Foodborne illnesses respresent a serious threat to health. The World Health Organisation (2000) recently passed a Resolution stating that "... foodborne illness associated with microbial pathogens, biotoxins and chemical contaminants in food present a serious threat to the health of millions of people in the world (p.1)". Overall notifications of foodborne illness and food poisoning have risen significantly and many outbreaks have been associated with the food industry. The Hospitality and Catering industry is of special concern because of it's size, diversity, individual characteristics, and direct interface with customers. This thesis focuses upon the Hospitality and Catering industry in Wales, a largely unexplored area of research. It applies an investigate approach to issues relating to the management and implementation of food safety in the industry across a range of industry sectors to be found in the Principality. Information was gathered by utlising a range of secondary and primary sources. Data collection instruments included questionnaires, structured interviews, and audit checklists and observations. These were administered by way of three discrete but interlinked primary data collection investigations. Both quantitative and qualitative data were obtained. Participating industry personnel included proprietors, managers and food handlers. Via a literature review, the key issues of knowledge, attitudes and behaviour related to food safety are discussed and evaluated within the contexts of the inherent characteristics of the Hospitality and Catering industry and food safety legislation. There three investigations are presented individually and the findings are consolidated in a synoptic discussion in relation to the Aims of the thesis. The findings indicated that within the Welsh Hospitality and Catering industry levels of knowledge and attitudes with regard to food safety and food safety legislation were variable and in some instances, unsatisfactory. In many instances, intentions to act in a positive manner towards the implementation of food safety precautions were not reflected in actual behaviour. It was further found that in establishments of all sizes and ownership categories, food handling practices were variable and in many cases, unsafe. Recommendations are made based upon the results obtained and discussed in this thesis.

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Les phycotoxines lipophiles sont des métabolites secondaires produits par certaines espèces phytoplanctoniques. Elles s'accumulent dans les mollusques filtreurs et peuvent provoquer une intoxication chez l'homme avec une grande variété de symptômes. Ce travail s’est attaché à mieux connaitre leur devenir chez l’homme et leurs effets après ingestion en apportant des données sur leur absorption intestinale et leur métabolisme hépatique puisque ces phénomènes affectent la quantité de toxine circulant dans l’organisme et donc la génération d’effets toxiques. En outre, plusieurs phycotoxines se retrouvent parfois simultanément dans les coquillages alors que les effets de ces mélanges sont encore méconnus. Quatre phycotoxines lipophiles, l'acide okadaïque (AO), la pecténotoxine-2 (PTX-2), la yessotoxine (YTX) et le spirolide (SPX-1), ont été sélectionnées. Le passage intestinal a été évalué à l’aide de cellules intestinales humaines Caco-2 mimant l’épithélium intestinal. Si des différences d’absorption ont été observées pour les 4 phycotoxines, nos résultats ont montré que l’épithélium intestinal était également capable de les renvoyer dans la lumière intestinale, limitant ainsi la quantité circulant dans l’organisme. De même, à l’aide d’extraits de foie, nous avons montré que la structure des 4 phycotoxines était modifiée, principalement par des réactions d'hydroxylation. Concernant les effets mélanges, l'ajout d'une autre toxine (PTX-2, YTX ou SPX-1) à l'AO entraîne des effets moins importants avec de faibles concentrations, et des effets additifs ou plus importants avec des concentrations plus élevées. Ces résultats apportent des données complémentaires pouvant servir à confirmer ou réviser les seuils réglementaires établis pour ces toxines. / Lipophilic phycotoxins are secondary metabolites produced by some phytoplankton species. They accumulate in filter-feeding molluscs and can cause intoxication in humans with a wide variety of symptoms. This work aimed at bringing better knowledge on their fate in humans and their effects after ingestion by providing data on their intestinal absorption and their hepatic metabolism since these phenomena affect the amount of toxin circulating in the body and therefore the generation of toxic effects. In addition, several phycotoxins are sometimes found simultaneously in shellfish while the effects of these mixtures are still unknown. Four lipophilic phycotoxins, okadaic acid (OA), pectenotoxin-2 (PTX-2), yessotoxin (YTX) and spirolide (SPX-1) were selected. The intestinal passage was evaluated using human intestinal Caco-2 cells mimicking the intestinal epithelium. If differences in absorption were observed for the 4 phycotoxins, our results showed that the intestinal epithelium was also able to send them back into the intestinal lumen, thus limiting the amount circulating in the body. Similarly, using liver extracts, we showed that the structure of the 4 phycotoxins was modified, mainly by hydroxylation reactions. For mixtures effects, the addition of another toxin (PTX-2, YTX or SPX-1) to OA results in lower effects at low concentrations, and additive or larger effects at higher concentrations. These results provide additional data that can be used to confirm or revise regulatory thresholds established for these toxins.

Moluscos bivalves são organismos filtradores capazes de concentrar susbtâncias produzidas por microalgas tóxicas. No estado de Santa Catarina, líder na produção nacional, os cultivos têm sido oficialmente monitorados para a detecção de ficotoxinas causadoras dos Envenenamentos Diarreico (DSP), Amnésico (ASP) e Paralisante (PSP) por Consumo de Moluscos nas partes comestíveis. Amostras de água também são coletadas para a quantificação de algas nocivas. O objetivo deste trabalho foi sugerir o uso de áreas amostrais para coletas semanais, bem como calcular o tamanho das amostras agrupadas e analisar os dados de ocorrência. Diferentes cenários foram desenvolvidos para simular a variação dos tamanhos amostrais, utilizando-se o EpiTools®. Considerando-se uma alta prevalência e altas sensibilidades dos testes, é possível sugerir dois pools amostrais para a detecção de Toxinas Lipofíficas (2x30), duas para detectar PSP (2x15) e uma para detectar ASP (1x20) em cada uma das 24 áreas amostrais sugeridas. Se o teste de Cromatografia Líquida com Espectrometria de Massa (LC-MS/MS) for validado para todas as biotoxinas, apenas um pool amostral seria suficiente (1x15). Informações espaçotemporais de ocorrência também foram analisadas e apenas ficotoxinas causadoras de DSP foram encontradas. Utilizando-se os softwares SaTScan® e QGIS 2.12.2- Lyon®, foram desenvolvidos mapas de calor com os dois clusters espaciais encontrados para as detecções de DSP em moluscos e os quatro para Dinophysis acuminata (≥100cels/L) em amostras de água. Os resultados com maiores riscos relativos corresponderam ao cluster temporal do segundo semestre de 2014, os clusters espaciais das áreas 7 a 11 para DSP e áreas de 7 a 9 para D. acuminata. Esses resultados poderão contribuir para o planejamento de estratégias a serem incorporadas num futuro sistema de vigilância de moluscos bivalves do estado. / Bivalve molluscs are filtering organisms capable to concentrate substances produced by toxic microalgae. In Santa Catarina state, main Brazilian producer, the crops have been officially monitored for the detection of phycotoxins that cause Diarrheic (DSP), Amnesic (ASP), and Paralyzing (PSP) Shellfish Poisonings in edible parts. Water samples are also collected for harmful algae quantification. The goal of this study was to suggest the use of areas to be weekly sampled, as well as to calculate pooled sample sizes and to analyze the occurrence data. Different scenarios were developed to simulate the variation of sample sizes in EpiTools®. Considering a high prevalence and high tests sensitivities, we can suggest two pools to detect Lipophilic Toxins (2x30), two to detect PSP (2x15), and one to detect ASP (1x20) in each of the 24 suggested sampling areas. If the test of Liquid Chromatography with Mass Spectrometry (LC-MS/MS) becomes validated for all biotoxins, only one pool would be enough (1x15). Space-time occurence information was also analyzed and only phycotoxins causing DSP were found. Using SaTScan® and QGIS 2.12.2-Lyon® softwares, we developed heatmaps with two clusters found for DSP detection in shellfish and the four found for Dinophysis acuminate (≥100cels/L) in water samples. The results with higher relative risk values corresponded to the time cluster of the second semester of 2014, spatial cluster of the areas 7 to 11 for DSP, and areas 7 to 9 for D. acuminate. These results can contribute for the strategic plans to be incorporated in a future bivalve molluscs surveillance system of the state.

Moluscos bivalves são organismos filtradores capazes de concentrar susbtâncias produzidas por microalgas tóxicas. No estado de Santa Catarina, líder na produção nacional, os cultivos têm sido oficialmente monitorados para a detecção de ficotoxinas causadoras dos Envenenamentos Diarreico (DSP), Amnésico (ASP) e Paralisante (PSP) por Consumo de Moluscos nas partes comestíveis. Amostras de água também são coletadas para a quantificação de algas nocivas. O objetivo deste trabalho foi sugerir o uso de áreas amostrais para coletas semanais, bem como calcular o tamanho das amostras agrupadas e analisar os dados de ocorrência. Diferentes cenários foram desenvolvidos para simular a variação dos tamanhos amostrais, utilizando-se o EpiTools®. Considerando-se uma alta prevalência e altas sensibilidades dos testes, é possível sugerir dois pools amostrais para a detecção de Toxinas Lipofíficas (2x30), duas para detectar PSP (2x15) e uma para detectar ASP (1x20) em cada uma das 24 áreas amostrais sugeridas. Se o teste de Cromatografia Líquida com Espectrometria de Massa (LC-MS/MS) for validado para todas as biotoxinas, apenas um pool amostral seria suficiente (1x15). Informações espaçotemporais de ocorrência também foram analisadas e apenas ficotoxinas causadoras de DSP foram encontradas. Utilizando-se os softwares SaTScan® e QGIS 2.12.2- Lyon®, foram desenvolvidos mapas de calor com os dois clusters espaciais encontrados para as detecções de DSP em moluscos e os quatro para Dinophysis acuminata (≥100cels/L) em amostras de água. Os resultados com maiores riscos relativos corresponderam ao cluster temporal do segundo semestre de 2014, os clusters espaciais das áreas 7 a 11 para DSP e áreas de 7 a 9 para D. acuminata. Esses resultados poderão contribuir para o planejamento de estratégias a serem incorporadas num futuro sistema de vigilância de moluscos bivalves do estado. / Bivalve molluscs are filtering organisms capable to concentrate substances produced by toxic microalgae. In Santa Catarina state, main Brazilian producer, the crops have been officially monitored for the detection of phycotoxins that cause Diarrheic (DSP), Amnesic (ASP), and Paralyzing (PSP) Shellfish Poisonings in edible parts. Water samples are also collected for harmful algae quantification. The goal of this study was to suggest the use of areas to be weekly sampled, as well as to calculate pooled sample sizes and to analyze the occurrence data. Different scenarios were developed to simulate the variation of sample sizes in EpiTools®. Considering a high prevalence and high tests sensitivities, we can suggest two pools to detect Lipophilic Toxins (2x30), two to detect PSP (2x15), and one to detect ASP (1x20) in each of the 24 suggested sampling areas. If the test of Liquid Chromatography with Mass Spectrometry (LC-MS/MS) becomes validated for all biotoxins, only one pool would be enough (1x15). Space-time occurence information was also analyzed and only phycotoxins causing DSP were found. Using SaTScan® and QGIS 2.12.2-Lyon® softwares, we developed heatmaps with two clusters found for DSP detection in shellfish and the four found for Dinophysis acuminate (≥100cels/L) in water samples. The results with higher relative risk values corresponded to the time cluster of the second semester of 2014, spatial cluster of the areas 7 to 11 for DSP, and areas 7 to 9 for D. acuminate. These results can contribute for the strategic plans to be incorporated in a future bivalve molluscs surveillance system of the state.

Marine biotoxins constitute one of the major hazards associated with seafood consumption. Risk assessments are essential for the effective management of problems arising from marine biotoxins occurrence, as they are a prerequisite for the establishment or periodic re-evaluation of marine biotoxins regulatory limits and for the adoption of appropriate risk management plans. Risk assessments are science-based data-intensive processes, and their successful outcomes are largely dependent on the quality of data used when they are carried out. In fact, data-related challenges are the most frequently reported issues rendering most marine biotoxins’ risk assessments conducted to date as inconclusive. Notably, data quality perceptions among the stakeholders involved in risk assessments may vary significantly, which may be a human factor influencing data quality. As such, the problem addressed in this thesis is the shortage of empirical information on how data quality is perceived by the different stakeholder roles involved in risk assessments relevant to marine biotoxins hazards. The focus of this thesis is thus to investigate the perceptions of diverse stakeholders within the information chain, namely data producers, collectors and consumers/users, regarding the quality of data used in risk assessments of marine biotoxins hazards, to provide a contribution directed towards data quality improvement. This was done by means of a survey, gathering data through interviewing a number of recognized marine biotoxins’ experts with documented experience in risk assessments. The research question of this study is: “What are the perceptions of data quality among diverse stakeholders along the information chain relevant to marine biotoxins’ risk assessments?” To answer the research question, the concept of data quality for marine biotoxins data destined for risk assessments was dissected into seven individual subtopics on which the perceptions of expert participants of all three roles were captured. The subtopics explored included: data quality challenges; changes in marine biotoxins data quality during the last decade; awareness on data quality legislation and standardization; importance of data quality dimensions, objectives and key performance indicators; importance of data quality-related feedback exchange between stakeholders of the relevant information chain; factors for successful adoption of harmonized standardized formats for marine biotoxins data collection; and suggestions for data quality improvement. The perceptions gathered per subtopic were analyzed using inductive thematic analysis, yielding a total of twelve themes, namely communication, compound, data/quality control, Information Technology or Data Collection Framework, legislation, method, organization, people, policy, risk assessment procedure, society/environment and toxicological aspects, with each subtopic containing items categorized within several of these themes. Certain differences were observed in the perceptions between participants of diverse data roles, in the sense that data producers and to a lesser extent data users mostly focused on themes relevant to analytical methodology, compound particularities, data and quality control, toxicological aspects and policies. On the other hand, data collectors’ views were more concentrated on items relevant to Information Technology or Data Collection Framework and organization. It is noted, however, that interpretation of these trends needs to consider that in many of the study participants different roles overlapped in the same person. This indicates that results should be cautiously generalized. Nevertheless, they could constitute a basis for further research to generate deeper knowledge in the field of data quality in risk assessments relevant to marine biotoxins and gain further insights on the differences in perceptions among data roles.