Environmental Impact of Homes

Home construction has a significant impact on the environment. Homes are a large consumer of electricity, using 46 percent of total US electricity consumption, 26 percent of the raw materials used globally (two billion tons annually), which eventually creates 80 million tons of construction/demolition waste in the U.S. per year (about 1.9 lbs per person per day).

Why IAQ is Important

Of all the exposure to environmental pollution people experience, nearly 72 percent comes from their home, especially since, in recent years, people have begun to spend more time indoors. IAQ is important because we’re dealing with all types of people with different sensitivities, including children and the elderly. Children are the most susceptible because they breathe faster and have smaller body mass, therefore absorbing more pollution than adults.

Indoor air pollutants are between 2-5 times higher than those found outdoors (sometimes 1,000 times higher in new construction). Some of those pollutants include carcinogens, reproductive toxins and neurotoxins. Indoor air pollutants can lead to health problems such as asthma, allergies, cancer, reproductive and developmental defects, cardiovascular disease, respiratory disease, irritation, autism and neurological diseases that affect a child’s ability to learn.

Asthma and allergies affect one out of every four Americans (without a cure). Even asthma found in adults is increasing. Four out of every 100 children are diagnosed with autism or a learning disability, a 360 percent increase in the last five years.

The most common indoor pollutants are mold and allergens, volatile organic chemicals (VOCs), formaldehyde, particles (dust), carbon monoxide, carbon dioxide and ozone. Additional residential pollutants include phthalates, mercury, pesticides and combustion VOCs. VOC sources are numerous and include wallcoverings, floor coverings, paints, adhesives, sealants, cabinetry, furniture, computers, printers, hobby/repair supplies, bedding (especially mattresses) and mold. Plastic products in your home can give off dust that contains phthalates, which become airborne (an average of 500-800 types of chemicals pollute the typical home). Newer homes may have even more.

VOCs and formaldehyde are prolific chemicals and can exacerbate asthma/allergic reactions. Furthermore, they are known carcinogens and are classified as reproductive toxins. Mercury is also a neurotoxin. Children are very sensitive to mercury, which passes easily from mother to child. Mercury can also cause nervous, digestive and kidney damage, and is found in dust (which allows it to become airborne).

Case Study: EcoManor

EcoManor was one of the first LEED Gold Certified homes, located in Atlanta, and is a model of how LEED certification can overlook indoor environmental quality. The EcoManor home was originally built for meetings, fundraising activities and parties (no one actually lived in it for the first six months). Later, the owners had to move in temporarily because of renovations to their other home. Once they moved in they noticed odors, and after a couple weeks they started experiencing irritation and flu-like symptoms. They called in AQS for testing and found out the chemical levels (a year after being constructed) were six times higher than in a typical home. Some of the primary chemicals found (more than 725 different types) were formaldehyde at 300 ppb, acetaldehyde at 200ppb, ethylene glycol, mercury, ammonia, and plasticizers found in the house dust. The typical home has formaldehyde levels of 50 ppb, and the EPA’s guidance level of acetaldehyde is 9. The permissible level of exposure to formaldehyde is 2 ppb. This was certainly not a perfect LEED Gold Home.

Sources of Chemicals in EcoManor

Analysis of materials used in EcoManor showed chemicals were coming from unsuspected places.

1. The gypsum board used was a recycled product and had fly ash in it. The fly ash had mercury in it and the product was off-dusting. Recycled products are not naturally better from a health standpoint.

2. Foam insulation with glycol was used in the walls. Glycol was a major component in this particular foam, and glycol evaporates very slowly, off-gassing for years.

3. The wood floor/adhesive contained acetaldehyde, a contaminating factor found mainly in the finish that was used. Also, the FSC certified wood floor was green, so as it dried the planks started to separate. The owners went in and filled the gaps with an adhesive that was high in VOCs.

4. Cellulose insulation was used in the attic which ended up off-gassing ammonia. Cellulose insulation is typically made from recycled newspaper, and this particular product had an ammonia-based fire retardant. A small water leak caused the moisture to react with the fire retardant which led to off-gassing of the ammonia.

5. The cabinetry finish contained formaldehyde. Even though the cabinets were made with no VOCs, the finish used possessed formaldehyde.

6. The bamboo mattress platform contained formaldehyde, too. The owners went through great effort to buy a green mattress, but the platform holding up the bed was made from bamboo planks. The planks had been glued together with an adhesive containing formaldehyde.

7. A water treatment containing plasticizers was used on parts of the floor tile, which caused off-dusting of the plasticizers.

Additional IAQ Issues

- The moisture leak also lead to mold growth (also caused by the ammonia off-gassing).

- Ozone was created from an electrostatic air cleaner.

- Terpenes/Butylcellusolve in the "green" cleaners used contained 50 times higher VOCs than their counterparts. The cleaners weren't verified.

General Construction Guidelines that should be used to Minimize Indoor Pollutants

-Elect low-emitting products and materials.

-Select mold-resistant products.

-Allow wet materials to dry/cure before installing porous materials (like carpet), and before re-occupancy flush-out and turn the fan on (and open windows).

-Test air before occupancy.

Key Products that Off-Gas or Give off Dust:

Paints/Wallcoverings, Adhesives and sealants, Cabinetry, Floor finishes (a water-based alternative will work well), Insulation, Wallboard, Decorative paneling (veneers and formaldehyde boards), Furniture (uses a lot of press board and particleboard), Carpet, Wood and resilient flooring, Bedding and Window treatments: these are important because light entering the home will heat the product.  If the product is vinyl, the heat will cause the material to off-gas.

Heating and Air Conditioning System guidelines

-No central humidification. These products work by putting a water spray in the system which can lead to mold growth. You’re better off getting a  portable unit.

-Do not choose an electrostatic system (these give off ozone).

-Make sure your unit meets ASHRAE ventilation standards to bring in fresh air.

-Use small particle filtration (pleated filters are more efficient than the old, flat ones).

-Make sure you have additional ventilation.

When choosing a product, look for an independent third party certification label, such as CHPS, Blue Angel, CRI, GreenSeal, SCS, or Greenguard. Products certified by a green label are tested, verified and usually require continual verification.

Perform Clearance Levels Prior to Occupancy

It’s recommended that you test the home’s air quality before moving in. The following clearance levels are standard allowances from LEED NC:

<500 mg/m3 TVOC (Total VOCs)

<50 ug/m3 particles (<10 um)

<27 ppb formaldehyde

<0.05 ppm ozone

<9 ppm carbon monoxide

-no measurable heavy metals

-no individual VOCs above acceptable health risk recommendations

Later in her presentation, Dr. Black referenced a June 25, 2005 Wall Street Journal report titled, “Common Industrial Chemicals in Tiny Doses Raise Health Issue”, which has more information on this topic.

Dr. Marilyn Black is a leading expert with more than 18 years experience in characterizing indoor air pollutants and their sources. She has directed numerous research studies involving indoor air pollution and human health effects, mold growth in buildings and the impact of indoor furnishings on indoor pollutant levels. Dr. Black wrote the state of Washington indoor air quality standards for new construction, established the emissions test protocols for carpet and flooring product and developed the GREENGUARD Program for the selection of environmentally preferred, low emitting products. Dr. Black holds Ph. D., M.S., and B.S. degrees in chemistry and environmental health. She has presented numerous training seminars in indoor air quality at EnvironDesign, NEOCON and AIA’s National Convention.