home Miscellaneous The hype about plants can clean indoor air continues unabated

The hype about plants can clean indoor air continues unabated

An old, badly flawed NASA study reported the air pollutant removal rates for a few common types of houseplants. The NASA researcher had been studying the use of biological wastewater treatment systems which are effective. He did one study before he left NASA and has been advocating the use of plants to clean indoor air ever since. In fact, the air cleaning efficiency of indoor plants, even using the inaccurate data from the original or subsequent studies, is less than that delivered by leakage through a building’s exterior envelope in a very efficient, tightly-sealed building. Nevertheless, the attractiveness of the idea that houseplants can clean indoor air and research funded by the indoor plant industry continues to feed the myth and mislead readers. You can see the latest popular media hype at

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6 thoughts on “The hype about plants can clean indoor air continues unabated

  1. I love plants and have many of them in my house. They are good decoration, providing color and a sense of life in the otherwise “dead” environment of building materials. BUT….
    I’m sorry John, one or two well-cared-for plants won’t have any impact at all on indoor air quality. Please read “Critical Review: How Well Do House Plants Perform as Indoor Air Cleaners?” You can read and download it free at http://www.buildingecology.com/search?SearchableText=plants. Here is the summary of the article:
    “In the late 1980’s, research indicated that plants had the capability to remove volatile organic compounds (VOC) from indoor air. The findings were based upon chamber studies involving injection of a pollutant into a small, sealed chamber and following the pollutant decay, with and without plants present. The results were striking with removal rates up to 90% in 24 hr. Other studies examining this effect followed. Today, even a casual search of the internet will find many articles extolling the benefits of using plants as indoor air cleaners. However, there has been little critical analysis of the application of plants to actual indoor environments and only a few field studies have been conducted. A critical review of results of both laboratory chamber studies and field studies leads to the conclusion that indoor plants have little, if any, benefit for removing indoor air of VOC in residential and commercial buildings. Finally, recommendations for improving future studies are presented.”

    There are a couple of other articles on plants at the same web site: http://www.buildingecology.com. Just go to the web site and search for “plants.”

  2. The comments about plants not performing as air purifiers are written by pr departments of big corporations so as they can sell their expensive machines. These people are also the climate change/global warming deniers like Sarah Palin.

    1. Your assertions may have a modicum of validity but in general are simply false.

      You provide no evidence to support your unfounded and incorrect assertions.

      I am not working for a big corporation that sells mechanical equipment. The only large organizations I ever worked for are the United States of America, The State of California, and the University of California.

      If you look at the article by John Girman, Tom Phillips and me, you will see a review of some of the most relevant articles published in peer reviewed journals as of 2009 when we wrote the article. You can download the article for free from my web site, BuildingEcology.com http://www.buildingecology.com/articles/can-house-plants-solve-iaq-problems .

      Girman and Phillips are now retired, Girman from the U.S. EPA and before that he worked for the State of California Department of Health Services (now the Dept of Health) and Phillips is retired from the California Air Resources Board.

      You will see statements that agree with us on the U.S. EPA IAQ web site and on the California Department of Health and the California Air Resources Board web site.

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