Microbial investigation of the air in an apartment building

Abstract

SUMMARYThe microbial and viral flora in the ventilating ducts of an apartment building was evaluated. Several types of sampler (slit sampler, Andersen sampler, large volume air sampler) were used to evaluate the hourly, weekly and seasonal variation of this flora. The mean bacterial concentration was 17-2 c.f.u./m3 with a maximum level at 07.30 h (41-3 c.f.u./m3) and a minimal concentration in the early afternoon (8 c.f.u./m3). The bacterial concentration observed correlated with the relative humidity in the air-ducts although there were no seasonal differences.The bacteria were mainly gram-positive cocci (73-5 %) represented by a large number of Micrococcaceae (47-1 %); gram-positive bacilli accounted for 14-2 % of the isolates, gram-negative bacilli 12-0 % and gram-negative cocci 0-3 %. The majority of the bacteria-carrying particles were in the respirable range with 80-4% of them being less than 5 ,tm. The methods used did not result in the isolation of viruses during the winter sampling period.

Longitudinal study of dust and airborne endotoxin in the home.

“…Home airborne endotoxin may be more closely related to moisture (dampness) than to temperature. Simard et al (26) reported that the level of bacteria measured inside the duct of an apartment building was associated with relative humidity in the duct. In numerous studies (27)(28)(29)(30)(31), home dampness has been significantly associated with children's respiratory disease and symptoms.…”

Significance of Airborne Transmission of Methicillin-Resistant Staphylococcus aureus in an Otolaryngology–Head and Neck Surgery Unit

“…Particles smaller than 5 µm may exist in the air for a long time and can reach the lungs and cause infection in susceptible tissues if inhaled. 14 As shown in Figure 1 and Table 3, MRSA was detected both during the rest period and when bedsheets were being changed; the latter period was particularly of interest, as MRSA of all stages was observed in that period. This finding suggests that MRSA is able to colonize in the nasal cavity or even reach the lungs.…”

“…The sampler is widely used in aerobiological studies. 6,13,14 As a rule, 6-stage cascade Andersen samplers allow for precise microbiological evaluation as well as for the separation of the organisms according to particle size. Larger microorganismcarrying particles, in the range of 4 to 8 µm, are separated in the first 3 stages, whereas smaller particles (Ͻ4 µm) are separated in the 3 lower stages.…”

Evaluation of bedmaking-related airborne and surface methicillin-resistant Staphylococcus aureus contamination

“…13 The Andersen is a sieve-type cascade impactor, which separates micro-organism-carrying particles into the following six stages according to diameter; stage 1: b7 mm; 2: 4.7±7 mm; 3: 3.3±4.7 mm; 4: 2.1±3.3 mm; 5: 1.1±2.1 mm; 6: 0.65±1.1 mm. 13,14 The sampler was placed on a rack, 1 m above the floor, and 1 m from the bedside (Fig. 1).…”