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A large body of jurisprudence has developed in Canada criminalizing the conduct of HIV positive persons who transmit or expose others to the HIV infection in an equivocal attempt to be seen to be doing something about individuals who are perceived to be driving the HIV epidemic. Convictions have been obtained for charges ranging from aggravated assault to, most recently, murder. The Cuerrier judgement, a landmark decision of the Supreme Court of Canada, left a number of issues unresolved. Given the ambiguities in the decision, this Thesis will address the unfortunate consequences resulting from the Cuerrier’s decision. The conclusion I will attempt to reach is that criminalization is an inadequate strategy to prevent further HIV infection, its increased use in practice is misguided, and counterproductive to public health goals, thus alternatives to the routine criminalization of HIV transmission that may enhance the goals of public health should be considered.

A large body of jurisprudence has developed in Canada criminalizing the conduct of HIV positive persons who transmit or expose others to the HIV infection in an equivocal attempt to be seen to be doing something about individuals who are perceived to be driving the HIV epidemic. Convictions have been obtained for charges ranging from aggravated assault to, most recently, murder. The Cuerrier judgement, a landmark decision of the Supreme Court of Canada, left a number of issues unresolved. Given the ambiguities in the decision, this Thesis will address the unfortunate consequences resulting from the Cuerrier’s decision. The conclusion I will attempt to reach is that criminalization is an inadequate strategy to prevent further HIV infection, its increased use in practice is misguided, and counterproductive to public health goals, thus alternatives to the routine criminalization of HIV transmission that may enhance the goals of public health should be considered.

In British Columbia harvested forests are manually replanted by seasonal workers. Fertilizers contained in perforated paper sachets are often planted with seedlings. There have been anecdotal reports of skin and respiratory illness associated with fertilizer exposure and due to potential metal content in fertilizer source material they may contain metals as contaminants. Workers may also be exposed to pesticide residues on seedlings. This study aimed to characterize fertilizer, metal and pesticide exposure among a sample of B.C. tree planters, and to examine worker respiratory and dermal health. Between May 2006 and April 2007 223 tree planters were interviewed about their respiratory and dermal health, and the exposures of 54 tree planters at five geographically-disperse worksites were monitored. Four worksites were using fertilizer and one was not. The health questionnaire was a modification of the American Thoracic Society standardized questionnaire with questions on dermal health taken from a previous UBC study. Workers were grouped in exposure categories and symptoms analysed using logistic regression. Metals were measured by ICP/MS on post shift hand wipes, full shift air sample filters, in whole blood, bulk soil, seedling root balls, and fertilizer samples. Pesticides were measured on post shift hand wipes and on bulk seedling samples. Using nursery pesticide application records, analyses focused on known pesticides applied to the seedlings at the study sites. Carbamate pesticides were analyzed by HPLC/MS and other pesticides by GC/MS. No evidence was found that tree planters who work with fertilizer are at an elevated risk of exposure to arsenic, lead, cadmium, chromium and nickel relative to other tree planters. Pesticide residues were found on seedlings taken from coastal work sites in April 2007. At coastal worksites the fungicides chlorothalonil and iprodione were found on the skin of workers at low levels (range 0.37 – 106.3 ng.cm² and 0.48 – 15.9 ng/cm² respectively). Work with fertilizer was linked with an increased risk of cough, phlegm, nasal symptoms, nose bleed, and skin irritation. Hygiene conditions at tree planting work sites are very poor. Although measured exposures were low, hygiene conditions should improve to reduce the risk of health symptoms among tree planters.

Environmental exposure and outcomes assessment is a great challenge to scientists. Increasingly more and more detailed data are becoming available to understand the nature and complexity of the relationships involved. The methodology of mixture models provides a means to understand, quantify and describe features and relation- ships within complex data sets. In this thesis, we focussed on a number of applied problems to characterise complex environmental exposure and outcomes, including: assessing the interaction between environmental exposures as risk factors for health outcomes; identifying di®ering environmental outcomes across a region; and estab- lishing patterns in the size and concentration of aerosol particles over time. Mixture model approaches to address these problems are developed and examined for their suitability in these contexts.

A New Zealand Qualified Health Physicist (QHP) is required, under the Radiation Protection Act of 1965 and the Radiation Protection Regulations 1982, to perform auditing compliance tests on x-ray equipment at regular intervals to ensure that this equipment conforms to the Code of Safe Practice with the use of x-rays. The protocol for these tests must be approved by the National Radiation Laboratory (NRL). One of these test protocols sets out the requirements for the functionality testing of the x-ray machine Automatic Exposure Control (AEC). The current NRL protocol for AEC testing is based on the radiographic film environment (NRL C5 1994). This protocol was tested to determine its applicability to the digital computed radiography (CR) imaging systems which are replacing screen-film systems. To begin this process a comparison of the different exposure indexes for each image medium was required. This proved to be achievable using a system of exposure dose comparison. The AEC test process for both image modalities follows identical requirements but differ slightly in the test methods used to achieve these. The most significant finding throughout this stage was not the differences between protocols but was the requirement to achieve consistent exposure index values over the clinical kVp range for each image medium. This requirement, applicable to any x-ray image medium, became the focus of this thesis. The thesis has explored through experimentation, the effect of optimisation of AEC kVp compensation for the variable kVp response of an image medium, on image consistency. At Christchurch Hospital where this investigation took place the work has shown that the performance of AEC devices can be optimised to improve image consistency, indicated by a more consistent exposure index over the clinical kVp range. The optimisation process also achieves a more consistent dose response to the image plate. A dose variation of 8.3% from the average was achieved compared to 26% in the unoptimised version. No clinically significant changes to image quality were apparent in test images. Under these conditions it was found that AEC functionality could be assessed solely by the measurement of AEC dose to the image plate (IP). Use of this test method provides quantifiable time management benefits for the Medical Physicist and for the radiology departments in which they work. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1369625 / Thesis (M.Sc.(Med.Physics)) - University of Adelaide, School of Chemistry and Physics, 2009