Mold Screening
It is possible to
identify houses with mold contamination by comparing the indoor and
outdoor levels of mold spores using the air sampling method. A review of
the recommendations by the nation's leading testing laboratories shows
air sampling to be the method of choice for residential mold screening.
When properties are found to have higher levels of mold indoors than
outdoors, further investigation is recommended. It is assumed that a
higher ratio of indoor mold is indicative of an internal mold growth,
which, if confirmed, should be corrected. It is generally believed by
the scientific community that elevated levels of mold would inevitably
lead to the discovery of some form of moisture penetration such as a
leaky roof, hidden plumbing leak or other water infiltration problem.
The following are two common methods of screening for mold: air sampling
and sterile swab sampling.
Air
Sampling
Screening by air sampling (one of the most reliable, quick and
cost-efficient mold tests available today) is recommended if, during an
inspection or otherwise, conducive conditions or evidence of mold are discovered. This
sampling method requires that at least two samples be taken, one outside
and one inside the property. Air samples should be taken inside in any
of the rooms where indications of mold are discovered. Only one sample
is taken outdoors, called the reference sample, and it is used for
comparison to all the other samples taken inside. Indoor/Outdoor mold
ratios are often the primary evidence suggesting the likely presence of
mold growth within the property.
The air samples are sent to a laboratory specializing in mold analysis.
Note: Air sampling should be avoided if it is raining or recently
rained, if it is windy (30 mph or more), or there is a heavy amount of
dust in the air (e.g. nearby construction).
Sterile Swab Sampling
Screening by
sterile swab sampling can be performed when there are visible signs of
mold growth. An individually packaged, sterile swab is used to wipe and
collect a sample from the surface of the mold. A separate swab is used
for each kind of mold found in the property.
The sample is then forwarded to the laboratory for analysis.
Mold - Overview
What is It?
Health Effects
Types
Conducive Conditions
Exposure
Screening
Media
Litigation
