After analyzing the dust of 1,200 North American homes, a group of researchers from the University of Colorado in Boulder (United States) has concluded that, on a microscopic scale, domestic squats proliferate .
The samples came from the ledges above the doors, a place that we often neglect in our cleaning tasks, so they constitute a kind of natural reserve for microbes. Thus they have been able to make a census that yields the following results: on average, our homes are home to 9,000 different types of microorganisms, 7,000 bacteria and 2,000 fungi.
In any case, this biodiversity varies depending on various factors , such as the geographical place where the dwelling is located – a town is not the same, obviously, as a large city -, the number, age and sex of human occupants or the eventuality whether or not they have a pet.
Among the bacteria, they have found examples of the genera Staphylococcus and Streptococcus , associated with human skin, but also Bacteriodes and Faecalibacterium , linked to feces. As for the species of fungi, those of well-known groups such as Aspergillus , Penicillium , Alternaria or Fusarium abounded. And unlike bacteria, almost all of them tend to creep into our clothes at home or when we open doors and windows. Researchers send a reassuring message to the squeamish: Most of these tiny neighbors are harmless, and some are even beneficial to our health.
Published in the journal Proceedings of the Royal Society B , the work is part of a citizen science project called The Wild Life of Our Homes .
