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This thesis examines the important and topical issue of food safety among member states of the European Union. After tracing the development of related legislation, a review of the literature focuses on its management within the European hotel industry. In attempting to account for differences in attitudes and practice towards food safety, the study explores the respective application oftwo opposing theoretical positions. The first, known as divergence theory, which tends to equate culture with nationality, maintains that variation is attributable to inter-country differences in norms and values. The second, convergence theory, argues that culture is more appropriately understood in the organisational sense as functioning at the corporate level of the hotel. Hence, under the latter perspective, an explanation of variance is more likely to be derived from differences in type or ethos of hotel (whether chain or independent) and the ways that they are structured according to mode ofoperation, size and hierarchy. After outlining the methodological difficulties of carrying out a comparative study capable of resolving the foregoing dilemma, the empirical section takes place in two major stages: (1 ) a canvassing of expert opinion, with a view to filling gaps in knowledge of the legislation and its implementation; and (2) the conducting of a sample survey among hotel personnel in a number of EU member states (this stage being preceded by a small, two-phase pilot investigation). In order to contrast the rival theories statistically, the data from the survey are analysed by a series of relevant independent variables and tested for significance. Although there are acknowledged limitations on the degree of generalisation that can be claimed, by and large the convergence theory is upheld. A summary of the findings is provided and a number of implications for the future of food safety legislation in the EU are highlighted.

This thesis describes research into a methodology for the systematic development of engineering line diagrams (ELOs) from process tlowsheets with a particular emphasis on safety, health and environmental (SHE) and operability issues. The current approach to the consideration of safety in design is largely reactive, relying on design reviews such as the HAZOP. If design safety is to be improved, then a comprehensive system, incorporating both proactive and reactive methods, must be adopted. The facility to develop proactive safety systems relies upon the presence of a systematic design procedure. Since design at this stage seems generally to be rather haphazard, there is a need to introduce structure to the design task before any progress can be made in the improvement of safety. Introducing structure to the design task not only provides a framework for the incorporation of SHE and operability issues, but should also improve the effectiveness of the overall design and the efficiency with which it is completed. More specifically, fewer good design opportunities should be lost due to poor information handling and thc amount of rework arising from misunderstandings between different disciplines should be minimised. In addition, learning how to perform the design task should become easier for new recruits. Relevant work in the fields of process design, process safety, engineering drawings and ELO development is discussed. An analysis of perceptions of the design task within industry is presented. The generation of a systematic method by iterative case study work with designers is described. The structural features of this method are explained. Some examples of the application of the method are given and the results of a trial within industry are discussed. This research has shown that there is no existing work which captures the logic for the order in which decisions for developing a first ELO are made. Neither is there a complete analysis of the activities and issues contributing to ELO development. A novel method for the systematic generation of ELOs has been produced and used as a framework for the incorporation of SHE and operability issues into design. Trials of the method within industry have shown it to be successful.

Safety cases must be produced by offshore operators to assess the risks posed to the personnel by potential accidents. On an offshore platform two of the major hazards are fires and explosions resulting from an accidental hydrocarbon release. The overpressures generated during an explosion can threaten the integrity of the platform structure. It is therefore important to be able to estimate the overpressures generated, should an explosion occur, and to predict the frequency of such an event. A methodology has been developed to predict the frequency of explosions of different magnitudes occurring in a module on an offshore platform. This methodology combines established risk assessment techniques, such as event tree analysis and fault tree analysis, with fluid flow modelling. Assumptions have been made in the methodology to simplify the calculation procedure. These assumptions relate to the conditions under which the leak occurs, the build up of gas in air concentration and the probability calculations. Frequency predictions are required to be as accurate as possible to enable the acceptability of the risk to be determined and reduced to a level which is as low as reasonably practicable. Hence each of the assumptions within the methodology has been addressed, to determine a more complete prediction tool. Once an accurate frequency for the explosion occurring has been determined, the risk to personnel must be minimised to an acceptable yet practical level. On existing designs it is impractical to alter the layout of the platform. However the nature of the safety systems may be changed. These safety features include isolation, blowdown, mitigation and detection systems. An optimisation study presents three schemes to identify the optimum configuration of the safety systems, in terms of the overpressures generated, as a means of reducing the risk to the platform.

This thesis describes a retrospective cohort study of cancer mortality among employees of the Celanese Canada Inc. synthetic textiles plant in Drummondville, Quebec. The study was commissioned by the company to confirm or refute a previous observation (Vobecky et al., Cancer 54:2537-2542, 1984) that there were higher mortality rates from colorectal cancer among male employees of the textiles unit, the cellulose acetate fiber manufacturing unit, and the cellulose triacetate and polypropylene extrusion units and to investigate whether mortality rates for other sites of cancer were associated with employment in each area of the plant and with occupational exposures. / Workers with more than one year experience at the plant were eligible for study if they were employed on January 1, 1947 or if they were newly hired between that date and December 31, 1977. Vital status as of December 31, 1986 was ascertained for 7,422 men and 2,720 women through a probabilistic record linkage to the Canadian Mortality Data Base. Among men, there were about 220,000 person-years of observation and 1,738 deaths and, among women, there were about 89,000 person-years of observation and 241 deaths. / Three reference regions were used to derive standardized mortality ratios (SMR): the entire Province of Quebec, semi-rural regions of the Province, and the area in which the plant is located. Results based on rates for these regions were generally similar. For men, the SMR for all causes of death was significantly less than unity (SMR = 0.71, 95%CI:0.68-0.74), as were the SMRs for most sites of cancer (SMR all neoplasms = 0.73, 95%CI:0.66-0.80). The SMR for colorectal cancer was 0.68 (95%CI:0.51-0.91). Of the 20 cancer sites examined in men, reticulum cell sarcoma was the only one having a significantly elevated SMR, and this occurred only among the subcohort of men hired prior to 1947 (SMR = 2.84, 95%CI:1.04-6.18, 6 deaths). For women, the SMR for all causes of death was 0.75 (95%CI:0.66-0.85) and there were moderately elevated SMRs for a number of sites of cancer, but none were significantly greater than expectation (SMR all neoplasms = 0.97, 95%CI:0.80-1.17). / SMRs were also calculated according to employment in each processing unit and exposure to occupational agents, and case-control analyses were carried out within the cohort for selected sites of cancer. Of the scores of associations tested, very few were significantly elevated. There were excesses of biliary cancers and non-Hodgkin's lymphomas among workers in the cellulose acetate fiber manufacturing unit. There were also significant associations between stomach cancer and exposure to cutting oils, and between prostate cancer and exposure to glycol monobutyl ether. However, none of these associations were persuasive. / With regards to colorectal cancer, there was a nonsignificant elevation in risk among workers who had ever worked in the polypropylene and cellulose triacetate extrusion unit (OR$ sb{ rm e}$ = 2.3, 95%CI:0.5-9.9) but there was no apparent increase in risk with increasing duration of employment. Thus, the evidence for an association was not convincing. For the cellulose acetate fiber manufacturing unit, the evidence of an increase, although based on few cases, was slightly more persuasive (OR$ sb{ rm e}$ = 1.9, 95%CI:1.0-3.6), but no trend was observed with duration. No association was observed with employment in the textiles unit (OR$ sb{ rm e}$ = 1.1, 95%CI:0.6-2.2) nor were there any noteworthy associations between colorectal cancer and any of the agents evaluated in the case-control analyses.

The prevalence of asthma and the role of occupational exposures was investigated in a cross-sectional study of 498 Montreal adults aged 20 to 44 years. Prevalences of asthma standardised for age and gender, using four definitions were: current wheeze: 23 8%, asthma symptoms and/or medicine: 12.9%, airway hyper-responsiveness: 15.1%, airway hyper-responsiveness and current wheeze: 7.0%. Imputation to adjust for non-response to airway challenge gave similar results. 56.9% of subjects reported occupational exposure ever to sensitisers and 10.8% to irritants. Current wheeze was associated with exposure to irritants (OR: 2.12 (1.03, 4.34)), and airway hyper-responsiveness with exposure to sensitisers (OR: 2.20 (1.10, 4.38)). Childhood asthma and atopy did not affect the associations. Population attributable risk was about 30% for airway hyper-responsiveness with exposure to sensitisers, and 5% for current wheeze with exposure to irritants. Studies with more precise exposure information may provide better evidence for the causality of the association.

The influence of psychological status on recovery from a first lifetime episode of acute low-back pain was assessed in compensated workers seen in a physiatry clinic. One hundred thirty-four participants of a back school intervention trial were selected and followed for 1 year. The objectives were to determine the evolution of psychological distress, well-being, pain, self-reported disability and spinal flexibility, and to determine the psychological factors associated with return to work and recurrence. Improvement occurred post-treatment in all measures except well-being which did not fluctuate over the year. Additional improvement in functional disability occurred at 6 and 12 months. Using multiple logistic regression, low baseline psychological distress predicted late return to work and high baseline well-being predicted recurrence. A second model for recurrence that was constructed with post-treatment scores on the longitudinal measures had greater predictive power than the model using baseline scores. These results have implications for the management of return to work.

The goal of this study was to verify if differences in respirable dust and respirable quartz concentrations exist with respect to the mines, the ore deposit types and the nature of workstations. / One hundred and seventy-nine respirable dust samples were collected in the six mines studied, in compliance with the method recommended by the Institut de recherche en sante et securite du travail du Quebec (IRSST). Then, samples were analysed using X ray powder diffraction technique to determine respirable quartz concentrations. / Results indicated statistically significant differences in the normalised exposure levels to respirable dust (p = 0.017), to respirable quartz (p < 0.001) as well as the quartz percentage in the respirable dust (p < 0.001) of the six mines studied. When grouped by ore deposit type, normalized exposure levels to respirable dust were not statistically different. However, statistically significant differences were noticed for normalized exposure levels to respirable quartz (p = 0.004) and respirable quartz percentage (p < 0.001) according to ore deposit types. / For all mines studied, respirable dust concentrations were all below the admissible exposure value whereas about 9% of the respirable quartz concentrations were equal or above the admissible exposure limit. Gold ore deposits hosted in quartz veins had the highest normalized respirable quartz exposure levels, as well as the highest percentage of quartz in the respirable dust when compared to gold ore deposits with sulfide lodes, the copper-zinc ore deposit and the disseminated gold ore deposit. / The study also revealed that workers who worked in the ore crushing and hoisting departments as well as loading and transport had higher normalised exposure levels to respirable quartz than workers who worked in the drilling and blasting or those who worked in the maintenance department. / In conclusion, this study stressed that quartz content in the mined rocks seems to be the most important factor influencing on respirable quartz concentrations in the mine worker's respiratory zone, but the relation between the two variables were not strongly correlated (Rs = 0.254, p = 0.005). Furthermore, the study showed that the gold ore deposits with quartz lodes had the highest normalized exposure levels to respirable quartz. Also, the workers assigned to ore crushing and hoisting departments as well as transport and loading had the highest exposure levels to respirable quartz. (Abstract shortened by UMI.)

How clinicians detect and differentiate near misses from adverse events in health care is poorly understood. This study adopted a constructivist grounded theory approach and utilized document analysis and semi-structured interviews with 24 managers (middle and senior) and clinicians to examine the processes and factors associated with recognizing and recovering and learning from near misses in daily clinical practice. While safety science suggests that near misses are sources of learning to guide improvement efforts, the study identified how clinicians and managers cognitively downgrade and accept near misses as a routine part of daily practice. Such downgrading reduces the visibility of near misses and creates a paradoxical effect of promoting collective vigilance and increased safety while also encouraging violations in clinical practice. Three approaches to correcting and/or learning from near misses emerged: “doing a quick fix,” “going into the black hole,” and “closing off the swiss-cheese holes”; however, minimal organizational learning occurs. From these findings, two key paradoxes that undermine organization-level learning require further attention: (a) near misses are pervasive in everyday practice but many remain undetected and are missed learning opportunities, and (b) collective vigilance serves as both safety net and safety threat. Study findings suggest that organizational efforts are required to determine which near misses need to be reported. Organizations need to shift the culture from one of “doing a quick fix” to one that learns from near misses in daily practice; they should reinforce the benefits and reduce the risks of collective vigilance, and further encourage learning at the clinical microsystem level. Future research is required to provide insight into how individual, social, and organizational factors influence the recognition, recovery, and instructional value of near misses and safety threats in health care organizations’ daily practice.

Anyone can upload news instantaneously to Twitter in 140-characters or less, therefore it is important to assess the credibility of tweets, particularly during a foodborne illness outbreak. According to a Microsoft study there are numerous Twitter features that impact the credibility of tweets. This study examines students’ use of Twitter, and their perceptions of how features and sources impact the credibility of tweets related to a foodborne illness. An online survey was completed by Texas A&M University students classified as U3 juniors (N = 200) in social science-based majors in the College of Agriculture and Life Sciences. The study revealed students to be moderate users of Twitter. Eight features were identified to impact credibility: verified author topic expertise, account has verification seal, tweet contains grammar/punctuation mistakes, author is someone you’ve heard of, author is often mentioned/retweeted, author often tweets on topic, and author has many followers. Three Twitter identities a professor, student, and student organization, were created to measure tweet credibility. Tweets from the professor were perceived more credible than tweets attributed to student or student organization. The results indicated statistical differences between features attributed to each source. These findings can help sources determine what features can make tweets the most credible. This study has important implications for organizations that engage consumers on Twitter when breaking news such as a foodborne illness outbreak occurs.