https://www.um.edu.mt/library/oar/handle/123456789/47635 2026-04-26T21:23:40Z https://www.um.edu.mt/library/oar/handle/123456789/48656 Title: Dioxins in food. Abstract: The aim of this dissertation is to provide some information regarding dioxins and the ways and means to reduce dioxin contamination in our islands. Another aim is to create awareness on the subject among the Maltese population. This dissertation includes a description of: • What are dioxins? And their structure, health effects, • Sources, • Analysis, • Control measures. Unfortunately, very little is known about the extent of dioxin contamination, human exposure to dioxins and the long-term health effects these may cause to the Maltese population. This is mainly due to the fact that there is no monitoring for dioxins going on. The local population is only just becoming aware of this type of pollution. The incident that occurred in Belgium in June 1999 seems to have contributed to this 'increase' in local awareness. Dioxins require three main factors in order to be formed: a source of chlorine, a source of organic matter and a reactive environment for these to combine. In other words, it is relatively easy to have dioxin formation. In Malta, our main source of dioxins is probably our landfill at Maghtab where various materials including PVC (a main contributor to dioxin formation) are burnt. Also, another problem with the dump is incomplete combustion that also contributes to dioxin formation. Other sources include the power station, especially the one at Marsa and car emissions, due to the fact that the quality of fuel that Malta imports is of rather poor quality. The greatest source of human exposure to dioxins is through the diet. About 90% of our exposure comes from the food we eat. Dioxins tend to accumulate in fatty foods, for example, meat, fish, and milk products. Therefore, the higher the amount of fat m ones diet, the greater the exposure! Dioxins have a large amount of serious health effects, both short term and long term. Short-term effects include chloracne, altered liver function and long-term effects include impairment of the immune, endocrine, nervous and reproductive systems. Also, chronic exposure to dioxins increases the risk of cancer. I believe that there is much research to be done on this subject. Also, in order to find out to what extent our island is polluted with dioxins, how high is the exposure of the Maltese population and most of all to reduce this pollution; a continuous monitoring system must in some way or other, definitely be put in place. Description: DIP.ENV.HEALTH 2000-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/48635 Title: Valleys : taking Wied is-Sewda as a case study. Abstract: "A valley (or wied) can be conveniently defined as a depression of the land surface formed as a result of erosion mostly by the passage of water or land movements and usually containing running water during some time of the year" (Sonya Vella, MCST, Water Network). The depth, width and length of valleys strengthen these hypotheses. The catchment causes a watercourse of a valley. The catchment area or drainage basin is an area made of ridges and land at a higher level. This serves as a natural basin where rainfall and consequently runoff is directed to the watercourse which is basically a water channel along which there is movement of water in the form of a stream or river. "Infact watercourse can be defined as a natural or man-made open channel on the land surface through or along which water may flow" (Sonya Vella MCST Vlater Netvvork). There are about 100km of of main watercourse in Malta and about double that amount in minor tributaries. Most of the Maltese Valleys are appropriately called river valleys because of watercourses actively occurred a long period of time. Different influences have reduced water flow, but the rivers have left behind the legacy of life, both natural and artificial, that water always generates. This is why valleys remain a very important part of Malta's natural, social and cultural history. The sloping sides have led to agricultural activities, the watercourse to very fertile land supporting ecological systems, which all combined, have resulted in a characteristic landscape particular to our islands. The importance of valleys can be summarised as below: 1. They are habitats of great ecological value due to the amount of flora and fauna they support, sometimes finding rare and endangered and indigenous species. 2. They are important water resources where aquifer replenishment is enhanced. 3. Their channel or watercourse along which water is carried prevents flooding over flat land. 4. Valleys enable storage of water temporarily or permanently to be used for agriculture. 5. They collect eroded soil. 6. They usually possess cultural, historical and archaeological heritage. 7. They have a recreational value for tourism and locals alike. 8. They have beautiful aesthetic values. These valuable assets have been exploited completely by human activities which has led to negative influence and sometimes resulted in undesired effects which are detrimental to public health either directly or indirectly and thus pose concern. So with this in mind, I asked my tutor which valley would be best to investigate, in order to note processes and activities practised, identify the hazards they pose and remedial measures taken and further recommendations possible. Our choice fell on 'Wied is-Sewda' and thus this thesis is going to observe how and why human influence has affected it through the valley of time based on the fact that the population of Qormi has increased tremendously throughout the years. In fact a publication of the Central Office of Statistics states that the population of Qormi stood at 17,848 on the 31st of December 1997. The increase in population poses greater pressures on this valley that passes through the village core and that the same damage affects not only the same population but is also wide-spread to many surroundings towns and villages. Description: DIP.ENV.HEALTH 2000-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/48568 Title: Legionnaire's disease and its public health implications Abstract: Infectious diseases are a very important Public Health issue. Legionnaire's disease is an infectious disease that has been attaining increasing importance since its discovery, mostly because of its tendency to occur in outbreaks and its high fatality rate. This dissertation includes an overall view of Legionnaire's disease, including its identification, diagnosis, Public Health aspects, and methods of control. These aspects of Legionnaire's disease are also discussed with particular reference to Malta. The implications that this disease could have on the tourist industry in particular, is one of utmost importance. A high level of awareness needs to be maintained and preventive measures constantly taken to ensure Public Health. As part of this dissertation, a small survey was carried out to roughly indicate the level of awareness of this disease and its methods of prevention among hotel establishments, as suggested in the Maltese Code of Practice. Description: DIP.ENV.HEALTH 2000-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/48267 Title: Quality assurance in the production of yoghurt and cheese. Abstract: Yoghurt and cheese are cultured milk products due to the production process whereby milk is inoculated with a starter culture converting lactose to lactic acid. Compounds such as carbon dioxide, acetic acid, diacetyl and acetaldehyde give these products their characteristic taste and aroma. In this dissertation emphasis is going to be given to set and stirred yoghurt for yoghurt production and to the locally produced cheeselets for the cheese production. Yoghurt originated from Bulgaria and nowadays its highest consumption is in the Mediterranean countries, Central Europe and Asia. In Malta, at the Malta Dairy Products (MDP), 3 main types of stirred yoghurt are produced- Light, Full Fat and Dessert yoghurt and 2 main types of set yoghurt- Full Fat and the Light varieties. In stirred yoghurt, inoculation and incubation take place in fermentation vessels whilst in the case of set yoghurts inoculation and fermentation take place in the same retail containers. Cheese production started in the fertile agricultural area known as 'Fertile Crescent' around 6000 - 7000 BC. Cheese can be classified as extra hard, hard, half-fat, semi-soft and soft cheese. Cheeselets, the cheese studied in this dissertation, are classified as soft cheese. In Malta, these are produced as peppered, semi-dried and soft white cheeselets and their peak season is between September to June or July. At the MDP, this production started in 1991 for peppered cheeselets and in 1995 for white cheeselets. In 1999, the production by this company was of 40,000 cheeselets every week where 46% are peppered cheeselets and 34% are white cheeselets. Other 350 licensed farms situated all over Malta and Gozo produce both pasteurised and unpasteurised cheeselets. In this dissertation, emphasis is going to be given to the implementation of Quality Assurance as followed by the International Standard Organisation (ISO) and Malta. In 1986, the ISO defined Quality Assurance as 'all those planned and systematic actions necessary to provide adequate confidence that a product or service will satisfy given requirements'. (Early R.,1995). Quality control, which is a measure of Quality assurance, is also going to be discussed as it is concerned with measuring and regulating processes and activities, by making sure that the given requirements are reached. A survey on the quality of yoghurt and cheese lets was also performed to check if the Maltese people are pleased with both products. 2 athletes. Description: DIP.ENV.HEALTH 2000-01-01T00:00:00Z