Environmental Engineering Reference
In-Depth Information
Table 6.3
Culturable/Viable and Total Mold Spore Concentration Ranges
Observed in Buildings
Concentration ranges
Total mold
spores
(S/m
3
)
Culturable/viable
(CFU/m
Building type
Conditions
3
)
Residence
New structure
<300
1000-3000
Not mold infested
(avg.)
>300<1000
>3000<10,000
Moderately infested
>1000<3000
>10,000<30,000
Heavily infested
>3000
>30,000
Mechanically ventilated
nonresidential
Not mold infested
(avg.)
<300
1000-3000
Moderate, localized
infestations
>1000<3000
>3000<10,000
Heavily infested
>3000
>30,000
encing less significant water damage and mold infestation, total airborne
culturable/viable mold concentrations >1000 CFU/m
3
are common. Con-
centrations <1000 CFU/m
are typical in buildings in which there is no
apparent mold infestation; when these are new houses and mechanically
ventilated buildings, levels are usually <300 CFU/m
3
Measurement of airborne mold concentrations as determined by total
mold spore/particle sampling methods in either indoor or outdoor environ-
ments has been limited. The method is amenable to identifying and quanti-
fying major mold genera, but few studies have reported quantitative expo-
sure by mold type. Most information is available as total mold spore counts.
In general, total mold spore levels in residential structures vary from 5000
to 15,000 spores/particles per cubic meter (S/m
3
); in mechanically ventilated
buildings without any visible mold infestation, airborne mold varies from
1000 to 3000 S/m
3
3
can be expected. Heavily contaminated school
buildings (25,000 to 200,000 S/m
3
3)
and flooded residences (200,000 to
1,000,000 S/m
) have been among the highest reports of airborne mold.
When very high concentrations are observed, they are typically dominated
by
3
Aspergillus
or
Penicillium
or both.
IV. Health concerns
Exposure to airborne mold and mold-produced environmental contaminants
may pose significant health risks to humans. These include well-known
mycotic diseases as well as other less well-defined health effects.
There are three basic categories of mycotic disease: infections, aller-
genic/immunological illness, and nonallergic illness.
