|
Sample |
Target |
Type |
Quantification |
Equipment |
|
Air-o-cell |
air |
non-cultured |
spores/m3 |
high
volume sampling pump + cassettes |
|
Allergenco |
air |
non-cultured |
spores/m3 |
Allergenco
sampler + greased slides |
|
Andersen |
air |
cultured |
CFU/m3 |
Andersen
sampler + petri dishes |
|
Bulk(a) |
bulk\dust |
cultured(a) |
CFU/g
(b) |
none |
|
Swab(a) |
bulk\dust |
cultured(a) |
CFU/m2
(c) |
sterile
swab (Q-tip or cotton ball will work) |
|
Tape-lift |
bulk\dust |
non-cultured |
ID only(d) |
clear
sticky tape (scotch, etc...) |
(a)
Bulk and Swab samples can be tape-lifted for direct
examination
(b)
Quantification of cultured
Bulk sample requires that more than 1 gram of sample be
provided
(c)
Quantification of cultured Swab sample requires that the
area sampled (9 cm2, 1 square inch, etc...)
be measured and provided
(d) A
semi-quantitative rating is provided to indicate
relative quantities present if more than one type of
mold is detected
|
|
Notes: |
|
|
|
Non-cultured |
- viable and
non-viable spores (and other particulate)
directly examined under a microscope |
|
|
Cultured |
- viable
spores are grown in a petri dish for several
days before identification |
|
|
CFU |
- colony
forming unit |
General:
Stachybotrys does not grow
well in standard culture media, and direct examination
is the preferred method of identification (airocell/allergenco
or tape). If you are specifically testing for
stachybotrys using a cultured method then Rose Bengal
type media should be used (Andersen) or requested (swab
or bulk).
Gravity plates (commonly
found in "home test kits") are not generally used by
professionals
Airocell & Allergenco
-
this is a non-cultured air sample. Results are reported
in concentrations of spores per cubic meter (spores/m3).
This test is referred to as a "snapshot" of the air at
the exact time of sampling. Results account for both
alive and dead spores as well as pollen, skin, insect
parts etc. if a full profile analysis is noted. It is
important to note that allergic reactions can come from
dead spores and alive spores alike. In addition, the
toxins that some fungal spores produce remain toxic
after the spore itself has died. Normal laboratory
turnaround time is 24 to 48 hours.
Interpretation of results:
the general guideline to
follow is that the concentration and types of spores in
the inside sample should be similar to or lower than the
concentration and types of spores found in the out of
doors sample. The category Aspergillus / Penicillium are
small (1-3 microns), round, colorless spores that may
be: Gliocladium, Trichoderma, other morphologically
consistent with Aspergillus / Penicillium types. A
culture sample would be necessary to differentiate
between them. Currently there are no dose response
relationship statistics for allowable or safe levels of
aeroallergens. However if spores of Aspergillus /
Penicillium or Stachybotrys are found inside regardless
of the concentration, further investigation to the
source should be conducted and evaluated by a
professional.
Andersen
– This is a cultured air
sample grown in the laboratory on Malt Extract Media.
Results are reported in concentrations of CFU’s per
cubic meter (CFU/m3). Results indicate the
number of viable (alive) spores in the air at the time
of sampling. Analysis does not and cannot include counts
for dead spores, pollen, skin, insect parts, etc. It is
important to note that allergic reactions can come from
dead spores as well as live spores. In addition, the
toxins that some fungal spores produce remain toxic
after the spore itself has died. Normal laboratory
turnaround time is 5 to 10 days.
Interpretation of results:
the general guideline to
follow is that the concentration and types of colonies
found in the inside sample should be similar to or lower
than the concentration and types of colonies found in
the out of doors sample. Currently there are no dose
response relationship statistics for allowable or safe
levels of aeroallergens. Please note that Stachybotrys
does not grow well on laboratory media and an absence of
Stachybotrys on a culturable sample report should not
rule out this type of mold.
Bulk
– this type of sample can
either be analyzed by direct exam (see below) or by
culture. The cultured sample is grown in the laboratory
on Malt Extract Media. Results are reported in
concentrations of colony forming units per gram of
sample (CFU/g). The results of a bulk sample culture can
be problematic because of the inconsistency of
contamination of the material sampled. Additionally,
Stachybotrys does not grow well on standard culture
media, and an absence of Stachybotrys on a culturable
sample report should not rule out this type of mold.
Normal laboratory turnaround time is 5 to 10 days.
Interpretation of results:
less than 10,000 is low
10,000 to 100,000 is medium
100,000 to 1,000,000 is
medium to heavy
greater than 1,000,000 is
heavy
Direct Exams (bulk) and Tape lifts
– this is a non-cultured
sample. Results are reported as "detected" for each type
observed. This test is primarily qualitative and should
not be used if quantitative results are needed. If a
direct exam results are negative, a bulk culture of the
material is recommended to verify results. Spores can be
down inside the material and can be missed by direct
exam. Most people use this test in combination with an
quantitative analysis such as Andersen or Allergenco.
Normal laboratory turnaround time is 24 to 48 hours.
Interpretation of results:
to be used to identify the
type of mold to a Genus level in most cases. Not for
quantitative analysis.
|
EPA,
OSHA, NIOSH and other occupational health
related associations in the U.S. have not
yet to this date established permissible
exposure levels (PEL), recommended exposure
limits (REL), or other limit values for
aeroallergens. The general guidelines listed
here represent commonly accepted
interpretations and practices derived from
various sources, including the
American
Industrial Hygiene Association and
Health Canada. Please realize that the
evaluation of one's specific results in
terms of potential health hazards and
subsequent courses of action are beyond the
scope of the laboratory analysis. Links on
the Consultants and Resources page provide
additional guidance in this regard. Those
requiring expert advisement on a particular
situation should retain the services of a
professional IAQ consultant |
|
