Příčiny výskytu a možnosti zamezení výskytu legionelly

Abstract

This thesis deals with the occurrence and the possibilities of preventing the occurrence of Legionella sp. in warm water. The topic intrigued me, because it is an ever-increasing risk of infection by this bacterium. In many cases it ends with death. It is mainly the fact that the occurrence of Legionella sp. in the water is likely in a wide range of places such as healthcare facilities, office buildings, sports facilities, swimming pools, air conditioning units, cooling towers, and not least at the outlet terminals in residential zones. For these reasons the prevention, knowledge about the causes of the occurrence and the subsequent measures to prevent the occurrence of this bacterium are very important. The thesis focuses on the presence of Legionella sp. in the warm water, the process of its elimination from the hot water and the subsequent comparison of the effectiveness of corrective measures including chemical and thermal disinfection. It is essential for the occurrence of Legionella sp. in warm water that it should be regarded as the technical condition of water distribution system and particularly the so-called destination blind spots where there is the highest risk of settlement not only of the bacteria. The aim of this study was to analyze the situation of the particular object. The object is a three-story building downtown sanitary laboratories, which houses administrative facilities (offices), laboratory facilities and staff (toilets, showers, kitchen, dining room, dressing room). Construction of the building was realized in 1993, water distribution is conducted mainly by galvanized material. Due to water pipes repair some parts are in plastic. Hot water manifold is fed from the boiler room to the attic space and then distributed down into the building. I conducted six control samples in September 2013, which confirmed the over-limit occurrence of Legionella sp. Based on the results a thermal disinfection of the water system was performed. To check its effectiveness 6 samples with lower tier finding were taken in the same places. This process was repeated in March 2015, the same sampling points and number of samples. Above the threshold incidence of Legionella sp. were recorded again therefore it was decided to perform a chlorine chemical disinfection. Control samples were taken in May 2015 to assess the effectiveness of chemical disinfection. My hypothesis was based on the fact that simple primary and secondary measures are not sufficient and it is temporary, unless the construction and technical adaptations are made to the old hot water distribution system. Due to the material incrustation pipe, the occurrence of dead arms and improper Project Solutions hot water supply is to prevent the occurrence of Legionella sp. in this case unfeasible.