Does an Air Quality Test Detect Mold?

Does an Air Quality Test Detect Mold?

When you see a bit of mold growing in an old loaf of bread, it’s easy to wrinkle your nose and throw away the loaf.

However, mold in your home can be a long-term risk to health and may even be a factor in the development or worsening of asthma symptoms.

Does an air quality test detect mold? Yes, air quality tests do detect mold. Professional air tests can tell if there is a mold problem even before someone smells it or finds it within the home by detecting spore particles in the air. Although you can purchase air test kits and send the results to a lab, it’s best to leave it to the professionals at the outset.

Continue reading to learn more about mold and what to do if you find it in your home. 

Mold in the Home

With so much moisture and damp around us, mold in buildings is widespread. It is most likely to occur in places that have a lot of moisture, such as kitchens and bathrooms, and will commonly form close to leaks.

There are several reasons to remove mold from the home or property. Namely, mold can damage a building, it is aesthetically displeasing, and it can have an adverse health effect on sensitive individuals (source).

Types of Mold

Mold can only grow on certain surfaces but, with the commonality of those surfaces — like cardboard, wood products, ceiling tiles, paint, wallpaper, and insulation — it’s easy to understand why you can find mold in many places around the home (source).

There are several types of common indoor mold: Fusarium, Penicillium, Aspergillus, and Cladosporium (source).

Generally, these molds will only grow when they have a constant source of moisture and a nutrient source. The material usually provides the nutrient that allows mold to grow on it.

One of the most toxic indoor molds is the Stachybotrys chartarum, also known as black mold (source).

This mold has many profound health implications, especially for children. It is as airborne as other fungi, and air sampling will not always be able to locate its presence.

Mold and mildew can often be confused as they both grow in damp areas, but the easiest way to tell mildew apart is by its lighter color and more powdery texture. 

To learn more about the distinction between mold and mildew, make sure you read our article, “What is the Difference between Mold and Mildew?

Signs of Mold

While you will find the bulk of mold in damp places, such as basements and kitchen cabinets, mold will always grow in houses that have suffered from water damage and floods.

The easiest way to tell if mold is growing is due to a musty odor found in the home. If one smells such, then someone needs to investigate where the smell is originating.

Mold is usually found in damp places and ranges in color from green to brown to black. It can appear as a blanketed fuzz or as random spotting in the affected area. It is generally smooth and sometimes slimy to the touch.

Keeping Mold Out of Your Home

Part of the nature of mold is its natural presence around moisture. It is challenging to keep mold out of the house, but there are ways to minimize the chances of mold.

It is essential to reduce indoor humidity by using air conditioners, dehumidifiers, increasing ventilation through air bricks and exhaust fans, and venting bathrooms and laundry rooms  (source). 

It is also important to dry any wet materials and furnishings within 48 hours, and even less if the surface is porous.

Cleaning and disinfecting surfaces that are prone to mold growth, such as bathroom tiles, also assists in keeping mold out of the home. 

If mold does begin to grow, you need to remove the mold along with the source, or it may regrow again. If we allow mold to grow unchecked, it can lead to health complications. 

Physical Implications of Mold

Mold generally indicates some sort of water damage. This damage can be through overexposure to moisture or flood damage.

You cannot ignore flood damage as it may have affected the structural integrity of a building, while normal mold indicates an unhealthy lack of ventilation.

You can generally scrub the mold away but, in porous items, mold can be more damaging. If you find mold in high concentrations, you will need to replace things like carpets and wallpapers.

Health Implications of Mold

Mold is primarily harmful to those who have allergies and can cause symptoms similar to hay fever, namely, runny nose, sneezing, skin rashes, and red eyes. Mold can especially be harmful to asthmatics (source). 

Since mold is most likely to affect respiratory function, it often affects the lungs, nose, and mouth. Some people have even found that it can cause headaches, coughs, and wheezing.

In extreme cases, it can even cause asthma in people and lower respiratory symptoms in children (source). Therefore, it is vital to deal with mold growth as soon as possible and not ignore it as an “out of sight, out of mind” situation.

Air Quality Tests

Image by Dustin Day via FreeImages

When a breeze blows in mold spores, or someone tracks them in under a pair of shoes, homeowners will want to know how they can detect mold. A simple place to begin is by obtaining an air quality test.

Air quality tests allow users to take air samples and test them, which is important as mold spores are invisible to the human eye, and only through proper laboratory analysis can we detect and deal with spores before things get worse.

You only need to conduct air sampling when mold is not visible. Only professionals should conduct air sampling — specifically, those who can interpret results and suggest the best ways to remove mold (source).

Another reason that sampling might be necessary is to indicate proof of mold for legal reasons, such as when buying a new home that may have mold damage. The results would allow potential homeowners to bargain for a lower price.

Managers also use air sampling to measure if an environment is safe to work or live in and, for businesses, it helps them meet standards for the Occupational Safety and Health Association (OSHA).

What to Look for in Testing

Generally, when testing, tests take place all over the property to ascertain differences between the indoors and outdoors.

If the test detects mold spores, then it is a good idea to retest a few times after treatment to ensure that the spores are thoroughly removed and are not replicating elsewhere (source). 

When sampling air, there are two types of mold inspection. Depending on the client’s needs, they will conduct a complete mold inspection or a limited mold inspection. A complete mold inspection examines all areas of the property, including outdoors and indoors (source).

With a limited mold inspection, they will only examine certain structures. It is important to note that since mold can grow quite quickly, the numbers provided during a mold inspection are only valid for that time period.

When the inspector conducts the sampling, they should follow a procedure similar to this. First, they conduct a visual examination of the property in easy-to-reach areas.

They also measure moisture, temperature, and humidity, which are all factors in the growth of mold.

When the inspector reports their findings, they will only comment on moisture intrusion, odors, water damage, and apparent mold growth. They may also comment on whether conditions are conducive to future mold growth. 

Finally, after laboratory analysis of mold or air samplings on the property, they will report their results.

Air Sampling Devices

There are different types of devices that can be used for air sampling. 

Most air samplers use some kind of air pump to analyze mold. Impaction samplers are a typical example in which an air pump pushes spores into a microscope slide, making it easy to examine in the lab.

If you remember the old obsolete cassette tapes, a cassette sampler employs a similar concept. Only they use forced air to propel spores onto a collection tape. Alternatively, airborne-particle collectors use a culture dish and trap spores directly onto them (source). 

One example of a sampling device is supposed to be easy to use. This device, initially used for air cleaning, has been adapted to collect samples instead. It does not require physical air pumping, like most other devices. 

It uses a plasma-induced charge to propel and catch aerosol particles (source). The device is a simple plug-and-play and can sample high volumes of air.

Gathering Air Samples

Scientists gather air samples in specialized bags and canisters made for that specific purpose. They then send the samples to the appropriate lab in sealed containers.

Professionals take samples if there is a hint of mold or the possibility that the local environment will encourage mold growth. Musty odors are a general sign of mold growth, even with no visual indication of mold presence.

Mold can often occur in the Heating, Ventilation, And Air Cooling (HVAC) system, which is why testers often check these units first. Unfortunately, if the HVAC unit does have mold growth, it increases the chances of being spread around. 

The wind is also a variable when deciding where to sample. While outdoor samples serve as control samples, even outdoor samples need to come from separate areas. For example, from the windward (upwind) and leeward (downwind) sides of the structure.

By looking at wind direction, professionals can judge what the air composition is and what kind of air enters the home. Professionals must gather outdoor and indoor air samples in the same period to ensure accurate readings.

Generally, they take samples in the center of the room, with the collection device standing at the height of 3 to 6 feet. The sample collector should run for about 10 minutes unless there are external factors that cause movement or increase pollution in the environment.

When taking samples, you should close doors and windows to stabilize air within the space. The controlled environment also allows for retesting later in the same conditions. Switch off any HVAC systems during the test.

Air pressure is also a contributing factor when taking air samples. Unfavorable weather conditions like thunderstorms and high winds are not conducive for sample collection. 

Barometric pressures also increase the likelihood of spores being sucked into the home, negating results.

Practicalities of Air Sampling

While air sampling is a positive method to identify a mold issue within a structure, it is not the sole method to confirm the problem. Complete data collection requires surface samples as well as visual confirmations.

Since there is the potential for damage during air sample collection, it is helpful to have other forms of data collection. An air sample test also allows purveyors to identify how extensive the mold might be, primarily if they cannot obtain visual signs.

Ambient air samples — when samples are taken for a period of 5 to 10 minutes — are not an ideal method of sampling.

That is why most professionals will sample in different areas, inside and outside, to develop a fuller understanding of a potential mold problem.

There are limitations to air sampling as well, as air samples only look at mold spores. However, there are fragmented mold particles called fungal fragments, which are not accounted for when air sampling.

Since these fungal fragments generally appear in far higher concentrations compared to mold spores, the environment may be far unhealthier than the average air sample test would show.

Studies have shown that fungal fragments can appear in much higher concentration, between 300 to 500 times more than mold spores (source).

Stachybotrys chartarum, also known as black mold, presents as fungal fragments, and an air sample test may not be able to detect it.

Generally, 0 to 50 spores in a sample indicate that an area is extremely clean, but experts consider Stachybotrys elevated at this level and deem it a cause for concern. 

When spore levels are between 500-1500, this indicates that there is a spore problem, but routine cleaning should be able to remove mold and lower levels. Anything above 10,000 mold spores requires professional cleaning of the area.

Testers can also easily misread results, which is why it is vital to have experienced professionals take samples. Due to other particles in the air, the sample may become more challenging to read and, in some cases, a false negative is reported. 

What To Do if You Have Mold

Photo by Ana Labate via FreeImages

Generally, you can deal with small amounts of household mold without involving professionals. After the mold is located, the first thing to do is cut off its supply of moisture. 

If there is a leaking pipe, you can fix it first. If there is a ventilation issue in a kitchen or bathroom, you will want to have an exhaust fan installed to minimize moisture in the atmosphere. Anything that has become damp or wet should be dried immediately.

If the mold has grown on a hard surface, homeowners can use detergent and dry water to scrub it off and then dry it thoroughly.

However, if the mold has grown on a porous surface, like a carpet, it is beyond saving, and disappointed owners can throw it away (source).

To clean mold, use a mixture of one part bleach to three parts water. Any cleaning requires a lot of elbow grease, along with heavy-duty cleaning materials like steel wool or a scrub brush.

Retailers also sell specialized mold cleaners for very stubborn molds.

If the mold has grown on an expensive or sentimental item like antique furniture or paintings that one would not be happy with throwing away, it is best to consult a professional to clean the item. 

If mold has grown on paint or between tiles, make sure these are thoroughly cleaned and dried before repainting or recaulking. Failing to do so will lead to the peeling of surfaces.

In a place like a shower where mold is likely to occur, cleaning often and using more ventilation will lessen the chances of mold.

To help avoid mold growing on the ceiling, you can purchase specialized acrylic paints available for kitchens and bathrooms which have anti-mold and anti-fungal properties.

In the case where there has been significant water damage due to floods or a long unattended water pipe leak/burst, it is better to hire a contractor who has experience in cleaning mold.

Only a professional with experience should conduct a major cleanup, especially if the mold has grown through a sewage leak.

The health implications of living in a home or building that has this mold are not the discounted prices of an amateur cleaner.

Final Thoughts

Air sampling is a positive way to identify mold within a home or property. With the implications of mold growth, it is vital to conduct air and surface sampling to identify and remove the problem as quickly as possible.

So when that musty smell hits or an unnatural cough develops, it is best to check the environment for mold. Your health is worth so much more than the effort of finding an expert to remove the offending mold from your home.


I'm a Pharmacist and a passionate researcher into clean air and pure water for the home. I believe these 2 elements play a significant role in our health and overall wellbeing.

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