Thesis submitted in fulfilment of the requirements for the MTech: Oceanography in the Faculty of Applied Sciences at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY, 2013 / The current status of metal pollution off the South African South coast is not well known. This study was the first to be undertaken in many years using Striostrea margaritacea as a subject species. The aims of the study were to determine the degree of metal contamination in the water, sediments, oyster tissues and oyster shells at sites selected in Witsand, Wilderness and Goukamma, as well as to establish if Striostrea margaritacea qualifies as a successful biomonitor when using lysosomal destabilization as a tool. Seasonal variations between sites were also considered. Other objectives, such as the potential of a Marine Protected Area (MPA) as a control site and the necessity of a monitoring program along the south coast were also included. Sites were sampled seasonally for one year at spring low tides. Ten oysters were collected from each individual site upon each visit. The Neutral Red Retention Time (NRRT) assay was used to determine lysosomal membrane integrity of oyster haemocytes, whereafter oysters were sacrificed for metal analyses. Metals that were analysed are aluminium (Al), copper (Cu), zinc (Zn) and iron (Fe). Metal analyses were done using an Inductively Coupled Plasma - Atomic Emission Spectrometer (ICP- AES). All statistical analyses were performed using ANOVA on Ranks to determine if there were significant differences between sites and between sampling occasions. Aluminium concentrations found in the water column at all sites were considered as low. Iron, zinc and copper concentrations within the water column can on the other hand be considered as high when comparisons are drawn with other studies and data sets. Sediment concentrations for all the metals within the present study were considered to be low when compared to other studies and guidelines. There were not many significant differences recorded between sites and no seasonal patterns were present. Within the tissues of the oysters, the metal ranges are considered to be low when compared to other studies. No definite conclusion about the contamination status of the oyster tissue could be drawn due to the lack of comparative literature. A field study in conjunction with a laboratory experiment should yield more reliable results. There were also no seasonal trends present and very few differences between sites. The bioaccumulation factors were considered as being low with a few exceptions where they were moderate when oyster tissue data was compared to water and sediment data. Concentrations for Al, Zn and Cu in the shells could be considered low when comparisons are drawn, with the exception of Fe that was found to be high. The bioaccumulation factors were considered to be low when oyster shell concentrations were compared to water and sediment data. There were also no seasonal trends present and a prolonged sampling period is suggested to further investigate these findings. When a comparison was drawn between the tissue and shell data a clear pattern was evident. Al and Fe concentrations were highest within the shell where as Zn and Cu concentrations were highest within the tissues of the animal. The theory of mineralization is supported by these findings where bivalves will use their shell as a reservoir for micronutrients and other substances. The NRRT assay revealed that lysosomal membrane destabilization had occurred and that the animals appeared to be stressed for the duration of the sampling period. Site 3, within the MPA, had the longest retention time. The retention times that were recorded were short when compared to other studies. This assay did however show potential as a basic monitoring tool from which more thorough investigations can be initiated. In conclusion, the study sites along the south coast of South Africa does not seem to be contaminated by Al, Zn, Cu or Fe when data is compared to international and local water quality guidelines, sediment quality guidelines and other studies. Also, as concentrations between sites did not differ greatly, it is inconclusive whether or not the MPA can be used as a reliable references site for in situ studies. More vigorous and lengthy studies should be undertaken to contribute to current knowledge of our indigenous species, Striostrea margaritacea and to aid in the development of better management of this resource as well as an ongoing monitoring programme.

Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2017. / Surface water is used as a source of water supply in many countries, including South Africa. One of the sources of surface water pollution is leachate and surface runoff from landfills. In agricultural soils, the landfill runoff and leachate deteriorate the quality and affect the fertility of soil. The entry of metals and microorganisms from landfill leachate to adjacent environments is through surface runoff due to rainfall. Adverse effects on human- and environmental health triggers a need to monitor and control contaminants in the environment. The aims of the study are to determine the effect of landfill runoff and leachate on agricultural soil and river water (Veldwachters River) running adjacent to the Devon Valley landfill site and to identify potential metal-tolerant organisms in environmental samples collected in Stellenbosch, Western Cape, South Africa. Samples (agricultural soil, river water and sediments) were collected once a month for a period of six months from the study area for analysis. Physicochemical parameters that are known to have major effects on environmental samples were assessed and the concentrations of various metals (Al, Pb, Cr, Mn, Mo, Co, Ni, Cu, Zn, Fe, Cd and V) were also determined by means of inductively coupled plasma mass spectrometry (ICP-MS). Soil texture analysis was tested in order to monitor the metal distribution in soils under the influence of environmental factors.

Orientador: Denis Moledo de Souza Abessa / Resumo: A Baía de Guanabara concentra aproximadamente 70% das indústrias do Estado do Rio de Janeiro. Os resíduos produzidos por essas fontes, somados à carga de esgoto doméstico, transformaram a região em umas das áreas mais poluídas da costa Brasileira. O presente estudo realizou a avaliação do risco ecológico dos metais em sedimentos da Baía de Guanabara, por meio de um método escalonado utilizando múltiplas linhas de evidência: caracterização do sedimento quanto à sedimentologia e concentração de metais, comparação das concentrações ambientais com guias de qualidade de sedimento, ensaios de toxicidade crônica utilizando os organismos Anomalocardia brasiliana e Nitocra sp., ensaios de toxicidade aguda utilizando os organismos Tiburonella viscana, Kalliapseudes schubartii, e Anomalocardia brasiliana. Para comprovar existência de relação causa e efeito entre os metais e a toxicidade, foram empregadas a técnica do TIE, análises multivariadas (PCA) e matrizes qualitativas. Os sedimentos mostraram níveis altos a moderados de metais (Zn, Pb, Cu, Cr) associados com a toxicidade. O TIE revelou que, além dos metais, amônia e compostos orgânicos são contaminantes presentes na região que tem a capacidade de causar toxicidade. Desse modo constatou-se que os metais constituem uma importante classe de contaminantes para a Baía de Guanabara, os quais, além de estarem presentes em altas concentrações, interagem com outros contaminantes e são também (co)responsáveis por efeitos biológicos negativos / Abstract: The Guanabara Bay (GB) comprises approximately 70% of the industries of Rio de Janeiro State. The wastes produced by these sources, combined with the domestic sewage loads, have transformed the region into one of the most polluted areas of the Brazilian coast. The present study evaluated the ecological risk of metals in sediments from the GB by the use of a tiered approach. The chosen method combines the following lines of evidence: geochemistry, comparison of environmental concentrations of metals with sediment quality guidelines, chronic sediment toxicity tests with Anomalocardia brasiliana and Nitocra sp.; and acute sediment toxicity tests with Tiburonella viscana, Kalliapseudes schubartii, and Anomalocardia brasiliana. To verify the existence of cause and effect relationships between metals and toxicity, the Toxicity Identification Evaluation (TIE) technique, multivariate analysis (PCA) and qualitative matrices were used. Sediments showed high to moderate levels of metals (Zn, Pb, Cu, Cr) associated with toxicity. In addition, the TIE has revealed that metals, ammonia and organic compounds contribute to cause sediment toxicity. We concluded that metals are an important class of contaminants for the GB, together with other chemicals, as they are present in high concentrations, interact with other substances and are (co)responsible for the negative biological effects / Mestre

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.

Contaminants may affect marine organisms through various pathways with impacts evident across a variety of spatial and temporal scales. Organisms may encounter short pulsed exposures which contaminate surface waters for hours to days, or more persistent but patchy contamination of benthic habitats throughout their entire life-cycle. This thesis examines the responses of epifauna associated with macroalgae to a pulsed exposure of contaminants (storm-water input) and to chronic contamination via metal accumulation within temperate algal beds. The effects of storm water were monitored during a two-year survey of Sydney Harbour which sampled epifauna before and after heavy rainfall. Epifaunal assemblages declined throughout the harbour following storm events but for the most part these declines were not attributable to storm-water runoff. However, transient (&lt 4 d) and localized impacts of storm water upon physico-chemical characteristics of recipient water and some epifaunal groups were identified around storm drains. A novel field dosing technique tested the relative importance of freshwater and associated metals as causative agents of behavioural avoidance and direct mortality responses. Strong avoidance of storm-water plumes was found which could be entirely explained by freshwater inundation, with no additional effects of metals. No direct mortality was observed following brief exposures. Contaminants introduced by storm water may accumulate within the tissues of macroalgae and potentially pose persistent threats to epifauna. Colonisation of epifauna was reduced on algae with enhanced copper levels, and the nesting behaviour, feeding and survival of an abundant amphipod were all negatively affected by copper load. Subsequent field surveys identified sufficient copper, lead and zinc contamination in Sydney Harbour algal beds to pose direct toxic threats to epifauna. The abundance of herbivorous amphipods correlated negatively with the copper content of a common algal species. However, differences in metal accumulation between algal species resulted in spatially variable levels of contamination. Small-scale patchiness of contaminants within these landscapes may allow populations of mobile species to persist if contaminated hosts are avoided. In summary, epifaunal assemblages appeared resilient to storm-water pulses. Recovery of affected groups was rapid and large fluctuations in abundance appear to be part of the natural flux of epifaunal communities. In contrast, assemblages responded strongly to algal-bound contaminants and this has emerged as an important pathway of contaminant exposure and impact within algal habitats.

Contaminants may affect marine organisms through various pathways with impacts evident across a variety of spatial and temporal scales. Organisms may encounter short pulsed exposures which contaminate surface waters for hours to days, or more persistent but patchy contamination of benthic habitats throughout their entire life-cycle. This thesis examines the responses of epifauna associated with macroalgae to a pulsed exposure of contaminants (storm-water input) and to chronic contamination via metal accumulation within temperate algal beds. The effects of storm water were monitored during a two-year survey of Sydney Harbour which sampled epifauna before and after heavy rainfall. Epifaunal assemblages declined throughout the harbour following storm events but for the most part these declines were not attributable to storm-water runoff. However, transient (&lt 4 d) and localized impacts of storm water upon physico-chemical characteristics of recipient water and some epifaunal groups were identified around storm drains. A novel field dosing technique tested the relative importance of freshwater and associated metals as causative agents of behavioural avoidance and direct mortality responses. Strong avoidance of storm-water plumes was found which could be entirely explained by freshwater inundation, with no additional effects of metals. No direct mortality was observed following brief exposures. Contaminants introduced by storm water may accumulate within the tissues of macroalgae and potentially pose persistent threats to epifauna. Colonisation of epifauna was reduced on algae with enhanced copper levels, and the nesting behaviour, feeding and survival of an abundant amphipod were all negatively affected by copper load. Subsequent field surveys identified sufficient copper, lead and zinc contamination in Sydney Harbour algal beds to pose direct toxic threats to epifauna. The abundance of herbivorous amphipods correlated negatively with the copper content of a common algal species. However, differences in metal accumulation between algal species resulted in spatially variable levels of contamination. Small-scale patchiness of contaminants within these landscapes may allow populations of mobile species to persist if contaminated hosts are avoided. In summary, epifaunal assemblages appeared resilient to storm-water pulses. Recovery of affected groups was rapid and large fluctuations in abundance appear to be part of the natural flux of epifaunal communities. In contrast, assemblages responded strongly to algal-bound contaminants and this has emerged as an important pathway of contaminant exposure and impact within algal habitats.

Este trabalho consiste na sÃntese de sÃlica mesoporosa de grande Ãrea superficial e seu uso para fins de tratamento de efluentes na remoÃÃo de metais tÃxicos e compostos orgÃnicos, alÃm do seu uso conjunto com CaCO3 e o extrato aquoso das folhas da planta Musa spp (Bananeira) que provavelmente contem taninos. Existem diversos trabalhos sobre a utilizaÃÃo de sÃlica mesoporosa, de taninos vegetais e do carbonato de cÃlcio, que possuem eficiÃncia na remoÃÃo de metais tÃxicos e de compostos orgÃnicos de corpos hÃdricos e efluentes. A sÃlica à um polÃmero inorgÃnico de formula mÃnima SiO2, onde muitos estudos utilizando sÃlica mostram sua eficiÃncia na remoÃÃo da grande maioria dos contaminantes das Ãguas por adsorÃÃo e/ou precipitaÃÃo, sendo esses contaminantes orgÃnicos ou inorgÃnicos e a sÃlica ainda podendo ser utilizada diversas vezes apÃs sua purificaÃÃo. Os taninos sÃo polihidroxifenois de origem vegetal (com massa entre 500 e 3000 g/mol) e os CaCO3 à um minÃrio com os mais diversos usos. Assim como os taninos, a utilizaÃÃo de carbonato de cÃlcio para o tratamento de efluentes jà se mostrou ser um mÃtodo simples e eficiente. Como amostragem para os testes de remoÃÃo de metais utilizando os compostos isoladamente e depois em conjunto foi utilizada uma soluÃÃo padrÃo dos sais de metais tÃxicos do 1 e do 3 grupos analÃticos, contendo aos metais de transiÃÃo da tabela periÃdica e o Al3+, que sÃo os grupos analÃticos de concentraÃÃo conhecida (1 grupo: Ag+, Pb2+, Hg22+; 3 grupos: Al3+, Cr2+, Fe2+, Mn2+, Zn2+, Co2+ e Ni2+); onde foram feitos os testes de eficiÃncia e as adiÃÃes dos compostos para retirada dos contaminantes. Ambos os testes de eficiÃncia e de adiÃÃo mostraram retirar boa parte de micro poluentes orgÃnicos e inorgÃnicos, sendo a concentraÃÃo de compostos orgÃnicos medidos pela DQO diminuÃdos a nÃveis abaixo de 5 mg/L e metais como Al3+, Fe2+ e Pb2+ foram removidos da soluÃÃo com eficiÃncia de 95% em relaÃÃo a concentraÃÃo inicial. / This work consists in the synthesis of mesoporous silica of high surface area and its use for wastewater treatment in the removal of toxic metals and organic compounds, and their use together with CaCO3 and aqueous extract of the leaves of the plant Musa spp (Banana) that probably contains tannins. There are several studies on the use of mesoporous silica, vegetable tannin and calcium carbonate, which have efficiency in the removal of toxic metals and organic compounds of bodies of water and wastewater. Silica is an inorganic polymer of formula minimum SiO2, with many studies using silica show its efficiency in removing the majority of contaminants from water by adsorption and / or precipitation with organic or inorganic contaminants such and the silica may still be used several times after its purification. The tannins are polihidroxifenois of plant origin (with mass between 500 and 3000 g / mol) and CaCO3 is a mineral with many uses. As tannins, the use of calcium carbonate to sewage treatment has proved to be a simple and efficient method. As a sample for testing for metal removal using the compounds separately and then together we used a standard solution of the salts of toxic metals of the 1st and 3rd groups analytical containing the transition metals of the periodic table and Al3+, which groups are Analytical known concentration (1st group: Ag+, Pb2+ HG22+; 3rd group: Al3+, Cr2+, Fe2+, Mn2+, Zn2+, Co2+ and Ni2+), where the tests were done and efficiency additions of compounds to remove the contaminants. Both tests of efficiency and plus shown remove much of micro organic and inorganic pollutants, and the concentration of organic compounds measured by COD reduced to levels below 5 mg / l and metals such as Al3+, Fe2+ and Pb2+ were removed from the solution 95% efficiency compared to the initial concentration.

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