Air conditioning systems have a lasting effect on indoor bacterial flora
There are over 30,000 different types of bacteria in interiors and offices. The architecture of the building and the intensity of use have a significant influence on the bacterial flora to be found, Canadian scientists report in the specialist magazine "PLOS One". In a recent study, researchers led by Steven Kembel from the Université du Québec à Montréal investigated "bacterial communities in the dust of 155 rooms in Lillis Hall, a four-story classroom - and office building on the campus of the University of Oregon."
The sequencing of the bacterial species found showed that architectural design features, room type, the room arrangement, human use and the ventilation source are closely related to the detectable bacterial community. For example, the toilet rooms had completely different microbial communities than most of the other rooms. The rooms with intensive use by many people were much more contaminated with bacteria than little used, remote rooms. In the offices, however, the source of ventilation air has shown the greatest influence on the structure of the bacterial community, Kembel and colleagues report. When air conditioning was used, the Deinococcus bacterium was surprisingly dominant.
Influence the bacterial flora via architecture?
In their investigation of the dust samples, the scientists identified three strains of bacteria in particular: proteobacteria, firmicutes and deinococcus. While the first two are more associated with human use, an increased settlement of Deinococcus is directly related to the use of air conditioning, report Kembel and colleagues. This may be due to the resistance of these bacteria to temperature fluctuations, dehydration and UV light, which favors a selection of the bacterial strains. The scientists come to the conclusion that the architectural or interior design of the buildings could have a direct influence on the settlement of the bacteria in order to create a healthy environment. The same applies to the effects of human occupancy and usage patterns, which in turn are closely related to the bacterial flora. (fp)
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