It is common knowledge that houseplants can help clean the air. Many houseplants remove volatile organic compounds (VOCs) deemed indoor air pollutants, such as toulene and xylene. These VOCs are emitted from a variety of indoor sources such as new carpets, paints, and cleaning agents. However, recent research from the University of Georgia questions the cleaning properties of four common houseplants and suggests they can actually add to indoor pollution levels.
University researchers measured the VOCs emitted by four common houseplants (areca palm, snake plant, weeping fig, and peace lily). They found up to 23 VOCs emitted by each plant. However, it seems the source of the VOCs may not be just the plants themselves. Pesticides used in growing the houseplants, the potting soil, and plastic pots all were major contributors to the off-gases. Houseplants still do more good than harm. Instead of removing houseplants from your room, consider growing them organically, covering the soil with mulch, and using a clay or ceramic pot.
For more information on this research, go to: Treehugger.