Plants are beneficial to our environment because they release oxygen during photosynthesis. However, plants that clean our environment may absorb air, soil and water pollutants that are harmful to humans. Since a 1989 NASA publication, research into using plants to clean chemical pollutants such as benzene, trichloroethylene, carbon monoxide and formaldehyde from the air, soil and water has exploded at military, university and private research institutions.
Phytoremediation is the process that uses plants and grasses to remove pollutants from soil and groundwater by strategically placing specific plants in the environment. Typical pollutants that may be address through phytoremediation include but are not limited to metals, benzene, trichloroethylene, polychlorinated biphenyls, polyaromatic hydrocarbons and pesticides. Each plant species that will uptake pollutants may have a specific chemical that it prefers so it is important to understand the type and location of the pollutants in your environment. The roots of the plants will uptake the pollutants from the soil or groundwater, thus cleaning the area.
Plants that Accomplish Phytoremediation
A 1997 study published by researchers at Rutgers University indicated that various plants have the ability to perform phytoremediation. Subsequent studies at Northwestern University and Rensselaer Polytechnic Institute indicate that hybrid poplar trees are common for targeting chlorinated solvents, polyaromatic hydrocarbons and carbon tetrachloride in soil and groundwater. Grasses such as rye and Bermuda are effective in cleaning hydrocarbons and ragweed and sunflowers target metals in the subsurface environment. Other plant species that are popular in phytoremediation include alfalfa, arrowroot, alpine bluegrass and the surface-water loving plants blue-green algae, duckweed and water lilies.
Indoor Air Quality
Indoor air quality will greatly improve when enough houseplants live in a home or office. Many common houseplants will absorb pollutants such as formaldehyde, carbon monoxide, trichloroethylene and benzene, among others, from the air. The 1989 results of a NASA study indicated that 15 to 18 houseplants would adequately clean the air of an 1,800-square-foot house. For optimal benefits, keep your houseplants healthy through routine feeding, watering and sunlight exposure.
Plants that Clean Indoor Air
Many varieties of houseplants will help reduce the concentration of indoor air pollutants that generate from building materials or through transfer from outdoor air. Since plant types prefer different pollutants, place a variety plants in your home for the most benefit. Houseplants that improve indoor air quality are English ivy, spider plants, peace lilies, snake plants, bamboo and reed palms, Chinese evergreens, weeping figs, and varieties of philodendron and dracaena.
- Northwestern Engineering; The Phytoremediation of Lead in Urban, Residential Soils; Joseph L. Fiegl, et al
- Rensselaer Polytechnic Institute; Phytoremediation of Soil and Organic Compounds; Nathan Florio and Hayes Rembijas; 1997
- American Society of Plant Biologists; Phytoremediation: Using plants to remove pollutants from the environment; Ilya Raskin, et al; 1997
- University of Minnesota Extension; Houseplants Help Clean Indoor Air; Deborah L. Brown; 1999
- University of Washington: Phytoremediation Research at the University of Washington