The EPA considers indoor air quality (IAQ) to be one of the top threats to public health. Today, most people living in industrialized societies will spend up to 90% of their time indoors. Improving indoor air quality is one of the most important things we can do to increase our health and wellness in the built environment. As contractors and designers, there are many things we can do to help with this issue when designing and building new structures or remodeling existing structures. As a homeowner, there are several things for you to consider as well. Many solutions are available to you right now to improve your health at home and at the office.
When we talk about indoor air quality concerns, we are mainly talking about three main culprits: bioeffluents, volatile organic compounds (VOC’s) and airborne chemicals, and airborne microbes. Bioeffluents are organic contaminants that emanate from the bodies of humans or animals. Our own exhaust is harmful to us and needs to be managed. VOC’s are organic compounds that essentially evaporate at room temperature (off-gas or outgas). These can be natural or synthetic, and many are very harmful to humans – either acutely, or more commonly over a long period of time – which makes research into their effects difficult to examine. VOC’s usually emanate from synthetic building materials inside our homes like glues, paints, and finishes. Airborne microbes include viruses, mold spores, dust, and allergens. These may exist in the outside air or may be a symptom of the humidity levels inside of your home.
Let’s take a look at simple steps we can take to improve our air quality with basic principles and solutions:
1. Limit Exposure.
Have doormats at all entrances. We track in chemicals, dust, and dirt into our homes every day. The less we bring in, the less we have to worry about. Request people to take off their shoes when they enter your home. If necessary, consider having slippers available for guests. This also applies to dirty clothing. This is especially important for us in the construction industry. If you have been exposed to lots of dirt, grime or dust throughout your day, try not to spread that throughout your home.
2. Vacuum with a HEPA air filter.
Carpet, upholstery, drapes, etc. hold onto dust and chemicals. By vacuuming regularly with a HEPA filter, we can help to safely remove a lot of these irritants from the home. If you are ever remodeling, consider getting rid of wall to wall carpet and just throwing down runners in high traffic areas.
3. Stop using conventional cleaners and air fresheners.
Avoid ingredients listed as just “fragrance”. These are synthetic, proprietary and can contain lots of different types of chemicals including Volatile Organic Compounds and Phthalates. Look for cleaners that don’t have artificial fragrances. Avoid aerosol sprays. Try more natural solutions like citrus for a fresh aroma.
4. Test for Radon.
Radon is known to cause lung cancer and can be found in nearly any type of soil, in any part of the country, in any type of home. Testing is relatively inexpensive and quick. The EPA has a “Consumer’s Guide to Radon Reduction” to help you with this.
5. Use healthy materials. 
When you have work done on your house, know what the materials are, and what is contained within them. Many paints, finishes, carpets, engineered and synthetic products contain VOC’s. These can off-gas for hours, days, or years. Know your exposure so you can make educated decisions on how to manage it. There are many no-VOC options out there. No-VOC doesn’t always mean it’s healthy for you, but it’s a good place to start. Consider a contractor who is well-versed in this type of construction and is able and willing to answer your questions on these topics. If you are concerned that you may have toxic materials already in your house that are causing you harm, like lead, have them tested by a professional.
6. Get a humidifier. 
Healthy humidity levels range from 35-65%. In the winter months, the relative humidity is very low, and with active heating systems it is reduced even further. Dry conditions irritate sensitive membranes in the nose and increase susceptibility of airborne microbes, leading to frequent colds, allergic attacks, and asthma. They make both stand alone humidifiers all the way up to whole house humidifiers that may be integrated into your existing HVAC system.
7. Ventilate. 
This is a big one, so I’m going to break it down a little.
a. Change your filters often. Even if your HVAC system brings in new air from the outside, it doesn’t mean that the outside air is clean. Consider getting HEPA filters for your HVAC system.
b. Have your ducts cleaned by a professional service. Dust and debris can collect inside your ductwork, causing bad air quality every time it runs.
c. Use Exhaust Fans.
There are so many sources of moisture inside of your building: cooking, bathing, breathing, etc. The most significant being your stovetop and your shower. Humidity in excess of 70% can cause mold and mildew growth within your house, especially within your wall cavity in conventional construction. Many times, you don’t even realize it is there. Trust your nose. Does it smell musty? Recognize symptoms that persist when only at home but not outside like congestion and irritated eyes. Cooking also produces potentially hazardous levels of gasses like nitrogen dioxide and carbon monoxide. Make sure you have a vent hood above your stove that exhausts to the outside of your building, not the kind that re-circulates back into your home or attic. When you shower, run your bath fan and leave it running for 5-10 minutes after you finish. Again, make sure the bath fan exhausts outside of your building and not to your attic. The main problem with exhaust fans is that people don’t use them, mainly because they are too loud. Consider investing in a new one that has a lower decibel level that you can run while carrying on a normal conversation.
d. Upgrade to an ERV (Energy Recovery Ventilator). If you are looking to upgrade your HVAC system, consider looking into continuously running ERV systems. These never turn off, giving you a constant supply of new air, as well as regulating temperature and humidity with up to 90% efficiency.
8. Get Indoor Plants. 
NASA has conducted several scientific studies showing the ability of plants to increase humidity, remove bioeffluents and VOC’s, and suppress airborne microbes. The first list was created by ‘The Clean Air Study’ back in 1989. Start with one plant from the list and place it close to where people most often occupy the space, like on a desk, next to the couch, or on the bedside table. You will get the most benefit if the plant is within your personal breathing zone. If you want to go all in, or want something to work up to, the most effective and efficient air cleaning ability will be achieved by growing one plant per 100 square feet of living space. This research doesn’t even take into account the numerous other studies showing the psychological benefits of growing plants, as well as the aesthetic beauty they add to your home.
Most of these solutions are within the budget and experience level of the typical homeowner. When in doubt, consult a professional. Most people feel that they can only control their diet and exercise. Well, now you have some power over your environment too, so use it. Take charge of your space and make it healthier for you and those around you, one small step at a time.
