Most air filters only catch dust and pollen, but the furniture, paint, and carpet among other things in your home can emit organic compounds like formaldehyde and benzene in concentrations 2 to 5 times higher than outdoors.  Based on research NASA did in the 1980s, a French product designer, Mathieu LeHanneur, and a Harvard University biomedical engineer, David Edwards, have devised an ultra-efficient filtration system that eliminates toxins using plants.Since plants can only clean the air that touches them, the system uses a fan to blow air around the leaves and another fan to suck air into the soil.  Microbes on the roots metabolize more toxins than the leaves.  The device has been able to reduce the concentration of formaldehyde in a test chamber by 80% in one hour.