Pace® Mold and Fungal Testing Services
Pace® provides analytical testing for evaluating and controlling health hazards in the built environment. The largest American-owned laboratory network, Pace® has the breadth and depth of capabilities to test indoor environments, systems, and materials for a wide range of environmental contaminants, including mold and other fungi. Whether you’re testing to ensure regulatory compliance, improve working conditions, protect occupant health, or ensure patient and product safety, our mold and fungal professionals can provide the expertise, personalized services, accuracy, and rapid turnaround time you need to get the job done right.
What are Mold and Fungi?
Mold is not a scientific term. Most of the organisms causing this type of growth belong to the fungi kingdom and more specifically the group of zygomycetes or ascomycetes. However, the lines of the non-scientific terms are blurry, and there are molds in the scientific taxon “Basidiomycota.”
Mold and other fungi benefit the natural ecosystem and our lives in numerous ways. They are essential to decomposition and nutrient cycling, a common food source, used in the fermenting process, a source of medicines such as penicillin, and more. Increasingly, scientists believe they may be also able to help us clean up environmental contaminants from microplastics to toxic chemicals. But mold and fungi also have a dark side, and that’s where Pace® can help.
The Dark Side of Mold and Fungi
As beneficial as they may be, some fungi can also contribute to health issues. For the most part, it is the members of the fungi kingdom classified as mold that are cause for the greatest concern. Known and suspected mold and fungi-associated health challenges include:
- Allergic reactions. Mild reactions include sneezing, coughing, and wheezing. In sensitive individuals, reactions to mold can lead to diseases such as hypersensitivity pneumonitis.
- Infections. Mold and fungi infections can be life threatening, especially in the immunocompromised.
- Toxicosis. Mold and fungi produce mycotoxins, which produce the pathological condition known as toxicosis. The severity of the condition depends on the type of mycotoxin, the level of exposure, and the overall health of the individual.
Who Should Test for Mold and Fungi?
Mold species such as Aspergillus, Penicillium, and Cladosporium can grow on wallpaper, ceiling tiles, carpeting, and other cellulosic materials – practically anywhere there is excessive moisture due to leaks, high humidity, or flooding. Fungal byproducts can lead to allergic reactions and have been associated with respiratory problems and other symptoms of what’s popularly known as Sick Building Syndrome (SBS).
In the pharmaceutical industry, mold can contaminate products and production environments, leading to product safety issues and non-compliance with regulatory and industry standards. Pharmaceutical manufacturers are required to comply with current Good Manufacturing Practices (cGMPs) governing product safety, including microbial contamination.
Learn more about Pace® services for pharmaceutical manufacturers
USP <797> sets minimum environmental safety standards for pharmacies that produce compounded sterile preparations (CSPs) for use in humans and animals. This includes compounding pharmacies that operate as part of larger institutions such as hospitals. USP <797> is a comprehensive standard. Among other requirements, it includes sampling for the presence of viable microorganisms, including mold and fungi, on surfaces and in air.
Invasive fungal infections are of particular concern in healthcare settings. Such infections carry high mortality rates, especially for immunocompromised individuals. Aspergillus is commonly associated with healthcare-associated infections, with some strains causing mortality rates as high as 60% according to the CDC.
Rhizopus is another genus of mold that can cause serious health problems in a healthcare setting, especially among individuals with weakened immune systems. Diseases caused by Rhizopus species fall under the umbrella of mucormycosis, which are serious, and often deadly, fungal infections. Rhizopus species, given their aggressive nature, can cause rapid-onset infections, leading to severe outcomes without prompt treatment.
Not all healthcare-associated infections are caused by mold. Candida auris (C. auris) is a type of yeast (fungus) that can cause serious healthcare-associated infections. An infected person may experience fever and chills that do not improve after typical antibiotic treatment. C. auris infections can be particularly concerning because the fungus has shown to be resistant to multiple antifungal drugs, making it a more dangerous public health threat.
Medically Relevant Fungal Infections
Certain fungi are of significant concern due to their potential to cause outbreaks of infections, especially among immunocompromised people. These infections are often caused by exposure outside of the medical facility, but there are cases of healthcare-associated exposure as well.
Aspergillosis is a disease caused by breathing in spores of Aspergillus, a common mold found in indoor and outdoor environments. Although most people exposed to Aspergillus spores do not get sick, people with weakened immune systems or lung diseases are at higher risk. Medical facilities are not required to report cases of Aspergillosis in the United States, so estimates are difficult. However, the CDC estimated that nearly 15,000 U.S. hospitalizations in 2014 were aspergillosis-associated.
Healthcare-associated Aspergillosis cases, particularly invasive Aspergillosis, are often tied to hospital construction or renovation projects that can release spores into the environment. These cases are significant because of the high risk they pose to immunocompromised patients residing in such settings. According to the CDC, Aspergillosis was found to be one of the top four most common causes of death in a systematic review of intensive care unit autopsy studies.
Cryptococcosis is an infection caused by the Cryptococcus fungi. While the infection can impact various parts of the body, it commonly leads to lung or brain infections (cryptococcal meningitis). This fungal disease arises from breathing in spores of the Cryptococcus species, which are found in the environment, including in soil, bird dung, and decaying wood. Cryptococcosis is primarily viewed as a community-acquired infection, although those living in assisted living facilities or recovering from major surgeries can be at increased risk.
Histoplasmosis is an infection caused by the Histoplasma capsulatum fungus. This disease can vary in severity from asymptomatic, to mild flu-like symptoms, to severe and possibly life-threatening lung infections. A disseminated form can affect multiple organ systems. While Histoplasmosis is primarily acquired from environmental exposure to spores in contaminated soil, particularly where bat or bird droppings are concentrated, its association with medical facilities is not commonly documented as a direct source of infection.
A Mucor infection, also known as mucormycosis, is a serious fungal infection caused by the Mucorales order of fungi. Mucor infections can affect different parts of the body, such as the sinuses, lungs, skin, and brain, leading to a wide range of symptoms depending on the area affected. Infections can be particularly aggressive and are more common among individuals with weakened immune systems, such as those with uncontrolled diabetes, cancer patients, or those receiving immunosuppressive medications.
Mucormycosis is considered rare and thought to most often occur due to environmental exposure. Although some procedures and healthcare settings have been identified as potential sources of infection, distinguishing between healthcare-associated Mucormycosis and infections acquired elsewhere can be difficult. There is no national surveillance for Mucormycosis in the United States.
A relatively common infection, Candidiasis is typically caused by the yeast-like fungus Candida albicans. This infection can lead to various conditions, ranging from superficial issues like thrush and vaginal yeast infections to invasive Candidiasis (Candidemia.) A bloodstream infection, Candidemia is particularly concerning in healthcare-associated illnesses due to its high morbidity and mortality rates. The CDC reports that 1 in 4 patients with Candidemia died during hospitalization.
Analyzing Mold Samples
Mold samples can be analyzed in different ways. The most common methods are direct observation and culturing, although more advanced techniques like Polymerase Chain Reaction (PCR) may also be used.
Direct observation of mold samples involved gathering a sample using one of the techniques listed in the next section and analyzing it under a microscope. Sample collection for direct observation is often easier and lab analysis is usually faster and less expensive.
The disadvantage is that while direct observation can determine the presence of mold spores, it does not determine their viability. In addition, because many species of mold produce spores that are nearly identical in appearance, species identification is often impossible. However, unless species identification is required, as in the case of healthcare-associated infections, direct observation may be sufficient.
Considered the gold standard in mold analysis techniques, culturing samples involves incubating spores in a growth medium to determine viability and species. By allowing spores to germinate and form larger colonies with more distinct characteristics, species identification is possible. Determining viability can also inform remediation best practices. Culturing mold samples is especially useful in industries, such as healthcare, pharmaceutical manufacturing, and food processing, where certain species can impact product quality and sometimes present grave health risks.
Polymerase Chain Reaction (PCR) is a versatile technique with a wide variety of applications in molecular biology and medicine. Pace® was one of the first commercial labs to use quantitative Polymerase Chain Reaction (qPCR) to analyze for SARS-CoV-2 in wastewater. It is also one of the tools used by the Pace® Legionella outbreak response team. Mold-specific quantitative PCR (MSQPCR) is recognized for its high specificity, quantification capabilities, and rapid turnaround.
Mold Sampling Methods
There are several ways to collect samples for mold analysis. The best method often depends on the scenario, the environment, and what you hope to learn. Contact us if you would like to discuss which method to use.
Samples can be collected from a surface in different ways. One of the most common, the tape-lift method, involves pressing a piece of tape against a smooth surface, such as drywall, wallpaper, or ceiling tiles, where fungal growth is suspected. The sample is then analyzed under a microscope to determine the density and type of spores and fungal structures on the sample.
An advantage of this method is that it is rather simple and requires easily obtainable tools like clear sticky tape and 3x5” microscopic slides. However, tape-lift samples cannot be cultured. In addition, they often contain a lot of background “noise” such as carpet fibers, skin cells, pet hair, dust mites, etc. Some of these add to the understanding of the mold infestation, while others can obscure results. A qualified mycologist can help interpret the results.
For uneven or hard to reach surfaces, swabs may also be used to collect surface samples. With the right preparation, these samples can be cultured in the lab.
Air sampling involves capturing a sample of air in a specially designed device and then having the sample analyzed by a qualified laboratory. This is often referred to as spore trap sampling. These samples are then analyzed under a microscope using direct observation. If species identification and viability analysis is required, airborne spores can also be trapped directly onto a nutrient agar growth medium using a specialized device.
Air sampling can be useful for detecting and identifying hidden sources of mold and for validating remediation. That said, some mold such as Stachybotrys chartarum are “stickier” and less likely to become airborne. Several other variables can also impact the number of airborne spores, including temperature, humidity, air flow, season, and more.
Bulk material sampling is particularly useful in assessing structures with long-term moisture issues from flooding, leaks, or high humidity. In bulk sampling, a section of building material, e.g., wallboard, wood beam, ceiling tile, flooring, etc. is sent to a lab for analysis, which can be performed by direct microscopic examination or by culture.
Dust sampling may also be used for uneven surfaces and hard to reach places. The process involves gathering dust samples using wipes, swabs, microvacs, or other tools. It is not unusual to find fungal spores in a dust sample, but the percentage rate is usually very low (<1%). A higher rate can indicate hidden mold growth. As with other methods, a qualified mycologist can help separate out background interferences and interpret results. Dust samples may also be cultured.
Need Supplies?
Visit the Pace® store to shop sampling supplies.
If you have questions about which method to use or which supplies to purchase, contact us.
Our mold and fungi experts would be happy to discuss your testing requirements with you.
Additional Resources
Taxonomic history and current status of Stachybotrys chartarum and related species
Measurements of Airborne Fungal and Endotoxin Levels in Water-Damaged Buildings
Microscopic Evaluation and Identification of Fungi From Tape-lift or Bulk Samples
Dust Characterization: dust and fibers in the indoor environment
Testing for airborne fungal spores: How to use the results derived from culture method
Navigating the Revised USP <797> Standard for Environmental Monitoring