than to differences in the suite of species which characterise these sites. It was not possible to identify temporal trends in the data set. Analysis of similarities revealed significant differences in species abundance among the three sites for the high shore, the low shore, and both tidal heights combined. Sites furthest apart (5 versus 140 m) exhibited the greatest, and sites closest together (90 versus 140 m) exhibited the least, difference in biological community structure, suggesting that storm drain outflow modifies benthic community composition immediately in front of the drain and up to <100 m away. Non‐metric multidimensional scaling (MDS) ordination of taxon abundance showed community structure at the two 5 m sites to be dissimilar from that at the other four sites, where it was similar. Despite this, however, changes in taxon abundance with increasing distance from the storm drain were minimal, with the result that indicator taxa could not be identified which explained significant differences in community structure on the scale of this study. A survey of heavy metal concentrations along the length of the inlet indicated that Cu, Pb, and Zn concentrations decreased in a linear manner with distance away from the storm drain and that biological communities in at least the southern half of the inlet are exposed to elevated levels of Cu, Pb, and in particular, of Zn, which exceed internationally recognised threshold, and sometimes, probable effect levels.

Spatial variation of heavy metals in surface sediments of Hong Kong mangrove swamps

The degree of heavy metal contamination in the fine-grained (<63 μm) and sand-sized (2 mm–63 μm) fractions of surface sediments in 18 different mangrove swamps (144 random samples) in Hong Kong was examined. Higher concentrations of heavy metals were found in the fine-grained than the sand-sized fractions of the sediment; however, the differences between these two fractions became less significant when the swamp was more contaminated. The principal component analyses show that the 18 mangrove swamps, according to the median concentrations of total heavy metals, were clustered into four groups. The first group included three mangrove swamps in Deep Bay region which are seriously contaminated, with heavy metal concentrations in sediments around 80 μg g −1 Cu, 240 μg g −1 Zn, 40 μg g −1 Cr, 30 μg g −1 Ni, 3 μg g −1 Cd and 80 μg g −1 Pb. The second cluster, made up of another four swamps distributed in different geographical locations (two in Sai Kung district and two in Tolo region), also had elevated levels of Cu, Pb, Ni and Cr in the sediments. Field observation reveals that these seven stands received industrial, livestock and domestic sewage as well as pollution from mariculture activities, suggesting that anthropogenic input is the main source of heavy metal contamination in Hong Kong mangroves. The sediments from other mangrove swamps were relatively uncontaminated.

Background concentrations of heavy metals in aquatic bryophytes used for biomonitoring in basaltic areas (a case study from central France)

Studies were made of the aquatic bryophytes Fontinalis antipyretica Hedw., Platyhypnidium rusciforme (Neck.)Fleisch and Chiloscyphus sp. (Hoffm.)Dum. from streams embedded in basaltic rocks (Le Puy, central France). Water from these streams possessed elevated levels of Cu, Zn, Sr, V, Ba, Ni and Co, reflecting the geochemistry of the basalts, a basic type of igneous rocks containing elevated levels of these elements. The concentration of elements in bryophytes is correlated to the chemical composition of water of their sampling sites. Contents of trace elements in plants were higher than background values. The elevated levels of these elements possibly caused disturbances in the ionic equilibrium within the bryophytes. The molar ratio between contents of Ca and Mg in water (from 0.44 to 1) was different from that typical for natural water.

Biotic and abiotic characteristics of ecosystems on acid metalliferous mine tailings near Sudbury, Ontario

INCO Ltd., a large mining company near Sudbury, Ont., deposits vast amounts of tailings on its property. These tailings contain elevated levels of Cu, Ni, and sulphides, and to curtail dust and acid drainage, INCO has undertaken a long-term project to cover its tailings with vegetation. Yearly amelioration of fresh tailings with limestone and fertilizer, followed by seeding with various grasses and herbs, transplanted conifers, and the later colonization of volunteer species of plants from adjoining forests, has resulted in the formation of ecosystems of varying age and complexity. To assess the long-term effectiveness of INCO's vegetation techniques, we studied floral diversity, attributes of developing soils, and the accumulation of Cu and Ni in various plant species growing on tailings at different stages of development. Habitat disturbance by tailings deposition, and its subsequent floral recolonizaton, is an example of "anthropogenic succession." Tailings that do not receive amelioration in the form of lime, fertilizer, and seeding remain free of vegetation, other than sparce clumps of the metal-tolerant grass Deschampsia caespitosa (L.) Beauv. Once amelioration begins, various species of grasses and herbs are able to subsist and within 8 years volunteer species begin to colonize. Substrate pH of dried tailings is less than 4 while the pH in upper horizons ranges from 5 to 6, increasing as the sites become more florally diverse; however, pH at lower depths remains less than 4. Substrate organic content in upper horizons at restored sites ranges from 4.5 to 5.0%. Water-soluble concentrations of Cu and Ni in upper horizons ranges from 1 to 5 µg/g dry mass, and 0.5 to 6 µg/g dry mass, respectively, and both metals decrease with increasing floral diversity. Levels of Ni increase at lower depths indicating greater substrate mobility. Levels of Cu and Ni are higher in plants from tailings than in those from control sites; however, concentrations do not decrease in plants from older and more florally diverse tailings sites. Root tissues contain significantly higher concentrations of Cu and Ni than aerial tissues. Monitoring air with moss plates indicates that dispersal of airborne metallic dust remains a problem.Key words: mine tailings, Sudbury, anthropogenic succession, copper, nickel, acid, monitoring.

Toxicity of copper, cobalt, and nickel salts is dependent on histidine metabolism in the yeast Saccharomyces cerevisiae.

The pH-dependent inhibition of 22 metal salts have been systematically investigated for the yeast Saccharomyces cerevisiae. We have established that the inhibition of growth by Cu, Co, or Ni salts is markedly enhanced by histidine auxotrophy and by increasing the pH of the medium. Each of the his1-his7 mutant strains were unable to grow in the presence of elevated levels of Cu, Co, or Ni at nearly neutral pHs, in contrast to His(+) strains, which grew under these conditions. The Cu, Co, or Ni inhibition was reversed by the addition of histidine to the medium. Deletion of the high-affinity histidine permease Hip1p in His(-) strains resulted in even greater sensitivity to Cu, Co, and Ni and the requirement of an even higher level of histidine to reverse the inhibition. These results suggest that intracellular histidine, most likely in the vacuole, diminishes the pH-dependent toxicity of Cu, Co, and Ni. Furthermore, the toxicity of many salts is exacerbated in strains with a defective vacuolar H(+)-ATPase, which abolishes the ability of yeast to maintain an acidic vacuole, a compartment known to sequester metal compounds. We suggest that the accumulation of histidine in the vacuole is a normal process used to detoxify Cu, Co, and Ni.

Biotic and abiotic characteristics of ecosystems on acid metalliferous mine tailings near Sudbury, Ontario

INCO Ltd., a large mining company near Sudbury, Ont., deposits vast amounts of tailings on its property. These tailings contain elevated levels of Cu, Ni, and sulphides, and to curtail dust and acid drainage, INCO has undertaken a long-term project to cover its tailings with vegetation. Yearly amelioration of fresh tailings with limestone and fertilizer, followed by seeding with various grasses and herbs, transplanted conifers, and the later colonization of volunteer species of plants from adjoining forests, has resulted in the formation of ecosystems of varying age and complexity. To assess the long-term effectiveness of INCO's vegetation techniques, we studied floral diversity, attributes of developing soils, and the accumulation of Cu and Ni in various plant species growing on tailings at different stages of development. Habitat disturbance by tailings deposition, and its subsequent floral recolonizaton, is an example of "anthropogenic succession." Tailings that do not receive amelioration in the form ...

CONCENTRATIONS OF HEAVY METALS (Cd, Cu, Pb, Ni & Zn) AND ORGANOCHLORINE CONTAMINANTS (PCBs, DDT, DDE & DDD) IN THE BLUBBER OF CAPE FUR SEALS ARCTOCEPHALUS PUSILLUS PUSILLUS OFF THE EASTERN CAPE COAST OF SOUTH AFRICA

SUMMARY The concentration of heavy metals (Cd, Cu, Pb, Ni and Zn) and organochlorine contaminants (PCBs, DDT, DDE and DDD) in the blubber of 12 adult male Cape fur seals, Arctocephalus pusillus pusillus, inadvertently caught in trawl nets off the Eastern Cape coast of South Africa during commercial fishing operations between May 1993 and October 1994, was investigated. The median and range of concentrations for each metal were, in μg/g wet weight: Cd, 0.4 (<0.04–0.53); Cu, 2.6 (2.17–7.43); Pb, 0.7 (0.54–0.99); Ni, 17.7 (9.39–23.18) and Zn, 11.5 (3.14–16.65). Dry weights were: Cd, 0.5 (<0.04–0.59); Cu, 2.9 (2.47–8.45); Pb, 0.6 (0.54–1.14); Ni, 17.0 (10.79–28.22) and Zn, 12.8 (3.61–20.26). Concentrations of Cd, Pb and Zn were in the limits of reported values; however Cu and Ni levels were considerably higher. There is no evidence that the elevated levels of Cu and Ni reported in this study would pose a serious threat to the health of individual animals; however, high concentrations of these metals may be sufficient to result in some additional stress to animals when they mobilise their lipid reserves during illness or starvation. Ni and Cd concentrations appeared to increase with age; however, small sample size prevented statistical analysis. Concentrations of organochlorines (μg/g wet weight) were below the limit of detection.

Heavy metal contamination in dusts and stream sediments in the Taejon area, Korea

Associated with the rapid pace of urbanization and industrialization is the increase of automobile emissions, factory emissions, and industrial wastewater. Heavy metal contamination from these point sources has received much attention in the Taejon area, Korea. In order to investigate the degree of heavy metal contamination, 81 road dusts, 79 house dusts, 40 indoor dusts of subway stations and 21 stream sediments have been analyzed for Cd, Cu, Pb and Zn. Copper, Pb and Zn levels in road dusts from the control area are lower than average levels, while those from the traffic and industrialized areas including the city center and highway junctions are relatively high. In particular, the highest Pb concentration in road dust, 161 μg g −1, is noted in dust samples from Yusung Highway Junction. The Pollution Index of multi-element contamination levels in road dust is found to correlate with a calculated Urbanization and Industrialization Index. Elevated levels of Cu, Pb and Zn are also noted in house dusts near the Yusung Highway Junction and industrialized areas. The age of property is found to influence the Pb levels in house dusts, with older houses (>15 years) having significantly higher concentrations than newer properties (<15 years). Levels of heavy metals in indoor dusts from subway stations in the city center range up to 4470 μg g −1 Cu and 660 μg g −1 Pb. Elevated levels of Cd, Cu, Pb and Zn are found in stream sediments from the Taejon industrialized area. The highest Zn concentration of 387 μg g −1 is found in the sediment close to the Sintanjin Industrial Complex. A sequential extraction procedure applied to stream sediments indicates a high percentage of easily exchanged metals. The exchangeable phase of the metals may originate not from parent materials but from wastewaters and exist in an adsorbed phase on the surfaces of sediments. These metals are easily dissolved into the water by reactions, and relative amounts of dissolved phase metals are in the order Cu = Zn > Pb.

Accumulation of Cu and Ni in successive stages of Lymantria dispar L. (lymantriidae, lepidoptera) near ore smelters at Sudbury, Ontario, Canada

The accumulation of Cu and Ni in successive life stages of the gypsy moth ( Lymantria dispar), feces, and foliage near an ore smelter at Sudbury, Ontario and a control site was investigated. Higher concentrations of Cu and Ni were found in all larval stages collected at Sudbury than in those from the control site indicating that elevated levels of these metals in the Sudbury environment is an important factor influencing body burdens. These differences were associated with higher metal concentrations in the foliage of host trees from this site. However, differences between sites became less significant for pupae and adult stages. At the Sudbury site, concentrations of Cu (μg g −1 dry wt) decreased in successive instars and then increased in tissues of pupae and adults. In contrast, Cu content (μg/individual) increased during larval development and then decreased in pupae and adults. The pattern of Ni concentration and content in larvae from the Sudbury site was similar to that of Cu. Patterns of Cu and Ni concentration and content throughout the life stages are explained by changes in weight resulting in a dilution effect in early stages, and a concentrating effect in later stages. Differences in Cu and Ni concentration and content between Sudbury and control populations became less significant following the pupal stage suggesting metal elimination with the exuviae and meconium. This study also illustrates the importance of sampling all stages in an insect's development when measuring accumulation of metals. Fecal and foliar concentrations of Cu and Ni from Sudbury were not significantly different suggesting that metal assimilation is low. Even though gypsy moths from Sudbury contain elevated levels of Cu and Ni, metal burdens in their tissues do not represent a significant route through the food chain. However, the conversion of foliage with high metal content to feces implies that other ecosystem consequences should be investigated.

Evaluation of chemical extractants for the prediction of plant‐available Cu in Arabian desert calcareous soils

Elevated levels of Cu in natural and contaminated soils could result in increased cycling of the element due to plant uptake. The relationships were examined between Cu removed from 22 calcareous soils by six chemical extractants and Cu taken up by wheat (Triticum asetivum L.) in a greenhouse experiment. One set of soils was untreated (noncontaminated) and another enriched (contaminated) with 300 mg Cu kg'’ as Cu(NO3)2. The chelating extractants (0.025 M Ca‐DTPA‐B4O7, 0.1 M EDTA, and 0.005 M DTPA) were the best, being equally effective in their ability to extract Cu from noncontaminated and contaminated soils. Soil test values collected with 0.025 M Ca‐DTPA‐B4O7 extractant were more precisely related to Cu uptake by wheat in both noncontaminated (r = 0.93) and contaminated (r = 0.94) soils, both significant at p = 0.001. In general, the relationships between the amounts of soil Cu extracted by the chemical procedures and by plant uptake were improved when soil parameters (e.g., soluble and exchangeable ca...

Copper and nickel pollution: frequency of endophytic fungi in Scots pine shoots and endophyte growth in vitro

The frequency of endophytic microfungi was measured from current-year shoots of Scots pine trees growing in Harjavalta, a heavily polluted area in western Finland. The copper (Cu) and (Ni) concentrations in bark plus phloem and needles of the same trees were measured. The frequency of isolates of endophytic taxa were either negatively (Hormonema sp. 2 and Sterile sp. 1) or positively (Hormonema sp. 1, BL132) correlated with the Cu and Ni concentration of bark plus phloem. Isolates of the most common endophytic taxa and the pathogenic Gremmeniella abietina from Harjavalta were grown in vitro in different levels of Cu (0.6 – 126 μg/mL) and Ni (0.3 – 50 μg/mL) separately and in combination. This experiment included also isolates of G. abietina and Hormonema sp. 1 from the northern (unpolluted) area. The concentrations of Cu and Ni that reduced the linear growth to 50% of control were estimated. The endophyte taxa with positively correlated frequency with increasing concentration of Cu and Ni in the shoots were able to withstand elevated levels of Cu and Ni in vitro. Compared with most of the other fungi, G. abietina isolates were particularly sensitive to addition of Ni. No evidence for intraspecific adaptation of G. abietina and Hormonema sp. 1 to Cu and Ni was found. Key words: endophyte, Gremmeniella, heavy metal, Hormonema, Scots pine.

The use of nuclear muprobe techniques to study the chemistry of lacustrine sediments and particles

The Oxford SPM has been used in two novel studies of lake chemistry: (a) The distribution of dissolved iron in sediment pore waters close to the sediment/water interface has been measured using the novel technique of diffusive equilibration in a thin film (DET). In this technique, which has a spatial resolution of < 1 mm, much less than that of competing techniques (1 cm), a thin layer of polyacrylamide gel is inserted into the sediment and after the rapid equilibration with the pore water, the gel is dried and fixed. The distribution of trace elements can then be measured using mubeam PIXE. Preliminary results have shown for the first time a subsurface maximum of Fe consistent with current theories of Fe dynamics. This paper presents some results obtained using the technique and discusses the limits on resolution and sensitivity, (b) Individual suspended lake particles (predominantly iron oxides and sulphides) have been analysed using point mubeam RBS and PIXE. Of particular interest in this study is the oxidation state of iron rich particles, so RBS with a 1 μm beam was used to determine the Fe: O stoichiometry of single particles. The particles were filtered from a depth of 14 m in Esthwaite Water in the English Lake District and handled in anoxic conditions until evacuation in the SPM sample chamber. Two distinct compositions of iron oxide were determined in clusters of about 5 μm diameter. Analysis by PIXE revealed that FeS was uniformly distributed in the particulate material and that it also contained elevated levels of Cu and Zn. This study was the first to demonstrate directly that discrete clusters of iron oxides are present in black particulate material which is commonly considered to comprise iron sulphides.

Trace element analysis by PIXE in liver samples from dogs with chronic active hepatitis and liver cirrhosis

Trace element levels of liver samples obtained from necropsied dogs suffering from hepatitis and/or liver cirrhosis were determined by PIXE. Two different techniques for preparation of the samples were compared: the pellet press method and wet digestion. Both methods gave similar results, but the pellet press method was chosen for the subsequent routine analyses because of its simplicity due to few preparation steps and little risk of contamination. Preliminary results indicate elevated levels of Cu in chronic hepatitis and cirrhosis. In hereditary copper-induced hepatitis (Bedlington hepatitis) Fe and Br levels were increased as well.

Heavy metal pollution from a point source demonstrated by mussel (Unio pictorum L.) at Lake Balaton, Hungary.

Few studies are concerned with heavy metal pollution caused by the use of various paints in water ecosystems. In a study on the content of metals in dockyard sediments, elevated levels of Cu and Zn from antifouling paints, and Pb from anticorrosive and primer paints were reported. In the present work, a study was performed close to a sailing boat harbor of heavy metal pollution using biological samples. The concentrations of Cu, Zn, Cd and PB were determined in the organs of freshwater mussel (Unio pictorum L.) by AAS technique.