No description available.

No description available.

Thesis (M.Sc.) -- University of Limpopo, 2005 / Six aerobic bacterial strains [GM 10(1), GM 10 (2), GM 14, GM 15, GM 16 and GM 17] were isolated from an antimony mine in South Africa. Heavy-metal resistance and biosorptive capacities of the isolates were studied. Three of the isolates (GM 15, GM 16 and GM 17) showed different degrees of resistance to antimony and arsenic oxyanions in TYG media. The most resistant isolate GM 16 showed 90 % resistance, followed by GM 17 showing 60 % resistance and GM 15 was least resistant showing 58 % resistance to 80 mM arsenate (AsO4 3-). GM 15 also showed 90 % resistance whereas isolates GM 16 and GM 17 showed 80 % and 45 % resistance respectively to 20 mM antimonate (SbO4 3-). Arsenite (AsO2 -) was the most toxic oxyanion to all the isolates. Media composition influenced the degrees of resistance of the isolates to some divalent metal ions (Zn2+, Ni2+, Co2+, Cu2+ and Cd2+). Higher resistances were found in MH than in TYG media. All the isolates could tolerate up to 5 mM of the divalent metal ions in MH media, but in TYG media, they could only survive at concentrations below 1 mM. Also, from the toxicity studies, high MICs were observed in MH media than TRIS-buffered mineral salt media. Zn2+ was the most tolerated metal by all the isolates while Co2+ was toxic to the isolates. The biosorptive capacities of the isolates were studied in MH medium containing different concentrations of the metal ions, and the residual metal ions were determined using atomic absorption spectroscopy. GM 16 was effective in the removal of Cu2+ and Cd2+ from the contaminated medium. It was capable of removing 65 % of Cu2+ and 48 % of Cd2+ when the initial concentrations were 100 mg/l, whereas GM 15 was found to be effective in the biosorption of Ni2+ from the aqueous solutions. It was capable of removing 44 % of Ni2+ when the initial concentration was 50 mg/l. GM 17 could only remove 20 % of Cu2+ or Cd2+. These observations indicated that GM 16 could be used for bioremediation of xvi Cu2+ and Cd2+ ions from Cu2+ and Cd2+-contaminated aqueous environment, whereas GM 15 could be used for bioremediation of Ni2+. / National Research Foundation and the University of the North Research Unit

Graduation date: 1993 / Figures in original are black and white photocopies. Best scan available.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Acid rmne drainage (AMD) is a major pollution problem througbout the world, adversely affecting both surface and groundwaters. AMD is principally associated with the mining of sulphide ores. The most commonly associated minerals being sulphur, copper, zinc, silver, gold, lead and uranium. As conventional methods for removing heavy metals from wastewater are often prohibitively expensive, the implementation of biological processes for the removal of heavy metals has become a realistic practice. The objectives of this project was firstly to establish the effect of copper, lead and nickel, heavy metals commonly found in AMD waters, on the enzyme carbonic anhydrase, which is an integral part of the carbon concentrating mechanism (CCM) and secondly, to determine the feasibility of using the alkalinity generated by Spindina for the precipitation of heavy metals from solution. Initially, batch flask experiments were performed and it was found that the algae were able to utilise the bicarbonate supplied in the medium, under CO, limiting conditions, through the induction of their CCM, resulting in the generation of carbonate. The effect of the inhibitors, acetazolamide (AZ) and ethoxyzolamide (EZ), were also investigated in order to determine the importance of carbonic anhydrase (CA) in inorganic carbon accumulation and photosynthesis. Results obtained were consistent with those observed in literature and it was found that at IOOf.LM AZ and EZ, complete inhibition of photosynthesis and carbonic anhydrase occurred, with no oxygen being evolved. The results obtained from the inhibitor experiments substantiate the findings that carbonic anhydrase is an important part of the CCM, and that the dehydration of bicarbonate to carbon dioxide and hydroxide ions, is in fact an enzymatic process regulated by the enzyme carbonic anhydrase and is essential for efficient photosynthesis. The effect of heavy metals on Spirulina was also investigated. Lead, copper and nickel were all found to cause a reduction in the synthesis of chlorophyll a, which resulted in a decrease in photosynthetic efficiency and eventually death of the culture. The morphology of the algae was also severely affected by heavy metals, with degradation and aJmost complete disintegration of the algal filaments occurring. Using the Wilbur-Anderson assay method, carbonic anhydrase activity was found to be lower in the experimental flasks containing heavy metals, than the control flasks, reducing the algae's ability to utilise the bicarbonate in solution for effective photosynthesis. The Wilbur-Anderson assay method did not prove to be a reliable method for measuring changes in enzyme activity as results were found to be erratic. Therefore attempts were made to use an oxygen electrode as an alternative method for determining the effects of various parameters on enzyme activity and photosynthesis, this proved to be more successful. Because of the toxic effects of heavy metals on Spirulina it was decided that the use of the biogenic alkalinity generated by the algae for the precipitation of heavy metals may be successfully employed as an alternative method for bioremediation and metal recovery. Carbonate reacts readily with metals, therefore the carbonate produced by this algal system was used for the precipitation of metals. It was possible to categorise the precipitation reactions observed into three groups, namely those metals which, a) precipitate as hydroxides, b) precipitate as carbonates generated from the dissociation of bicarbonate and c) metals which can only precipitate if there is free carbonate present in solution.

D.Phil. / The main objective of this study was to describe the population genetic structure of African Whitebacked Vultures (Pseudogyps africanus) and to compare values to those previously documented for the Cape Griffon Vulture (Gyps coprotheres). The percentage of polymorphic .loci (P = 34.15%, 0.99 criterion) and average heterozygosity (17 = 0.108, ±0.032) calculated for P. africanus, confirm low levels of genetic -variation as reported for G. coprotheres. Blood samples' obtained from Lappetfaced (Torgos, tracheliotos) and Egyptian (Neophron percnopterus) Vultures enabled an evaluation of the genetic differentiation among the four southern African vulture species from allele frequency data assessed at 19 presumptive gene loci. Six (31.58%) of the 19 shared loci were polymorphic. Values of 1.26 (10.1), 26.32% and 0.076 (±0.047) for P.'africanus, 1.21 (±0.1), 21.05% and 0.097 (±0.045) for T. tracheliotos, 1.11 (±0.7), 21.05%. and 0.053 .(±0.053) for N: percnopterus and 1.05 (±0.5), 5.26% and 0.044 (±0.047) for G. coprotheres were obtained for the mean number of alleles per locus, P and Ti respectively. An average between-population fixigion index (FsT) value of 0.322 was obtained, which is indicative of significant (P < 0.01) differentiation between the four accipitrid species studied. Reference values for some haematological and plasma chemical parameters were established in 33 apparently normal, free-living, African Whitebacked Vulture nestlings. This .information can be. used in future ornithological research. A total of 27 variables . were examined, which include: leucocyte and erythrocyte counts, haemoglobin concentration, .haematocrit, haematimetric indices, glucose, creatinine, urea, total prOtein, albumin, globulin, albumin/globulin ratio, cholesterol, total lipids, triglycerides, aspartate aminotransferase, cholinesterase, lactate dehydrogenase, alkaline phosphatase, calcium, phosphorus, chloride, potassium, sodium and osmolarity. Only five parameters exhibited statistically significant (p < 0.05) differences between the two populations assayed. The Sandveld population showed elevated mean corpuscular haemoglobin concentration and alkaline phosphatase levels relative to the Dronfield population, whereas, the latter group displayed higher erythrocyte counts and potassium and sodium values than birds from the Sandveld community. Gaschromatography was used to establish the presence of quantifiable . residues .of 14 persistent chlorinated hydrocarbon pollutants in whole blood, clotted blood, heart, kidney, liver, bone, fat and muscle samples obtained from individual African Whitebacked, Cape. Griffon and Lappetfaced Vultures from different localities in South Africa. Concentrations of seven essential elements (Ca, Co, Cr, Cu, Fe, Mn and Zn) and four toxic metals (Al, Ni, Pb and Sr) were, furthermore, measured. The levels of pollutants measured in whole blood samples of live specimens were compared between nestlings from two natural breeding colonies, adults from a wildlife area and birds held in captivity. Statistically significant differences between populations were detected in geometric means calculated for y-BHC, a-chlordane and a-endosulfan. Five of the organochlorine contaminants displayed significant variations between concentrations detected in the clotted blood, organs and muscles excised from vulture carcasses. This includes residues ofy-BHC, a-chlordane, dieldrin, ,8-endosulfan and heptachlor epoxide. Values of the respective organochlorines obtained in vulture samples were generally low in comparison to results documented for a number of avian species. Levels of the , majority of metals analysed differed significantly- between two or more of the sampling localities, between adults and nestlings, and between captive and wild individuals. Metals which did not occur in such distinctly defining concentrations were Sr, Cu and Fe. Birds from Moholoholo maintained the highest overall blood metal burden, while nestlings from Dronfield were the least contaminated Significant differences were present between two or more tissues types for all the metals. The predominant sites for metal accumulation in vultures were the fatty tissues and bones. Most of the levels of metals measured in vultures compared well with concentrations reported for other avian species, and were generally within the range documented for species devoid of deleterious symptoms induced from heavy metal poisoning. However; certain individuals exhibited potentially toxic concentrations of specific metals such as Cu, Fe, Ni, and Pb. Continual monitoring of breeding colonies is recommended. The suitability of African Whitebacked Vulture nestlings as basic bioindicatori is highly advocated. The genetic data from this study can be used to compare levels of genetic diversity remaining in captive and wild vulture populations. An assessment of the amount and pattern of genetic variation of current populations of vulture species is an essential step towards ensuring the longterm survival of these birds. The phylogenetic conclusions found in. this study through allozyme electrophoresis correspond to results obtained from nucleotide sequence studies of the mitochondrial cytochrome b. gene. This points to an extent of positive corroboration between the two techniques. The haematological profile established for African Whitebacked Vulture nestlings constitutes a set of reference values that was previously unavailable for southern African vulture species. This data can assist in diagnosing and monitoring pathological and clinical' incidents detected in vultures. Values for a number of organochlo?ine pesticides and heavy metals, which have not been analysed in vulture species in the past, are documented. These values can serve as guidelines for future research, as well as control values for monitoring the occurrence and distribution of these contaminants within the habitats of vulture species. This study, therefore, presents information for research fields directly related to the survival of vulture populations. These factors must be included in future vulture management and reintroduction programmes as they will serve to enhance the success of conservation attempts.

Heavy metal pollution in water and soil is a serious concern to human health and the associated environment. Some heavy metals have bio-importance but the bio-toxic effects of many of them in human health are of great concern. Hence, there was a need for proper understanding of the concentration levels of these heavy metals in ground water and soil around the community residing in the vicinity of the defunct mine. Mining has become prominent in this area because of the existence of copper lodes, veins and veinlets. It was therefore necessary to assess these selected metals associated with copper mining as their concentration has a tendency to affect the environment and human health. The objective of this study was to establish the levels of lead (Pb)-zinc (Zn)-copper (Cu)-arsenic (As)-nickel (Ni) metals in ground water and soil associated with an old copper mine in the vicinity of the township and to compare them with the South African and international standards in order to safeguard the health of the community using such water for drinking purpose. Clean sampling plastic bottles were used to collect water from five water boreholes being used at present. Water samples were filtered using membrane filtration set LCW (0.45 μm). The samples were digested sequentially with different procedures for the total metal concentration. Concentrations of four metals commonly associated with Cu mining were examined at five different water boreholes which are used for drinking and industrial purposes. Flame Atomic Absorption Spectrophotometer (Perkin Elmar S/n 000003F6067A, Singapore) was used to analyze metals in water samples at Eskom Ga-Nala Laboratory: pH, electrical conductivity and turbidity were analyzed using an auto titrator meter (AT- 500,Japan), conductivity meter (Cole-parmer® YO-19601-00) and turbidity meter (AL 250TIR, Agua lytic, German) respectively. Soil samples were collected from the selected areas where human health is of a serious concern, and a hand held auger drill was used to recover samples, while shovels were used to prepare the sampling area. The samples were sieved up to 63.0 μm particle size and digested with aqua-regia. Flame Atomic Absorption Spectrophotometer (Model: AA400; Year: 2008; Manufacturer: Perkin Elmer; Germany; Serial no: 201S6101210) was used at the University of Venda Laboratory to analyze soil from the study area for possible heavy metal contamination due to the defunct Cu mine in the area. v The results showed variation of the investigated parameters in water samples as follows: pH, 6.0 to 7.51; EC, 70.0 to 96.40 μS/cm and turbidity, 1.05 to 4.56 NTU. The mean concentration of the metals increased in the followed order: Pb<Cu<As<Ni. Ni is the most abundant in the ground water determined with value of (6.49 μg/g). The observations have confirmed that most ground water contains an appreciable quantity of Ni. The mean value of As in water is (4.20 to 4.84 μg/g), Pb and Cu have (2.13 to 2.58 μg/g) and (1.52 to 2.52 μg/g) respectively. For soil samples, the mean concentration of the metals increased in the following order: Pb<Cu<Zn<As<Ni. Pb ranged from (0.023 to 0.036 μg/g) followed by Cu (0.28 to 0.45 μg/g) then Zn (0.026 to 0.053 μg/g), the mean range of As in soil ranged from (0.054 to 0.086 μg/g). However, some studies show much higher contamination of As from the natural sources and Ni with (0.057 to 0.144 μg/g) lastly. Accumulation of heavy metals in soil is of concern due to their toxic effects on human and animals. The quality of ground water from the five boreholes studied was satisfactory with turbidity (T), electrical conductivity (EC) and heavy metals (HM’s) below the WHO limit. The water therefore may, according to the WHO Standards be safely used as a drinking water. The concern lies on pH which was slightly (0.5) below the standard. There is a serious need to monitor the ground water which is now used for drinking purposes. This study revealed that heavy metal pollution in soil from the abandoned Cu mine in Musina is a threat to the health of the community. Although pollution was between medium and low in the contamination index, it is therefore important for the Musina Municipality or mine owner of Musina (TVL) Development Co Ltd copper mine to advocate possible remedial actions which will safeguard the environment and human health. The tailing at Musina’s old Cu mine have high pH and they lack normal soil stabilization processes, as a result the tailing does not develop a good plant cover. Pollution of the ground water resources is also evident in the study area where there is seepage or ingress of polluted water to the underground aquifers. Small-scale mining in Musina is causing further degradation to the environment but it supports the South African Waste Hierarchy by promoting the reuse and recycling of the tailing and mine dumps for the production of bricks. Mine workers are exposed to the above mentioned toxic heavy metals daily. Medicine will not help stop the poisoning. The only way to stop the metal poisoning is to stop being exposed to the heavy metals. / Environmental Sciences / M. Sc. (Environmental Management)

Splenic and lymph node lymphocytes from Balb/C mice were activated in vitro by the heavy metal cations, Zn⁺⁺ and Hg⁺⁺, as noted by the several-fold increases in ³H-thymidine incorporation at 144 hours of culture. Optimal mitogenic concentrations of Zn⁺⁺ and Hg⁺⁺ were 200 μM and 10 μM, respectively. Data from experiments in which three different methods were used to enrich for either T or B splenic lymphocytes, i.e. cell passage over nylon wool columns, use of athymic Nu/Nu mouse spleen cells, or cell lysis with monoclonal anti-Thy-1 antibody plus complement, suggested that Zn⁺⁺ and Hg⁺⁺ were mitogens for T cells. Removal of macrophages from spleen cells by treatment with carbonyl iron followed by cell passage through nylon wool eliminated the lymphocyte responses to Zn⁺⁺ and to Hg⁺⁺. Moreover, addition of these macrophage-depleted lymphocytes to monolayers of resident peritoneal macrophages restored the lymphocyte responses to these mitogens. Both Zn⁺⁺ and Hg⁺⁺ activated splenic lymphocytes to display lectin-dependent cytotoxicity and to produce gamma interferon. Furthermore, Zn⁺⁺ induced low levels of natural killer activity in spleen cells. In contrast to spleen and lymph node cells, thymocytes and bone marrow lymphocytes did not respond to either cation under standard culture conditions. However, when cultured in the presence of E. coli-derived lipopolysaccharide (LPS) and 2-mercaptoethanol for 144 hours, thymocytes were activated by Zn⁺⁺ (200 μM) but not by Hg⁺⁺. Quantities of LPS as low as 1.0 ng/ml satisfied this culture requirement. Purified interleukin 1 could not replace the helping activity mediated by LPS. Thymocyte subpopulation studies showed that Zn⁺⁺ activated enriched peanut lectin receptor-negative mature thymocytes, but LPS was required for the response. Spleen cells from mice, intraperitoneally injected with ZnCl₂ for 7 to 14 days, were not activated in vivo as assessed by ³H-thymidine incorporation in vitro, nor did they display enhanced responses to T-cell or B-cell mitogens. However, zinc administration had negative effects by decreasing spleen cell numbers by 31% and thymic weight by 59%. A theoretical model is presented in which Zn⁺⁺ and Hg⁺⁺ may mediate their stimulating effects in vitro by altering histocompatibility "self" structures on the surface of lymphocytes and macrophages via interactions with sulfhydryl groups on these structures to which T lymphocytes with receptors for "altered self" structures respond with proliferation or cytotoxicity.

by Wong Pik-kwan. / Thesis submitted in: September 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 116-139). / Abstract also in Chinese. / ABSTRACT --- p.i / ACKNOWLEDGEMENT --- p.iii / TABLE OF CONTENTS --- p.iv / LIST OF TABLES --- p.viii / LIST OF FIGURES --- p.ix / Chapter CHAPTER ONE --- GENERAL INTRODUCTION --- p.1 / Chapter CHAPTER TWO --- LITERATURE REVIEW / Chapter 2.1 --- Introduction --- p.4 / Chapter 2.2 --- Heavy metals --- p.6 / Chapter 2.3 --- Mechanisms of metal toxicity --- p.9 / Chapter 2.4 --- Toxic effects of metals on marine organisms --- p.10 / Chapter 2.4.1 --- Cadmium --- p.10 / Chapter 2.4.2 --- Chromium --- p.10 / Chapter 2.4.3 --- Copper --- p.11 / Chapter 2.4.4 --- Lead --- p.12 / Chapter 2.4.5 --- Nickel --- p.12 / Chapter 2.4.6 --- Zinc --- p.13 / Chapter 2.5 --- Metal uptake and elimination in marine organisms --- p.14 / Chapter 2.5.1 --- Uptake of metals --- p.14 / Chapter 2.5.2 --- Elimination of metals --- p.15 / Chapter 2.5.3 --- Metal detoxification system in fish --- p.16 / Chapter 2.6 --- Heavy metals in marine fish --- p.17 / Chapter 2.7 --- Bioaccumulation --- p.20 / Chapter 2.7.1 --- Models of metal accumulation --- p.21 / Chapter 2.7.2 --- Compartment model --- p.21 / Chapter 2.7.3 --- Physiologically based pharmacokinetic (PB-PK) model --- p.22 / Chapter 2.8 --- The influence of environmental factors on bioaccumulation of metals --- p.23 / Chapter 2.8.1 --- Temperature --- p.23 / Chapter 2.8.2 --- Salinity --- p.23 / Chapter 2.8.3 --- Organic matter --- p.24 / Chapter 2.8.4 --- pH --- p.25 / Chapter 2.8.5 --- Chelators and surfactants --- p.25 / Chapter 2.8.6 --- Other metals --- p.26 / Chapter 2.9 --- Biological effects of heavy metals on man --- p.26 / Chapter 2.10 --- The use of biological indicator organisms for metal pollution --- p.28 / Chapter CHAPTER THREE --- HEAVY METAL CONCENTRATIONS IN CULTURED MARINE FISH IN HONG KONG / Chapter 3.1 --- Introduction --- p.31 / Chapter 3.2 --- Materials and methods --- p.36 / Chapter 3.2.1 --- Sampling --- p.36 / Chapter 3.2.2 --- Water analysis --- p.36 / Chapter 3.2.3 --- Sediment analysis --- p.39 / Chapter 3.2.4 --- Mussel analysis --- p.40 / Chapter 3.2.5 --- Fish analysis --- p.40 / Chapter 3.2.6 --- Quality control and statistical analysis --- p.41 / Chapter 3.3 --- Results --- p.42 / Chapter 3.3.1 --- Seawater --- p.42 / Chapter 3.3.2 --- Sediment --- p.46 / Chapter 3.3.3 --- Mussel --- p.46 / Chapter 3.3.4 --- Fish --- p.50 / Chapter 3.4 --- Conclusion --- p.67 / Chapter 3.4.1 --- "Metal concentration in seawater, sediment, green mussel and fish" --- p.67 / Chapter 3.4.2 --- Accumulation of heavy metals in different tissues of cultured fish --- p.69 / Chapter 3.4.3 --- Relationship between the body weight and metal accumulation --- p.71 / Chapter 3.4.4 --- Heavy metal pollution in fish culture sites --- p.72 / Chapter 3.4.5 --- Selection of fish culture site --- p.72 / Chapter CHAPTER FOUR --- ACUTE AND SHORT-TERM EFFECTS OF COPPER(II) IONS ON SPARUS SARBA / Chapter 4.1 --- Introduction --- p.76 / Chapter 4.2 --- Materials and methods --- p.79 / Chapter 4.2.1 --- Experimental animals --- p.79 / Chapter 4.2.2 --- Determination of the 96 hour median lethal concentrations --- p.19 / Chapter 4.2.3 --- Determination of growth rate --- p.80 / Chapter 4.3 --- Results --- p.82 / Chapter 4.3.1 --- Determination of the 96 hour median lethal concentrations --- p.82 / Chapter 4.3.2 --- Determination of growth rate --- p.82 / Chapter 4.3.3 --- Distribution of Cu concentration in whole body and different tissues of S. sarba --- p.82 / Chapter 4.4 --- Conclusion --- p.91 / Chapter 4.4.1 --- Determination of the 96 hour median lethal concentrations --- p.91 / Chapter 4.4.2 --- Determination of growth rate --- p.93 / Chapter 4.4.3 --- Distribution of Cu concentration in whole body and different tissues of S. sarba --- p.94 / Chapter CHAPTER FIVE --- ACCUMULATION AND ELIMINATION OF COPPER(II) IONS TO SPARUS SARBA / Chapter 5.1 --- Introduction --- p.96 / Chapter 5.2 --- Materials and methods --- p.98 / Chapter 5.2.1 --- Experimental animals --- p.98 / Chapter 5.2.2 --- Uptake and elimination of Cu ion in S. sarba during continuous exposure to waterborne Cu --- p.98 / Chapter 5.3 --- Results --- p.100 / Chapter 5.4 --- Conclusion --- p.108 / Chapter CHAPTER SIX --- GENERAL CONCLUSION --- p.112 / CHAPTER SEVEN REFERENCES --- p.116