Mold Testing – How to Identify Hidden Mold Growth

Unlike home DIY kits, professional mold sampling includes a thorough visual inspection. This is the most accurate way to track down hidden mold growth that spore testing can’t catch.

Testing can identify a portion of the live (viable) molds in a sampled environment, but this misses and undercounts nonliving or dead molds. The health effects of these organisms depend on a person’s susceptibility to the mycotoxins they produce. Contact Mold Testing NYC now!

Mold growth and the spores it releases are airborne and can cause various symptoms, including nasal and sinus, throat, skin, and eye irritation. For some people with severe mold allergies, symptoms can be more serious, such as a dry hacking cough, wheezing, shortness of breath and persistently watery eyes. Identifying and correcting the mold problem is essential to preventing health problems and protecting building materials, household goods and furnishings from damage.

Mold can grow indoors in any climate, year-round, and is capable of consuming organic material, which can cause structural damage to buildings and furniture. It can also affect occupants in the spaces it invades, potentially leading to respiratory issues and other health problems. Early detection of mold helps prevent these problems, and is an important part of any property inspection.

The best way to detect mold is through careful detailed visual assessment and recognizing the odor of mold. Many molds produce a musty odor as they break down the organic material they are eating, and this odor is noticeable in most properties. Mold is often spotted as staining or fuzzy growth on building materials, such as walls, ceilings, and wood furniture. Water stains on surfaces and signs of condensation indicate high humidity levels, which are ideal for mold growth.

It is common to find moisture problems in homes, especially Florida, and these can be a significant contributing factor to the growth of mold. Routinely checking the areas around air conditioning and furnaces for standing water, drips on evaporator coils or on liner surfaces, as well as examining damp or cold walls and floors, can help spot potential problem spots before they lead to mold. The same goes for the area around any windows, where condensation can occur and may be indicative of a leak.

Air Samples

Air sampling is a method of collecting airborne mold spores to determine their number and type in a specific area. This is accomplished by pulling a metered amount of air through a special filter that traps any particulate including mold spores. This sample is then analyzed to determine the number and types of mold spores present in the air at that time and location. This sample is often compared to an outdoor control or baseline sample to help determine the extent of an indoor mold contamination.

One problem with this approach is that it only provides a snapshot of what is occurring at that moment. If the air sample is collected before or after a large disruption, such as someone opening a door, walking across the carpet, or moving an object in a room, the number of spores will greatly increase and may skew the results. This also misses any spores that are clinging to the walls, ceiling, or HVAC system where they may remain undetected.

An alternative to this method is Envirobiomics, which uses a DNA-based analysis called MSqPCR to identify the molds and their toxins in the air. This method is more accurate than an ambient air test because it does not depend on spores. It will identify the toxins produced by molds such as satosporium, stachybotrys chartarum, and other toxic fungal metabolites that are emitted into the air. It will also report the levels of endotoxins, which are a group of bacteria toxins from Gram-Negative bacteria that can contribute to Chronic Inflammatory Response Syndrome (CIRS).

In many scenarios, an ambient air test is still recommended because it does provide important information. However, a more comprehensive testing regimen is typically required to address a serious contamination. This will usually include surface samples, a clearance sample, and an independent air test. The clearance sample is used to prove that the mold spore count in the contained/remediation zone has returned to normal. Occasionally, an air test outside the remediation zone will also be conducted to ensure that the contamination is not being carried into unaffected areas of the home or building.

Swab Samples

Mold sampling involves taking a small sample of suspect materials and sending them to a laboratory for testing. The most common samples are surface swabs, air samples and bulk samples (cutting up small amounts of carpet, drywall or other porous materials). Surface swabs use what is essentially a sanitary Q-Tip with a cotton-like media rolled against the suspected material to collect spores and growth structures. The swab is then placed in a tube containing specialized fluid to preserve the sample for analysis.

The advantages of surface swab testing are that it is relatively quick and non-destructive. It can also be used to test wet or heavily soiled surfaces that may not respond well to other methods. It is important to note, however, that surface swabs aren’t able to identify the concentration of spores in the air, which is an important factor in determining if there is a mold issue.

Tape sampling is a more precise method than surface swabs and can be performed on most surfaces without causing damage. It can provide valuable information, including the species of mold present and the likelihood that it is producing spores. It can also help to pinpoint the source of a mold problem by identifying areas of higher spore counts.

ERMI and DNA-type tests are other more specialized forms of testing that can determine the specific genus of the mold. These tests are more expensive than a Bulk sample, but they can offer more accurate results.

Mycotoxins are toxic compounds produced by some types of mold and can have serious health effects in people if they are exposed to them. They are most commonly produced by Aspergillus and Penicillium molds, but can be created by other types of mold as well.

A mycotoxin test is a blood test that can detect the presence of these neurotoxins/poisons in a person’s body. These tests are usually only ordered by individuals who are concerned that they may be displaying symptoms of exposure to mycotoxins or have been diagnosed with certain medical conditions that are associated with mycotoxins. The CDC recommends only having these tests done by a licensed physician.

Bulk Samples

The best test method for determining the type of mold growth in a home is to collect a bulk sample. This is done by physically removing a small piece of the impacted material (such as drywall or baseboards) and sending it to the lab for testing. The lab can determine the genus and species of the mold growth, which is useful in deciding appropriate remediation strategies. Bulk sampling is also useful for identifying if mycotoxins (a type of neurotoxin/poison gas that can have negative health effects in humans) are present in the home. The mycotoxins can be ingested when occupants are exposed to dust particulates containing the mold spores, so it is important to have an accurate determination of what type of mold is in the home.

This type of testing is usually performed as a follow-up to other tests, such as a swab or tape lift sample, and to an Environmental Relative Moldiness Index (ERMI) sample. The ERMI test is not recommended for homes with visible mold growth because it does not provide enough information on what types of mold are in the air to properly inform remediation strategy.

In addition, a swab or tape-lift sample can only be collected from the surface of a substrate; it cannot determine what types of mold are in the dead air spaces behind walls, above ceilings, and underneath floors. That is why it is often necessary to use both a bulk sample and an air sample in conjunction with each other.

When using a bulk sample, take care not to disturb the suspected mold growth. It is important to wear gloves and not touch the suspect material, as contaminating the sample can alter the result of the laboratory analysis. It is also important to press the tape or swab on the surface in one location rather than pressing over a large area. Doing so may over-load the sample and ruin the microscopic mold structures in the adhesive areas of the tape or swab. It is also important to use a freezer bag, as these are stronger and make it easier for the lab to remove the samples for analysis.