They occur because they are emitted from furnishings, office equipment and some building materials. Under controlled conditions, in the NASA study, certain houseplants were found to remove as much as 87 percent of indoor air pollutants within 24 hours. But during the 1970's, after energy shortages occurred, more and more of us began to insulate our houses and office buildings to conserve energy and lower heating and cooling costs. As a result, indoor air might linger for five hours or more allowing pollutants to accumulate. Researchers are just beginning to understand how indoor pollutants such as cigarette smoke, for example, can harm humans.
Effects range from skin and eye irritations to headaches and allergies.
Some of the pollutants may be carcinogenic. According to the NASA study, the plants listed below proved effective in removing certain indoor air pollutants. Indeed, it would appear that plants have many useful qualities, including one of making our indoor air cleaner to breath. Photograph courtesy of Judy Sedbrook.