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.

Tránsito desda la higiene hacia la salud pública en Colombia en el contexto de las internacciones internacionales =The transition from hygiene to public health in Colombia in the context of international interactions

[No Abstract]

Naval instruction : a comparative research study

Naval training communities use a systems approach to training. This study considers the question "what is effectiveness in naval training?" Instructor courses of five navies were observed and naval instructors surveyed. Conclusions and recommednations are drawn from the data. It is proposed that most problems of effectiveness identified can be overcome without investment in technology or significant system changes.

Report of Captain A. B. Thomas, naval commandant on the Victorian Navy : from 1883 to 1886, together with regulations for permanent naval forces and naval brigade

Details the operations of the Victorian Navy for the period 1883 to 1886, including information on ships, training, stores, list of officers on the active and unattached list, list of ships including their armament, and the regulations under which the navy ran.

Food hygiene knowledge in adolescents and young adults

Purpose – The purpose of this paper is to utilise the comprehensive Food Safety Knowledge Instrument to compare food hygiene knowledge across a population of high school and university students in Australia and the UK. Design/methodology/approach – In total, 475 students from secondary schools and universities in Australia and the UK took part in a survey, which included a Food Safety Knowledge Instrument and demographic items. Findings – Food safety knowledge was generally very low. High school students had a mean score of only 38 per cent, while university students just reached a “pass” with a mean of 54 per cent. Demographics accounted for 41 per cent of variance in food knowledge scores. Female gender, being at university rather than high school, and living out of home rather than with parents were associated with greater food knowledge. Residing in Australia rather than the UK and being older were also associated with greater knowledge; however, these findings were subsumed by education group. Socio-economic status was not a significant predictor of food knowledge. Practical implications – Identifying demographic and cultural differences in food knowledge can help to identify at-risk populations to better target in theory and knowledge-based interventions. Originality/value – This study is the first to apply the knowledge instrument in an Australian population. Understanding the baseline knowledge in this population is an important first step at developing effective interventions for food safety.

Disentangling quality and safety indicator data: a longitudinal, comparative study of hand hygiene compliance and accreditation outcomes in 96 Australian hospitals.

The study aims are twofold. First, to investigate the suitability of hand hygiene as an indicator of accreditation outcomes and, second, to test the hypothesis that hospitals with better accreditation outcomes achieve higher hand hygiene compliance rates.

Social capital and hygiene practices among the extreme poor in rural Bangladesh

We investigate the effect of social capital on hygiene practices pertaining to lives of the extreme poor in rural Bangladesh. Analysing a unique survey dataset for 5,600 extreme poor households, we document a significant positive effect of social capital on sanitary latrine use and wearing shoes/sandals at home for hygiene. We account for the endogeneity of social capital by instrumental variable estimation. Our findings emphasise the role of social capital in preventing common diseases through improving hygiene practices for the extreme poor, who usually lack access to medical services in the event of illness, which has important policy implications.

Street vendors in Patna, India: understanding the socio-economic profile, livelihood and hygiene practices

Street food vending is fundamental to daily life in many low and middle income countries where much of the urban population rely on food provided by street vendors. While street vendors are known to be important providers of food; limited research has investigated vendor's hygiene practices and their socioeconomic circumstances in India. The aims of this study were to investigate the hygienic practices of food vendors and the context of their socioeconomic and living circumstances. Structured interviews were conducted with 31 street food vendors in Patna, India. The interviews explored issues around vending, hygiene practices, planning, and financial stability. Findings from this study indicate that food vendors are aware of good basic hygiene practices despite having low levels of literacy, low incomes, and limited job security.

Keeping it clean : bird bath hygiene in urban and rural areas

In a dry continent like Australia where the provision of water in bird baths is a common and popular practice, very little is known about it. We describe the use of different types of bird baths and how these were maintained by residents (n = 1,728 respondents). The most commonly monitored bird baths were pedestal/elevated baths (>80%). Participants refilled bird baths more frequently in summer compared with winter (water changed once a day: winter respondents, 37.5%; summer respondents, 53.8%). Bird baths were also cleaned regularly (‘Yes I do’: 26.4%; winter respondents, 23.1%; summer respondents; ‘I do but not every time’, 55.6% winter respondents, 58.6% summer respondents). Overall our study indicates good hygiene practices for the maintenance of bird baths, which may help prevent the spread of avian diseases; and that residents are providing water seemingly based on the perceived need for water by birds.