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orange coast
INSPECTION
provides a full range of sampling services in order to get timely and
relevant information returned from the laboratory.
The goal of biological
sampling is to confirm or deny an investigator's original hypothesis
regarding potential contamination of a site. (Here's why we won't automatically sample every house we survey.) It helps to determine whether
the biological particles present in a particular environment are affecting
or causing irritation in certain individuals. Sampling is also used
to locate the sources of indoor microorganisms and determine the magnitude
of the contamination in order to facilitate an effective remediation.
While we are typically surrounded by a wide variety of different microorganisms
every day, sampling provides us with a method to establish, with scientific
methods, whether the environment in question contains more organisms
than would normally be present. There are numerous techniques that may
be used to evaluate the level of indoor microorganisms. We believe,
however, that scientific comparisons are only possible when measured
volumes of air are sampled and compared against the outdoor environment
and another "non-affected" area inside the property, if one
exists.
Surface Samples
Surface sampling during IAQ investigations is a common
tool used by investigators. It is often performed in conjunction with
air and bulk sampling techniques and its nondestructive nature serves
several useful purposes. Surface sampling can be performed to determine
whether microbial levels in various areas are greater than background
levels and to determine possible sources of microbial contaminants that
may be a source of aerosolization. Surface sampling is also useful for
performing presence/absense analyses and measuring relative degrees
of contamination.
Microbial contamination on surfaces can be caused by the settling of
previously aerosolized organisms or by the actual surface acting as
a medium for the growth of the organism. Sampling strategies vary from
randomly picking areas to highly targeted sampling strategies. Two of
the most common surface sampling techniques for fungi include swab sampling
and tape sampling. Each method has its advantages and disadvantages
and should be chosen based on the sampling strategy and the purpose
of the investigation.
Tape sampling is a common and easy to perform surface sampling technique.
It is a very useful tool so long as information about the viability
of the microorganism is not required since tape samples cannot be cultured.
The investigator needs only clear adhesive tape for obtaining the samples
and glass slides or a sterile container or ziplock bag to transport
the samples to a laboratory. The investigator removes a portion of the
clear tape, approximately one to two inches long, and places the adhesive
side on the surface to be sampled. If the sample contains to much debris
it may then be difficult to examine in the laboratory and the sample
should be retaken.
There are a number of benefits to tape sampling. These include the
ease of sampling, lack of expensive sampling supplies, and no requirements
to ship the samples rapidly in any type of refrigerated containers.
Tape samples are also rapidly processed. The value of the data generated
by tape sampling depends heavily on the investigators choice of sample
locations. A single surface with visible growth may have multiple fungi
present in different areas and thus one sample may not give an accurate
representation of the various species present. Tape samples cannot be
cultured for the determination of viable versus nonviable contamination
nor is it useful for the determination of bacteria.
Swab sampling is the other common nondestructive surface sampling technique.
It can be used for a microscopic screen and fungi identification and
it can also be cultured onto a media for viable fungi and bacteria indentification.
One weakness of using swabs for microscopic identification over tape
methods is that more fungal stuctures tend to be disrupted and thus
makes laboratory identification more difficult. It is of course important
to use a sterile swab when performing this sampling technique and it
should be clearly stated to the laboratory if the sample is for microscopic
identification and/or culture methods.
The ability to recover various organisms is also dependent on the surface
material to be tested. Generally smoother surfaces are more easily and
effectively sampled using surface sampling techniques. Porous and fleecy
areas are often more difficult to sample utilizing tape and swab sampling
techniques. When utilizing these methods it is a good procedure to send
a blank to the laboratory for quality control purposes.
"Several attempts have been made to identify surface concentrations
of biological materials that indicate unhealthy conditions. No currently
available guidelines have been generally accepted due to the large variability
in surface sampling results and poor correlations with inhalation exposre"
(ACGIH, Bioaerosols Assessment and Control, 12.2.4). This position by
the ACGIH exemplifies the need to use surface sampling data as a tool
in conjunction with other aspects of the IAQ investigation to help support
or disprove a hypothesis of an investigation.
Air Samples
 Air
sampling for fungi should be conducted to test hypotheses regarding
indoor environments and potential bioaerosol sources. Many investigators
use impaction sampling to assess bioaerosol levels. Sampling should
be done indoors and outdoors at suspect and control locations. This
method is appropriate for identification and quantification of fungal
spores such as Stachybotrys.
orange coast
INSPECTION
is proud to announce its implementation of Environmental Monitoring
Systems' latest innovative design in Bioaerosol Impact Samplers. The
CyClex Sampler was pioneered to be the first non-viable impaction system,
offering exceptional  versatility
and cutting-edge, superior performance. Gone are the days of the
old-fashioned, less-efficient, Air-O-Cell™ cassettes!
The CyClex utilizes a unique 360 degree aluminum impaction chamber
designed to enhance performance and efficiency associated with Bioaerosol
sampling. The CyClex has the ability to evenly & qualitatively collect
aeroallergens such as pollens, mold & fungal spores, fibers, dander,
insect components and other air-borne contaminants. In addition, the
CyClex has the distinguishing feature of having the ability to collect
"inner" wall samples, making it the most efficient and feasible
impaction device on the market.
If a client has a particular request for using the Air-O-Cell™
cassettes we will be happy to accomodate, realizing that it will not
be as thorough or efficient as the CyClex Sampler.
Carpet Testing
One significant facet of many Indoor Air Quality (IAQ) microbial investigations
is the assessment of the carpeting in an occupied building. Carpet is
listed as one of the nine potential sources of biological agents in
an occupied space by the American Conference of Governmental Industrial
Hygienists (Bioaerosols - Assessment and Control, ACGIH 1999). The difficulties
in assessing carpet contamination arise from the porous nature of the
material, lack of standardized sampling methods, and obscurity of data
interpretation.
 Sampling
for the CarpetChek System™ includes collecting carpet dust by vacuuming
relatively large areas of carpet (1ft 2in – 9ft 2in based on amount
of dust present) with a high-volume pump and a dust cassette. Any 3-piece
cassette fitted with a 0.8m polycarbonate filter is sufficient. The
area of carpet sampled is inconsequential as the fungi are analyzed
on a per gram basis. The sampling technique, however, should be consistent,
working the inlet tube as deep as possible into the carpet to collect
a representative sample. Approximately 1 gram of dust should be collected.
Viable
versus Non-viable Testing
We know that some
bacteria and fungal spores can cause disease only when they are alive
(viable), while others are capable of producing allergies or irritation
even when no longer living. Also, while cultures may permit greater
accuracy in speciating some fungal organisms present, spores vary widely
in their ability to grow and compete on laboratory media. This may result
in an inaccurate characterization of the area sampled. Therefore, a
complete sampling protocol for the biological flora in any environment
may sometimes use both a culturable and non-culturable sampling method.
Viable testing is an important factor prior to medical treatment.
Continue on to REMEDIATION PROJECT
SCOPE DESIGN....
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