So, do houseplants really filter the air inside your home? The answer is yes and no, so let's resolve the question with a simple "sorta, but not really." A new article in "The Atlantic" magazine says the idea that houseplants purify the air is basically nothing more than a myth.
People often get houseplants to freshen the air because they assume the same plant life that cleans the air outside, should logically do the same INSIDE. It does make sense when you think about it I suppose. The idea of cleansing houseplants also stems from a couple of studies conducted in 1989 and 1996. The studies found that plants CAN clean the air, just not enough to make you any healthier.
However, if you filled every square inch of your home with plants, the air quality would indeed improve. Problem is even if you did that, there would always be new dirty air coming in from outside. One expert put it like this: In a 10-foot room, you'd need about a THOUSAND plants to achieve the same rate of turnover as the average ventilation system. So there ya go. Do plants freshen the air? Sorta, but not really.