Table of contents:
- How plants clean the air
- Scientists' research on air purification by plants
- Air purification in the apartment
- Current research on indoor plants
- Useful indoor flowers
- The best indoor plants for air purification
In recent years, people's attitudes towards their health and environmental friendliness of their homes and food have changed a lot. A whole line of ecological phytodesign has appeared. From the point of view of indoor floriculture, we can only be interested in the neutralization of harmful volatile compounds by plants that inevitably surround us from day to day.
The information base on the content of harmful volatile substances is regularly updated, we constantly learn about the next harmful compounds that are hidden in any object: from face powder, children's toys, to flooring. But if linoleum and vinyl wallpaper to varying degrees smell of these very harmful substances, then many things only seem harmless to us, because they do not have a pungent smell, although its absence does not mean safety.
How plants clean the air
Phytoremediation is a complex of neutralization and purification from harmful substances and compounds of soil, groundwater and atmospheric air using green plants. The term is translated from Greek "fiton" - plant and Latin "remedium" - to restore. From the point of view of home floriculture, we are interested in air purification.
Plants can directly decompose organic pollutants (pollutants) using their own enzymes to inorganic compounds that accumulate in the plant, or they can be converted by the plant into a volatile form and released into the surrounding space in a harmless form.
But there are many plants that we grow on window sills, and the ability to phytoremediation is expressed in all different ways. Perhaps everyone has heard only about the benefits of chlorophytum and ficus …
Scientists' research on air purification by plants
The oldest known document is dated September 1989, research was carried out to determine the usefulness of tropical plants in the event of a space station, observatory and residential complex on the Moon, and maybe on Mars. 50 plants were studied, mainly tropical and subtropical, some from temperate climates. The chemicals chosen for the study are benzene, trichlorethylene and formaldehyde.
Looking ahead, I will say right away that all 50 plants have shown the ability to neutralize harmful volatile compounds in the air, to varying degrees.
National Institute of Food and Agriculture National Institute of Food and Agriculture (USA), Department of Tropical Plants and Soil Science, published in 2001 on the Use of Houseplants for Indoor Air Purification. The work presents the most common interior items, household items, as well as building materials and the most toxic substances in them. The document also mentions that not all indoor plants are effective in terms of cleaning, but it is advisable to grow those that are easiest to care for, grow quickly and do not require much.
Here are just a few of what we breathe:
Pollutants can accumulate in confined spaces, especially high doses and toxicity of volatile substances from synthetic building and finishing materials.
Air purification in the apartment
One way to clean your home air is to grow indoor plants. Which house flowers are more effective, which ones are less - information is constantly changing. Here is an example: a study by Korean scientists was carried out in 2006 and was presented at the 8th International Congress of Physiological Anthropology in Kamakura (Japan):
Two laboratories - sealed rooms 3.5 by 3.5 m, 2.4 m high, without ventilation, in which the sensors are placed. The first laboratory was filled with potted plants, the second, the control, remained empty. Harmful volatile gases were fed equally into both rooms. An hour later, the readings of the instruments were taken - the changes in the levels of benzene, toluene, ethylbenzene, xylene and formaldehyde were measured.
To show the role of the quantitative influence of plants, the experiments were carried out twice: in the first case, such a number of plants were placed in the room that they occupied 10% of the total space, in the second - only 5%.
The experiment involved three plants:
- Aglaonema short-coated Aaglaonema brevispathum
- Pakhira aquatic Pachira aquatica
- Ficus benjamin Ficus benjamiana.
Surprisingly, all three plants undoubtedly purified the air, more efficiently, almost twice as good in those groups where the number of plants was 10% of the area of the premises. But Pakhira turned out to be more effective in neutralizing ethylbenzene and especially benzene - the decrease was 76.3% compared to the initial level - 15.7 mg / m3 was neutralized per hour. Aglaonema reduced the level of benzene by 44.7% - it neutralized 8 mg / m3, and ficus - by 40%, neutralized about 6 mg / m3 per hour.
For other gases, the efficiency of plants has changed: Aglaonema coped better with toluene. The picture looked like this: Aglaonema neutralized 45.6 mg / m3 per hour, ficus - 36.1 mg / m3, Pakhira - 31 mg / m3 toluene - this is 10% of the vegetation area.
In relation to xylene, Aglaonema and Pakhira showed the same efficiency, a little less - ficus. The reductions were 10.4-11.9 mg / m3. Formaldehyde was most effectively removed by Aglaonema - 330.8 mg / m3.
The experimenters Jeong-Eun Song, Yong-Shik Kim and Jang Yeul Sohn did not stop there, they tested the "work" of plants to remove harmful gases under different lighting conditions … During testing, it turned out that the intensity of sunlight has a serious effect on air purification, but also depends on the type of plant. Two groups were compared, placed under intense lighting and with light diffused light.
The results are as follows: Aglaonema and Pakhira purified the air much better under more intense lighting, Ficus benjamin is almost the same under any light.
Current research on indoor plants
More recent studies on air purification from benzene, toluene, ethylbenzene and xylene using popular houseplants such as Dracaena deremska Dracaena deremensis and Opuntia Opuntia microdasys were published in the Journal of Environmental Health Science and Engineering in December 2014.
The experiments were carried out in a chamber with a volume of 30 m3 - this is approximately an average room 4 m long, 3 m wide and 2.5 m high.Three-year-old plants were used, planted in pots with a diameter of 10 cm.But a visual assessment of the equivalence of plants is a weak argument, therefore, for the clarity of the experiment Plants were selected over the same leaf area: 1380 cm2 for dracaena and 1350 cm2 for prickly pear.
Two months before the experiment, the pots lived and got used to the laboratory conditions: a temperature of about 20 ° C ± 3, and a light regime of 12/12 hours of dark / light periods. The plants were watered every three days. All plants were watered one hour before the experiments under the influence of the gas mixture.
The chamber was filled with: 16 mg / m3 benzene, 8 mg / m3 toluene, 22 mg / m3 xylene and 22 mg / m3 ethylbenzene. Opuntia removed all toxic substances completely after 36, 40, 30 and 39 hours, respectively.
For the purity of the experiment, the indicators were compared
- in an empty cell
- in a chamber with plants
- in a chamber with pots of soil from which the plants were removed along with the roots (only the soil was left)
And I must say that prickly pear coped twice faster and more efficiently than dracaena:
The prickly pear was able to completely neutralize 2 ppm benzene (6.5 mg / m3) from the air in the test chamber after 48 hours. Dracaena deremskaya - in 105 hours.
Useful indoor flowers
Screening of indoor plants for air purification from volatile organic pollutants was carried out by Dong Sik Young, Stanley J. Keyes and other group of scientists. They tested twenty-eight of the most common houseplants for their effectiveness in removing aromatic hydrocarbons (benzene and toluene), aliphatic hydrocarbons (octane), halogenated hydrocarbons (trichlorethylene - TCE), and terpenes (a-pinene).
Here are the test results:
As you can see, Hemigraphis alternata, Ivy Hedera helix, Hoya beautiful Hoya carnosa, and Asparagus densiflorus have shown the highest removal efficiency of all pollutants. Tradescantia pallida has been shown to be very effective in removing four of the five volatiles (benzene, toluene, trichlorethylene, and a-pinene).
As you can see, some plants are more effective at removing some carcinogens, and less effective against others. Therefore, the more diverse the plants on your windowsills, the more of them, and the healthier they are, the cleaner the air in your home. The number and health of plants are important because the air-cleaning capacity of plants is related to the large number of stomata on the leaves.
Recommendations from iplants.ru: in order for the air in your house to become significantly cleaner, you need at least three medium-sized plants (in a pot with a diameter of 20 cm) for an apartment of approximately 55-56 sq. m. If your apartment has been recently renovated or new furniture has been purchased, you will need about 20 indoor plants (4-5 per room) to neutralize harmful fumes, which will be actively released for another 6-12 months.
Returning to the NASA study, I consider it necessary to draw your attention to the following point. The first studies proved all the usefulness of indoor plants, but during the tests, scientists became interested in the question of defoliation of leaves, is it really only plant leaves that purify the air? Therefore, NASA scientists conducted a second study and received very interesting results.
Dracaena marginata participated in the experiment:
- ordinary potted plants, with a developed crown
- potted plants (with leaves) covered the soil with a thick layer of gravel
- dracaena cut off all the leaves, left hemp up to 5 cm tall, the soil in the pot is not covered
- control pots with soil (no roots)
The results of the experiments showed that the roots of plants, and related microorganisms, as a mini-ecosystem, are the main cause of chemical cleansing, at least in this study! This is not surprising, because the cut plant continued to function - after a week it already grows new shoots, and after three it has a small crown.
Another test showed that even within the same genus of plants, different species purify the air in different ways:
- Dracaena fragrant Dracaena fragrans "Mass Cane"
- Chrysanthemum pot
- Gerbera jamesonii
- Dracaena deremskaya variety Varnekey Dracaena deremensis "Warneckei"
- Ficus benjamin Ficus beniamina
Please note: Dracaena is fragrant - significantly exceeds its sister Dracaena deremskaya in terms of air purification efficiency.
The best indoor plants for air purification
- Aglaonema curly Aglaonema crispum
- Aglaonema short-coated Aaglaonema brevispathum
- Adiantum capillus-veneris hair adiantum
- Alocasia large rhizome Alocasia macrorrhizos
- Aloe Vera Aloe Vera
- Anthurium Andre Anthurium andraeanum
- Araucaria varifolia Araucaria heterophylla
- Asparagus dense-flowered Asparagus densiflorus
- Asparagus bristly Asparagus setaceus
- Aspidistra high Aspidistra elatior
- Dwarf banana Musa acuminata
- Begonia ever-flowering Begonia Semperflorens
- Hemigraphis alternata
- Fragrant geranium Pelargonium graveolens
- Gerbera jamesonii
- Guzmania Guzmania
- Dendrobium Dendrobium
- Dipsis yellowish Dypsis lutescens (Chrysalidocarpus Chrysalidocarpus)
- Dieffenbachia spotted Dieffenbachia maculata
- Dracaena deremskaya Deacaena dermensis
- Dracaena fragrant Dracaena fragrans
- Kalanchoe Blossfeld Kalanchoe blossfeldiana
- Calthea makoyana
- Calathea rose-colored Calathea roseopicta
- Clivia cinnabar Clivia miniata
- Codiaeum variegated Codiaeum variegatum
- Liriope spicata Liriope spicata
- White-necked arrowroot Maranta leuconeura
- Monstera delicacy Monstera deliciosa
- Nephrolepis sublime Nephrolepis exaltata
- Nephrolepis obliterate
- Opuntia small-haired Opuntia microdasys
- Opuntia compressed Opuntia stricta
- Pakhira aquatic Pachira aquatica
- Pachira large-fruited Pachira macrocarpa
- Peperomia clusiformis Peperomia clusiifolia
- Common ivy Hedera helix
- Poliscias shrub Polyscias fruticosa
- Poinsettia or Euphorbia beautiful Euphorbia pulcherrima
- High rape Rhapis excels
- Rhodedendron simsii
- Ruellia tuberous Ruellia tuberosa
- Sansevieria Three-lane Sansevieria trifasciata
- Syngonium leg-leaved Syngonium podophyllum
- Spathiphyllum Wallis Spathiphyllum wallisii
- Tradescantia pallida Tradescantia pallida
- Phalaenopsis Phalaenopsis
- Ficus benjamina
- Ficus binnendijkii "Alii"
- Ficus rubber (elastica) Ficus robusta
- Philodendron blushing Philodendron erubescens
- Philodendron bipinnate Philodendron selloum
- Philodendron domesticum Philodendron domesticum
- Philodendron ivy Philodendron hederaceum
- Phoenix roebelenii date
- Fittonia albivenis Fittonia albivenis
- Chamedorea Seifritz Chamaedorea seifrizii
- Hamedorea graceful Chamaedorea elegans
- Chlorophytum crested Chlorophytum comosum
- Howea belmoreana
- Hoya lovely Hoya carnosa
- Homalomen Wallace Homalomena wallisii
- Chrysanthemum garden (pot forcing) Chrysanthemum morifolium
- Persian cyclamen Cyclamen persicum
- Cissus rhomboid Cissus rhombifolia
- Schefflera arboreal Schefflera arboricola
- Schefflera elegantissima
- Schlumberger Schlumbergera
- Epipremnum golden Epipremnum aureum
- Ehmeya striped Aechmea fasciata
This is just a list of plants that have been studied, and have shown some or quite significant effectiveness in neutralizing harmful fumes in the air. If we talk about families, the most promising are Aroid, Palm, Asparagus.
Grow indoor plants, among the 70 species on the list you can find plants for every taste and any complexity of growing. The more varied the vegetation in your home, the better, provided the plants are healthy and regularly dust-free. If you are new to floriculture, I strongly advise you to choose fragrant Dracena, Benjamin Ficus or Monstera for a start, as the most unpretentious and affordable.