Date of Award
Doctor of Philosophy
School of Exercise, Biomedical and Health Sciences
Computing, Health and Science
Professor Jacques Oosthuizen
This thesis outlines the results of occupational respiratory health surveillance at Minara Resources, Murrin Murrin mine site. The research was conducted as part of a collaborative agreement between Edith Cowan University and Minara Resources, the overarching title of which was ‗Establishing best practice protocols in the management of occupational and environmental health in a high-risk mining and ore-processing environment‘. To form the basis of this research it was hypothesised that although the chemical hazards had been adequately identified, and the occupational exposures in each work area at Murrin Murrin were generally well below their respective occupational exposure levels, it was still possible that additive, or even synergistic biological effects could cause adverse respiratory health effects due to the exposure to a combination of these atmospheric contaminants. This was the perception and a concern voiced by the Murrin Murrin workforce. Therefore, in working through the hypothesis, a literature review concentrating on the gaps in current knowledge and research for the early detection of occupational respiratory diseases was conducted, and the research tool and experiment design determined. The case for using pulmonary function tests in conjunction with a respiratory questionnaire in assessing early respiratory changes due to occupational exposures was established. Over a period between 17 February 2004 and 21 June 2006, a longitudinal study was conducted to ascertain the prevalence of respiratory symptoms and lung function of employees at the Murrin Murrin Operation, and compared with a local control group consisting of catering staff who resided at the accommodation camp approximately eight kilometres from the mine site. Lung function data were also compared to established predicted normal values from a reference population with normal lung function. Lung function data were analysed to determine whether there was an effect due to the area worked, and the employee‘s length of service. The lung function parameters of the study group, corrected for age and height were compared using linear regression analysis with both the control group and the predicted normal values. Repeat lung function tests were conducted on a sample of the original study group approximately two years after the initial study and statistically analysed to determine whether there was an effect on lung function over this time period. In addition, lung function tests were conducted for a cohort of refinery workers at the start and end of their two-week work period to determine whether there was a before-and-after effect due to their working conditions. The prevalence of respiratory symptoms was less in the study group compared to the controls; and these respiratory symptoms were determined to be non-work-related. On statistical analysis, for the ‗presumed healthy‘ workers (minus the smokers and those with known non-work-related respiratory symptoms) there was no overall decrement in lung function. Similarly, there was no overall statistically significant decrement in lung function for the ‗presumed healthy‘ workers in the repeat study conducted approximately two years after the initial study. There was no decrement in lung function associated with area work; nor was there a decrement in lung function for the cohort of refinery workers from the start to completion of their two-week work period. However, there were decrements in lung function for the smokers in the study and control groups. There was a significant difference in FEV1 between non-smokers and smokers with length of service (p <0.05); and a significant difference (p <0.05) in FEV1 from first spirometry test compared with the repeat spirometry test for the smokers/asthmatics sub-group in the repeat study. This in effect acted as ‗internal validity‘ indicating that spirometry was sensitive enough to detect a decrease in lung function due to smoking in the initial and repeat studies; and that if there were adverse respiratory health effects due to the exposure of atmospheric contaminants at the Murrin Murrin Operation, that this would have been detected. Hence the concern shown by the employees at the Murrin Murrin Operation, that workplace emissions may be harming their respiratory health, appears to be dispelled by this study.
Cross, Martyn, "Occupational Respiratory Health Surveillance at Minara Resources, Murrin Murrin Mine Site" (2011). Theses: Doctorates and Masters. Paper 418.