Publications
4-H Clean Air Preoject
Plants add beauty to indoor settings in our
homes, offices, and classrooms. Most people
would agree that having plants nearby
while working or studying makes the
experience more pleasant and the surroundings
more enjoyable. However,
NASA research scientists have found that
plants do more than just look good. They
can actually clean indoor air, making our
interior breathing spaces healthier.
NASA researchers working on the SKYLAB project in 1973 discovered 107 volatile organic compounds (VOCs) in the space laboratory air. The VOCs were at levels harmful to humans. Some of the chemicals they found included acetone, toluene, xylene, benzene, ethyl acetate, and naphthalene. Following these findings, the U.S. Environmental Protection Agency discovered 900 VOCs contaminating the air of offices, hospitals, nursing homes, and schools. Some of these 900 included benzene, formaldehyde, and pesticides. These studies raised our understanding of indoor air pollution.
In 1997, retired NASA research scientist Dr. B.C. Wolverton wrote a book called “How to Grow Fresh Air” to share his clean-air discoveries. In his book, Wolverton listed common sources of VOCs that cause indoor air pollution (Table 1).
Perhaps one of the most surprising sources of indoor air pollution is electronic devices. Personal computers, computer monitors, and televisions emit many of the same chemicals that were found in SKYLAB, including benzene, dodecane, and many other “enes” and “anes,” along with substances like formaldehyde.
Once these volatile organic chemicals were found in our breathing spaces, scientists in the medical field conducted additional studies to determine if there were related human health issues. Numerous studies demonstrated that many common illnesses and diseases could be linked to indoor air pollution (Table 2).
Resolving the problem of indoor air pollution is a subject of much interest to NASA scientists and health professionals. Some might say, “Just open the windows and get some fresh air!” Ventilation might work in a country home, but never in outer space! Often, it’s not possible to open the windows where we work and learn or even at home, especially during inclement weather. Neither can common air filters do an adequate job of removing sources of indoor air pollution.
NASA research scientists eventually obtained excellent results by using plants to remove harmful volatile chemicals from indoor air. In his book, Wolverton names 50 plants that were found to remove harmful chemicals. Table 3 lists some of those plants.
One additional study considered the effect of plants on the moisture content (humidity) of indoor air in relation to the number of airborne microbes that may cause illnesses. As they did with VOCs, plants reduced the number of airborne microbes significantly from 25 down to 10 colonies. Plants also helped maintain a 72 percent humidity level, which is more desirable for humans, as opposed to a 56 percent humidity level where plants were not included.
The purpose of the 4-H Clean Air Project is to familiarize youth with some of the facts about indoor air pollution and teach them the value of maintaining plants within their breathing spaces. With sufficient plants, indoor air quality will improve. This is typically accomplished by giving a brief age-appropriate presentation, followed by an activity where youth will plant rooted cuttings in pots and/or receive potted plants for their classroom donated by volunteers or Extension agents.
Agents and volunteers have successfully used materials from the Junior Master Gardener Teacher/Leader Guide: Level One (Texas Agricultural Extension Service, 1999) to supplement instruction. A favorite lesson for teaching younger children is the Oxygen Factory, found on page 17 of the JMG teacher/leader manual. In this lesson, designed for elementary-aged students, the simple facts about photosynthesis are briefly covered. Plants are presented to the children for adoption and naming. This guidebook can be ordered online at http://jmgkids.us/. Other resource materials, such as the 4-H Cooperative Curriculum System Horticulture manual, also are available from your county Extension office.
One way to minimize the cost of plants is to purchase
one mature spider plant (Chlorophytum comosum),
also called airplane plant or spider ivy. The offsets
produced by the “parent” plant are easily potted
and easily grown. After a group of children help
raise their “baby” plant to maturity, they may harvest
new offsets to pot and take home or share with
other classrooms.
NASA studies concluded that something can be done about indoor air pollution. Indoor plants can effectively reduce toxic chemical levels and harmful microbes in our poorly ventilated homes, businesses, schools, and other buildings. For maximum effectiveness, 15 to 18 plants are suggested for a 1,800 squarefoot home. While it’s not likely we can put this many plants in a classroom at any one time, the 4-H Clean Air Project teaches youth valuable life lessons and builds plant-growing skills while having a positive impact on indoor air.
If you and your children would like to know more about this project or how to get it started in your community, contact your local county Extension office and ask about the 4-H Clean Air Project. Spider Plant
References
Buckley, J.D., et al. “Indoor pesticide use increased child cancer rates.” Cancer 89: 11, 2000.
Burkhard, C. “Chemical emissions from office equipment,” IVF Research Publication 99826, 1999.
Corsi, R. and J. Gabbs. “VOC emissions from packaged and active computers,” Poster, Annual Meeting of the International Society for Exposure Analysis 2000, Monterey, CA, 2000.
Daniels, J.L., et al. “Neuroblastoma linked to homes treated with pesticides.” Epidemiology 12(1): 20-26, January 2001.
Pezzoli, G. “Hydrocarbon exposure and Parkinson’s disease.” Neurology, Vol. 55: 667-673, Sept. 2000.
Rumchev, K., et al. “Association of domestic exposure to volatile organic compounds with asthma in young children,” Thorax, 2004, 59:746-751.
Steffen, C. “Benzene linked to childhood leukemia.” Occupational and Environmental Medicine, Vol. 61: 773-778, 2004.
Weisel, C.P. “Assessing exposure to air toxics relative to asthma.” Environmental Health Perspectives, Vol. 110, No. 4, Aug. 2002.
Wensing, M. “Determination of organic chemical emissions from electronic devices.” Raw, G., Aizlewood, C., and Warren, O. (Eds). Proceedings of the 8th Intl. Conf. on Indoor Air and Climate, Edinburg, U.K., Vol. 5, pp. 87-92, 1999.
Copyright 2010 by Mississippi State University. All rights reserved. This publication may be copied and distributed without alteration for nonprofit educational purposes provided that credit is given to the Mississippi State University Extension Service.
Revised by Dr. Lelia Kelly, Associate Extension Professor, North Mississippi Research and Extension Center, from an earlier edition by Dr. Kerry Johnson, retired Area Horticulture Extension Agent.
Discrimination based upon race, color, religion, sex, national origin, age, disability, or veteran’s status is a violation of federal and state law and MSU policy and will not be tolerated. Discrimination based upon sexual orientation or group affiliation is a violation of MSU policy and will not be tolerated.
Publication 2527
Extension Service of Mississippi State University, cooperating with U.S. Department of Agriculture. Published in
furtherance of Acts of Congress, May 8 and June 30, 1914. JOE E. STREET, Interim Director (POD-11-10)