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Identifier 000039506
Title Μελέτη της παρουσίας των πολυχλωριωμένων διφαινυλίων κα των πολυκυκλικών αρωματικών υδρογονανθράκων στην ατμόσφαιρα και στις επιφάνειες εσωτερικών χώρων
Author Αποστολάκη, Μαρία
Thesis advisor Στεφάνου, Ευριπίδης
Abstract Although the production of polychlorinated biphenyls (PCBs) was banned in the late 1970s, electrical equipment such as transformers and condensers, manufactured before that period is still in use. As this equipment contains PCBs it poses a contamination threat especially for the indoor environment where is located and where people spend a great proportion of their day time. Moreover, PCB-filled transformers and capacitors are still kept in service, because of the expense of replacing them and of the long useful life of such appliances. For these reasons the study of PCBs concentrations in indoor environments is very important. The present work includes the study of the occurrence of polychlorinated biphenyls in indoor air and surfaces of an office building in Athens. Inside this building electrical equipment (transformers), containing PCBs was used from the mid seventies. Two intensive sampling campaigns took place, one before and the other after the removal of the transformers, in order to determine the variation of PCBs contamination levels inside the building. In general, air concentrations of PCBs in the basement of the building, where the transformers were located, exceeded those measured in other indoor, non-industrialized environments. In the other floors of the building, PCBs levels were comparable or higher than those measured in homes or other work places. Indoor air concentrations in the building were 130 up to 1,829 times higher than outdoor air concentrations which had been recently measured in various sites around the city of Athens. Because of the high indoor concentrations, PCBs have been sorbed or deposited onto surfaces within the building. Due to desorption and resuspension, a more prolonged emission in the building took place. Consequently, indoor air concentrations remained elevated even after transformers were removed. Congener distribution of PCBs in all samples (air and surface) was enriched with high molecular weight congeners having five and six chlorine atoms, which are the more persistent and more toxic congeners. The statistical comparison among individual congeners suggested that Clophen A 60 or Aroclor 1260 might have been the technical mixtures of PCBs used in the transformers. Taking into account the indoor air concentrations of PCBs, it was estimated that people working at the building were exposed to PCBs via inhalation 49 times more than Athens residents who did not work in contaminated buildings. The arithmetic mean of daily exposure of employees via inhalation and dermal contact was 1.08 mgPCBs/person/day. Concurrently the study of polycyclic aromatic hydrocarbons (PAHs) in the building has shown that indoor air concentrations of PAHs were in the same range with those determined in smoker homes. The most important indoor source of PAHs in the gas phase was the tobacco smoke. As for PCBs, also for PAHs indoor surfaces acted as a "buffer" of their air concentration. The comparison of PCBs and PAHs indoor air concentrations stated an indoor source for PCBs and excluded the possibility that PCBs were transported from outdoor air.
Language Greek
Issue date 2004-07-01
Collection   School/Department--School of Sciences and Engineering--Department of Chemistry--Post-graduate theses
  Type of Work--Post-graduate theses
Permanent Link https://elocus.lib.uoc.gr//dlib/e/5/1/metadata-dlib-2004apostolaki.tkl Bookmark and Share
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