The Danger of Polluted Indoor Air


It’s that festive time of year again, time to join together with family and loved ones in your home and celebrate the holidays. Spending more time indoors in the winter months is unavoidable for most but according to the American Lung Association, your home may not be a healthy place to gather due to poor air quality. Understanding the health impact of mold and poor indoor air quality may send many homeowners on the hunt to find solutions to these problems.

When homeowners learn that poor air quality can lead to lung infections and even cancer, they frantically look to fix this pressing problem. Common searches include improvement projects involving: filtration, moisture and humidity, and how to prevent mold.

Why We’re Asking:

We invest a great deal of money and pride into our homes. Even more, we spend over half of our lives in these homes that we build, and they should not be hazardous to our health. This week, we look to our home improvement specialists for expert advice on how to create a healthier environment inside our personal dwellings.

So experts, it’s time to weigh in:

What can homeowners do to improve the quality of air in their homes?

Which products help contribute to healthy interior air in homes? Drywall? Paint? Filtration systems? Ventilation systems?
What are the leading causes of poor air quality or circulation in homes?
How can homeowners or renters prevent the growth of mold in their homes?
What do you do after you discover mold in your home?
What behaviors can homeowners change to improve air quality in their homes?

We look forward to learning more about clean air and mold prevention from our experts. Check back next week to see what they have to say!

Experts, post your answers in the comment field below!


  1. Improving air quality in your home can be done in a few basic steps. Begin by eliminating any materials in your home that trap allergens. Choose resilient flooring over wall to wall to carpet. Use area rugs instead and clean them seasonally. Buy bedding that contains hypo allergenic fill. Reduce the amount of dust shelves on tops of cabinets and clean light fixtures regularly. Indoor plants can also help with producing oxygen.

    Your mechanical system can also help by using a HEPA filter on your unit. Also confirm whether your system has an outside air intake or if it recirculates the same air in your home. Fresh air and a clean home are the keys to a better interior environment.

  2. This is a large and extensive question that covers Mechanical, Construction, and Behavioral issues in one.

    I will let the HVAC folk respond to that issue. The Contractors to discuss the build issue and I will address the behaviorial apsect.

    Home Owners have a large role in mitigation when it comes to Indoor Air Quality. The way one lives and how they live is a large contributor to what that means.

    Do you cook? Do you have plants? Do you have pets? Do you have furniture? Do you have electronics? Do you have household cleaners and chemicals? Do you have health problems that require medical equipment use – such as a humidifier? The list could go on.

    Hence if you have all the bells and whistles that any HVAC installer provides. Your home is well constructed without water infilitration and is built to circulate air and dry. Your baths and kitchens are appropriately ventilated and used, now you are half way there. Your home has low VOC paint, all the fabrics and fibers in your furniture, curtains and other design are all green, clean and toxic free. Then all of it falls to you.

    You never wear shoes inside your house and you have an area in which to remove and leave them isolated from the main living area. Your pets do not shed, they wear shoes when they are outside and prompty remove them. Any kitty litter or waste is out of the house. All the cleaners you use are green and toxic free. You do not smoke, or if you do, you do so outside wearing a smoking jacket while doing so and leaving that in the shoe/coat disposal area. You have a strong industrial mat outside every door which to wipe feet. You live in an area where there are sidewalks, no chemical waste sites or electrical charges. You live away from a main transportation road.

    I could go on… and on. Indoor Air Quality is what it is and you simply need to try living simply. Have a great entry mat, leave shoes at the door. Clean with non toxics and use the ventilation you have appropriately and when necessary. Open windows for 20 minutes a day, close them once you have cross ventilated.

    We all live and we all have to live in our houses. There are many simple affordable things you can do behaviorally that can be excellent surrogates when you can’t do the Mechanical/Construction alterations that can do the same, but even they can’t if you don’t use them right.

  3. Sometimes, the solution to a problem isn’t obvious because it’s hidden somewhere – out of sight and out of mind. That is often the case when it comes to air quality issues in your home. A major cause of the problem is typically hidden – literally, behind the walls and ceilings of your home. It has to do with your ductwork.

    The furnace and air conditioner of your home are connected to long sprawling roads of ductwork that travel between the recesses of your walls, through your crawl spaces and across the floor of your attic. When you use your furnace or air conditioner, heated and cooled air are pushed along this ductwork and out to each room of the house. If that ductwork has leaks, then untreated and unclean air from around the outside of the ductwork will enter the inside of the system and be spread along with the treated air throughout the rest of your house. Yuck!

    More alarming is the fact that most U.S. homes today suffer from leak ductwork. According to the U.S. Department of Energy, the duct system of an average home has a leakage rate of between 20% and 40%. Obvious signs of severe duct leakage include the spread of allergens throughout the house, uneven heating and cooling from room to room, and of course, an abundance of dust on tabletops and on top of shelves and furniture.

    Fortunately, there are solutions to leaky ductwork. First, check exposed and accessible ducts for cracks and leaks. This easy-to-reach portion of the ductwork can be manually sealed using metal tape (not duct tape!) or mastic sealant on the outside of the ducts. The rest of the system can be sealed using a newly developed aerosol-based duct sealing technology that works from the inside of the ductwork. This has to be applied by professionals but it is an easy, unobtrusive process that takes just a few hours to complete.

    Once your air ducts are effectively sealed, you’ll notice the difference right away. Not only will the air inside your home smell fresher, but chance are, problems with dust will diminish, room comfort will improve and you’ll even notice a significant drop in your energy bill.

  4. My fellow professionals have really done a great job on this one. The only advice/reminder that I can add is to open windows to air out your living space whenever air quality and weather permit. And always open windows to allow ventilation when using cleaning products.
    Best wishes on the Holidays.
    Pablo Solomon
    Artist & Designer

  5. My top favorite in-home air resource is the Alpine Eco Quest Living Air Purifier. I came to love this brand after finding out this was the top choice for the Pentagon after 9-11. They are made for optimal, pure, clean air and not to make consumers purchase silly parts to drive sales. If and when fresh air is available I prefer a combination of both. Garbage dishes, cigarettes or anything with moisture can contribute to odors in the home. To prevent moisture and mold keep an eye on pipes under sinks and discolored patches on the ceilings and walls. With mold, although early detection can mean a swift solution, I recommend keeping all crevices well sealed. If you discover mold and you are concerned, immediately cover your mouth and seal the area with garbage bags and painting tape until an expert can assess if the mold is toxic. Best practices for improving air quality in the home include air drying moist garments and shoes outside of the unit, opening windows when you are able and investing in a quality air purifies. Be mindful of guarantees, warrantees and replacement guidelines.

  6. My fellow respondants have done a great job! What I can add is the following:

    Which products help contribute to healthy interior air in homes? Drywall? Paint? Filtration systems? Ventilation systems?…Products that can help include: NO-VOC paints/stains/adhesives, recycled carpeting or carpeting made from natural fibers (such as wool) along w/a rubber backing/pad, HEPA filters/hvac system, proper ventilation in the bathrooms/kitchen to inhibit mold/mildew growth & LIVE PLANTS. Just 1 live plant for every 100 sq feet act as a natural air purifier in your space!

    What are the leading causes of poor air quality or circulation in homes? …..wall-to-wall carpeting, VOC-laden paints/stains/adhesives & any FRAGRANCING (NOT aromatherapy which is essential oils & NOT a synthetic fragrance) are leaders in “polluting” your indoor air quality. Add lack of proper ventilation (especially in the bathroom/kitchen!!!!!) & poor maintainance (not changing hvac filters is a prime example!) all lead to unhealthy indoor air & a prime home for mold to take up residence. For proper “scenting” of your home, which is extremely popular at this time of the year, look for products made from essential oils/flower essences, a COTTON wick (many wicks have a lead or zinc core & this causes the smoking/sooting/blackening you see when you blow out the candle). A candle made from soy, palm or beeswax will also help those w/allergies.

    How can homeowners or renters prevent the growth of mold in their homes? …..ALWAYS run the fan when taking a shower, open a door/window to ensure proper air circulation to “dry out” the room. If this isn’t possible (no fan, no outside window…) make sure to wipe down the surface after showering & open the door to the space as soon as you can to let the warm, humid air out.

    What behaviors can homeowners change to improve air quality in their homes? ….have LIVE plants in the home, make more informed choices regarding aromatherapy/scenting of the home, READ product labels to KNOW what you are bringing into your space, whether it’s a cleaning product, decor accessory, bedding…Knowledge is power! (& healthier!

  7. In the kitchen remodeling industry we have new building code requirements for “Make up air”. The guidelines differ by state and city codes so be sure and check your specific area. When we install a hood fan or down draft unit we are pulling the moist, oily and odor laden air out of the home. This is a good thing, but what is actually happening is air has to come from somewhere; your chimney, leaky windows or if you have an energy efficient tight home you may be pulling natural gas literally from pilot lights in fireplaces or furnaces. This is the hazard and the reason these codes exist. A mechanically operated vent has to be electrically tied into the fan switch so when you turn on the fan the vent on the outside of your home opens automatically. This can be trickier than you might think because kitchens are on exterior walls and many times the mechanical room is below and on the same wall. The location of the intake vent has to be a certain distance (check codes with your city or HVAC professional) from the gas meter and any other noxious gas ventilation such as the venting of a gas furnace. This make up air also will need to mix and temper with your home, or have a supplemental heating source. Imagine the make-up air coming through the toe kick of your cabinets. This might be fine in southern California but not appropriate for Alaska. Sometimes the make-up air can enter a room that isn’t used as often, but it must have a clear path to reach the kitchen.

    Venting your kitchen and your bathrooms is very important, that’s the source of most of your moisture in the home. Encouraging clients to turn them on and use them regularly and long enough is a good idea too. One last word of advice about exhaust fans, everyone hates the noise and may not use them all the time. Think of a paddle fan at the ceiling, it’s almost silent. If you think remoting the fan motor to the outside will change things it really won’t. What you are hearing is the air rushing through the ducting. If you have the opportunity to run the largest ducting circumference you can based on the manufactures specifications do it. The noise level goes down. Once people understand that it’s actually the air moving and not a loud motor they seem more agreeable to using their fans. You’ll also need to paint less frequently and that loops right back into air quality issues.

  8. Mold is one of the oldest living organisms on the planet.  It is still unclear as to how or when mold has an ill affect on us.  The EPA has not even been able to rap their hands around why it affects certain people more than others.  What we do know is that like other allergens, mold can have adverse effects on people, some more so than others.  As such, an industry has been created to identify and remediate mold and it’s growth.  

    As a simple rule,  If you see it or smell it, you have it.  If we ran a mold test on our toothbrushes or towels, the results would be frightening.  There are too many strains of mold to even keep count and mildew is one of them.  Since mold needs organic material to live the control of mold can be easily dealt with, in most situations, without calling out the HazMat team.  If you can remove moisture, you can control mold, mildew and rot.

    During the energy crisis of the Seventies and the recent “Green” explosion it has become common practice to almost over seal our homes and buildings to better keep outside temperatures out and inside temperatures in.  This has caused a lack of natural ventilation and drying out of moisture when we have extensive leaks, flooding, or ongoing condensation issues.  In short, moisture gets on organic material, such as some paint, drywall paper, wood, insulation, etc.  this creates an environment for mold to feed and grow.   Often if we clean the mold, dry the moisture and cut out any damaged material, we are in pretty good shape.  With that said, if the moisture keeps coming back, so may the mold. So the demand to control mold has created a variety of dehumidification products that can remove the moisture from the air or area to control the growth of a pro mold environment.

  9. There are several ways to make the air quality better in your house. Number one is duct a 6 inch sheetmetal run from return air to an outdoor window. It does two things introduces fresh air to your house and gives some pressurization which adds to your insulation factor. The second thing is using a air to air heat exchanger which introduces fresh air and will preheat the outdoor air coming in to your house with your exhausted air from bathrooms or kitchen. The third thing you can use UV lamps helps in controlling varies odors and bacteria growth. All these methods work very well and are proven

  10. Most drywall available today in the market is of excellent quality compared to some of the drywall that was imported from China after the Hurricane Katrina crisis. Paint and other material are about as environmentally friendly as ever. However housekeeping habits etc along with central HVAC and or filtration systems etc., can make a huge difference in the quality of air in a home.

    In my observation in the field, sudden damage such as pipe breaks that are not cleaned up well or professionally can contribute to fungal growth and spread into the air duct system. Another reason is lack of good housekeeping and changing of filters in the HVAC system. Certainly if it is a situation of hoarding etc., this will add to poor air quality as items made from cellulose materials will decompose.

    As a professional mold remeditator, maintaining appropriate levels of humidity [which may be different for various regions across the country, 40% to 50% RH should be comfortable] can make all the difference. Utilize exhaust fans in bath and kitchen. Regular cleaning of bath rooms, sinks, showers etc., prevent mold and mildew from taking hold. It is important to understand that mold spores are present everywhere, the challenge arises when they are elevated and begin to take root into other cellulose materials. In the winter months when humidifiers are used, be sure to make sure the window sills are kept free of condensation. Another area to watch is furniture placed closed to the exterior walls. Due to lack of air flow behind couches or head boards, the walls tend to be colder and will cause additional condensation. Since drywall is mainly made of gypsum and paper, it tends to develop mold quite quickly.

    If mold is found in caulking in bath or kitchen where there is greater use of water, remove the old caulking and replace with new. If found mold on drywall, at times it is possible to wipe down with a sanitizing solution when under 10 square feet or so, if it is greater, I would opt to cut out the drywall. If there is extensive mold on structural components such as trusses, or main frame, it might be advisable to seek a professional. On mold inspection and remediation companies, it is different discussion due to the various business practices that are done which I professionally disagree with.

    Simply put, keep a home clean of debris and clutter. Clean your carpets annually, this will keep less dust in the air that eventually ends up in the HVAC system. Clean your air-ducts periodically. I clean my air duct every 3 years. Keep an eye on the return vent covers; it is obvious when they need to be cleaned. Maintain appropriate levels of humidity in a home. Should you have a leak or water damage, have it cleaned or corrected professionally based on severity.

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