Myths About Mold: It’s Not as Simple as You Might Believe

The Number One Complaint
The number one complaint that we get on indoor air quality is mold; however, we rarely find that mold is actually the source of the problem. The reason for the discrepancy between perception and reality is that there are still a lot of myths about where mold comes from, why it’s a problem, and how to deal with it.

Myths about Mold
The most critical pieces of information when evaluating any complaint is to determine what kind of mold you have and whether it’s the same kind inside the building as outside. Ideally, you shouldn’t find more than 10% of the concentration inside as you would find outdoors because the air handling system should filter most of it out.

If we find higher levels, that’s when it becomes problematic. However, testing for mold isn’t as simple as it might seem because many factors can skew the results of a test. The weather can have a significant impact on data; on a sunny day there won’t be a lot of growth, but on a muggy day you’ll find levels 2 – 4 times higher. During the winter there’s practically no mold growth at all.

One Test Isn’t Enough
The most common testing method due to its low price is an air cell trap analysis. This test works by dragging air through a filter and examining the results in a microscope. The obvious downside is that the sample only runs for 3 to 5 minutes. Mold levels in a building can vary from hour-to-hour, so a 5-minute sample isn’t indicative of what’s going on. It also doesn’t show what is live mold and what is dead mold.

If you have visible mold – the blue-green or black stuff growing on the wall – we can take a piece of plastic tape, stick it on the growth, and make a slide to determine the kind of mold in the sample. The petri dish method requires collecting an air sample, so you can grow mold to identify the species and get an idea of concentration.

Overall, the most effective way to evaluate mold in a building is to use a combination of two or three testing methods to compare the results. Each test alone only provides a piece of the puzzle; only an indoor air quality professional can piece together the results of the tests to determine the correct action.

About The Lawson Group
Since 1978, The Lawson Group has been in the “White Horse” business. That is to say, we help companies do things that are ultimately beneficial for them that they are sometimes unaware of. Our first endeavor was worker health and safety, mostly related to OSHA compliance issues, focusing on the industrial hygiene side of that equation regarding chemicals and noise, indoor air quality, and lead and asbestos in the workplace. Since becoming a third-party administrator in 1994, we now manage the workers’ comp programs for over 300 New Hampshire employers. In 2000, we entered the employee wellness business. Our primary effort is to work with employers and their employees to make better use of their health insurance dollars by working to help them become healthier and better consumers of healthcare. We welcome your inquiries regarding our services. Contact us to learn more.




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