107
But
Legionella
disease is not the only building water system associated
problem. Other pathogens associated with building water systems that
are known to cause disease include
Acinetobacter
(Kohlenberg 2009),
Pseudomonas
(WRF2013)
Mycobacterium
(Steinert1998),
Stenotrophomonas
(Looney 2005),
Aspergillus
(Anaissie 2002),
Fusarium
(Anaissie 2001,
Short 2011) and from free-living amoeba in treated drinking water systems
(Thomas 2011).
The Hazards
Exposureofbuildingoccupants tomicrobialhazards (suchaspathogenic
bacteria), chemical hazards (such as disinfection by-products) and physical
hazards (such as scalding from attempts to control hazards with thermal
eradication) often result from processing and use of the water in buildings.
Biofilms
The root cause of the problem in building water systems is communal
microorganisms living on surfaces, in deposits and in sediments. These
microbial communities are called“biofilms”.Theyaredynamic, adaptive, and
difficult to control. When biofilms become complex and microbiologically
diverse enough to include amoeba and other protist hosts, growth to
dangerously high levels of opportunistically pathogenic microorganisms
such as
Legionella
,
Pseudomonas
and
Mycobacterium
in building water
systems is often the result (WRF 2013).
