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Legionellosis, which led the Health Department to regulate climate-
controlled environments.
Highly controlled environments, where the air must be very pure, are
necessary for several activities such as preparation of medicines, in the
industry of electronic components, in the health care services, among others.
But in everyday places, often, common citizens are exposed to pollutant
gases, dust, fungi, bacteria, algae, virus, protozoan and several chemical
substances. Even in the open, this mixture is present in different levels. The
average amount at open areas is 200 CFU (colony forming units). In sealed
buildings, with climate-controlled system, the indoor air quality requires
special care, at least, periodic cleaning of the filtration systems.
The first set of rules aimed to ensure the quality of the air in climate-
controlled environments was the Directive 3.523/98, of the Ministry
of Health, which establishes a routine of cleaning procedures in large
refrigeration systems. The Resolution nr. 9 of ANVISA and the technical
standard NBR 16401 of ABNT define what air with good quality is. The
WHO also deals with the subject and recommends 500 UFC, that is, twice
and a half more microbiological concentration than is normally found at
open air.
If these standards are not met, the Sick Building Syndrome (SBS) can
occur, which can be temporary in recent constructions where there is a
lot of particulate material suspended in the air and volatile compounds,
originated from glues and paints. The residents and visitors feel unease in
these places, but with no specific symptoms, without relating the cause of
their sickness to the environment where they are. In these new buildings,
after some months from the conclusion of the works, the tendency is the
improvement of the condition of the environment.
