" Indoor Air Quality (IAQ) deals with the content of interior air that could affect health and comfort of building occupants. The IAQ may be compromised by microbial contaminants (mold, bacteria), chemicals (such as carbon monoxide, radon), allergens, or any mass or energy stress or that can induce health effects. Recent findings have demonstrated that indoor air is often more polluted than outdoor air (albeit with different pollutants) although this has not changed the common understanding of Air pollution. In fact, indoor air is often a greater health hazard than the corresponding outdoor setting. Using ventilation to dilute contaminants, filtration, and source control are the primary methods for improving Indoor Air Quality in most buildings. We spend 90% of our time indoors, and climate change and how we adapt and respond to it will have an impact on our health. Experts say research on the health benefits of commercial duct cleaning is still in its infancy. Glenn Fellman, the Indoor Air Quality Association's executive director, says that despite the lack of scientific data, he's seen and heard much common-sense evidence of improved air quality. ""This is the heart and circulatory system of your house,"" Fellman says. ""If any of it is gunked up with dust or mold, the core system isn't going to function correctly."" Those particularly vulnerable to indoor pollutants include infants, elderly, and people who already suffer with heart and lung diseases, asthma, chemical sensitivities, or compromised immune systems. Making matters worse, these are often the people who typically spend the most time indoors. Like adults, children are spending more time indoors than ever before. A recent study shines new light on the severity of the indoor air pollution problem. Ultimately, the decision to clean air ducts comes down to a wner's own judgment. ""Get a screwdriver, open up the register and look in there yourself,"" Schulte says. ""Most can make up their mind at that point."""