Many American homes are insulated with synthetic fibers and plastic that emit VOCs (volatile organic compounds) including benzene, formaldehyde and trichloroethylene (TCE). Air filters can capture dust and dander, but they do little to eliminate VOCs, cigarette smoke and the fumes of household cleaners, paints and varnishes. Is it possible that house plants can filter some of these poisons? The answer is yes.
NASA has long been interested in the potential of plants to maintain healthy living environments in space. In 1984, NASA research scientist Dr. Bill Wolverton used sealed chambers to test plants that could be used to clean the air of lunar habitats. He released the results of his research suggesting that from one to three plants could improve the air in a 100-cubic-foot area. His findings remain controversial, but some plants have in fact been proven to improve indoor air quality.
A 1989 NASA study asserted that tested houseplants filtered up to 87 percent of toxic indoor air in 24 hours. Wolverton also argued that indoor plants help maintain an optimal humidity of between 35 to 65 percent. Excessive humidity encourages the growth of mold spore.
In 1994, a German study concluded that one spider plant could clean a formaldehyde-laden, 100-cubic-foot room in six hours.
Researchers for the Environmental Protection Agency have been unconvinced by the NASA and German studies, claiming they were done in controlled environments. They were not conducted in rooms with people coming and going, opening and closing doors. Wolverton countered by saying home tests suggest that rooms without plants have 50 percent more microbes than those that do.
As a result of his research, Wolverton touted the air-filtering abilities of the "Janet Craig" dracaena, peace lily and the lady palm. He also noted these plants with air-filtering capabilities:
Philodenrons and golden pothos were said to be excellent in controlling formaldehyde. Chrysanthemums were good at purging benzene. Pot mums and peace lilies got high ratings for removing TCE. Gerbera daisies are pretty flowers with surprisingly impressive air filtration abilities. Those lovely little daisies can help filter out benzene, trichloroethylene and formaldehyde.
Red-Edged dracaena (tall evergreens) can filter benzene, xylene, tolulene, and fermaldyhyde, and tolulene. Xylene can cause confusion, dizziness and lack of musculene. Tolulene causes weakness, nausea, tiredness, confusion and memory loss,
Finally, the Warneck dracaena, also known as the Dragon, tree has long leaves that are said to be effective at filtering air.
The NASA studies showed that bamboo plants, easily adaptable to a home environment, were especially effective in filtering formaldehyde and trichloroethylene from the air--both carcinogenic and toxic chemicals found in modern homes.