AIR - Living Wall Technology Scrubs Indoor Air

plants whose rhizospheres (the area around the roots) are 200 times more powerful at removing pollutants from indoor air than are plant leaves - hydroponically grown—using nutrient-rich drip irrigation but not soil—the rhizomes of these plants are able to purify the air that circulates inside the system, reducing VOC levels in typical offices by 80 percent, and providing 60 percent of the “fresh air” needed according to standards set by the American Society of Heating, Refrigeration and Air-Conditioning Engineers.
http://www.earthtechling.com/2012/03/living-wall-technology-scrubs-indoor-air/