Indoor Air Quality and Indoor Plants
(Is it true what they say?)
July 13, 2016 by Susan Browne Rosenberg, Certified Indoor Environmental Consultant
Recently, I googled this topic and was astounded to find that I got nearly 6 million websites using the words indoor air quality and indoor plants. When I used quotes around “indoor air quality” and “indoor plants” the search results narrowed to under 200,000 websites. Finally, I added “.gov” to the search and got a manageable 52 results.
It has long been known that toxic air contaminants such as formaldehyde and solvents such as acetone, toluene and benzene, can build up in the indoor environment when there is poor ventilation, especially in closed-up “energy efficient” buildings. Studies by NASA dating back to 1989 provided strong scientific data documenting the reduction in air pollution levels when certain types of plants are placed in a space. NASA realized that the air inside a space capsule would quickly be contaminated by the occupants and studied this problem at great length for many years.
Plants provide natural air cleaning in two ways. One is their ability to convert carbon dioxide (CO2), which is exhaled by humans, into oxygen via photosynthesis. Desert Cities Indoor Air regularly measures CO2 in indoor air as an indicator of air quality. Many overcrowded classrooms have elevated CO2 levels due to inadequate levels of fresh outdoor air. This can lead to drowsiness, headaches, nausea and poor learning conditions.
The second way plants clean the air is through mechanisms in their root systems. According to a 2011 article in Environmental Health Perspectives by Dr. Luz Claudio, a tenured associate professor in the Department of Preventive Medicine at Mount Sinai School of Medicine in New York City, plants “can metabolize some toxic chemicals, releasing harmless by-products, and second, they can incorporate toxicants such as heavy metals into plant tissues, thus sequestering them.” She summarized the NASA studies in this article http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3230460/ . Listed in her top 10 Houseplant Air Cleaners are several varieties of palms, ivy and ferns. I think it is fitting that Desert Cities Indoor Air’s logo contains a palm tree.
The tricky part of using plants to clean your indoor air is choosing the right plants and non-toxic containers; keeping the plants healthy and pest free without using pesticides; and using just the correct amount of water and sunlight. Overwatering plants can cause mold growth and mite infestations. New plastic containers can off gas toxic chemicals just like new paint and new carpet. Some plants are toxic when eaten by pets, such as poinsettias, and must be avoided by homeowners with cats and dogs.
And yes, you can have too much of a good thing. I visited a government building in the Bay Area several years ago to investigate indoor air quality complaints and possible mold issues. When I arrived at the building of concern with the Maintenance Director I was stunned to find that nearly every horizontal surface was covered by a potted plant. There were over 100 plants in a large cubicle type office space designed for 20 employees. There was a strong mold like odor similar to walking through a Pacific Northwest rain forest. Many of the plants were overwatered and diseased. Air sampling demonstrated elevated levels of mold spores in the indoor environment. The recommendation was to remove all the diseased plants and limit healthy plants to one per cubicle.
Besides cleaning the air, plants have a mental benefit to the occupants of indoor space. Why do we bring flowers and plants to our friends and family in the hospital? They brighten the space and make us feel happier. Some restaurants and hotels have taken to installing living walls when there are no available horizontal surfaces.
Talk to a qualified nursery or landscape expert when choosing plants. Or, if you do not have a green thumb, or you manage a large office building, hotel or restaurant, consider hiring a plant service operated by a Certified Interior Landscape Technician that will deliver and take care of healthy plants for you. One such option is www.insideplants.net. Contact Heddy Salerno to speak with a certified expert.
Do you want your office or home tested for Volatile Organic Compounds (VOCs)? Desert Cities Indoor Air has the capability and expertise to collect air samples for Carbon Dioxide, Formaldehyde, VOCs, mold, allergens and much more. Call today for a quote or to talk to a certified expert in Indoor Air Quality. Our phone number is 760-902-2545.