"How to Grow Fresh Air, 50 houseplants that purify your home or office" by Dr. B.C Wolverton, Peguin Books, 1997

Approximately 0.64 kg of new dry plant material must be produced by photosynthesis each day to supply the oxygen needs of one adult. Picture found on Natural Fuse's website by Usmann Haque . Found on Natural Fuse by Usmann Haque