Mold and Fungi Identification

The process of sampling for mold and fungi is very nuanced, choosing the right location to sample as well as the appropriate test method can be a daunting task and is best left to professionals. With that in mind there are a number of home test kits available on the market which can help guide you through the mold sampling process. Should you choose to purchase one of these kits, or simply make your own, the following guidelines should be considered for each sample type:

When collecting air samples for non-culturable (direct examination) based analysis you should use an appropriate air cassette and follow the manufacturer’s instructions. Often times this sampling process will require a special air pump to meet the flow requirements. Make sure to seal the inlet and outlets of the cassette after sampling to prevent contamination of the sample.
When collecting air samples for culture based analysis you should have already purchased an agar media plate, this will be used to collect the spores which fall out of the air. Place the plates on a surface approximately 1 Meter (3 feet) off the ground. Remove the lid and let the plate sit out for 1-4 hours, label the lids and place them face down next to the plate. Once the time is up replace the lid on the plate and seal with tape around the edge of the plate and lid, ensuring the plate and lid are firmly sealed together. Keep the samples in a cool dark place until they can be brought in to the laboratory, samples should be submitted as soon as possible.

Bulk samples are quite simply pieces of material which have mold or fungi growing on them. When collecting a sample of bulk material ensure you are wearing appropriate personal protective equipment to protect yourself from any exposure caused by disturbing the material. Using a clean knife cut a small piece approximately 10cmx10cm (4 sq inch) and place it in a clean zipper sealing plastic bag.
Note: Materials which may contain asbestos such as drywall, plaster, flooring, popcorn ceilings or other materials should be tested by a professional as proper procedures are required to protect against contamination.

Swab sampling kits are one of the more common types of surface sampling products. Swab samples can provide some information about a colony without the asbestos risk of bulk sampling procedures. When collecting swab samples it is important to use proper technique. Before taking the sample consider the surface; is the surface wet or dry? If wet you should use a dry sterile swab, if the surface is dry you should use a wet sterile swab. When taking the actual sample it is important to roll the swab along the surface, wiping or streaking the surface will disrupt the fragile characteristics of the mold structures and make the analysis less accurate. After the sample has been taken return the swab to the tube it came in and bring it in to the lab promptly to avoid sample degradation, store samples in a cool dark place until they can be brought in.

Mold is a term referring to a group of fungi which grow in the form of multi-cellular structures called hyphae which will then form conidia and spores. Molds differ from other fungi which are typically single celled such as yeasts. The spores produced by the conidia are how a mold spreads throughout its environment. Mold spores are an important part of the global ecosystem, they can be found both indoors and outdoors and have colonized essentially every continent on the planet. While the amount of mold spores in the air is typically low enough not to cause any issues the invention of indoor heating and plumbing has made molds a formidable presence in homes across the globe.
The growth cycle of a typical mold colony starts at the spore, which is a microscopic particle which contains all the information and resources required to start a new mold colony. Spores are spread through the air by wind or forced ventilation systems, mold spores can also attach themselves to clothing, pets, building materials or even your skin (which needs to have a fairly diverse eco-system to maintain your health). Once a mold spore lands somewhere moist it will begin to grow and divide, producing structures called “hyphae”-long filament like structures which will appear as a fuzzy patch once they have grown enough. When the conditions are just right and the mold colony is particularly happy it will begin to produce spores at the ends of the hyphae in specialized structures called “conidia”. These conidia will start shedding spores, which will be picked up by moving air, pets or other means and land on another surface, if that surface has the moisture and food the mold needs it will start a new colony and the cycle continues. Mold spores are extremely resilient, with some able to survive long dry periods and many others that are resistant to even the strongest cleaning chemicals.
While molds are an integral part of the microscopic world, they can be a nuisance or health hazard when they invade a living space. Large colonies of mold are unsightly, often producing large brown, black, green, blue or white stains on surfaces and large colonies have also been suspected of causing health problems. At present there is no conclusive evidence for or against the hazards of molds, however it is generally recommended that any mold growth is dealt with promptly as it can produce a number of unwanted smells and can damage the surface it is growing on.

As stated above there has not been a causal link established between mold or fungi and negative health effects except in immunocompromised individuals. With that in mind there have been a number of reports which seem to show a link between mold exposure and asthmatic response in individuals who already have asthma. Mold exposure may also cause symptoms which resemble allergic reactions such as a runny nose, cough or difficulty breathing and irritation of the eyes, although the fact that molds are abundant both indoors and outdoors makes any studies relating to the specific health effects of indoor mold growth difficult. Despite the lack of causal evidence mold growth is unsightly, produces a number of offensive odors and damages building materials, for these reasons alone it is highly recommended that any significant mold growth is dealt with promptly by professionals.

The lack of causal evidence between mold and heath problems has led to somewhat ambiguous regulations around mold detection and remediation. With that in mind it is the recommendation of WorkSafeBC, Health Canada and most municipalities that mold or any water damaged material is cleaned and sanitized properly or removed if the damage is great enough. There may be some re-occupation restrictions when a living or working space has been contaminated with mold and it is recommended that any water damage be inspected by a certified professional to provide guidance on clean-up or remediation. There is a wealth of information about mold available to interested parties, including the following:
Mold Hazards (WorkSafeBC)
Indoor Air Quality (CCOHS)
Mould and Your Health
Indoor Air Quality (Health Services BC)