Heavy metals inUlva lactuca collected within Tolo Harbour,an almost landlocked sea

Summary The sea lettuce (Ulva lactuca), a littoral and sublittoral marine macroalga grows abundantly around shorewaters of Hong Kong, especially Tolo Harbour whereU.lactuca is collected from the mudflat for local human consumption as well as for export. Samples ofU.lactuca, together with the ambient seawater and sediment, were collected from several localities around Tolo Harbour, an almost land-locked sea, receiving polluted water from several major streams. For comparison samples were also collected from areas near the unpolluted south coast of Hong Kong Island. It was demonstrated that the samples of seawater and sediment collected within Tolo Harbour were polluted from domestic, agricultural and industrial sources. The extent of the metal (copper, lead, zinc and iron) contamination was further reflected and amplified in the tissue ofU.lactuca.     

CEHIXM Extraction of Pb,Cd, Zn,and Mn from High Permeable Soils

A new method CEHIXM for extracting hea vy metals from high permeable soils under coupled electric-hydraulic gradient was investigated. Spent foundry sand, containing high levels of Pb, Cd, Zn, and Mn, was used as the contaminated source. A suitable ion-exchange resin was used for trapping and recovering the metals from the aqueous medium. Control experiments were conducted using hydraulic gradient alone to assess the leachability of the contaminants. The experiments were repeated with 50?V across the soil sample and without hydraulic gradient to evaluate ion migration under electric gradient. A number of CEHIXM experiments involving both hydraulic and electric gradients were conducted at a constant DC voltage of 50?V and a constant flow velocity of 0.0178?cm/ sec. With hydraulic gradient only, 3 to 8% metals were extracted, whereas with electric gradient only the metal removal rate was 0 to 0.7%. When the electric and hydraulic gradients were coupled, as much as 93% of Pb, 97% of Cd, 98% of Zn, and 94% of Mn were extracted, after 100?h of the processing.     

Seasonal Variability in the Levels of Fe, Zn, Cu, Mn, and Cd in the Hepatopancreas of the Japanese Scallop Mizuhopecten yessoensis

The relationships between concentrations (g/g of tissue) and content (g/organ) of the metals Fe, Zn, Cu, Mn, and Cd with seasonal changes in the weight of the hepatopancreas in the Japanese scallop Mizuhopecten yessoensis are studied. It is shown that, during a year, the weight of the hepatopancreas in the mollusk shows significant (more than twofold) changes. A positive correlation is revealed between the seasonal changes in the concentrations of the physiologically important metals Fe, Zn, Cu, and Mn and the weight of this organ, although no general consistent pattern of seasonal variability in the metal concentrations is found. For toxic Cd, a negative correlation is found between its concentration and the weight of the hepatopancreas.     

Interactions of Cd with Zn, Cu, Mn and Fe for lettuce (Lactuca sativa L.) in hydroponic culture

Abstract. The effect and accumulation of cadmium (Cd) in lettuce grown by means of the hydroponic technique was investigated by multivariate analysis, and was found to be affected by the concentration of other trace elements. Particularly iron acted in a strongly antagonistic way against Cd. Consequently, no absolute toxicity limits for Cd can be drawn without considering other trace elements.     

Metals (Fe, Mn, Zn) in the root plaque of submerged aquatic plants collected in situ: Relations with metal concentrations in the adjacent sediments and in the root tissue

We have investigated the extent of iron oxyhydroxide deposition on the roots of two common freshwater species, Vallisneria americana Michx. and Heteranthera dubia (Jacq.) MacM., collected from different sites in the St. Lawrence River, Québec, Canada, and have related metal concentrations in the root plaques both to the geochemical conditions prevailing in the host sediments (pH; metal partitioning) and to the metal concentrations within the plant root tissue. Possible effects of root plaque on sediment geochemistry are also discussed.At those sites where the two submerged plants co-existed, the amounts of Fe deposited on their respective root surfaces were positively correlated, indicating that sediment geochemistry (pH; concentration of labile metal) exerted a more important influence on plaque formation than did inter-species differences (root physiology, morphology). Iron and Mn concentrations in the root plaque were positively correlated with each other, and with the readily extractable fractions (F1, 172) of these metals in the adjacent sediments. In contrast, Zn concentrations in the root plaque of V. americana were not related to Zn concentrations in the sediments — the dominant geochemical process at the root surface is Fe deposition, such that the quantities of Zn deposited on the roots are determined not by Zn geochemistry per se but rather by the amount of Fe deposition. Indeed the Zn/Fe ratios in the root plaque were related to the Zn/Fe ratios in the surrounding sediments (NH₂OHHCl extract).On a concentration basis (g/g), more Fe, Mn and Zn was found outside the root, in the iron plaque, than inside the root tissues. For all 3 metals, significant relationships were observed between the metal concentrations in the plaque and those inside the roots. For Zn, however, the best statistical relationship was not with [Zn]_plaque, but rather with the [Zn]/[Fe] ratio in the plaque. It is hypothesized that the Zn/Fe ratio in the root plaque reflects the free Zn²⁺ concentration adjacent to the root surface, and that this in turn affects Zn uptake by the plant root. For a given value of Zn in the sediments or in the root plaque, the Zn content of the root is inversely related to the concentration of Fe oxyhydroxides, implying that Fe plays a protective role in regulating Zn bioavailability.     

Der Einfluss einiger Schwermetallsalze (Zn,Cd, Mn,Fe) auf die chemische Zusammensetzung von Aspergillus niger

Ohne ZusammenfassungMit 4 Textabbildungen.Dissertation der Mathematisch-Naturwissenschaftlichen Fakultät der Friedrich-Wilhelms-Universität zu Berlin.     

A preliminary survey of organic pollution of shellfish in Tolo Harbour,Hong Kong

A preliminary survey on the contamination of clams and sea-waters in various towns in Tolo Harbour was carried out using bacteriological tests. The ‘percentage clean’ method and the ‘most probably number’ method were employed. The pH, salinity and temperature of the seawater were also tested in the field. It was discovered that the number of coliform bacteria obtained by the ‘percentage clean’ was zero in both seawater and clams from all sites including the control. The ‘most probable number’ indicated that the water and the clam tissue collected in the three sites in Tolo Harbour ranged from 15–1,100/100 ml in the water and 825–11,000/g in the clams compared with 0/100 ml and 115/g of the control site. Due to the high level of organic pollution in Tolo Harbour, improvement of the sanitary situation is urged. Cultivation of clams collected in this area in clean and sterilized water for a few days before consumption is recommended.     

Phytoremediation of Cd, Cr, Cu, Mn, Fe, Ni, Pb and Zn from aqueous solution using Phragmites cummunis, Typha angustifolia and Cyperus esculentus

A comparative bioaccumulation pattern and ultra structural changes were studied in Phragmites cummunis, Typha angustifolia and Cyperus esculentus in mixed metals solution of cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn). P. cummunis was observed to be a shoot accumulator for Cr, Fe, Mn, Ni, Pb, and Zn. However, T. angustifolia was found to be a root accumulator for Cd, Cr, Cu, Fe, Ni and Pb. In addition, C. esculentus also accumulated most of the tested heavy metals in the roots, while Mn and Fe were translocated up to leaves. Further, the long term metal treatment showed maximum accumulation of all heavy metals in P. cummunis followed by T. angustifolia and C. esculentus. Among heavy metals, Fe was accumulated maximum, i.e., >1000 microg g(-1) by all three plants. Simultaneously, the adverse effects on biochemical parameters were noted earlier in C. esculentus than T. angustifolia and P. cummunis. Ultra structural observation showed the cellular changes in wetland plants after longer exposure. Results revealed that P. cummunis and T. angustifolia had more potential for tested metals than C. esculentus. This study established that these wetland plants could be used for heavy metals phytoremediation from metal containing industrial wastewater.     

Concentrations of Cd, Co, Cu, Fe, Mn, Rb, V, and Zn in formalin-fixed brain tissue in amyotrophic lateral sclerosis and parkinsonism-dementia complex of guam determined by high-resolution ICP-MS

Amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC) are neurodegenerative disorders that occurred with extremely high frequency among the native population on Guam, especially in the 1950s and 1960s, but have substantially declined over the last half-century. The etiology of these diseases is unknown, but the most plausible hypothesis centers on imbalances in essential and toxic metals. We have determined the concentrations of Cd, Co, Cu, Fe, Mn, Rb, V, and Zn in formalin-fixed brain tissue collected during the period 1979–1983 from eight Guamanian patients with ALS, four with PDC, and five control subjects using high-resolution inductively coupled plasma-mass spectrometry. The concentrations of Cd are markedly and significantly elevated both in gray and white matter in ALS, but not in PDC patients. The concentrations of Zn are elevated for both patient groups, in both gray and white matter, but only the difference in gray matter for PDC is significant. For the other metals, no significant differences are found.     

Seasonal variations of metal contents (Cd, Cu, Fe, Mn and Zn) in seaweed Ulva lactuca from the coast of El Jadida city (Morocco)

The quality of El Jadida Atlantic coastal water was monitored from April 1998 to March 1999 by measuring hydrological parameters (dissolved oxygen, suspended particulate matter, phosphates and nitrites) and using the seaweed Ulva lactuca as a quantitative bio-indicator of cadmium, copper, iron, manganese and zinc contamination. Metal content in seaweeds, collected every month from four stations characterized by the discharge of urban and industrial waste water, showed significant variations depending on the station and sampling period. However, the seaweed of El Jadida exhibited generally lower contents compared to those of similar species from other geographical areas.     

Distribution patterns of Cd,Cu, Mn,Pb and Zn in wood fly ash emitted from domestic boilers

Abstract

Wood fuels being a renewable source of primary energy have been considered environmentally friendly. However, wood combustion in domestic boilers is a source of air pollution. The lack of a dust collection device is the reason why flue gases emit a significant load of particulate pollutants into the air, including heavy metals. The aim of this research was to assess the environmental hazard caused by both emissions of heavy metals during wood combustion in domestic boilers and their chemical forms present in fly ash.

From the various wood fuels burnt in domestic boilers, the fly ash selected for this study came from the combustion of briquettes of softwood from non-polluted areas, and from burning hardwood fuel from trees exposed to pollutants from heavy traffic. The wood fuels satisfy the quality demands determined in the EN 14961 Solid Biofuels - Fuel quality assurances. However, the concentrations of Cd, Cu, Pb and Zn in the fly ash are considerably higher than the appropriate limit values determined for soil improvers. Sequential extraction shows that Cd and Zn are associated mainly with the water leaching and carbonate fractions, regarded as mobile and bioavailable, and pose the potentially greatest hazard to the environment and human health. Cu, Mn and Pb associated with less mobile fractions may not pose a direct air quality hazard but, due to their high concentrations, medium-term and long-term effects on soils and surface and subsurface waters should be considered.     

Effect of rhizosphere pH on the availability and uptake of Fe,Mn and Zn

In pot experiments the relationships between rhizosphere pH, the extractable levels of Fe, Mn and Zn in the soil and their uptake into the roots and shoots of dwarf French beans have been studied. Variations in rhizosphere pH were induced by applying three different sources of nitrogencholine phosphate, ammonium phosphate and calcium nitrate-to an initially homogenised soil (preadjusted to either pH 7 or 8). The rhizosphere pH was found to be significantly lower following the application of either ammonium or choline phosphates and to be increased by calcium nitrate treatment.The Fe and Zn contents of both shoot and root were inversely proportional to rhizosphere pH. The Mn contents also increased with decreasing pH but a sharp increase was apparent below pH 5.5. The shoot Fe, Zn and Mn content were significantly correlated with the extractable levels determined in the rhizosphere and non-rhizosphere soil.This paper forms part of the Ph. D. thesis submitted by A.N.S. to the University of Wales in 1977.     

Effects of different proteins on the metabolism of Zn, Cu, Fe, and Mn in rats

Many factors are known to influence trace element metabolism and one of them is dietary protein. The present study examines the effects of casein, soybean protein, and peanut protein on the metabolism of the Zn, Cu, Fe, and Mn in growing rats. The results showed that Zn, Fe, and Mn excretions in the feces of peanut protein-fed rats (PPERs) were similar to that of casein-fed rats (CPFRs) (p>0.05), whereas all of the Zn, Cu, Fe, and Mn excretions in the urine of PPFRs were significantly higher than that of CPFRs (p<0.05), but its apparent absorption rate (AAR) of Cu, Fe and its apparent retention rate (ARR) of Cu were all higher than that of CPFRs (p<0.05). Hepatic Zn content of soybean protein-fed rats (SPFRs) was higher than that of CPFRs and PPFRs (p<0.05 respectively) and serum, renal, and femoral Cu contents of SPFRs were significantly lower; however, hepatic Cu, and renal Mn contents were significantly higher than that of CPFRs (p<0.05, respectively); The hepatic Fe content of SPFRs was significantly higher than that of CPFRs and PPFRs (p<0.01, respectively). To sum up, compared to casein, soybean protein might be a good dietary source to make up for Zn and Fe deficiency, and also peanut protein to make up for Cu and Fe deficiency.     

Study of phytoplankton characteristics in Tolo Harbour,Hong Kong,by HPLC analysis of chemotaxonomic pigments

Spatial and seasonal characteristics of phytoplankton in Tolo Harbour, Hong Kong, were studied by microscopic observation of phytoplankton samples and HPLC analysis of chemotaxonomic pigments. Diatoms dominated the phytoplankton. Common diatoms included Skeletonema costatum and species of Cerataulina, Leptocylindrus, Pseudo-nitzschia and Thalassiosira. Dinoflagellates occurred sporadically and mainly in the inner part of the harbour. The dinoflagellate Scrippsiella trochoidea was the causative organism for the red tide occurrences in March, April and September 2001. Significant positive correlations between fucoxanthin and diatoms and between peridinin and dinoflagellates suggested that fucoxanthin and peridinin were valuable chemotaxonomic markers for diatoms and dinoflagellates, respectively. Analysis of pigment ratios revealed that red tide events caused by dinoflagellates were marked by increase in the value of PERI:chl a and decrease in the value of FUCO:chl a. Increase in the value of FUCO:chl a also revealed the presence of a dense population of Pseudo-nitzschia that was not indicated by increase in chlorophyll a and fucoxanthin concentrations. Pigment analysis also revealed the presence of cyanobacteria, silicoflagellates, cryptophytes and green algae in the surface waters of Tolo Harbour.     

Structural study of few p-phenylenediacetate complexes of Mn, Cu, Zn and Cd

Different metal carboxylate complexes are prepared by reactions of manganese (+2) acetate, copper (+2) acetate, zinc (+2) acetate and cadmium (+2) acetate with p-phenylenediacetic acid under ambient condition with or without a nitrogen donor ligands and each of them are characterized by conventional spectroscopic techniques along with crystallography.     

A comparison of Zn, Mn, Cd, and Ca transport mechanisms in oat root tonoplast vesicles

Oat root tonoplast vesicles were used to determine if tonoplast transport of the divalent cations Zn and Mn occurs via an antiport mechanism, like that described for Ca and Cd. Also, inhibitors reported to affect Ca transport were tested for their effects on Cd versus Ca transport and tonoplast ATPase activity. The ability of Ca, Cd, Zn, and Mn to alter the proton gradient was monitored using both the fluorescent probe acridine orange and C-methylamine accumulation. After the proton gradient was established in MgATP-energized vesicles, addition of Ca, Cd, and Zn to the reaction restored the fluorescence of acridine orange, indicating dissipation of the proton gradient. Fluorescence recovery was linearly correlated with metal concentration and followed the order Ca>Cd≧Zn. Addition of Mn did not restore the fluorescence of acridine orange. All four ions released C-methylamine from MgATP-energized vesicles in an ion-concentration-dependent manner, and with relative initial rates in the order of Ca>Cd>Zn>Mn. The observed ion-concentration-dependent release of protons from sealed vesicles suggests that Zn and Mn, like Ca and Cd, can be antiported into the plant vacuole. In an effort to assess whether Ca and Cd use the same carrier, we tested the effects of verapamil, Do-Tea-Br, nifedipine, ruthenium red, and LaCl₂ on Ca versus Cd transport, and also on MgATPase activity. These compounds are shown to alter Ca transport in plants. Although some of the inhibitors had a negative effect on MgMAPase activity, the decrease in this activity did not account for the decrease in Ca or Cd transport observed in any case. Particularly verapamil had a much greater effect on Ca transport than Cd transport activity while not inhibiting ATPase substantially. Data presented provide evidence for Zn and Mn antiport activity in oat root tonoplast and show differences in responses of Ca and Cd antiport activities to several transport inhibitors.     

Metal (Fe, Zn, Mn and Cu) levels in the Antarctic fish Notothenia coriiceps

During the 1994/1995 Antarctic summer 20 Antarctic cod (Notothenia coriiceps) of both sexes were collected at King George Island, South Shetland Islands, Antarctica, to determine the levels of Fe, Zn, Mn and Cu in muscle, liver, gonad and kidney. Metal levels were assessed using the inductively coupled plasma-atomic emission spectrometry (ICP-AES) technique. The levels of Fe, Zn, Mn and Cu observed in both sexes of N. coriiceps were significantly lower in muscle tissue than in liver, kidney and gonad; the livers of males and gonads of females had the highest levels. The differences between the sexes were significant for Zn and Mn in gonads and for Cu in liver. Despite the modest size-range of the specimens, the Cu levels in liver, muscle and kidney were significantly inversely correlated with female mass (P < 0.05) as was gonad Cu level and male body length. Fe mainly presented the highest concentrations and Cu and Mn the lowest ones. Mean muscle metal levels are similar to those of hake, cod, herring and mackerel; however, the level of Fe was slightly higher. Accumulation may occur for Fe, Zn and Mn in liver, kidney and gonad, which have higher levels than those of most prey. Received: 21 October 1997 / Accepted: 1 February 1998     

New supramolecular complexes generated from Mn, Fe, Co, Zn, Fe with a bent dipyridyl ligand: Metal- and anion-directed assembly

Assemblies of an angular dipyridyl ligand 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo) with a series of metal perchlorate afford five new supramolecular complexes with the general formula of [M(4-bpo)₂(H₂O)₄] · (4-bpo)₂ · (anion) · (solvent), in which M = Mn^II for 1, Fe^II for 2, Co^II for 3, Zn^II for 4, and Fe^III for 5. Although similar molecular structures and compositions are found for these mononuclear complexes, they display two types of supramolecular lattices. Complexes 1, 4 and 5 similarly crystallize in space group P2/n or P2/c. The complex cations, free 4-bpo and lattice water are linked to generate 2D layered frameworks with the aid of hydrogen bonding, and the counter anions are located within and between (also methanol in 5) these 2D arrays. However, complexes 2 and 3 are isostructural in space group . Two types of alternate 2D layers consisting of complex cations and free 4-bpo components, respectively, are observed with the anions and lattice water locating between them. These motifs are interlinked by complicated hydrogen-bonding to form a 3D intercalated network. Moreover, when Co(NO₃)₂ is used instead of Co(ClO₄)₂ in the assembly of 3, a 1D polymeric chain complex {[Co(4-bpo)(H₂O)₂(NO₃)₂](H₂O)₃}_n (6) is generated. These results indicate that the choice of metal ion and anion exerts a significant influence on governing the target complexes. A comparison of the structural features for all metal perchlorate complexes with 4-bpo is also briefly discussed.     

Natural ingestion rates and grazing impact of the marine cladoceran Penilia avirostris Dana in Tolo Harbour, Hong Kong

The gut fluorescence method was used to study algal grazingby Penilia avirostris in a semiestuarine embayment. Grazingimpact estimated from ingestion rate and animal abundance revealedthat only {small tilde}1% of the algal biomass was grazed perday by the cladocerans.