What does your heating and air conditioning system have to do with your unexplained headaches or brain fog? Perhaps a great deal, suggests William Dolch, founder and owner of Certified Indoor Air of the Triangle. “Those symptoms may well be caused by exposure to environmental toxins—such as mold—resulting from water damage in your home,” he explains.

“The Environmental Protection Agency estimates that 50 percent of buildings have water damage significant enough to produce health problems—some very serious—from mold and bacteria growth in water-damaged buildings,” says Mr. Dolch. “However, most people are unaware of the toxins they’re exposed to in their own homes, and the first cues may be an unexplained illness.”

In contrast, Mr. Dolch—whose company provides comprehensive mold assessment and air quality testing in the Greater Triangle area—is well aware of the prevalence of contamination resulting from water damage. “You may not be aware of contamination, because indoor pollutants are often hidden,” he explains. “However, just because you can’t see mold, that doesn’t mean you don’t have it. Mold is likely to be found—and to thrive—behind walls, in basements and crawlspaces, or ventilation ducts. The toxins produced by molds and other microbes are spread through the home ventilation system, posing an invisible but serious health hazard.”

Which brings us back to the original question: what does your HVAC system have to do with it?

Toxins Moving Through the Home

“The fact is,” says Mr. Dolch, “typical home construction invites the spread of toxins when there has been water damage. The materials we use to build our homes can be described as ‘mold food.’ Mold loves wood, it loves drywall—especially the paper on the drywall; and it loves to eat dust. Hollow walls create drafts that move toxins throughout the house. And HVAC systems—which recirculate air—contribute to the problem of spreading toxins.

“Pollutants are everywhere,” notes Mr. Dolch; “they’re a normal part of our everyday outdoor environment. And when we open a door or window they come into our homes; that’s also normal. And for most people, that’s never a problem. But with water damage, ‘normal’ pollutants—molds and other toxins—can grow out of hand quickly.

“And contaminants can be hard to find,” he notes. It’s common to find mold growth in basements and crawlspaces—areas that are damp. But sometimes the location is surprising. In one recent home we examined, there weren’t any visible signs of moisture damage or mold. But when we pulled off the dry wall, we found a major mold colony inside the insulation.”

When to Test

“Although routine testing for household toxins isn’t necessary,” says Mr. Dolch, “there are a several instances when it makes sense to get an inspection. A water damage event—flooding or burst pipes—should put you on the alert. But most important: listen to your body. Symptoms—especially unexplained symptoms—that persist and don’t respond to treatment and can’t be tracked down are the red flags.

“Among the common symptoms people experience as a result of exposure to these toxins are fatigue, pain, brain fog, rashes, and weight gain (see box). In such cases, talking with your health care provider is an important next step.

“If plagued by such symptoms, you can also do a simple, inexpensive test, to see if your house might be involved,” he adds. “Take a short ‘vacation’ from your home. A common experience of many of our clients was that they felt better when away from home and their symptoms returned when they crossed the threshold. That’s good information to share with your health care provider as they work to determine the cause of your symptoms.”

Other cues invite further investigation. “Pay attention to any water event that occurs, even if you think it’s minor,” advises Mr. Dolch. “It’s important that building materials dry out within 24 hours of an event. If they don’t, there’s potential for serious problems. And certain types of water damage, as from sewage, are also dangerous.”

Comprehensive Detective Work

“What we do at Certified Indoor Air,” says Mr. Dolch, “is detailed detective work. Every evaluation is comprehensive—inside and out. Although 90 percent of our work is mold related, we also test for wide variety of toxins, including organic compounds and chemicals that can come from cleaning supplies or off-gassing from different kinds of building materials or furniture. In addition to mold, many people are sensitive to chemical odors or may react to bacteria, which harbor in the dust inside the home and circulate through the HVAC system.

“So, finding all contaminants is our first priority. And identifying the specific irritants is also critically important. Different toxins will produce similar symptoms, but treatment will likely be different for different sensitivities.

“So, we have to listen closely to our clients, to learn about symptoms and health issues they’re experiencing. That information tells us a lot about the potential contamination we should be testing for.”

Comprehensive Assessments

Home assessments, says Mr. Dolch are extremely detailed and thorough. “They have to be, if we are to find the source of an airborne toxin. Our inspections involve careful examination of both the exterior and interior of a home as well as searching for signs of water infiltration, past and present water damage, and mold growth.

“Our list is a long one: we inspect attics, crawl spaces, ductwork, HVAC units, under sinks, behind appliances, and anywhere that water may have caused damage As a part of that process, we collect samples of dust to be analyzed for bacteria and specific species of mold.”

A good assessment, says Mr. Dolch, includes a thorough understanding of the HVAC system and how it works. “The HVAC system is like the lungs of the house. It’s a critical piece to the puzzle, because it is often source of the passageways by which these toxins are spreading throughout the home.

“We’re also looking for potential as well as current problems,” he adds. “For example, we examine the outer shell of the home—windows, siding, gutters, and downspout systems—for structural issues that may invite water damage in the future.” The outcome of the assessment is a detailed  phone call reviewing all findings and recommendations—from normal building maintenance to remediation. “We don’t do the remediation,” he explains, “but we provide all the information needed to ensure that problems can be remedied.”