Air Samples

Types of Air Samples – Mold Testing

SafeAir Certified Mold Inspection offers two different mold testing methods to collect airborne mold spores, which are called spore trap air sampling and cultured air sampling. The two different mold testing methods are both referred to as impact sampling and can both offer useful and unique information in regard to the mold testing and mold inspection services that we provide. The reason they are both referred to as impact sampling is because airborne mold spores collide with a collection medium and stick to the surface of the medium. (A mold testing medium is the material that is used to collect airborne mold spores when an air sample is collected. An example of a medium that is used during air sampling is the sticky-tape part located inside of a spore trap that is used for the collection of mold spores during spore trap air sampling, the malt agar solution that is placed in a petri dish for the collection of mold spores when collecting a cultured air sample, etc.). Air sampling is commonly referred to as air quality testing for the presence of mold growth.

This is a closeup photo of what appears to be mold on kitchen cabinets.  Call SafeAir Certified Mold Inspection Inc. for all of your Atlanta Mold Testing Needs 404-695-0673
When there is mold growth present indoors, the mold growth colony can broadcast its mold spores into the air, oftentimes in extremely high numbers. It is the airborne mold spores that are collected during air sampling and not the actual source of mold growth (mold colony). The types of mold spores that are collected in air samples is directly correlated to the types of mold growth identified in the collection of the mold spores identified in the air samples. For example, if Stachybotrys mold spores are collected in an air sample, the Stachybotrys mold spores collected originated from a source of Stachybortys mold growth. It then needs to be determined if the Stachybotrys mold spores collected during air sampling originated from the indoors or the outdoors.

We collect an outdoor air sample to use as a baseline comparison for which to compare indoor air samples to in order to determine which mold spores originated from the indoors and which mold spores originated from the outdoors. If a type of mold spore is anticipated to originate from the indoors, then the source of mold growth that the mold spore originated from must be located and removed. All the mold spores that originated from the source of indoor mold growth must also be located and removed as part of the process of remedying an indoor mold problem.

Spore trap air sampling is a mold testing method that is most often used for the purposes of determining if mold growth that originates from the indoors is influencing the airborne indoor mold spore flora, establishing a plan to remove an indoor mold problem, as well as for medical and / or legal purposes when used in conjunction with a cultured air sample.

During the air sampling collection process, a known quantity of air (usually 75 liters of air) is drawn with a device called an air sampling pump and is then drawn through a collection device called a spore trap during the collection of a spore trap air sample. A spore trap is the device that collects airborne mold spores, in the 75 liters of air that is sampled, for the purpose of identifying the genus types of mold spores that originate from the indoors. Spore trap air samples collect both the viable (alive) and non-viable (dead) mold spores as well as other particulates such as mold hyphae (roots of mold), dust particulate, pollen, skin fragments, insulation particulate, as well as other allergens that may be in the air sample. Spore trap air samples are not collected on a petri dish; instead they are collected on a sticky surface that resembles tape, which is located on the inside of the spore trap. The spore trap air samples can then be visually analyzed under the magnification of a microscope.
I find that spore trap air sampling is a very useful mold testing method for evaluating if a mold problem is present in an indoor environment and if mold growth that originates from indoors is influencing the mold spore flora in the air in the indoor environment where the spore trap air sample is collected. It is important to understand that a spore trap air sample provides information about the indoor mold spore flora only for the moment that the spore trap air sample is collected and is considered a “snap-shot-in-time” of the mold spore flora. The indoor mold spore flora can change from hour to hour and fluctuations in the types and quantities of mold spores in the air can be rapid and substantial. It is also important to understand that an indoor source of mold growth may not be releasing mold spores into the air. For example, if there is a source of mold growth inside a wall cavity, the mold growth colony may not be releasing its mold spores into the air of the room and may not be detected when a spore trap air sample is collected inside the room. However, oftentimes a hidden source of mold growth, in a wall cavity for example, will release its mold spores into the air of the room and can therefore be detected when collecting a spore trap air sample.

This is a close-up view of anticipated mold on wood building components in a crawlspace. SafeAir Certified Mold Inspection
We have inspection tools such as moisture meters a thermal imaging camera that we can use for detecting hidden mold growth in wall cavities. When we do anticipate a hidden source of mold growth inside a wall cavity, we can drill a small hole, in the location where the hidden mold growth is anticipated and collect a spore trap air sample inside interior of the wall. A spore trap air sample inside a wall cavity will provide us information in order to determine if a source of mold growth is present in the location where the spore trap air sample is collected. One of the limitations of collecting a spore trap air sample in a wall cavity is that a spore trap air sample will only determine if mold growth is present between two wall studs located behind the sheetrock where the wall sample is collected. This is because the studs inside of a wall can trap mold growth and mold spores and the mold spores may not be influencing the air located between two adjoining wall studs that are behind the walls surface. Hidden mold growth inside walls can be difficult to locate. If we do not see visible signs of moisture and mold on the surface of the wall and if a thermal imaging camera does not detect the heat signature associated with a moisture source behind a walls surface, a source of hidden mold growth can go undetected. We cannot guarantee the absence of a hidden mold growth problem. We can only use excellent mold testing, mold inspection, and mold detection equipment to detect a hidden source of mold growth.

Spore trap air sampling is also useful in determining a cleaning plan, since it is necessary to identify areas where mold spores that originate from indoors are present, so the indoor type mold spores can be removed along with the source(s) of indoor mold growth. When we detect a mold problem in a room that is influencing the airborne mold spore flora, it may be necessary to collect air samples in other areas of the home or business since mold spore can travel to other areas of an indoor environment. When we anticipate there to be a mold problem in one room, we usually recommend collecting an additional spore trap air sample in the adjoining room(s) and possibly other indoor areas as well. One spore trap air sample will provide information on the airborne mold spore flora for the room the spore trap air sample is collected or an open area up to approximately 1,000 s.f.

The spore trap air sample is a useful mold testing method for determining statistical data such as the number of mold spores per cubic meter of air for each genus type of mold spore that is collected. A spore trap air sample will also provide statistical data in regard to the percentage of each genus type of mold spore that makeup the total mold spore flora as well as the estimated numerical quantities for each genus type of mold spore for each of the spore trap air samples that are collected. The statistical data that we are able to gather regarding each genus type of mold spore, in a spore trap air sample that is collected, is useful information for determining which mold spores originate from the indoors and which mold spores originate from the outdoors. When we see genus types of mold spores in the indoor spore trap air sample that is in elevated quantities and the same genus type of mold spore is not present in the outdoor air sample, we anticipate that the elevated genus type of mold spores collected in the indoor air sample to have originated from a source of mold growth indoors. Also, if the percentage of total mold spore flora for a specific genus type of mold spore collected in an indoor spore trap air sample is much higher than the outdoor spore trap air sample, we anticipate the elevated portion for the genus type of mold spore identified in the indoor air sample to have originated from a source of mold growth indoors. We can also identify if there are genus type of mold spores present in a spore trap air sample that is commonly associated with water damage. Mold spores that are commonly associated with water damage are usually only found in indoor environments where water damage has occurred that has resulted in mold growth.

The information that a spore trap air sample will not provide is that it will not identify a genus type of mold spore down to the species level. Each genus type of mold has a number of different species. Identifying a genus type of mold spore down to the species level is usually not needed in order to determine if there is mold growing indoors that is influencing the indoor air quality or to establish a cleaning plan to remove a source of mold growth. A cleaning plan to remove an indoor mold growth problem is the same regardless of the genus or species of mold that is present. All indoor mold growth and mold spores associated with the indoor type mold growth are recommended to be removed regardless of the type of mold that is present. In addition, the genus and species of indoor type mold growth and mold spores can change to a completely different genus and species of mold depending on moisture conditions, length of time the mold growth has been present, as well as other environmental factors. Therefore, a mold colony that is known to be allergenic can transform into a mold colony that is known to be toxic or pathogenic in a short period of time. Identifying a genus type of mold down to the species level is needed in order to determine if the mold is known to be a toxic or pathogenic type of mold. So, identifying a source of mold growth or airborne mold spores are generally not recommend unless it is for medical or legal purposes. When mold spores that are collected need to be identified down to the species level, a cultured air sample must be collected.
One outdoor spore trap air sample is always collected for which to compare the indoor spore trap air samples to. This is because mold spores are present in the outdoor air and they find their way indoors. We need to collect one outdoor spore trap air sample to determine what a normal mold spore flora is for baseline comparison purposes. When we compare the indoor spore trap air sample(s) to the outdoor spore trap air sample, we are able to better differentiate which genus type and numerical quantity of mold spores originate from the indoors. If we are able to determine that indoor type mold spores are present during the mold testing process, we anticipate there to be indoor mold growth present for the same genus type of mold spores collected that are anticipated to originate from the indoors.

This is a photo of what appears to be water damage and mold on the ceiling in a closet.  I recommend removing sheetrock in this area to remove and inspect for hidden mold growth. SafeAir Certified Mold Inspection provides mold testing services in Atlanta. Call 404-695-0673 to schedule an appointment!

Cultured air samples is another air sampling method that is able to provide additional information that that a spore trap air sample is not capable of providing. The primary purpose of collecting a cultured air sample is if your medical doctor wants to know both genus and species of mold spores present in the indoor air or perhaps for lawsuit purposes. For litigation purposes, it may be necessary to establish if there are airborne mold spores present that are known to be harmful to humans. Both toxic and non-toxic mold are removed using the same cleaning process, and individuals removing mold growth are recommended to take the same precautions in removing mold growth regardless of if the mold is a toxic mold or non-toxic mold. Therefore, collecting cultured air samples is not necessary in order to establish a cleaning plan to remove a mold growth problem.

Cultured air samples are collected in order to identify both genus and species mold spores present in the air. A spore trap air sample can only identify a mold spore at the genus level and cannot identify a mold spore down to the species level. Therefore, a cultured air sample is necessary to identify both genus and species of mold spores that are collected during air sampling.

Each genus type of mold has a number of different species. There are approximately several thousand different genus types of mold and approximately 100,000 different species of mold that have been identified by scientists. For example, Aspergillus genus type mold has over 150 different species. Aspergillus is a type of mold that is commonly found in indoor environments when there is a mold growth problem indoors. Some species of Aspergillus are known to produce mycotoxins; some species Aspergillus are pathogenic (capable of growing on human tissue); and some species Aspergillus are commonly found in the outdoor air.

When a spore trap air sample is collected, the laboratory observes the mold spores that are collected with their eyes using the magnification of a microscope. Identification of a mold spore down to the species level cannot be determined by visually observing a mold spore under the magnification of a microscope, such as with the case when a spore trap air sample is analyzed. Spore trap air sampling analysis can only determine the genus type of mold spores that are collected, since the mold spore that are collected are identified by appearance and are not grown into a mold colony. Mold spores can only be grown into a mold colony when a cultured air sample is collected.

When an identification of airborne mold spore down to the species level is requested by a client, a cultured air sample would need to be collected. When a cultured air sample is collected, the mold spores that are collected have to be cultured in the laboratory and grown into a mature mold colony, for identification down to the species level, for each genus type of mold that grows in the cultured air sample. A spore trap air sample is always collected in each location where a cultured air sample is collected. The spore trap air sample provides all of the statistical data for each of the genus types of mold spores that are collected, such as how many of each genus type of mold spores were collected, as well as the percentage each genus type of mold spore contributes to the total airborne mold spore flora in the spore trap air sample that is collected. Also, the dead mold spores are identified in a spore trap air sample and are not capable of being identified in a cultured air sample.
Also, a cultured air sample is needed to determine if there is a genus and species of mold spores collected in the air that is known to be a toxic mold, pathogenic mold, allergenic mold, etc. Statistical data can be collected from the spore trap air sample for the genus type of mold spores collected. When a cultured air sample is collected, a species identification can be determined for each of the genus type of mold spores that have been identified in the spore trap air sample.

This is a photo of what appears of the water damage and mold on the baseboards in a closet leading to an attic.  I anticipate there to be hidden water damage and mold in this area.  I recommend removing building material as needed to remove water and mold damaged building material that is associated with this anticipated mold and water damage.
A cultured air sample answers the following question: are the mold spores collected a type of mold that is known to be a toxic mold, pathogenic mold, etc.? Collecting a cultured air sample is not necessary for establishing a plan to remove a mold problem.

During the collection of a cultured air sample, 75 liters of air are sampled and the mold spores are collected on a liquid agar solution that is placed inside a petri dish. It is important to note that different types of liquid agar solution are conducive to the amplification of different types of mold growth. When SafeAir Certified Mold Inspection collects cultured air samples, we use two different liquid agar solutions in our petri dishes. Each agar solution is conducive to the amplification of different types of mold growth. Each type of mold, that commonly grows indoors, grows best on one of the two agar solutions that we use during the collection of a cultured air sample. We therefore collect two cultured air samples for each location where a cultured air sample is collected in addition to one spore trap air sample that is always collected in each location where a cultured air sample is collected.

During the collection process of a cultured air sample, mold spores are sucked in by a vacuum pump and into the impactor. The mold spores are then trapped on the surface of the liquid agar solution that is poured into the petri dish. The petri dish is covered and sealed, delivered to the laboratory, and placed in an incubator so that the mold spores that were collected can grow into a mature mold colony. Mold spores must be incubated and grown into a mature mold colony in order to identify the mold growth down to the species level. The process to grow mold spores into a mature mold colony, that is ready for laboratory analysis, takes approximately two week.
Some of the drawbacks to the cultured air sampling method are that only viable mold spores (mold spores that are alive) are capable of germinating and growing into a mold colony even though dead mold spores can pose the same health risk as a living mold spore. Therefore, the dead mold spores that are collected in a cultured air sample are not able to be analyzed and no information regarding the dead mold spores is can be provided. (In fact, inside an indoor environment, there may be as many as fifty times as many dead mold spores as living mold spores.) In addition, mold hyphae (the roots of mold) will not grow into a colony of visible mold growth in a petri dish even though the hyphae can cause adverse health conditions. Another drawback to the cultured air sampling method is that living mold spores that are collected do not always grow into identifiable mold colonies because yeast, bacteria and faster growing types of mold may be present that can overtake the liquid agar solution in the petri dish.

Airborne mold spores are often present in the air in large clusters of a dozen or more. Another drawback of cultured air sampling is that when a cluster of mold spores lands on a petri dish, regardless of the number of mold spores in the cluster, the mold growth that grows into a mold colony will appear on the petri dish as a single mold colony and the numerical quantity of living or dead mold spores cannot be determined. A single mold colony can be the result of one mold spore that has germinated or many mold spores that have germinated on a single location in the petri dish.

Given all of this information, a cultured air sample can underestimate the actual concentration of mold spores and the exposure to allergens associated with the total amount of mold spores that are collected when a cultured air sample is collected. This is another reason that a spore trap air sample needs to be collected at each location where a cultured air sample is collected. Statistical data can be determined for each genus type of mold spore that is present in the spore trap air sample and it can be correlated with the genus and species identification information that is determined when a cultured air sample is collected.

An additional drawback to cultured air samples are that the laboratory will not be able to determine if the mold spores that are collected contain mycotoxins. Mycotoxins are the toxic compounds in mold and mold spores that are commonly referred to as toxic mold. We are only able to determine if there is a genus and species of mold present that is known to produce mycotoxins. It is possible for there to be a mold present that is known to produce mycotoxins, and is not producing mycotoxins. Also, even if mycotoxins are present, it cannot be determined if mycotoxins are being produced in sufficient quantities to cause adverse health conditions.

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