February 18, 2009

Plants clear air of formaldehyde

In an experiment, researchers in South Korea found two plants removed most of the chemical formaldehyde from the air within four hours.

Kwang Jin Kim of Korea's National Horticultural Research Institute in Seoul said formaldehyde is contained in building materials -- especially new building materials -- including carpeting, curtains, plywood and adhesives. As the gas is emitted from these sources, it deteriorates air quality, which can lead to multiple chemical sensitivity and sick building syndrome.

The researchers used the Weeping Fig, or Ficus benjamina, and Fatsia japonica, an evergreen shrub, in three configurations: whole, roots-only with the leafy portion cut off, and stem and leaves exposed with below-ground portion sealed off. Equal amounts of formaldehyde were pumped into containers holding each type of plant.

The study, published in the Journal of American Society for Horticultural Science, found complete plants removed about 80 percent of the formaldehyde within four hours. Control chambers pumped with the same amount of formaldehyde, but not containing any plants, decreased by 7.3 percent during the day and 6.9 percent overnight within five hours.

As the length of exposure increased, the amount of absorption decreased, which appeared to be due to the reduced concentration of the gas.