Aims and objectives: To investigate the epidemiology, risk factors, and preventive strategies for serious head and spinal injuries related to rugby league and union football in New South Wales (NSW). Methods: The three main components of this study included. 1. A retrospective analysis of clinical and compensation case file records during the 16-year period, 1984-1999. 2. A review of game rules, weights and heights of players, over the past 100 years. 3. A review of film and video footage of rugby football games spanning most of the 20th century. A method was developed to allow valid comparisons in style of play over a 70-year period. Results: The estimated annual incidence rate of SCI for rugby league players was 1.9 (95%CI 1.3 - 2.8) per 100,000 estimated players per year, and 3.3 (95%CI 2.2 - 4.8) per 100,000 estimated rugby union players per year over the study period 1984 to 1999. There was no significant change in the incidence of rugby league related serious spinal cord injuries (1984-1999), fatalities (1984-1999) or serious head injuries (1984-1999). There was a small but significant decline in rugby union related serious spinal cord injuries (1984-1999, P<0.05). However, the relative risk of spinal cord injury was 1.34 times greater for rugby union compared to rugby league over the entire study period (95%CI 1.01 - 1.67, P<0.05). For rugby football, the evidence suggested that the force of impact between participants was a key causal risk factor for serious injury. Elite rugby league and union players from 1999-2000 teams were significantly heavier (P<0.05) and taller (P<0.05) than players pre 1950. Players in modern elite games post 1989 were more likely to be tackled by multiple opponents (P = 0.000), tackled head on (P<0.05), at chest level (P<0.05) and at greater speeds than their earlier counterparts pre 1958. However, modern players appear to be no more aggressive or perpetrate greater foul play than their predecessors. Conclusions: There was a continued annual occurrence of catastrophically serious injuries leading to permanent brain damage and quadriplegia associated with rugby league and union in NSW. The critical risk factors found to be associated with serious injury in rugby football suggest relatively novel approaches to the development of preventive strategies.

Elevated arsenic concentrations have been reported in a drinking water and irrigation-supply aquifer of Stuarts Point, New South Wales, Australia. Arsenic occurrence in such aquifers is potentially a major issue due to their common use for high yield domestic and irrigation water supplies. Ten multi-level piezometers were installed to depths of approximately 30 m in the sand and clay aquifer. Sediment samples were collected at specific depths during drilling and analysed for chemical and mineralogical composition, grain size characteristics, potential for arsenic release from solid phase and detailed microscopic features. From this data, a full geomorphic reconstruction allowed the determination of source provenance for the aquifer sediments. The model proposed herein provides evidence that the bulk of the aquifer was deposited under intermittent fluvial and estuarine conditions; and that all sediments derive from the regional arsenicmineralised hinterland. More than 200 groundwater samples were collected and analysed for over 50 variables. The heterogeneity of the aquifer sediments causes redox stratification to occur, which in turn governs arsenic mobility in the groundwater. The bulk of the aquifer is composed of fluvial sand deposits undergoing reductive dissolution of iron oxides. Arsenic adsorbed to iron oxide minerals is released during dissolution but re-adsorbs to other iron oxides present in this part of the aquifer. The deeper, more reducing fluvial sand and estuarine clay groundwaters have undergone complete reductive dissolution of iron oxides resulting in the subsequent mobilisation of arsenic into groundwater. Some of this arsenic has been incorporated into iron sulfide mineral precipitates, forming current arsenian pyrite sinks within the aquifer. The extraction of groundwater from the aquifer for irrigation and drinking water supply induces seawater intrusion of arsenic-rich estuarine water, bringing further dissolved arsenic into the aquifer. A greater understanding of the source, sinks and mobilisation of arsenic in this aquifer contributes to our broad understanding of arsenic in the environment; and allows aquifer specific management procedures and research recommendations to be made. Any coastal or unconsolidated aquifer that has sediments derived from mineralised provenances should consider monitoring for arsenic, and other potentially toxic trace elements, in their groundwater systems.

This study considers relocatable homes as an alternative housing choice for male and female retirees fifty years of age and over. Homogeneous parks and estates planned for a specific type of relocatable home are compared with those which evolved from tourist parks and retain sites for both permanent and short-term occupancy. Four relocatable home environments are considered: caravan parks, mobile homes in mixed parks, manufactured homes in mixed parks and manufactured housing estates. The differential effects of 'age', 'house type' and 'housing environment' upon 'residential satisfaction', 'sense of community within the neighbourhood', 'social integration in the community' and 'psychological adjustment' form the analytical framework of the study. Residents of 34 parks/ estates on the North Coast of New South Wales completed 778 questionnaires. Case studies, interviews, letters and written comments provided data for qualitative analysis. Approximately 94% of respondents are satisfied with their homes and housing environments. Residential satisfaction is most influenced by the interactions and perceptions of residents; psychological adjustment is influenced by a positive attitudes towards self and one's neighbours; integration in the community is affected by levels of network. Each of these relate strongly with having a sense of community in the neighbourhood. Space internal to the dwelling relates to satisfaction, adjustment and community integration. External space relates to the need for a well planned neighbourhood which affords privacy, safety and amenities. The need for meeting places for small and large groups was recurrent. The results suggest that residents of relocatable homes tend to retain affiliation with organisations joined prior to relocation. They are not reliant on their new neighbours to integrate in their community. This result is contrary to prior research which studied site built homes and traditional neighbourhoods. The present high levels of residential satisfaction would rise if it were not for the overwhelming uncertainty of tenure and unjustifiable rises in site rent. The study reviews government policy especially in relation to tenure. A relocatable home offers no more affordability than a site-built home in the same area in the long-term but it does offer a preferred retirement lifestyle.

This thesis presents data on incidence and risk factors for individual sexually transmissible infections (STIs) and STIs as risk factors for HIV acquisition in a community-based cohort of HIV negative homosexual men in Sydney. Nearly half of men aged under 25 years were seronegative to hepatitis A and B infection. The prevalence of hepatitis C (HCV) was 0.85%, which was close to that of the general population. HCV infection was strongly associated with injecting drug use (OR 60.43, 95% CI 6.70-544.79), and sexual transmission was not demonstrated in this cohort. There was a nearly 40 fold increase in syphilis notifications in inner Sydney between 1999 and 2004. The stable incidence of 0.6% per year in the HIM cohort suggests that it was disproportionately affecting HIV positive men. Oral sex was an important transmission route and about one third of cases were asymptomatic. The incidence of urethral and anal gonorrhoea was 3.78 and 3.19 per 100 person-years, and for urethral and anal chlamydia it was 7.98 and 5.20. In addition to unprotected anal intercourse (UAI), insertive oral sex was related to urethral infections and anal infections were associated with non-intercourse anal sexual practices. The prevalence of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) was 75% and 23% respectively. Sexual contact not only with men, but with women, was significantly associated with both infections. Among those susceptible at baseline, the incidence for HSV-1 and HSV-2 was 5.58 and 1.45 per 100 person-years. Oral sex was associated with incident HSV-1 infection and certain non-intercourse anal sexual practices were significantly associated with incident HSV-2 infection. HIV incidence was 0.94 per 100 person-years. It was significantly associated with a higher number of episodes of receptive UAI with a partner of unknown HIV status (p trend&lt0.001) or a partner known to be HIV positive (p trend&lt0.001). After controlling for sexual behaviour, HIV seroconversion was significantly associated with anal gonorrhoea (HR 12.68, 95% CI 3.66-44.00). The association with anal warts and prevalent HSV-1 infection was of borderline significance. These data will inform intervention designs targeting STIs which aim to prevent HIV in homosexual men.

This thesis explored the effect of cocaine use on treatment outcomes for heroin dependent individuals in Sydney, Australia. A naturalistic, longitudinal design was employed in order to examine the effects of cocaine on outcomes over a two year period. Study 1 assessed the prevalence and correlates of cocaine use among heroin dependent individuals. Cocaine use was found to be common among entrants to all three of the major treatment modalities in NSW. Heroin users who also used cocaine (CU) displayed a poorer clinical profile at baseline than non-cocaine users (NCU), reporting higher levels of drug use and dependence, and a greater prevalence of needle risk-taking and criminal behaviour. Study 2 examined outcomes three months post-study entry. CU and NCU were found to have been equally well retained in treatment. Despite significantly reduced levels of cocaine use amongst the cohort, however, CU continued to display the higher levels of drug-related harm that characterized them at baseline. In order to determine whether cocaine use itself was responsible for the greater levels of harm observed amongst CU, or whether instead CU were an inherently more dysfunctional group for whom cocaine use merely served as a marker, comparisons were made within groups on the basis of cocaine use patterns over the study period. The results of these analyses demonstrated that commencing cocaine use resulted in a clear decline in functioning, whereas cessation resulted in corresponding improvements. In Study 3 outcomes were examined twelve months post-study. Baseline cocaine use was again found to predict poorer outcome, despite a large scale reduction in cocaine use amongst the cohort. Importantly, CU were significantly less likely than NCU to be abstinent from heroin at twelve months and more likely to have been incarcerated since study entry. In addition, the effect of persistence of cocaine use was examined. Results indicated that the harms associated with cocaine use increased with increasing persistence of use. Outcomes at two years post-study entry were explored in Study 4. At this time CU and NCU recorded similar outcomes in most domains. Thus, it appeared that the harms caused by cocaine use may take a substantial period of time to diminish. Patterns of cocaine use and motivations for cessation and commencement were also examined. Responses suggested that cocaine use amongst the cohort was largely opportunistic, with participants ceasing use for a variety of reasons, including the financial and psychological problems caused by cocaine use. Past year prevalence of cocaine dependence was measured in this study, with the majority of those who had used cocaine in the past year meeting criteria for dependence. In Study 5, generalized estimating equations were used to measure the effect of baseline cocaine use on major outcome variables over the entire two year study period. Even after controlling for treatment variables, heroin use and other baseline polydrug use, the results of this study confirmed previous findings within the thesis by demonstrating the negative effect of baseline cocaine use on most outcome variables. Evidently, cocaine use among dependent heroin users has serious, long lasting, consequences. To date, however, there has been a stark lack of research examining the effect of cocaine use on treatment outcomes for heroin dependence. To that end, the results of this thesis are encouraging, suggesting that treatment for heroin dependence may also aid in reducing cocaine use among this group.

The Patonga Claystone, a red bed facies in the Narrabeen Group of the Sydney Basin, is one of the most unfavorable rock units in the basin from a geotechnical point of view. This rock unit is composed of sandstone, siltstone, mudstone and claystone. One of the unfavorable characteristics is the low shear strength, which causes instability of cut slopes; another is its slaking-prone behaviour. Numerous measurements of geotechnical properties, along with extensive mineralogical and geochemical determinations, were carried out to identify cause of this slaking behaviour. Key techniques were the use of quantitative X-ray diffractometry for mineralogical analysis, and the determination of slake durability index and related properties to evaluate the slaking behaviour under both standard and more extended conditions. Standard (two cycle) slake durability test results indicate a range from low to high slake durability index values, with some mudstone samples having very low durability and some sandstones having very high slake durability indices. Jar slake test results indicate that the rock samples break rapidly and/or develop several fractures (Ij = 4) in an as-received state, but degrade to a pile of flakes or mud (Ij = 1) if the samples are oven dried before testing. The results for jar slake testing of oven-dried material are comparable, for individual samples, to those obtained from the more comprehensive slake durability tests. The mineralogy of the samples was evaluated by quantitative X-ray diffraction techniques using the Rietveld-based Siroquant processing system. Comparison to independent chemical data show a generally good level of agreement, suggesting that the mineralogical analysis results are consistent with the chemical composition of the individual rock samples. Good correlations were also obtained between clay mineralogy determined from orientedaggregate XRD analysis of the &lt2 micron fraction and the results from powder diffractometry and Siroquant analysis of the whole-rock samples. Evaluation of the slake durability characteristics and other geotechnical properties in relation to the quantitative mineralogy suggests that quartz and feldspar form a rigid framework in the rocks that resists the disruptive pressures that cause slaking. Expansion of the clay minerals by various processes, including the incorporation of water into the interlayer spaces of illite/smectite as well as changes in pore pressures associated with entry of water into micro-fractures in the clay matrix, are thought to produce the disruptions that cause slaking and degradation. An abundant clay matrix also reduces the strength of the rock materials, probably because of the less rigid nature of the clay minerals relative to the quartz and feldspar particles. As well as the mineralogy, the loss on ignition (LOI) and water absorption percentage were found to provide good indicators of longer-term slaking behaviour. Both properties are also related to the overall clay content. Rock samples with water absorption values of &lt10, 10-15 and &gt15% behave as highly durable, intermediate and less durable materials respectively. Rocks with LOI values of greater than 5% by weight behave as less durable rock materials, at least for the strata encompassed by the present study. The water absorption and LOI values were also used to develop a predictive model of slake durability characteristics for the different rock materials in the Patonga Claystone, providing a relatively simple basis for predicting longer-term stability in a range of geotechnical studies.

Elevated arsenic concentrations have been reported in a drinking water and irrigation-supply aquifer of Stuarts Point, New South Wales, Australia. Arsenic occurrence in such aquifers is potentially a major issue due to their common use for high yield domestic and irrigation water supplies. Ten multi-level piezometers were installed to depths of approximately 30 m in the sand and clay aquifer. Sediment samples were collected at specific depths during drilling and analysed for chemical and mineralogical composition, grain size characteristics, potential for arsenic release from solid phase and detailed microscopic features. From this data, a full geomorphic reconstruction allowed the determination of source provenance for the aquifer sediments. The model proposed herein provides evidence that the bulk of the aquifer was deposited under intermittent fluvial and estuarine conditions; and that all sediments derive from the regional arsenicmineralised hinterland. More than 200 groundwater samples were collected and analysed for over 50 variables. The heterogeneity of the aquifer sediments causes redox stratification to occur, which in turn governs arsenic mobility in the groundwater. The bulk of the aquifer is composed of fluvial sand deposits undergoing reductive dissolution of iron oxides. Arsenic adsorbed to iron oxide minerals is released during dissolution but re-adsorbs to other iron oxides present in this part of the aquifer. The deeper, more reducing fluvial sand and estuarine clay groundwaters have undergone complete reductive dissolution of iron oxides resulting in the subsequent mobilisation of arsenic into groundwater. Some of this arsenic has been incorporated into iron sulfide mineral precipitates, forming current arsenian pyrite sinks within the aquifer. The extraction of groundwater from the aquifer for irrigation and drinking water supply induces seawater intrusion of arsenic-rich estuarine water, bringing further dissolved arsenic into the aquifer. A greater understanding of the source, sinks and mobilisation of arsenic in this aquifer contributes to our broad understanding of arsenic in the environment; and allows aquifer specific management procedures and research recommendations to be made. Any coastal or unconsolidated aquifer that has sediments derived from mineralised provenances should consider monitoring for arsenic, and other potentially toxic trace elements, in their groundwater systems.

Elevated arsenic concentrations have been reported in a drinking water and irrigation-supply aquifer of Stuarts Point, New South Wales, Australia. Arsenic occurrence in such aquifers is potentially a major issue due to their common use for high yield domestic and irrigation water supplies. Ten multi-level piezometers were installed to depths of approximately 30 m in the sand and clay aquifer. Sediment samples were collected at specific depths during drilling and analysed for chemical and mineralogical composition, grain size characteristics, potential for arsenic release from solid phase and detailed microscopic features. From this data, a full geomorphic reconstruction allowed the determination of source provenance for the aquifer sediments. The model proposed herein provides evidence that the bulk of the aquifer was deposited under intermittent fluvial and estuarine conditions; and that all sediments derive from the regional arsenicmineralised hinterland. More than 200 groundwater samples were collected and analysed for over 50 variables. The heterogeneity of the aquifer sediments causes redox stratification to occur, which in turn governs arsenic mobility in the groundwater. The bulk of the aquifer is composed of fluvial sand deposits undergoing reductive dissolution of iron oxides. Arsenic adsorbed to iron oxide minerals is released during dissolution but re-adsorbs to other iron oxides present in this part of the aquifer. The deeper, more reducing fluvial sand and estuarine clay groundwaters have undergone complete reductive dissolution of iron oxides resulting in the subsequent mobilisation of arsenic into groundwater. Some of this arsenic has been incorporated into iron sulfide mineral precipitates, forming current arsenian pyrite sinks within the aquifer. The extraction of groundwater from the aquifer for irrigation and drinking water supply induces seawater intrusion of arsenic-rich estuarine water, bringing further dissolved arsenic into the aquifer. A greater understanding of the source, sinks and mobilisation of arsenic in this aquifer contributes to our broad understanding of arsenic in the environment; and allows aquifer specific management procedures and research recommendations to be made. Any coastal or unconsolidated aquifer that has sediments derived from mineralised provenances should consider monitoring for arsenic, and other potentially toxic trace elements, in their groundwater systems.

Elevated arsenic concentrations have been reported in a drinking water and irrigation-supply aquifer of Stuarts Point, New South Wales, Australia. Arsenic occurrence in such aquifers is potentially a major issue due to their common use for high yield domestic and irrigation water supplies. Ten multi-level piezometers were installed to depths of approximately 30 m in the sand and clay aquifer. Sediment samples were collected at specific depths during drilling and analysed for chemical and mineralogical composition, grain size characteristics, potential for arsenic release from solid phase and detailed microscopic features. From this data, a full geomorphic reconstruction allowed the determination of source provenance for the aquifer sediments. The model proposed herein provides evidence that the bulk of the aquifer was deposited under intermittent fluvial and estuarine conditions; and that all sediments derive from the regional arsenicmineralised hinterland. More than 200 groundwater samples were collected and analysed for over 50 variables. The heterogeneity of the aquifer sediments causes redox stratification to occur, which in turn governs arsenic mobility in the groundwater. The bulk of the aquifer is composed of fluvial sand deposits undergoing reductive dissolution of iron oxides. Arsenic adsorbed to iron oxide minerals is released during dissolution but re-adsorbs to other iron oxides present in this part of the aquifer. The deeper, more reducing fluvial sand and estuarine clay groundwaters have undergone complete reductive dissolution of iron oxides resulting in the subsequent mobilisation of arsenic into groundwater. Some of this arsenic has been incorporated into iron sulfide mineral precipitates, forming current arsenian pyrite sinks within the aquifer. The extraction of groundwater from the aquifer for irrigation and drinking water supply induces seawater intrusion of arsenic-rich estuarine water, bringing further dissolved arsenic into the aquifer. A greater understanding of the source, sinks and mobilisation of arsenic in this aquifer contributes to our broad understanding of arsenic in the environment; and allows aquifer specific management procedures and research recommendations to be made. Any coastal or unconsolidated aquifer that has sediments derived from mineralised provenances should consider monitoring for arsenic, and other potentially toxic trace elements, in their groundwater systems.

Elevated arsenic concentrations have been reported in a drinking water and irrigation-supply aquifer of Stuarts Point, New South Wales, Australia. Arsenic occurrence in such aquifers is potentially a major issue due to their common use for high yield domestic and irrigation water supplies. Ten multi-level piezometers were installed to depths of approximately 30 m in the sand and clay aquifer. Sediment samples were collected at specific depths during drilling and analysed for chemical and mineralogical composition, grain size characteristics, potential for arsenic release from solid phase and detailed microscopic features. From this data, a full geomorphic reconstruction allowed the determination of source provenance for the aquifer sediments. The model proposed herein provides evidence that the bulk of the aquifer was deposited under intermittent fluvial and estuarine conditions; and that all sediments derive from the regional arsenicmineralised hinterland. More than 200 groundwater samples were collected and analysed for over 50 variables. The heterogeneity of the aquifer sediments causes redox stratification to occur, which in turn governs arsenic mobility in the groundwater. The bulk of the aquifer is composed of fluvial sand deposits undergoing reductive dissolution of iron oxides. Arsenic adsorbed to iron oxide minerals is released during dissolution but re-adsorbs to other iron oxides present in this part of the aquifer. The deeper, more reducing fluvial sand and estuarine clay groundwaters have undergone complete reductive dissolution of iron oxides resulting in the subsequent mobilisation of arsenic into groundwater. Some of this arsenic has been incorporated into iron sulfide mineral precipitates, forming current arsenian pyrite sinks within the aquifer. The extraction of groundwater from the aquifer for irrigation and drinking water supply induces seawater intrusion of arsenic-rich estuarine water, bringing further dissolved arsenic into the aquifer. A greater understanding of the source, sinks and mobilisation of arsenic in this aquifer contributes to our broad understanding of arsenic in the environment; and allows aquifer specific management procedures and research recommendations to be made. Any coastal or unconsolidated aquifer that has sediments derived from mineralised provenances should consider monitoring for arsenic, and other potentially toxic trace elements, in their groundwater systems.