The NASA Clean Air Study was a project led by the National Aeronautics and Space Administration (NASA) in association with the Associated Landscape Contractors of America (ALCA) to research ways to clean the air in space stations. Its results suggested that, in addition to absorbing carbon dioxide and releasing oxygen through photosynthesis, certain common indoor plants may also provide a natural way of removing volatile organic pollutants (benzene, formaldehyde, and trichloroethylene were tested). These results failed to replicate in future studies, which stated that 'future research is needed to fully understand indoor VOC removal by plants. ' List of air-filtering plants The following plants were tested during the initial 1989 study:English ivy (Hedera helix)Spider plant (Chlorophytum elatum)Devil's ivy, Pothos plant (Epipremnum aureum)Peace lily (Spathiphyllum 'Mauna Loa')Chinese evergreen (Aglaonema modestum)Bamboo palm (Chamaedorea seifrizii)Variegated Sanseviera, (Dracaena trifasciata 'Laurentii')Heartleaf philodendron (Philodendron cordatum)Selloum philodendron, lacy tree philodendron (Philodendron bipinnatifidum)Elephant ear philodendron (Philodendron domesticum)Red-edged dracaena, marginata (Dracaena marginata)Cornstalk dracaena, mass cane/corn cane (Dracaena fragrans 'Massangeana')Weeping fig (Ficus benjamina)Barberton daisy, gerbera daisy (Gerbera jamesonii)Florist's chrysanthemum, pot mum (Chrysanthemum morifolium)Aloe vera (Aloe vera)Janet Craig (Dracaena deremensis 'Janet Craig')Warneckei (Dracaena deremensis 'Warneckei')Banana (Musa oriana)= Study Summary Table = Additional research Since the release of the initial 1989 study, titled A study of interior landscape plants for indoor air pollution abatement: An Interim Report, further research has been done including a 1993 paper and 1996 book by B. C. Wolverton, the primary researcher on the original NASA study, that listed additional plants and focused on the removal of specific chemicals. A different study in 2004 has also shown that the micro-organisms in the soil of a potted plant remove benzene from the air, and that some plant species themselves also contribute to removing benzene. See also Dracaena reflexaGreen wallIndoor air qualityPhytoremediationRain gardenSick building syndrome References External links 'Interior Landscape Plants for Indoor Air Pollution'Best Houseplants for removing toxins from air and how they reduce pollutants An Article by My Garden StoryHow to Grow Your Own Fresh Air TED 2009. An extension of the TED Talk.