Multi-walled carbon nanotube aggregates can be suspended in the aqueous phase by natural organic matter. These aggregates are ingested by filter feeding zooplankton. Ingested aggregates result in decreased growth and decreased reproduction. These effects may be caused by reduction in energy input from normal feeding behavior. pH alters natural organic matter structure through changes in electrostatic repulsion. Altered natural organic matter structure changes multi-walled carbon nanotube aggregate size. This size variation with variation in pH is significant, but not large enough a change in size to alter toxicity, as the aggregate size range remains well within the particle size selection of the organisms.

by Wong Siu Fun. / Bibliography: leaves 55-59 / Thesis (M.Ph.)--Chinese University of Hong Kong, 1986

Thesis (M. Phil. (Environmental Law)) -- University of Limpopo, 2013 / This study examines the effectiveness of a particular segment of the legal framework regarding water pollution control in South Africa. A review is conducted of relevant environmental legislation (including the National Environmental Management Act 107 of 1998, the National Water Act 36 of 108) and the Water Services Act and related literature in order to portray the history, scope and content of the water law framework that applies to local authorities in the specific. In order to situate the phenomenon of water pollution in the context of the theoretical review, some observations are included concerning international and domestic developments and phenomena. The theoretical base of this study is furthermore substantiated and supported by the inclusion of a basic case study that portrays the actual challenges facing some local authorities in South Africa in the management and governance of water resources and the combating of water pollution. This study concludes with a set of recommendations towards improved water governance and the combating of water pollution in the local government sphere based on the finding that deficient compliance and enforcement measures remain a real challenge in municipalities’ effective implementation of South Africa’s water law.

This study used a geographic information system (GIS) and an empirical pollutant load model to estimate average annual pollutant loads contained in storm water charges from the City of Carrollton, Texas. The Geographic Resource Analyses Support System (GRASS) was used to create a number of spatial data layers as input variables to a model that estimates loads in Kilograms/Hectare/Year, and Kilogram/Basin/Year. Average annual pollutant loads for twelve pollutants were derived from average annual rainfall/runoff volumes, coupled with Local Dallas/Fort Worth Metroplex storm water Event Mean Concentrations.

4-nonylphenol (NP), a surfactant degradation product, is an unregulated, ubiquitous aquatic contaminant and endocrine disruptor, for which aquatic life criteria are currently under development by U.S. EPA. The effects of NP on estuarine amphipods and chinook salmon fry were investigated, and this dissertation reports research into the impacts of NP bioaccumulation on the amphipods and resultant endocrine disruption of their juvenile salmon predators. Sensitivity to, and bioaccumulation of, NP by benthic amphipods were quantified. Factors affecting the bioavailability of NP to three species of amphipod (Eohaustorius estuarius, Grandidierella japonica, and Corophium salmonis) were determined in contaminated sediments. Standard bioassay techniques were modified to determine toxicity and bioaccumulation, with varying amounts and differing nutritional qualities of sedimentary organic carbon. �����C-Ring-labeled NP was used as a tracer in the experiments to quantify amphipod exposures. NP was acutely toxic to Eohaustorius estuarius from aqueous exposures, mean (+/-SD) LC50=227 ��g/L +/- 56, 1 h mean reburial EC50=138 +/- 36. The predicted LC50 for NP (202 ��g/L) from an amphipod-derived structure-activity relationship was not significantly different (p>0.05) from our empirically derived LC50 (227 ��g/L). All three amphipod species accumulated significant NP body burdens. Accumulation was inversely proportional to the total amount of organic carbon, but it did not differ between types of organic matter. Calculated accumulation factors indicated that amphipods could be an important and previously unrecognized source of NP to higher trophic levels. Plasma vitellogenin (Vtg) was quantified in juvenile chinook salmon following dietary exposure to NP contaminated amphipods and aqueous exposure to multiple NP concentrations. Fry that had fed upon contaminated amphipods did not have significantly greater Vtg levels than controls; however, Vtg was detected in 30 percent of fry. NP aqueous concentrations at 60 and 240 ��g/L significantly induced Vtg in fry following 5 d exposures. The 240 ��g/L aquatic NP treatment fry had comparable levels of Vtg to the positive control treatment in which fry were injected 17B-estradiol. These results indicate that amphipods are potential vectors of sediment NP to higher trophic levels within the water column, including juvenile chinook salmon. / Graduation date: 2003

Concentrations of 17 organochlorine and 14 organophosphorus pesticides were measured in 27 ground and 11 surface water samples collected from a heavily agricultural area, Kumluca, in spring and fall seasons of 2005. The samples were preconcentrated by Solid Phase Extraction. GC-ECD and GC-NPD systems were used for quantitative determination of organochlorine and organophosphorus pesticides respectively. The quality check/quality assurance tests were performed by the analysis of field and laboratory blanks, standard reference materials, spiked control and sample matrices, surrogate standards, sampling and analysis replicates. It is observed that, sample matrix lowers average percent recoveries from 89% to 76%. The uncertainties of measurements were calculated to determine major factors affecting the analysis results. It was observed that uncertainty arising from extraction procedure was generally the highest. The most commonly observed pesticide was endosulfan (70%) and chlorpyriphos (53%) for organophosphorus and organochlorine pesticides. The highest average concentration was observed for heptachlor (26 ng/L) and fenamiphos (184 ng/L). Generally pesticides were detected more often in surface waters, where the concentrations were also higher. The concentrations of organophosphorus pesticides in spring, and organochlorine pesticides in fall season were higher. The high occurrences and detection of degradation products of chlorinated pesticides clearly indicate their intense use before 1980s. It is shown that, in Kumluca environment, degradation of these pesticides mostly occurs in surface waters. It is observed that agricultural activities affect water quality in the region. The total concentration limit (500ng/L) was exceeded for 27% of surface and 14% of ground water samples, at least once in both seasons. The legal limit for a single pesticide (100ng/L) was exceeded by 32 % of surface, 24 % of ground water samples.

The hydrocarbons of recent polluted sediments, in-reservoir and laboratory biodegraded crude oils, and certain petroleum products (e.g. lubricating oils) often display 'humps' or Unresolved Complex Mixtures (UCMs) when analysed by gas chromatography (GC). Although widespread and often abundant, to date little is known of their detailed molecular composition. Standard chromatographic methods of isolation of model aliphatic and aromatic hydrocarbon UCMs from lubricating oils followed by conventional methods of analysis provided little compositional detail. Thus GC and GC-electron impact mass spectrometry (GC-EIMS) was limited to an estimate of carbon number ranges and to the identification of certain series of 'biological marker' compounds. However, these were well resolved and were estimated to account for <10% of the total detector response. Further analyses were performed by chemical ionisation-MS (CI-MS), probe distillation EI-MS, field ionisation-MS (FIMS), and elemental analysis; yet the information provided by each was limited to a few 'average' molecular types. In view of the limitations of conventional methods of analysis, alternative methods were adopted. These utilised novel chemical and pyrolytic degradations of the UCM hydrocarbons. Chemical oxidation with Cr03 in glacial acetic acid produced reasonable yields of total recoverable material (40-80%). Furthermore, a high proportion were functionalised (>90%), and many resolved, which allowed their identification by EI and CI GC-MS. Surprisingly, the most abundant products of oxidation of hydrocarbon UCMs were straight chain monocarboxylic acids. This appeared to contradict literature consensus on UCM composition, namely a predominance of highly branched and/or cyclic hydrocarbons. However, from literature reported CrO oxidations of hydrocarbons, potential precursor compounds were proposed. These were monoalkyl substituted 'TO-branched acyclic and monocyclic alkanes for the aliphatic UCM and alkyl 'TO-branched monoaromatic hydrocarbons for the aromatic UCM. Proposed precursor UCM hydrocarbons were confirmed by synthesis and chemical oxidation under the same conditions. Thus each of the synthetic candidate UCM hydrocarbons [7-n-hexylnonadecane, 9-(2-phenylethyl)-heptadecane and 9-(2- cyc 1 ohexyl ethyl j--hep tade cane] produced n-acids on oxidation with Cr03- Further correlations were found for products of other synthetic alkanes and less abundant UCM oxidation products. For example, n-alkan-2-ones. iso alkan-2- ones, and 7-methyl--y-lactones could all be correlated with methyl substituted acyclic alkyl linkages on UCM hydrocarbons. The application of chemical oxidation to aliphatic UCMS of varied origin showed the technique has great potential for fingerprinting such samples. GC-MS analysis of a selected series of resolved product compounds (alkyl ketones, -y-methyl--y-lactones) showed good correlations for samples of the sane origin, yet distinct differences for UCHs from different sources. Biodegradation of the three candidate UCM hydrocarbons alongside acyclic isoprenoid alkanes and normal and monomethyl alkanea showed the UCM hydrocarbons were at least as resistant to microbial degradation as the isoprenoid alkanes. In this context it is therefore concluded that the candidate UCM compounds serve as good molecular models for hydrocarbon UCMs.

This research investigated the effects of waterborne zinc (Zn) on the interactions between guppies, Poecilia reticulata (Peters), and Gyrodactylus turnbulli Harris, 1986, a monogenean parasite of its skin and fins. The first objective was to determine if sublethal concentrations of waterborne Zn (up to 240 mug/L added to artificial freshwater) exerted a concentration-dependent effect on the population dynamics of Gyrodactylus on isolated guppies. Whereas survival of uninfected fish was unaffected, mortality of infected fish increased linearly with increasing Zn concentration. In addition, the improved parasite population growth at concentrations up to 120 mug Zn/I suggested either that the elevated Zn promotes survival and/or reproduction of the parasite, or impairs host defense mechanisms. Analysis of lifetime survival and reproduction of individual parasites on and off the fish revealed Zn toxicity to the parasite as survival of detached parasites decreased linearly with increasing Zn concentration and parasite survival on the host was also lower at the highest Zn concentrations. Also, all morphological parameters decreased linearly in response both to increasing concentration and duration of exposure to waterborne Zn. The guppy epidermis responded rapidly to both infection and waterborne Zn, and the cumulative effects of these combined stressors were synergistic for epidermal thickness and mucous cell numbers, but antagonistic in terms of mucin composition. Both Zn and infection induced mucous production, but at elevated Zn concentrations and/or at high parasite burdens, the capacity for continued mucous production was apparently exceeded. I hypothesize that this condition is favorable for parasite survival because of the impaired host response; but unfavorable for host survival because of the high numbers of pathogenic parasites and the inability to control entry of Zn into host tissues. In conclusion, sublethal concentrations of waterborne Zn are more detrimental to the infected host than to the parasite.

Millions of people rely upon the Ganges River as a source of water provision and a site of disposal for sewage, solid waste, agricultural runoff and industrial effluent. The river is also a goddess in the Hindu pantheon who is worshipped for her purificatory powers, despite water quality levels that fall far short of standards for use in bathing, washing, and drinking. In recent years, a number of non-governmental organizations (NGOs) have formed to oppose both pollution of the river and the failure of state-run pollution abatement programs. They are joined by an increasingly frequent number of seemingly spontaneous protests held during the large Kumbh Mela festival gatherings at Allahabad, Uttar Pradesh. Led by priests, sadhus and religious leaders, these protestors refuse to participate in the ritual bathing that is central to river worship until local and state officials take action to improve water quality at the site. These events indicate that the politics surrounding pollution abatement in the Ganges River Basin (GRB) are changing and that civil society organizations are struggling to gain greater representation and influence in the processes that shape pollution abatement and water use management in the GRB. This dissertation investigates the growing debate around pollution and pollution abatement in the Ganges River Basin and interprets the struggle over pollution abatement and river water management as a struggle over meaning in which various groups attempt to influence the context and context of local environmental knowledge(s). The research compares abatement efforts, civil society activity, and the "pollution knowledge" and water use practices of water users in three urban centers in the central GRB. An analysis of archival data, policy documents, a survey of water users, and interviews with government officials, NGO leaders and members, and other local scientists and activists conducted during fieldwork in 2008 and 2009. Discussion centers on the meta-discursive productions surrounding public participation and popular "awareness" as precursors to public participation in decisionmaking and policy-making processes. Findings indicate that water users in the GRB are well aware of pollution in the river and that many users exhibit a degree of cognitive dissonance in their pollution knowledge, indicating that a disconnection may exist between the knowledge that guides opinion and the knowledge that guides water use activity. Anti-pollution social movement organizations are found to employ methods and tactics that reflect local contexts of environmental degradation and pollution production, but which ultimately aim to reproduce broads shifts in the ideas, values, and power relations associated with water quality and water use in the Basin. Discussion considers the politics of upstream/downstream relations in shaping pollution abatement measures and the occurrence of "missing movements", or the absence of anti-pollution civil society activity. Research findings contribute to literature on the role of environmental knowledge in shaping the “politics of meaning” around which ideological struggles over natural resource use, access, and conservation are waged.

The occurrence of unresolved complex mixtures of hydrocarbons (UCMs) in the aliphatic fraction of marine sediments and organisms from areas impacted by petroleum hydrocarbons is well documented and widely accepted as an indication of fossil fuel contamination. In contrast, the presence of an aromatic UCM is often ignored and environmental concentrations of aromatic UCM hydrocarbons in marine biota and sediments are rarely reported. The aims of this study were to establish the quantitative significance of aromatic UCMs in environmental samples and to assess the toxicological significance of both aliphatic and aromatic UCMs. A reproducible method was developed and validated for the analysis and quantification of petroleum hydrocarbons in mussel (Mytilus edulis) tissue. Emphasis was placed upon development of a method which minimized losses of more volatile, lower molecular weight, toxicologically significant hydrocarbons, without compromising recovery of higher molecular weight compounds which are useful for source identification in environmental monitoring schemes. Analysis of mussels from a small number of U. K. coastal locations indicated that aromatic hydrocarbon UCMs may form a significant proportion (ca 20 %) of the total hydrocarbon body burden of mussels from areas contaminated with petroleum hydrocarbons. Aromatic UCM hydrocarbons were not observed in mussels from relatively uncontaminated areas but concentrations of 430 μg g'' (dry wt tissue) were measured in mussels from heavily impacted areas. Aliphatic UCM concentrations ranged from 7- 3445 μg gg' (dry wt tissue). For the purposes of toxicological studies, a low molecular weight model aliphatic UCM hydrocarbon, 4-propyloctane (4-PO) was synthesised. Two low molecular weight model aromatic hydrocarbons 7- cyclohexyltetralin and 7-cyclohexyl-l-propyltetralin were also synthesised using a modification of the Haworth synthesis. All three target compounds and synthetic intermediates were characterised by NMR, MSandIR. Exposure of M. edulis to 4-PO caused a significant reduction in mussel ciliary feeding activity indicating that 4-PO was indeed toxic as measured by this bioassay. The demonstrable narcotic activity of 4-PO is presumably related to the greater aqueous solubility of branched hydrocarbons compared with similar straight chain hydrocarbons. Further experiments investigating the effect of 4- PO over exposure periods up to 120h provided a unique and detailed insight into the relationship between concentration of toxicant in the gills of M. edulis and observed feeding rate. The established method of mussel feeding rate determination was modified in light of this relationship to produce an " improved rapid and reproducible screening technique. Both of the model aromatic UCM hydrocarbons were also found to be toxic to mussel ciliary feeding activity. This appears to be the first report of investigations into the toxicity of the aromatic UCM and suggests that previous studies have ignored an environmental burden of toxicological significance. Estimates of the tissue effective concentration (TEC50) for the model UCM hydrocarbons gave comparable values with those reported for the effect of other narcotic hydrocarbons upon mussel feeding rate, providing support for the theory that non-specific narcosis occurs at a relatively constant tissue concentration of toxicant. The demonstrated narcotic activity of each of the three model UCM hydrocarbons has extended the molecular weight range of narcotic hydrocarbons studied to date. The results presented herein suggest that a small proportion of low molecular weight aliphatic UCMs and perhaps a greater proportion of aromatic UCMs are of toxicological significance.