There are a number of different aspects that are important to understand about mold, and how mold grows in indoor environments. Understanding the characteristics about mold will help you develop a effective strategy to combat it
- Mold spores are too small to be seen by the naked eye. Only when mold grows in significant quantities and colonizes on various surfaces can it be seen without the aid of magnification such as microscopes used in laboratories.
- It is important to understand that an indoor environment can have significantly elevated mold spores dispersed throughout the air and there not be any visible mold colonization on various surfaces that can be observed visually.
- When mold is actively growing in a indoor environment there are a number of factors which are necessary in order for mold to grow. First, There must be excessive relative humidity, or elevated moisture in the building materials , or in active water intrusion present in order for mold to grow actively. Second, mold requires nutrients in order to grow. Organic matter is necessary and is used as a “food source“ for mold to proliferate. This can be comprised of dirt in the air that has settled on Virtually any surface found in a typical home or business environment. Thirdly, eliminating the source of the moisture, water intrusion or excessively high relative humidity is important. However, it is even more important to kill the mold at the same time or prior to improving the indoor environmental conditions. This is because certain species of mold try to reproduce more aggressively when their environment is being deprived of water/moisture/humidity. After you have killed the mold and the mold is no longer living/viable then improving the environmental conditions will help prevent the recurrence of mold proliferation.
- When mold is actively growing/proliferating frequently there is a odor associated with the “growth” of mold. This odor is caused by microbial VOCs, volatile organic compounds being actively released into the air during the growth cycle. This odor is most commonly described as a: “musty” odor. Typically, this odor will strengthen and weaken. The strength of the odor is related to the moisture/water/humidity environmental conditions. As humidity/moisture decrease the strength of the odor will also decrease.
- It is extremely important to understand that mold does not “die” (no longer viable), when it is deprived of water/moisture/humidity. The mold transitions into a “dormant” state and waits for the next opportunity to continue growing when the environmental conditions are right. Scientists have cultured mold which several thousand years old and was in a dormant state when they recovered it from the Egyptian pyramids.
- Since mold cannot be seen by the naked eye, collecting air samples from various locations in a suspect environmental area is one of the best methods for determining the presence or absence of elevated mold spores. Air samples can also be collected from HVAC systems, wall and floor cavities. In general, the more samples collected of suspect areas, the more data you will have available to you from which to base your decisions on how to proceed. There is a wide range of collection sundries that are used to collect mold samples, and as with every industry, there is a significant difference in the quality of these products and their effectiveness. At Violet Frog, we believe in the importance of using quality testing sundries because if your data is compromised for any reason, your decision making will also be compromised.
Recently, I was attending a certification course in Florida. One of the other students who was a man in his early 60s who owned a home inspection company told me he and his company had performed over 10,000 home inspections. He had some of his testing equipment with him and I asked him why he was using a particular type of sundry which was inappropriate. He simply looked at me in disbelief until a laboratory technician showed up about 20 seconds after our conversation and asked him why he was using that type of sundry for collection of mold particulates. The laboratory technician said they were going to throw those sundries into the trash which is where they belong and they would give him as a courtesy more appropriate sundries as a replacement.
If you decide to have mold testing performed in your home or business it is vitally important to have a person who has been appropriately trained and is experienced in the collection of microbial data. There are numerous issues that are related to the collection of microbial data that are important to be performed correctly in order for that data to have the highest degree of validity as possible.
That being said, “do it yourself home test” kits are of highly questionable value for a number of reasons including the quality of the testing materials, the amount of effort and quality the laboratory puts forth for a non-repeat customer such as a homeowner. Laboratory’s as with other industries often provide different levels of service depending on the profitability of their customers.
- If you see a substance on a surface which is a concern, there are a number of methods for testing that substance. This may involve taking a “surface” sample with either a “tape lift” or a “swab” both have distinct advantages and disadvantages depending on your needs. Sometimes, it is possible to take part of the actual surface such as for example “drywall” and have that tested.
- It is extremely important to use a quality laboratory. Less than 8% of microbial laboratories nationwide are “accredited”. Third-party accreditation costs laboratory’s money and personnel resources.