Medycyna Wet. 67 (4), 267-269, 2011

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Paszkiewicz W., Pyz-Łukasik R.
Degree of the reduction of bacterial air pollution under the influence of UV rays
Due to certain properties of ultra violet rays they are primarily used for sterilizing a surface or the air. UV rays are used, among others, to disinfect isolation wards for sterile work, laminar flow cabinets, bacteriological and virusological laboratories, operating rooms, rooms in animal houses, as well as the surfaces of tables, walls or floors. The evaluation of bacterial pollution as well as the effectiveness of methods for sterilizing the air remain relevant problems in many fields, e.g. in industry, animal production, investigative laboratories or health clinics. The aim of the study was to evaluate the degree that the level of bacterial air pollution was reduced in a cabinet for microbiological investigations, sterilized by a UV lamp with a 30 watt florescent lamp. Sampl'air Lite (AES Laboratoire Chemunex) apparatus was used to gather air from the atmosphere. Samples were sampled after 15, 30, 45, 60, 75, 90, 120, 150 and 180 minutes of sterilizing the air in the cabinet with 6 repetitions for each period of irradiation. The initial and final level of the bacterial air pollution in the cabinet for microbiological investigations in relation to the period of the action of the UV rays as well as the level of bacterial reduction were evaluated. The minimal period of the action of the UV rays that ascertained a statistically significant and simultaneously the largest reduction of the bacterial air pollution was 180 minutes. With regards to all the remaining periods of irradiation no essential differences in the levels of bacterial reduction were noted, despite considerable (1.7-4.0 times) reductions of bacteria. An essential correlation was indicated between initial air pollution in the cabinets and 15, 45, and 60 minute periods of the action of UV rays. The correlation coefficients were 0.95 (p ≤ 0.01), 0.82 (p ≤ 0.05) and 0.96 (p ≤ 0.01), respectively. In the remaining cycles of the experiment the correlations were not statistically significant, and the correlation coefficients include in the interval of 0.45-0.60. There is a need, also noted by other authors, of unifying acceptable levels of microbiological air pollution for the purposes of laboratory investigations and production processes.
Keywords: bacterial air pollution, UV rays