We currently live in a world where little is untouched by man. Pollution reaches the farthest corners of the planet. It is almost enough to make you want to run inside and hide! However, this may not be the best idea because according to modern scientific research, indoor environments may be as much as ten times more polluted than the outdoor environment. This is known as “Sick Building Syndrome”.

The average person spends over 90% of their time indoors. We are constantly being bombarded with indoor air pollution. This includes toxic fumes such as formaldehyde, VOCs, trichloroethylene, carbon monoxide, benzene, toluene, xylene, and countless others.

The good news is that all plants absorb and clean pollutants from the air. Certain tropical species are more efficient than others.

Our modular systems allow you to use hundreds of different plants. So you can always easily make sure that each green wall contains ample numbers of the plants which are best at improving air quality. A single potted plant removes a portion of these airborne toxins and with each additional plant this increases. A green wall can contain over a thousand plants, all of which filter air and in addition create energy-rich oxygen. If you were to have this many plants in pots you would most likely fill your whole house!

Below is more information about common indoor air toxins and how green walls help.

Formaldehyde (CH2O)

is found in products such as furniture, wall paper, cardboard, and facial tissues. It is also used in some plastics, paints, varnishes, dishwashing liquids, fabric softeners, and cosmetics, such as nail polish. It enters the indoor environment through natural sources such as forest fires and certain human activities, including burning tobacco, gasoline and wood. As a result of being in so many common products and so prevalent in the environment, it is present, in its breathable gas form, in virtually all homes and buildings. Studies have suggested that people who are exposed to low levels of formaldehyde for long periods of time are more likely to experience asthma-related respiratory symptoms, such as coughing and wheezing. In higher amounts formaldehyde is known to cause cancer of the nasal cavity.

VOC’s

or volatile organic compounds are found in all petroleum products; however there are many other sources such as flooring adhesives (used for carpeting, hardwoods, etc), paint, furniture, wall materials, electronic equipment, cigarette smoke, household cleaning products and even air fresheners! The main reason we should be worried about VOCs is because they are the primary precursor to the formation of ground level ozone and particulate matter in the atmosphere which are the main ingredients of the air pollutant referred to as smog. The negative health effects of smog are well documented.

Trichloroethylene (TCE)

is a common indoor pollutant being released from paints, dry cleaning, adhesives, pesticides and the ink in copy machines, faxes, and printers. Short-term exposure to TCE causes irritation of the nose and throat and depression of the central nervous system. Higher concentrations have caused numbness and facial pain, reduced eyesight, unconsciousness, irregular heartbeat and even death.

Carbon monoxide (CO)

is a dangerous gas which is produced from open fires, gas stoves, appliances and heaters. It is also present in high concentrations in cigarette smoke and vehicle exhaust. Low level exposure causes dizziness and headaches while more acute exposure can lead to death because CO actually prevents the delivery of oxygen to the body's cells.

Benzene (C6H6), Toluene (C7H8) and Xylene (C8H10)

are found in the vapour of products such as gasoline, oils, paints, glues, inks, plastics, and rubber, where they are used as solvents. These three pollutants also enter into the composition of detergents, explosives, pharmaceuticals, foams and dyes. They are skin and eye irritants and are known carcinogens, in connection to human leukemia.

According to the Environmental Protection Agency, “people living and working in buildings of manmade materials inhale over 300 contaminants every day.” Concerns about these contaminants arise from the hypothesis that, when combined, the toxicity of hundreds of different chemicals can "add up" to create major health hazards.

How green walls can help

So how does this all relate to green walls, you may ask. Well, research undertaken by the National Aeronautics and Space Administration (NASA) proves that plants are capable of cleaning indoor air of the toxic chemical soup that is common in modern buildings.

Dr. William Wolverton, NASA's principal investigator researching air quality on space stations, stated that chemicals such as formaldehyde and carbon monoxide can be removed from indoor environments by the plant leaves alone. VOCs, TCE, benzene, toluene, xylene and numerous other toxic chemicals can be removed by the roots of plant (or by the microorganisms living around the roots which degrade and assimilate these chemicals).

The chart below lists toxic chemicals commonly found inside buildings and just a few examples of green wall plants which are the most efficient at absorbing and neutralizing them.

Common indoor toxic chemical

Green wall plants best at removing these toxins

Formaldehyde (CH2O)

Peace lily (Spathiphyllum sp.)
Boston fern (Nephrolepis exaltata ‘Bostoniensis’)
English ivy (Hedera helix)

Carbon Monoxide (CO)

Spider plant (Chlorophytum comosum)
Janet Craig Dracaena (Dracaena deremensis ‘Janet Craig’')
Ficus sp.

Volatile Organic Compounds (VOCs)

Golden Pothos (Scindapsus aures)
Devil’s ivy (Epipremnum aureum)
Philodendron sp.

Trichloroethylene (TCE)

Mother-in-law’s tongue (Sansevieria trifasciata ‘Laurentii’)
Chrysanthemum (Chrysantheium morifolium)
Dracaena sp.

Benzene (C6H6) / Toluene (C7H8) / Xylene (C8H10)

Kimberly Queen Fern (Nephrolepis obliterata)
Orchid sp. (Phalenopsis sp.)
Dieffenbachia sp.

Toxic chemicals and the tropical (green wall) plant species which are best at removing them. Adapted from Dr. B.C. Wolverton's book - How to Grow Fresh Air, 1996.

Through the process of photosynthesis, plants take in carbon dioxide (CO2) and release oxygen (O2). An increase in oxygen helps to keep us awake and alert.

Another advantage of having a green wall is that it saves a lot of space. If the same number of plants that we use on our living walls were growing in pots on your floor you could probably fill your whole house! You will benefit from a dramatic increase in air filtration and oxygen production and do so using much less valuable floor space.