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1.
Summary The uptake of trace metals by two plant species (French bean and maize) has been measured on two soils subjected to various waterlogging regimes. Uptake of both manganese and iron was increased due to soil waterlogging, although reoxidation of the soil affected iron more than manganese. Zinc and copper uptake was influenced by a species factor; French bean (Phaseolus vulgaris) showed preferential uptake of zinc, whereas maize (Zea mays) took up copper preferentially. Uptake of cobalt by both species was increased due to waterlogging, following the pattern of manganese.The abilities of these species to take up trace metals from soil followed the pattern predicted by selective extraction of soil for manganese, iron and cobalt, but not for zinc and copper.  相似文献   

2.
Summary Synthesis of citric acid by Aspergillus fonsecaeus in a basal medium supplemented with trace metals (iron, zinc, copper, and manganese) and methanol has been investigated. Methanol was found to be stimulatory to acid synthesis when manganese or manganese and iron were present. No other mineral tested could be substituted for manganese in the presence of the alcohol. However, comparable yields of citric acid could be obtained if methanol were deleted, the concentration of iron increased and zinc substituted for manganese.This investigation was conducted under a contract with the United States Department of Agriculture, authorized by the Research and Marketing Act, and administered through the Northern Regional Research Laboratory.  相似文献   

3.
Metal bioaccumulation and metallothionein were investigated in different organs of the red-blooded teleost, Trematomus bernacchii and the haemoglobinless Chionodraco hamatus. Specimens of the two Antarctic fish were sampled from Terra Nova Bay (Ross Sea), and their levels of Cd, Cu and Zn in homogenates and in soluble fractions of liver, muscle, gills, heart and plasma were determined. Dosages of metallothioneins (MTs) or MT-like proteins were assayed by the silver saturation method in soluble fractions of the same organs. In both T. bernacchii and C. hamatus the highest MT contents were found in liver. Hepatic MT and Cd, Cu and Zn concentrations correlated positively in T. bernacchii, whereas in C. hamatus hepatic MT showed a positive correlation only with Cd. Positive correlations were also found between Cd and MT in gills of the two species. A metal-binding protein containing a high percentage of cysteine from C. hamatus was purified and compared with the MT from T. bernacchii and mammals. Accepted: 27 November 1999  相似文献   

4.
Heavy metals in Antarctic organisms   总被引:8,自引:1,他引:7  
 To evaluate levels of essential (zinc and copper) and non-essential (mercury and cadmium) heavy metals, 34 species of organisms from different areas close to the Antarctic Peninsula were analysed. These included algae, filter-feeders, omnivorous invertebrates and vertebrates. Mercury was not detected, while cadmium was found in the majority of organisms analysed (detection limit was 0.05 ppm for both metals). The highest cadmium concentration was observed in the starfish Odontaster validus. Anthozoans, sipunculids and nudibranchs showed maximum levels of zinc, while the highest copper level was found in the gastropod Trophon brevispira. Mercury and cadmium levels in fishes were below the detection limit. Concentrations of essential and non-essential metals in birds were highest in liver followed by muscle and eggs. Cadmium and mercury levels in muscle of southern elephant seals were above the detection limit, whereas in Antarctic fur seals they were below it. The objective of the study was to gather baseline information for metals in Antarctic Ocean biota that may be needed to detect, measure and monitor future environmental changes. Received: 17 July 1995/Accepted: 11 April 1996  相似文献   

5.
The paucity of investigations on the presence of artificial radionuclides and their bioaccumulation in Antarctic fauna is due to the erroneous belief that this area is pristine. We report evidence that significant levels of the artificial radionuclides Sr-90, Cs-137, Am-241 and plutonium isotopes can be found in sponges, bivalves, krill and demersal fish fauna of Terra Nova Bay (Ross Sea), sometimes with a seasonal pattern. Increasing concentrations of Cs-137 were detected in the bivalve Adamussium colbecki (Antarctic scallop) during austral summer months, as a result of major trophic activity and changes in metabolic rates. Bioconcentration factors for artificial radionuclides in different Antarctic species are presented and discussed in relation to their different trophic strategies. Unexpectedly high radiocesium bioconcentration factors determined in bivalves suggested the particular role played by filter feeding in bioaccumulation, particularly in summer when radionuclide bioavailability is enhanced. The feeding preference of the trematomiid fish Trematomus bernacchii for the scallop A. colbecki is confirmed, not only by fish gut content analyses, but also through radiometric results. Transuranics bioaccumulation by sensitive species allowed some interesting comparisons on the different plutonium contamination of the southern hemisphere with respect to the northern one. Accepted: 25 April 2000  相似文献   

6.
Changes in essential trace elements and heavy metals may affect the atherosclerotic state of patients on maintenance hemodialysis (HD). The aim of the study was to evaluate the relation between the serum levels of some trace elements and heavy metals (iron, zinc, manganese, copper, magnesium, cobalt, cadmium, lead, and copper/zinc ratio) and carotid artery intima-media thickness (CIMT) in HD patients. Fifty chronic HD patients without known atherosclerotic disease and 48 age- and sex-matched healthy individuals were included in the study. The serum levels of trace elements (iron, zinc, manganese, copper, and magnesium) and heavy metals (cobalt, cadmium, and lead) were measured by Atomic Adsorption Spectrophotometer (UNICAM-929). CIMT was assessed by carotid artery ultrasonography. The serum levels of iron, zinc, and manganese were lower; levels of copper, magnesium, cobalt, cadmium, lead, and copper/zinc ratio were higher in HD patients compared to controls. CIMT in HD patients were higher than the control group (0.64?±?0.11 vs 0.42?±?0.05, p?相似文献   

7.
The speciation of cadmium, lead, copper, zinc, manganese and iron into exchangeable, carbonate, reducible and organic bound fractions was studied in sediments from coastal and freshwater environments in Ghana. This was relevant as the species in which metals are stored within specific sediment components is important in determining their impact on the environment. For both coastal and inland sediments, a higher percentage of cadmium was associated with the more available exchangeable and carbonate fractions, while iron, zinc and manganese were mainly associated with the reducible and organic fractions. Lead and copper were found to have the greatest ability to form different species in the samples examined and were more evenly associated with all the fractions. The metals generally showed more ability to form different species in inland freshwaters than in coastal relatively saline waters. However, differences between inland and coastal waters were based more on whether the environments were oxidising or reducing than on whether they were fresh or saline. The metals may be divided into three groups of high mobility consisting of lead and copper; moderate mobility made up of cadmium, manganese and zinc; and low mobility, represented by iron.  相似文献   

8.
Monitoring levels of mineral concentrations in animal tissues is important for assessing the effect of contamination on animal health and safety of animal origin products in human nutrition. This study evaluated the levels of certain trace elements (copper, zinc, iron, and manganese) in cattle from an industrial and mining region in the north of Spain (Asturias). Samples of 312 animals aged 9–12 mo were collected from the whole region and analyzed after acid digestion using atomic absorption spectrophotometry (AAS). The geometric mean concentrations obtained per wet weight for the liver, kidney, muscle, and blood were 34.3 mg/kg, 4.04 mg/kg, 1.65 mg/kg, and 0.651 mg/L for copper, respectively, and 38.5 mg/kg, 23.0 mg/kg, 47.0 mg/kg, and 2.44 mg/L for zinc, respectively. For iron, blood was not analyzed and results were 96.2 mg/kg, 105 mg/kg, and 56.0 mg/kg for the liver, kidney and muscle, respectively. For manganese, only the liver and kidney were analyzed, and the results were 3.11 mg/kg and 1.19 mg/kg, respectively. There was no evidence of an accumulation of toxic levels of trace metals in Asturian cattle. Females accumulated more iron in the liver (p<0.001, F 1,310=18.4) and the kidney (p<0.001, F 1,310=13.5) and more manganese in the liver (p<0.01, F 1,310=9.55) than males.  相似文献   

9.
Quantitative determination of the elements potassium, sodium, manganese, magnesium, iron, cobalt and zinc was performed in mycobacteria by neutron activation analysis. Mycobacterium phlei ATCC 19 249 at different phase of growth (4, 8, 13, 23 and 37 days old cultures), and 14 days old Mycobacterium bovis BCG cultures and uninoculated semi-synthetic Sauton culture media were examined. The elements studied could be divided into three groups; sodium, potassium and magnesium could be regarded as major, iron as minor, and zinc, manganese and cobalt as trace elements. M. phlei contained, with the exception of zinc, higher amounts of elements than M. bovis. Other metals (aluminium, antimony, rubidium) could also be detected.  相似文献   

10.
Pore water concentration gradients and fluxes of chemical components have been studied in sediments from six intertidal sites in the Tamar Estuary, SW England over the course of a year. Fluxes of nutrients (ammonia, nitrate, nitrite, phosphate and silicate) and trace metals (iron, manganese, zinc, copper and cadmium) were determined using a laboratory microcosm incorporatingin situ pore water samplers. Nutrients (except nitrate) were transported out of the sediment throughout the year, but nitrate fluxes were directed into the sediment in the summer (denitrification) and out of the sediment in the winter (nitrification). The activities of benthic macrofauna resulted in enhanced fluxes but these differed between sites depending on population structure and density and whether irrigation or sediment reworking predominated. Fluxes of trace metals were seasonally and spatially variable and specific differences were observed that could be attributed to both chemical and biological activity.  相似文献   

11.
Plant, soil, and sediment samples were taken from the Fuqiao area within the Huayuan River basin in South China. Concentrations of manganese, zinc, cadmium, and lead in the samples were measured, and the characteristics of the plant samples to absorb, transfer, and accumulate the target metals were analyzed. It was indicated that the concentrations of target metals in 13 plant samples greatly exceeded the background values of target metals in plants over the world, and that the plant species might evolve to the accumulating ecotypes for the target metals under the long-term stress from the contaminated environment. Among 13 plant species, Alternanthera philoxeroides exhibited the highest accumulation capacities for the target metals, amounting to 6511, 13,784, 155, and 104 mg/kg in its shoots for manganese, zinc, cadmium, and lead, respectively. Its bioaccumulation coefficients for manganese, zinc, cadmium, and lead were 5.08, 49.23, 36.78, and 34.81, respectively, and its transfer factors for manganese, zinc, cadmium, and lead were 7.53, 3.19, 7.38, and 1.29, respectively. The results showed that Alternanthera philoxeroides satisfied the criteria for the hyperaccumulator for zinc and cadmium, and that it might be a potential native plant species for phytoremediation of the contaminated soil, sediment, and river water by the target metals within the basin.  相似文献   

12.
The concentration of trace elements in L-cells has been studied as a function of the trace metal content of the growth medium. Cells were cultured in synthetic media which contained varying trace amounts of the elements manganese, iron, cobalt, copper, zinc and molybdenum. The cellular concentration of the elements potassium, iron, copper and zinc were then determined. It was found that the cell accumulates trace metals at a different rate than they are made available. Deficiencies in zinc could be “induced” in the cell by increasing the concentration of iron, manganese and cobalt; cellular iron deficiencies were observed at larger medium concentrations of zinc, manganese, copper and cobalt. Trace metal uptake by the cell was seen to parallel the utilization by multicellular organisms.  相似文献   

13.
Abstract

Seasonal variations of mineral nutrients and trace elements in Fagus sylvatica L. leaves at Vallombrosa (FI). - During the vegetative periodo 1987 monthly samples of beech leaves were collected in Vallombrosa forest area to determine the nutritive situation of beech trees by leaves analysis. Among nutrients, potassium appears the worst supplied one. Even copper is present in very low values, under the critical level. Heavy metals as manganese, aluminium, lead, cadmium and also iron show a clear increase during the vegetative season.  相似文献   

14.
Acidic, metal‐rich water that had accumulated within two abandoned, adjacent copper mines in north Wales was removed to prevent its possible catastrophic release. About 274 000 m3 of acidic (pH ~2.4) mine water was pumped out of the mines over a 14‐week period. Concentrations of dissolved species (iron, sulfate, aluminium, copper, manganese and zinc) increased as water at lower depths within the mines was accessed. The discharged water flowed through a small wetland area, reaching the sea about 3 km north of the mine site. Analysis of the water at three sampling stations revealed that there was very little removal of aluminium and most of the heavy metals present except (ferrous) iron, which was partially removed as a result of oxidation and hydrolysis of the resulting ferric iron. The dominant bacterium in the subterranean mine water, which was essentially devoid of oxygen, was the iron‐ and sulfur‐oxidizer Acidithiobacillus ferrooxidans. The microbial populations in the pumped mine water were monitored using combined cultivation‐dependent (isolation on solid media) and cultivation‐independent (terminal restriction fragment length polymorphism and clone library) techniques. Other bacteria detected in the mine water included other iron‐oxidizers (Leptospirillum spp., ‘Ferrimicrobium acidiphilum’ and Gallionella‐like organisms) and heterotrophic acidophiles (Acidiphilium, Acidisphaera and Acidobacterium). Archaeal clones were also detected; most of these were related to methanogens. Owing to the absence of an effective remediation strategy, an estimated 7.5 tonnes of copper, 3.1 tonnes of manganese, 14.8 tonnes of zinc and 15.3 tonnes of aluminium was discharged into the Irish Sea as a consequence of the dewatering of the mines.  相似文献   

15.
Ham's Lake was destratified in the summers of 1977 and 1978 by pumping surface water to the bottom. However, an arm was prevented from mixing by a submerged dam of a former farm pond and remained stratified. The concentration of manganese in the water increased to over 5 000 µg 1–1 in the hypolimnion of the anoxic arm in summer. Soluble manganese averaged 28% of total concentration. Total iron concentrations were relatively high in the water and sorbed iron values were extremely low in the sediments. Soluble iron averaged 12% of total concentration. Zinc values were low in the water and sediments. Chaoborus punctipennis and Chironomus riparius concentrated iron and zinc and discriminated against manganese. Concentration factors were unaffected by mixing.  相似文献   

16.
Abstract

The speciation and bioavailability of zinc (Zn) in smelter-contaminated sediments were investigated as a function of phosphate (apatite) and organic amendment loading rate. Zinc species identified in preamendment sediment were zinc hydroxide-like phases, sphalerite, and zinc sorbed to an iron oxide via X-ray adsorption near edge structure (XANES) spectroscopy. Four months after adding the amendments to the contaminated sediment, hopeite, a Zn phosphate mineral, was identified indicating phosphate was binding and sequestering available Zn and Zn pore water concentrations were decreased at levels of 90% or more. Laboratory experiments indicate organic amendments exhibit a limited effect and may hinder sequestration of pore water Zn when mixed with apatite. The acute toxicity of the sediment Zn was evaluated with Hyalella azteca, and bioaccumulation of Zn with Lumbriculus variegates. The survivability of H. azteca increased as a function of phosphate (apatite) loading rate. In contaminated sediment without apatite, no specimens of H. azteca survived. The bioaccumulation of Zn in L. variegates also followed a trend of decreased bioaccumulation with increased phosphate loading in the contaminated sediment. The research supports an association between Zn speciation and bioavailability.  相似文献   

17.
This study compares the seminal plasma trace metal levels of hospital workers with groups of industrial workers in a petroleum refinery, smelter, and chemical plant. The metals measured were the essential metals (copper, zinc, nickel, cobalt, and manganese) and the toxic metals (lead, cadmium, and aluminum). The group mean±SE metal level for each group (50 subjects per group) was calculated, and the statistical significance of the group mean differences of the industrial groups with the hospital group (control) was determined by the Student’s t-test. The differences observed in the smelter group were increased copper and zinc (p≤0.001) and decreased nickel, cobalt, and manganese (p≤0.001,≤0.01). The refinery group differences were increased copper, zinc, and nickel (p≤0.001) but decreased cobalt and manganese (p≤0.001). The chemical group differences were increased zinc (p≤0.001) and decreased cobalt (p≤0.001). The seminal plasma levels of the toxic metals lead and aluminum were increased in each of the industrial groups (p≤0.001). Concurrent differences were (1) decreased accumulation of nickel, cobalt, and manganese in the smelter group, (2) decreased cobalt and managanese in the refinery group, and (3) only decreased cobalt in the chemical group.  相似文献   

18.
Bioaccumulation of trace elements in jellyfish has so far received little attention, despite their being prey for many animals from multiple trophic levels and targeted by commercial jellyfish fisheries. Scyphozoan and cubozoan jellyfish were collected over a three year period from across-shelf and along the northern and central Great Barrier Reef, Australia. To test the hypotheses that jellyfishes were able to accumulate elements above ambient background levels, and if there were spatial or temporal variations among species, soft tissue concentrations of 14 trace elements were compared with ambient seawater concentrations. Most elements, including aluminium, arsenic, barium, cadmium, chromium, copper, iron, manganese and zinc were measured at concentrations above ambient seawater levels indicating bioaccumulative capacity. Results showed some regulation of lithium in Cassiopea sp., Cyanea sp. and Mastigias sp., while calcium, magnesium and strontium reflected ambient conditions for all species. Accumulation varied significantly among species and sampling locations. For Mastigias sp. and Netrostoma sp., tissue concentrations of Al, As, Cu, Fe and Zn decreased with distance from the mainland. The hypothesis that jellyfishes are capable of accumulating trace elements was accepted, and their use as biomonitors should be investigated further.  相似文献   

19.
Abstract

Metal fractionation is a powerful tool for studying the mobility, bioavailability and toxicity of metals in sediments and soils. A seven-step sequential extraction technique was used to determine the potential mobility of selected heavy metals (Fe, Mn, Zn, Cu, Pb, Cd and Ni) in the sediments of Lake Naivasha. Results indicate that residual fraction was the most important phase for the elements Fe, Mn, Cu and Zn. However, Pb and Cd are highly enriched in the non-residual phases. Nickel on the other hand was distributed evenly between the non-residual and the residual fractions.

The total concentrations of the heavy metals suggested a decreasing order of iron ?> manganese ? zinc > nickel > copper ? lead > cadmium. However, the detailed sequential extraction data indicated an order of release or mobility of cadmium > lead ? nickel ? zinc > manganese > copper > iron. The high percentage of Cd and Pb in the mobile fractions suggests high bioavailability of these two elements in the study area and maybe a pointer to anthropogenic input of the two elements in the study area.  相似文献   

20.
Antarctic fish, such as the Trematomus bernacchii, living at −1.9°C maintain a serum osmolality of around 600 mOsm kg−1, nearly twice that of temperate fish. Upon warm acclimation, Antarctic fish significantly lower their serum osmolality. It has been suggested that this response to warm acclimation is due to stress. The purpose of this study was to determine, whether upon warm acclimation there was a change in the levels of the stress hormone cortisol and hematocrit associated with the decrease in serum osmolality. T. bernacchii were warm acclimated up to 4 weeks and serum osmolality, cortisol and hematocrit were measured. Upon warm acclimation to +1.6 and +3.8°C over the course of 4 weeks, T. bernacchii significantly lowered their serum osmolality (from 547 ± 4 mOsm kg−1 to 494 ± 6 and 489 ± 4 mOsm kg−1, respectively), yet did not alter their serum cortisol (29 ± 6 nl ml−1) or hematocrit (22 ± 1%) levels. These results suggest that warm acclimation does not induce a stress response in T. bernacchii.  相似文献   

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