title: [Biological contamination in office buildings related to ventilation/air conditioning system].
abstract: BACKGROUND
  Indoor air is contaminated with microorganisms coming from both the atmospheric air and sources present in premises. The aim of this study was to analyze the concentrations of biological agents in office buildings, dependending on ventilation/air conditioning system and season.
  
  
  METHODS
  The study covered office buildings (different in the system of ventila-tion/air conditioning). Air samples for assessing the levels of inhalable dust, endotoxins and (1-->3)-beta-D-glucans, were taken at the selected stationary points of each building during summer and winter. The air was sampled for 6 h, using portable sets consisting of the GilAir 5 pump and the head filled with a filter of fiber glass. The samples for the presence of airborne bacteria and fungi were collected twice during the day using the impaction method.
  
  
  RESULTS
  Average concentrations of inhalable dust, bacteria, fungi, endotoxins and (1-->3)-beta-D-glucans in office premises were 0.09 mg/m3, 6.00 x 10(2) cfu/m3, 4.59 x 10(1) cfu/m3, 0.42 ng/m3 and 3.91 ng/m3, respectively. Higher concentrations of the investigated agents were found in summer. In premises with air conditioning concentrations of airborne fungi, (1-->3)-beta-D-glucans and inhalable dust were significantly lower in winter. In summer the trend was reverse except for (1-->3)-beta-D-glucans.
  
  
  CONCLUSIONS
  Concentrations of biological agents were affected by the season and the presence of air conditioning. Concentrations of inhalable dust, bacteria, fungi, endotoxins and (1-->3)-beta-D-glucans, observed inside the office buildings, were significantly higher in summer than in winter. The presence of the air conditioning system modified in various ways the levels of biological agents. Its influence was greater on the concentration of fungi and (1-->3)-beta-D-glucans than on that of bacteria and endotoxins.
authors.affiliation: Department of Environmental Health Hazards, Nofer Institute of Occupational Medicine, Łódź, Poland. kbrodka@imp.lodz.pl
authors.forename: Karolina
authors.initials: K
authors.lastname: Bródka
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Sowiak
authors.forename: Anna
authors.initials: A
authors.lastname: Kozajda
authors.forename: Marcin
authors.initials: M
authors.lastname: Cyprowski
authors.forename: Szadkowska-Stańczyk
authors.initials: SS
authors.lastname: Irena
mesh_terms: D000389:Air Conditioning; D000391:Air Microbiology; D000395:Air Pollutants, Occupational / Q000009:adverse effects*; D016902:Air Pollution, Indoor / Q000032:analysis*; D001419:Bacteria / Q000302:isolation & purification; D004391:Dust / Q000032:analysis; D004731:Endotoxins / Q000032:analysis; D005658:Fungi / Q000302:isolation & purification; D006801:Humans; D012621:Seasons; D014691:Ventilation; D047071:beta-Glucans / Q000032:analysis
chemical_list: D000395:Air Pollutants, Occupational; D004391:Dust; D004731:Endotoxins; D047071:beta-Glucans