I suspect that most of us grow houseplants because they enhance our indoor décor and therefore we probably are not aware that at the same time we’re improving the air quality in our homes. While you might believe this is a recent discovery, in fact, the study that confirmed that indoor plants improve air quality was actually published in the late 1980’s. NASA, in partnership with the Associated Landscape Contractors of America, was investigating ways that air quality in space station facilities could be improved.
Tests were conducted to find out what benefit indoor plants might offer in terms of cleaning the air and the results turned out to be rather interesting and are only now really coming to people’s attention. The study found that certain indoor plants can provide a natural way to clean air and remove toxic agents including benzene, trichloroethylene, and formaldehyde. The conclusions of the study estimated that nearly 90% of these harmful toxins could be removed by indoor plants.
When I hear the mention of these chemical compounds I typically think of products such as gasoline and other petrochemicals but these chemicals find their way into our homes rather easily. Benzene can be found in household goods such as rubber products, lubricants, paints, glues, furniture wax, and detergents. Unfortunately, the use and exposure to tobacco products is the main way that we come in contact with this carcinogen.
Trichloroethylene is used as a solvent, grease cleaner and up until fairly recently, it was used as part of the dry cleaning process. Humans come in contact with trichloroethylene mainly through contaminated groundwater and the most common way this occurs is through taking a shower with contaminated water. This chemical is released from hot water directly into the air during long, hot showers and in a home insulated to reduce the costs associated with heating and cooling, these vapors end up recirculating throughout the building. Finally, as many of us may have found out in high school chemistry class formaldehyde is used as a preservative but it is also found in paint and in insulation used in both residential and commercial buildings.
So how exactly do indoor plants help clean the air? You may be aware from a basic biology course that plants absorb carbon dioxide and release oxygen as part of the process of photosynthesis and during this process, the plants absorb these chemicals as well. The NASA study not only confirmed that indoor plants improve air quality but it gave an indication of how many plants are required for optimal absorption of these harmful chemicals. The study indicated that in an 1800 square foot building you would need 15 to 18 indoor plants growing in pots that were six to eight inches in diameter.
It has been found that certain plants are better at cleaning the air than others. It’s possible to find a comprehensive list of these through Wikipedia but some of the more well-known houseplants include the following:
- Spider Plant-They remove both benzene and formaldehyde
- Peace Lily-Removes all of these chemicals and ammonia as well
- Snake Plant-Removes all of these chemicals
So, the next time you prune or water your indoor plants you can inhale deeply knowing that the air you’re breathing is cleaner because of them.