Healthy indoor air quality is a necessity for healthy living. We breathe in over 15,000 liters of air every day! A lot of people think that outdoor air is the most polluted air we breathe, but in most cases the air in our homes is more polluted than outdoor air. Outdoor air pollution is caused by traffic, farming, industrial practices, and construction. But that outdoor air pollution doesn’t stay outside. It finds its way into our homes through doors, windows, and all the tiny holes in the walls, roof, and foundation. And believe me, even though they can’t be seen, houses are generally full of tiny holes!
The inside of our homes creates its own set of pollutants as well. Everything from insulation in the walls to the furniture we sit on is contaminating our air. What makes the indoor air so much more polluted than the outdoor air is not just the fact that there are more pollutant sources, but that all of the pollutants are getting trapped in a confined space. And we are living our lives in that confined space, breathing the heavily polluted air.
What does poor indoor air quality do to our health?
Poor air quality can contribute to asthma, allergies and upper respiratory illnesses. Children and anyone with a weakened immune system are especially vulnerable to the harm of poor air quality. Other outcomes of poor air quality are headache, eye, throat, and skin irritation and feeling run down all the time. Poor air quality can also lead to distraction (‘that smell is so bad, I can’t concentrate!’). And it can create a fogginess in our brains, making us less productive.
How can we fix it?
Things to be considered during the design phase:
Material Choices – The best way to prevent poor air quality is to not allow the sources to come into the house in the first place. Choosing building materials that do not contain harmful chemicals is the best way to have healthy indoor air.
Air Tight Enclosures – The next thing that needs to happen is to stop uncontrolled outdoor air from coming into the home. Building homes that are not leaky is the way to do this. An air tight enclosure (meaning the walls, roof, and floor that separate the indoor air from the outdoor air) needs to be properly designed before construction begins. Bringing outdoor air inside is often a good thing, but we want to control when and how that happens. We don't want outdoor air to be able to come in anytime through cracks in the house.
Separate Garage From Home – Garages are a major source of air pollution from cars, products and activities that release harmful fumes, so we don’t want garage air to find its way into our homes. Providing an air tight enclosure between the garage and the home will reduce the transfer of pollutants. Physically separating the garage from the home is another way to keep garage fumes out of the house.
Operable Windows – Providing windows that can be opened is a good idea to get fresh air into and circulating through the home. Windows should be properly placed to maximize air flow through the home.
Avoid Wood Stoves and Fireplaces - Both heat sources are a major cause of poor indoor air quality. Anytime combustion occurs, carbon monoxide is created. Plus smoke releases toxic particulate matter, formaldehyde and benzene, to name a few health risks. Humans are attracted to fire for good reason. It is calming and entertaining, but the best place to enjoy a cozy fire is outdoors.
Mechanical Ventilation – A house that has an air tight enclosure needs ventilation to bring fresh air into the home. Well placed operable windows help, but the best way to do this is by mechanical ventilation systems.
Keep Water Out and Let the Walls Dry – Mold is a source of air pollution. When water gets into the walls of our homes and can’t dry out, mold will grow. It is the responsibility of the designer and contractor to understand how to keep water out of the walls. And when water gets into walls, the walls need to be designed and constructed to allow them to dry out.
Clean Up After Construction – A house must be properly cleaned after construction to ensure chemicals and debris are removed from the house. All surfaces and air ducts should be thoroughly cleaned. Provide an air flush. An air flush is a technique that replaces the current indoor air with fresh air, removing any lingering polluted air such as VOCs and particulate matter that were introduced during construction.
Things to be considered during occupancy:
Entry Mats – Another important way to stop outdoor pollutants from coming into our homes is to incorporate door mats at all entrances. It is best to have a weather proof mat at the outside of the door as the first line of defense, and a large interior mat inside the door to grab any last pieces of dirt from our shoes. Dirt is contaminated with pesticides, bacteria and heavy metals, and these pollutants get into our air when brought into the home.
Filter the Air – Dust and particulate matter will find their way into our homes and create lung irritation. This is especially concerning for people with already compromised lung health. Providing an air purifier with a HEPA filter will reduce our exposure to the particles. Wood stoves are a big source of creating particulate matter so consider investing in an air purifier if one is used regularly.
Test For Radon – Radon is a naturally occurring radioactive, odorless gas that can cause lung cancer. Radon comes from the ground and will usually be at its highest amount in the lowest level of a house. Testing for radon is easy and a kit can be purchased from a hardware store, then mailed to a lab to be tested. If levels are high, there are multiple options for lowering radon levels.
Don’t Smoke In or Near a Home – This should go without saying, but cigarette smoke pollutes the air and is linked to cancer. It is best to avoid having cigarette smoke in or near our homes. If there is, or was, a smoker in the home, be sure to have the air ducts cleaned to eliminate the spread of the contaminants.
Don’t Use Pesticides – Pesticides, herbicides and fungicides contain chemicals that are linked to cancer, Alzheimer’s, birth defects, and reproductive issues. Pesticides that are sprayed outside are carried into our homes through our shoes and get circulated into the air we breathe. We can limit our exposure by using natural pest and weed deterrents.
Clean Cleaning Products – Typical household cleaners are made from chemicals. They can cause eye, nose and throat irritation and trouble breathing. There are plenty of readily available alternatives to chemical cleaners. Look for eco-friendly. We can also make our own cleaners easily with household products that are commonly on hand.
Clean the House Regularly – Dust is a vehicle for pollutants to travel around our homes. If we keep the dust and dirt away, then pollutants are less likely to spread throughout the house. Use a vacuum with a HEPA filter to trap the pollutants while cleaning.
Replace Air Filters and Clean Air Ducts – Central heating and air conditioning provided through air ducts is an easy way for dust and mold particles to be spread throughout the house. Change air filters regularly to keep the particles from being transferred through the air ducts. Cleaning air ducts is beneficial for homes with pets and for people with asthma and allergies. Ducts must be cleaned if mold is suspected to be growing in them. A sign of mold growth is seeing condensation on the outside of the duct.