Exposure estimation, uncertainty and variability in occupational hygiene retrospective assessment

This thesis reports on a quantitative exposure assessment and on an analysis of the attributes of the data used in the estimations, in particular distinguishing between its uncertainty and variability. A retrospective assessment of exposure to benzene was carried out for a case control study of leukaemia in the Australian petroleum industry. The study used the mean of personal task-based measurements (Base Estimates) in a deterministic algorithm and applied factors to model back to places, times etc for which no exposure measurements were available. Mean daily exposures were estimated, on an individual subject basis, by summing the task-based exposures. These mean exposures were multiplied by the years spent on each job to provide exposure estimates in ppm-years. These were summed to provide a Cumulative Estimate for each subject. Validation was completed for the model and key inputs. Exposures were low, most jobs were below TWA of 5 ppm benzene. Exposures in terminals were generally higher than at refineries. Cumulative Estimates ranged from 0.005 to 50.9 ppm-years, with 84 percent less than 10 ppm-years. Exposure probability distributions were developed for tanker drivers using Monte Carlo simulation of the exposure estimation algorithm. The outcome was a lognormal distribution of exposure for each driver. These provide the basis for alternative risk assessment metrics e.g. the frequency of short but intense exposures which provided only a minimal contribution to the long-term average exposure but may increase risk of leukaemia. The effect of different inputs to the model were examined and their significance assessed using Monte Carlo simulation. The Base Estimates were the most important determinant of exposure in the model. The sources of variability in the measured data were examined, including the effect of having censored data and the between and within-worker variability. The sources of uncertainty in the exposure estimates were analysed and consequential improvements in exposure assessment identified. Monte Carlo sampling was also used to examine the uncertainties and variability associated with the tanker drivers' exposure assessment, to derive an estimate of the range and to put confidence intervals on the daily mean exposures. The identified uncertainty was less than the variability associated with the estimates. The traditional approach to exposure estimation typically derives only point estimates of mean exposure. The approach developed here allows a range of exposure estimates to be made and provides a more flexible and improved basis for risk assessment.

Occupational health and safety management systems : system types and effectiveness

The aim of this thesis is to develop a framework to evaluate the relative performance of different types of health and safety management system. This objective is an analytical one, but it stems from a policy issue of public importance. Over the past decade Australia, like other countries, has seen the emergence and growth of interest in developing health and safety management systems. But are they all the same, and if not, do they differ in their effectiveness? The thesis does not seek to give a definitive answer to these questions. Given the novelty of the phenomenon and the lack of research on this subject, the research is exploratory. An hypothesis about the effectiveness of different health and safety management systems is developed rather than tested. The thesis proceeds by first defining health and safety management systems as a combination of the planning and review, the management arrangements, the consultative arrangements and the specific program elements that work together in an integrated way to improve health and safety performance. A research procedure is described involving twenty exploratory case studies. The thesis then - develops - from the literature and the case study research - an analytical framework to evaluate the performance of different health and safety management systems. That framework has two parts. First is a typology of health and safety management systems. This is constructed from two distinctions - between 'safe place' and 'safe person' approaches to health and safety; and between 'innovative' and traditional' management methods and structures. These distinctions yield four types of system. The typology was applied to the case studies which yielded a reasonable fit in most instances. The second part of the framework is a 'process evaluation' technique akin to Quality standards. Derived from the Victorian SafetyMAP audit criteria, the "e;process evaluation tool "e; is preferred to traditional outcome measures such as incident or claim rates. Using this measure, the twenty case study enterprises were classified as above average, average or below average in performance. These results correlated poorly with traditional incident trend and benchmark measures. The two elements of the framework are then combined to explore the relationship between the different types of system and their performance. Evidence from the twenty case studies showed a tendency for innovative/safe place firms to perform better than traditional/safe person firms. This finding can form the basis for a hypothesis that may be subject to statistical testing on a generalisable sample. In addition five 'best practice' cases were selected and subjected to a cross case analysis to search for common characteristics that might explain their performance. This analysis suggests the importance of a number of factors: senior managers who drive health and safety change and mobilise all possible resources in the pursuit of change; health and safety representatives who work with managers in a 'joint regulatory relationship' across system activities; the involvement of employees more generally, but not as a substitute for action by managers and health and safety representatives; a comprehensive approach to elimination of all hazards; and the introduction of innovative programs to continually improve systems and facilitate employee involvement in health and safety.

Allocating risks in public-private partnership projects using a transaction cost economics approach - a case study

Public-private partnership (PPP) projects are often characterised by increased complexity and uncertainty due to their idiosyncrasy in the management and delivery processes such as long-term lifecycle, incomplete contracting, and the multitude of stakeholders. An appropriate risk allocation is particularly crucial to achieving project success. This paper focuses on the risk allocation in PPP projects and argues that the transaction cost economics (TCE) theory can integrate the economics part, which is currently missing, into the risk management research. A TCE-based approach is proposed as a logical framework for allocating risks between public and private sectors in PPP projects. A case study of the Southern Cross Station redevelopment project in Australia is presented to illustrate the approach. The allocation of important risks is put under scrutiny. Lessons learnt are discussed and alternative management approaches drawing on TCE theory are proposed.

Building interactive relationships : the risks, dilemmas and learning initiatives associated with partnerships with 'real' purpose

Many teachers already do all kinds of interesting and potentially useful data collection with their students but in a fridge door context the data is rarely kept, the analyses are rarely shared beyond the classroom (except on a family’s fridge door) and it is very rare that data is stored and added to over time. (Bigum, 2002)

Relationship of body condition score, live weight, stocking rate and grazing system to the mortality of Angora goats from hypothermia and their use in the assessment of welfare risks

Body condition scoring is widely used for sheep and cattle but the practice is included in only one Code of Practice for the welfare of goats in Australia. There is no published scientific evidence to support or defend its use in the assessment of welfare risks to farmed goats.

PROCEDURE: The significance of stocking rate, grazing system, body condition score (CS) and live weight were investigated in explaining the risk of mortality of individual and flocks of grazing Angora goats from hypothermia following a severe weather event in April. This event occurred 5 weeks after shearing the goats. Angora goats and Saxon Merino sheep were grazed alone, or mixed together in equal numbers at each of three stocking rates.

RESULTS: There was no mortality amongst Angora goats provided they grazed at the lowest stocking rate even when their CS was < or = 2.0. Mortality in flocks of Angora goats was most related to the CS reached during the preceding 2 months. For flocks of Angora goats there was no mortality at CS > or = 2.5 and mortality increased sharply at mean CS < 2.0. For individual Angora goats, mortality increased as CS declined and stocking rate and grazing combinations were additive in effect on mortality. Grazing with sheep increased mortality of Angora goats at higher stocking rates. The individual goat mortality rate was not dependent on individual plot effects suggesting that these results are applicable widely. Live weight loss was not related to mortality rates of goats once CS had been accounted for.
CONCLUSION: It was concluded that CS and stocking rate were highly significant determinants of welfare risk in Angora goats.

Occupational therapists and the use of constraint-induced movement therapy in neurological practice

There is adaquate evidence for supporting the use of constraint-induced movement therapy (CIMT) in post-stroke rehabilitation. However, the actual usage of CIMT in routine occupational therapy practice appears limited. Further research is required to study why this might be so.

Analytical relationship between family history and genetic and environmental risks, with application to female breast cancer

It is well established in genetic epidemiology that family history is an important indicator of familial aggregation of disease in a family. A strong genetic risk factor or an environmental risk factor with high familial correlation can result in a strong family history. In this paper, family history refers to the number of first-degree relatives affected with the disease. Cui and Hopper (Journal of Epidemiology and Biostatistics 2001; 6: 331-342) proposed an analytical relationship between family history and relevant genetic parameters. In this paper we expand the relationship to both genetic and environmental risk factors. We established a closed-form formula for family history as a function of genetic and environmental parameters which include genetic and environmental relative risks, genotype frequency, prevalence and familial correlation of the environmental risk factor. The relationship is illustrated by an example of female breast cancer in Australia. For genetic and environmental relative risks less than 10, most of the female breast cancer cases occur between the age of 40 and 60 years. A higher genetic or environmental relative risk will move the peak of the distribution to a younger age. A more common disease allele or more prevalent environmental risk factor will move the peak to an older age. For a proband with breast cancer, it is most likely (with probability ge80%) that none of her first-degree relatives is affected with the disease. To enable the probability of having a positive family history to reach 50%, the environmental relative risks must be extremely as high as 100, the familial correlation as high as 0.8 and the prevalence as low as 0.1. For genetic risk alone, even the relative risk is as high as 100, the probability of having a positive family history can only reach about 30%. This suggests that the environmental risk factor seems to play a more important role in determining a strong family history than the genetic risk factor.

Application of the psychological contract to occupational safety

Psychological contracts were applied to occupational safety. A psychological contract of safety measure was developed and validated, and a model of safety developed to investigate breach and fulfilment of the psychological contract of safety. Findings suggest that the psychological contract of safety impacts safety attitudes and safety behaviour.

Costs, benefits and risks of IT in construction

Construction organisations were found to be reluctant to invest in IT due to the lack of a technique that accurately assesses the costs, benefits and risks. More importantly the associated indirect costs that are often overlooked can constitute up to 80% of costs related to investing in IT.

Safer injections, fewer infections : management of needles and sharps and occupational blood exposure in rural north Indian health settings

This study investigated injection practices and occupational exposure to blood in rural north Indian health settings. The findings highlighted a range of practices potentially contributing to the transmission of hepatitis and HIV to both patients and staff in these settings. Interventions need to focus on the development of organisational structures to support and facilitate safer practices.

Taking risks- experiential learning and the writing student

The role of a professional and creative writing degree is to provide resources, structured workshops, professional interactions - and the potential for creative risk. Opportunities for risk, within the structured environment of the university, challenge the individual's perspectives and judgements, as well as their ability to analyse and to reflect on their writing and creative practices.

From this starting point the authors, both writing industry practitioners and academics, have developed experiential projects with the aim of transforming their teaching practice from a model of narrative hierarchies of knowledge to learning through performativity, social correctedness and immersive workplace learning.

As the case studies illustrate, this transitional approach has enabled our millennial learners more confidently to take risks, accept challenges and transform their understanding of their own knowledge, skills and identities.