Green Design: Indoor Air Quality

The extent of the harm that chemicals and dust do to indoor air quality is only just beginning to be understood and are a big concern of Green Design. So far, statistics for health in workplaces are more readily available than for health in homes.

Indoor Air Pollutions

Most people are familiar with the, detrimental effects of outdoor air pollution, but indoor air pollution may be equally (if not more) hazardous to one's health. Indoor air quality, or IAQ, has come under close scrutiny because it is estimated that Americans spend 90% of their time indoors. In general, indoor air pollution results in what has been termed sick building syndrome or SBS. SBS defines a building where inhabitants complain of health problems, such as respiratory, sinus, and digestive problems, irritability, and fatigue. The sources of indoor air pollution are complex but can be divide into three general types of pollutants:

1. Biological - organic toxins such as bacteria, molds, dust mites, and insects.

2. Earth elements harmful naturally occurring materials such as sheetrock dust, asbestos, and radon.

3. Volatile organic chemicals (VOCs) - chemicals that are emitted into the air from building materials, furniture, fabrics or finishes, and other building processes. Typical VOCs include formaldehyde, styrene, and benzene.

According to the American Society of Interior Designers Indoor Air Quality Two-Part Program, pollutants may stem from a variety of sources throughout a building, including:

- Construction products such as sealers, insulation, paint, caulks, and adhesives.

- Fixtures and furnishings such as carpet, carpet pads (see also green flooring materials) and adhesives, furniture, finishes, and chipboard

- Waxes, polishes, solvents, and insect repellents.

- Machines and electronics such as computer screens, printers, and lasers, which may emit electromagnetic fields.

- Photographic processes, perfumes, and sprays.

- Operational equipment, inadequate air filtering, poorly deigned HVAC systems, or standing water.

Carpet and Indoor Air Quality

The chemicals involved in carpet and carpet padding production can contribute to poor air quality. As with textiles, the manufacturing process involves a wide range of chemicals that remain as residues in the fibers. Backings and adhesives, with their potential off gassing, present further health hazards. The smell of new carpet is, in fact, the off-gassing of VOCs, which can continue for up to 6 months after installation. Many cases of fatigue and eye or mucous membrane irritation in office environments have been attributed to new carpet.

When buying carpets, choose products certified as safe by the CRI (Carpet and Rug Institute Indoor Air Quality Testing) label in the United States. However, compliance with the statutory limits of these agencies does not necessarily mean products are totally problem free.

There are a lot of IAQ issues and products. For instance, the Carpet and Rug Institute (CRI) has developed a testing program for carpet, cushions, and adhesives. Products that meet low levels of emissions of VOCs are allowed to carry their label. CRI also makes the following installation recommendations.

- Carefully plan the carpet installation using the manufacturer's installation guidelines and/or the CRI 104 Standard for Installation of Commercial Textile Floor-covering Materials.

- Ensure adequate fresh air ventilation during the entire installation process and for 48-72 hours afterwards.

- Vacuum the old carpet prior to removal to minimize airborne dust.

- Vacuum the sub-floors prior to carpet installation.

- Use low-VOC adhesive in glue-down installations.

- Use low-emitting carpet cushion.

- Vacuum the new carpet with a high-efficiency vacuum, using a high-efficiency particulate filter bag to minimize airborne particles. Make sure all moisture and cleaning agents are removed with each cleaning.

Creating a Healthy Home

One part of an IAQ program is the installation of live plants, which act as air filters by absorbing indoor air pollutants. For example, the philodendron and the spider plant absorb formaldehyde, and the common peace lily absorbs benzene. Through the process of photosynthesis, plants trap airborne contaminants, as well as regenerate the air with oxygen. However, plants are not a quick fix for a sick building. They do require maintenance and proper light.

The better the ventilation, the healthier the home. Poor indoor air is also a result of dust particles. The problem is that the finer the particles, the less we are aware of them, but the more potential they have to harm our lungs. In addition, unventilated moist air encourages mold spores and bacterial growth - all of which affect our lungs and can potentially lead to respiratory diseases. To create a healthy home, try to eliminate the majority of pollutants at their source by avoiding materials that off-gas unwanted chemicals. But the need to replenish fresh air in your home regularly will always remain: The better the ventilation, the healthier the home.

In addition to the proper selection of products, you should remember the following:

- Avoid blocking air intakes and vents with window treatments or furnishings (see more in home energy conservation).

- Install exhaust fans in smoking areas, bathrooms, kitchens, and other areas where chemicals or sprays may be used (green design: indoor air quality).

- Provide humidity controls.

- Encourage proper maintenance.

- When installing open office systems, allow airflow at the base of the partition (1"-6")

- Arrange computer terminals so that users are seated 30" away from the computer screen to avoid the electromagnetic fields.

- Avoiding furniture that causes environmental pollution during its production or that damages indoor air quality. Select comfortable pieces of green furniture for your home.