Asbestos sampling and monitoring data, starting from 2003, located in a large federal facility’s Asbestos Air Database Management (AADM) repository will be queried and analyzed on airborne asbestos fiber concentrations generated from abatement activities of asbestos-containing materials (ACM) and asbestos-containing building materials (ACBM). Historically, concerns expressed by personnel outside of the containment areas, whether adjacent to or quite a distance from the asbestos abatement activities present operational challenges for the project manager, potential angst and uneasiness to personnel residing next to the abatement activity as well as programmatic concerns to the building/facility managers. The concerned individuals working outside the abatement enclosure, in an unrelated activity to the abatement often believe there is a high probability for personal exposures of asbestos fibers based on their proximity to the abatement activities. Perceptions regarding containment performance, the uncertainty surrounding the long latency period between asbestos fiber exposure and onset of disease, and the lack of understanding about containment efficacy are just some of the elements that can generate worry. Using statistical analysis tools, such as regression analysis, relationships between one or more predictor variables relative to a response variable were investigated. This research reviewed and compared airborne asbestos fiber sample data relative to the specific activities, whether abatement or other, that were performed. In an effort to establish a holistic awareness to the reader as to why individuals are concerned about being located near asbestos abatement activities, the history of asbestos regulation and epidemiology is also discussed. The dataset contained 5534 sampling records made up of 3738 area samples (1426 outside containment structure and 2312 inside containment structure) and 1796 personal samples. Analysis identified that 1779 (>99%) out of the 1796 total personal exposure samples in the dataset indicated the asbestos workers were appropriately protected from overexposures. Only seventeen (<1%) of the 1796 total personal exposure samples exceeded the respective Occupational Exposure Limits (OELs): • Fifteen of the 17 exceeded the 8-hr TWA, 0.1 f/cc OEL. These exceedances were positively correlated with work tasks identifying that no respirators were required due to a Negative Exposure Assessment (NEA). • Two of the 17 exceeded the Assigned Protection Factor for the Half Face APR (10x the OEL protection) adjusted 8-hr TWA OEL, 1 f/cc. • There were no OEL exceedances identified for any 30-min Excursion personal sampling events. The focus for this assessment was to determine the efficacy of the asbestos abatement process and increased health risks to personnel. The findings suggest there is performance variability in the containment structures; however, the abatement process was effective and protective of the non-asbestos personnel outside of the abatement work area. It can also be concluded that the abatement process of containment structures, negative air, work methods (e.g. wet methods) and Personal Protective Equipment (PPE) have provided a protective environment for both workers and non-asbestos personnel outside of the containment structures.

No description available.

Recently, several novel technologies have emerged with substantial benefits in toxicological analysis. These include the development of beadbased multiplex immunoassay (Suspension Bead Array, SBA), the use of reduced-volume centrifugal ion-exchange extraction (SpinSPE), and Ultra-Performance (TM) liquid chromatographic separation coupled to mass spectrometry (UPLC(TM)/MS n ). This work sought to investigate the efficacy and practicality of these innovative approaches against a benchmark of established methods and instrumentation for the screening and confirmation of amphetaminetype substances. This study begins with a statistical survey of amphetaminetype substances encountered in an accredited forensic laboratory supporting the Australian Capital Territory and regional New South Wales. Over the 5year period 2001-2005, it was determined that 6683 case submissions required presumptive screening for amphetamines. Of these cases, 1269 (19.0%) required confirmative analysis of amphetaminetype substances, including amphetamine, methamphetamine, MDA, MDMA, MDEA, ephedrine, pseudoephedrine, and phentermine. Such analytical needs were then used in comparative assessment of the novel and established methodologies, including examination of immunoassay specificity, extraction efficiency, chromatographic resolution, general resource efficiency, and total analysis time. Development of a beadbased immunoassay platform (SBA) for multiplex amphetamines analysis proved to be a complex task. Efforts to multiplex the amphetamine and methamphetamine immunoassay models into a single assay exhibited a significant degree of non-specific antibody cross-reactivity. However, the merits of the individual bead assays were demonstrated. Upon comparison with commercially available enzyme-linked immunosorbent assays for amphetamine or methamphetamine (ELISA), it was observed that the SBA models exhibited specificity comparable to that of the ELISA assays and linearity over a concentration range of toxicological relevance (0-1000 ng/mL amphetamine or methamphetamine). In addition, the results indicated the practical applicability of the individual SBA assays for an oral fluid matrix, and demonstrated significant reductions in the volumes of reagents required and length of time of analysis. Additionally, in an optimised multiplex system, the amount of sample required for screening could be reduced as the SBA technology theoretically permits analysis of up to 100 different drugs or metabolites from one volume of sample. The aspect of forensic sample conservation was further explored with investigation of reduced-volume extraction techniques, such as the application of centrifugal ionexchange extraction columns (SpinSPE). Following initial development, the SpinSPE technique was applied to the isolation of amphetaminetype substances from oral fluid and compared with a mixedmode SPE method for both extraction and resource efficiency. From the observed results, both extraction methods were demonstrated to be effective in the isolation of amphetamine, methamphetamine, ephedrine, pseudoephedrine, PMA, MDA, MDMA, MDEA, MBDB, and 2CB from an oral fluid matrix with detection by heptafluorobutyric acid derivatisation (HFBTA) and GC/MS. The SpinSPE model demonstrated comparable efficacy with reduced sample volume (200 쌩, as well as significant reductions in the volumes of reagents required for column conditioning, washing, and elution. In addition, the linear working range (0-2000 ng/mL) and sensitivity of the method indicated the potential to further reduce sample volume. In the confirmative separation and identification of drug compounds, the technological advancement of UltraPerformance (TM) liquid chromatography (UPLC(TM)) has recently evolved from efforts to improve LC resolution, sensitivity, and time of analysis. In this research, UPLC(TM) coupled to mass spectrometry was demonstrated to be capable of rapidly identifying several amphetaminetype substances (phenylethylamine, amphetamine, phentermine, methamphetamine, ephedrine, pseudoephedrine, PMA, 4MTA, MDA, MDMA, MDEA, MBDB) and ketamine in an analysis time of less than five minutes. In addition, UPLC(TM)/MS demonstrated a resolving power comparable to GC/MS with significantly reduced instrumental analysis time. This research reveals the promise of these new applications in advancing towards a more efficient and modernised systematic toxicological approach. The continued development and optimisation of SBA multiplex immunoassays will permit customisable systems capable of simultaneously detecting numerous compounds with antibodybased sensitivity and selectivity. In circumstances where low sample volumes are required for confirmation of drug use, such as in roadside saliva drug testing for driving under the influence offences, reducedvolume SpinSPE has been demonstrated to be a practical and effective alternative for sample preparation. In addition, a more streamlined procedure is further enhanced with the use of UPLC(TM) coupled to mass spectrometry for analyte separation and molecular identification. It is expected that illicit drug use will remain a significant public concern. With the continued desire for more rapid and comprehensive methodologies, further study of these and other innovative technologies will be of considerable future benefit to laboratories such as that serving the Australian Capital Territory region.

Errata pasted onto front end paper. / Bibliography: leaves 193-211. / xiv, 211 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Describes the development and application of an in vitro model used to investigate the cytoprotective effects of a whey-derived growth factor extract in reducing epithelial cell death caused by chemotherapy agents. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physiology, 1998

<p>The understanding of effects of chemical exposure in nature is lagging behind. Predictions of harmful effects of chemicals on aquatic organisms rely mainly on ecotoxicity tests. To improve the understanding of the biological linkage between the cellular and organismal responses to a chemical in an ecotoxicological test, the major aim of this doctoral thesis was to investigate the usefulness of two biochemical endpoints, contents of RNA and ecdysteroids, by incorporating them with life-history traits of copepods (Crustacea). To do so, the two methods needed to be established at our laboratory. Both biochemical methods are more commonly used in basic biological research, but I here present its usefulness in ecotoxicological testing. It was found that individual RNA content as a biochemical endpoint was significantly altered in the brackish water harpacticoid copepod Nitocra spinipes when exposed to the pesticide Lindane (paper IV) and low concentrations (0.16<g . L-1) of the pharmaceutical Simvastatin (paper I) during partial life cycle tests. However, the RNA content was insensitive as endpoint in the fresh water harpacticoid Attheyella crassa during multigenerational exposure (2 – 3 generations) to naturally contaminated sediments (paper III). The second biochemical endpoint, ecdysteroid content (a crustacean growth-hormone), was shown to be a useful tool for ecotoxicological studies using N. spinipes (paper IV), as well as for increasing the understanding of lipid turnover and reproduction of the marine calanoid copepod Calanus finmarchicus (paper V). In paper I and IV, I present a balanced ecotoxicological test, useful for substances with suspected developmental disruptive effects. In this type of test, a balance between test adequacy, exposure time, and costs has been proven useful. Further, the reliability of tests (paper II) with N. spinipes was increased by optimizing its food regime. In paper II, 25 different combinations of micro-algae were tested during short- and long time exposure, and a suitable food source (Rhodomonas salina) was identified, whilst poorer development and reproduction, malformations, and even mortality was induced by other algae. In conclusion, my studies provide useful tools for ecotoxicological testing, as well as for basic understanding of developmental biology of different copepod species.</p>

Graduation date: 1983

Reported here is an investigation to determine the in vitro and in vivo metabolism of xanthohumol (XN). XN is the major prenylated flavonoid of the female inflorescences (cones) of the hop plant (Humulus lupulus). It is also a constituent of beer, the major dietary source of prenylated flavonoids. Recent studies have suggested that XN may have potential cancer chemopreventive activity but little is known about its metabolism. We investigated the in vitro metabolism of XN by rat and human liver microsomes, and cDNA-expressed cytochrome P450s, and the in vivo metabolism of XN by rats. The metabolites and conjugates were identified by using high-pressure liquid chromatography, liquid chromatography-mass spectrometry, and nuclear magnetic resonance. The antioxidant properties of two metabolites and two glucuronides were examined. The possible risk of XN consumption from beer or dietary supplements is discussed. The involvement of metabolites of XN in cancer chemoprevention remains to be established. / Graduation date: 2001

The immune system has been identified as a very sensitive target for the toxic effects of 2,3,7,S-tetrachlorodibenzo-p-dioxin (TCDD). Exposure to TCDD has been shown to disrupt the generation of both cell-mediated and humoral T cell-dependent immunity in laboratory animals; however, the mechanism remains unknown. In this dissertation, the hypothesis is tested that TCDD exposure alters T cell activation and differentiation either directly or by inhibiting the activation of antigen presenting cells (APC). Previous studies from our laboratory using the PSI5 tumor allograft model suggest that TCDD inhibited T cell activation by suppressing the induction of the costimulatory molecule CDS6 on B220+ and Mac-1+ cells. To address the effects of TCDD on APC, we further characterized the activation of splenic APC in the PSI5 model and found that TCDD suppressed the induction of the accessory molecules CDS6, CD54 and MHC II on APC as well as their production of IL-12. Although it was determined that the induction of these costimulatory molecules following PSI5 immunization was CD40independent, their in vivo expression could be enhanced by administering an agonistic antibody to CD40 to mice. APC from anti-CD40 treated mice expressed significantly higher levels of these accessory molecules and IL-12, and this enhanced APC activation was largely unaffected by TCDD. However, TCDD-treated mice receiving both P815 and anti-CD40 were unable to generate T cell-dependent allograft immunity suggesting that suppression of APC activation may not be underlying TCDD immunosuppression. To address the direct effects of TCDD on T cell activation, we adoptively-transferred DO11.10 TCR transgenic T cells into syngeneic recipients and monitored their activation in vivo following exposure to antigen. Although treatment of adoptively-transferred mice had no effect on the expansion or activation of the OVA-specific CD4+ T cells, the production of the T cell-derived cytokines IL-2, IFN-��, IL-4 and IL-10 was suppressed. These data suggest that TCDD may suppress the differentiation of OVA-specific T cells into effector T helper cells which are capable of driving T cell-dependent immune responses. / Graduation date: 2000

Graduation date: 1999

Graduation date: 1997