Did you know that the air inside your home could be anything from two to one hundred times more toxic than the air outside?
Your inside air is typically contaminated with a bunch of toxic chemicals including volatile organic compounds (VOCs) like formaldeyde (a known caricinogen), phthalates, and brominated fire retardants. If you have a gas stove you may also have nitrogen dioxide in your kitchen, and higher levels of carbon dioxide.
There may be as many as 50-100 different VOCs in your indoor air at any time. They come from furniture (particularly particle board and plywood), paint, bedding, upholstery, conventional cleaning supplies, foam insulation, carpeting, air fresheners, inks, oils and plastics, to name just a few of the common sources. They tend to be emitted at high levels from new materials, but many VOCs continue to be “off-gassed” throughout a product’s life.
Indoor air can also be filled with all the same pollutants from cars and trucks and industrial pollution that are in outdoor air.
Since children breathe 20% more air per kilo of body weight than adults, air quality is even more important for them. According to Linda Cockburn (Living the Good Life) research has found that childhood asthma may be decreased by as much as 65%, just by reducing the level of VOCs indoors.
Happily, there are several things you can do to improve the situation, some of which will be covered in more detail in future articles and many of which make great Christmas presents. Today I’m focussing on house plants that clean the VOCs from the air.
Indoor plants that clean the air
Most people now know that house plants can help remove some of the pollution from our indoor air, including volatile organic compounds like formaldehyde, benzene and toluene. What you may not know is that it is actually the natural soil bacteria that does the job, rather than the plants themselves. However, you do need a live plant to draw the VOCs into the soil and keep the bacteria working for you, and different plants are better at removing different pollutants.
Plants also help clear the air of carbon dioxide, returning the oxygen for us to breath.
A study run by NASA in the late 1980s looked specifically at how well plants clean the air of benzene, trichloroethylene, and formaldehyde. Later studies have included other VOCs including xylene, toluene and ammonia.
Plants that have been found to be particularly effective at cleaning the air include:
- Peace lilies (benzene, formaldehyde, trichloroethylene, xylene, toluene, ammonia) (pictured below)
- Devil’s ivy/golden pothos (benzene, formaldehyde, trichloroethylene, xylene, toluene, carbon monoxide) – note that this is poisonous if chewed of swallowed by children or pets
- Mother-in-law’s tongue/variegated snake plant (benzene, formaldehyde, trichloroethylene, xylene, toluene)
- Chrysanthemum morifolium/florist’s daisy (benzene, formaldehyde, trichloroethylene, xylene, toluene and ammonia)
- English ivy (benzene, formaldehyde, xylene, toluene)
- Spider plant (formaldehyde, xylene, toluene, carbon monoxide) (pictured above)
- Red-edged dracaena/Song of India (benzene, formaldehyde, trichloroethylene, xylene, toluene)
- Bamboo palm (benzene, formaldehyde, trichloroethylene)
- Aloe Vera (benzene, formaldehyde)
- Gerbera Daisy/Barberton daisy (Gerbera jamesonii) (benzene, formaldehyde, trichloroethylene)
You can see from the list that having a variety of plants is a good idea to maximise the effects. It’s also worth noting that there are many VOCS that are not listed here, because the studies of house plants did not measure them. That doesn’t mean plants can’t help clean them from the air, but again, a bit of variety is a good idea.
Many of these plants – like the peace lily and the spider plant – are very easily divided and propagated. So rather than going out to buy a bunch of plants, why not ask a friend if you can take a root division of theirs? Or, divide up one of your own, and re-pot it for an awesome, sustainable Christmas present.
How many plants do you need? The advice on this varies, from one per nine square metres (100 square feet) to one per square metre. I asked building biologist Nicole Bijlsma, author of Healthy Home, Healthy Family, why there was such a large discrepancy. She replied that the number required depends on several factors including contaminants, surrounding building materials, ventilation, humidity levels, room size and so on. “However,” she said, “the point is that they are wonderful as part of any building.”
What about mould?
One issue with house plants can be mould allergy. I know my sister has avoided house plants for years since being told they were aggravating her allergies. However, this need not be the case. Of course, plants that are constantly moist will harbor more mould than those which are allowed to dry out. According to the Asthma and Allergy Foundation of America though, mould in house plants is mostly only an issue if the soil is disturbed. (source) It is sometimes recommended to cover the soil surface with gravel to reduce mould growth, although this does also reduce the reduction of some VOCs.
Other ways to clean the air
There are a number of other ways to clean your air, from using negative ions to filters. I will cover some of these in more depth in later articles but for starters you can:
- Vacuum regularly with a HEPA filter to remove the household dust, which typically contains chemical flame retardants, the ubiquitous phthalates and other chemicals, along with your dead skin cells and dust mite deposits.
- Burn beeswax candles. Not only are they a non-toxic alternative to paraffin candles, but they may actually remove pollutants from the air. The burning beeswax is said to create negative ions in the air, which bond with the positively charged pollutants, causing them to be sucked back into the candle or to fall to the ground (see note above about vacuuming regularly!).
Beeswax candles are on my Christmas wishlist. In Australia you can buy gorgeous 100% pure Australian beeswax candles from Queen B. You can also buy a selection of 100% beeswax candles on Fishpond with free shipping Australia wide. Outside Australia you can find 100% pure beeswax candles here.
- Himalayan salt lamps are also said to release negative ions, and to offset the effects of EMFS.
- Ventilate. “Open your windows as often as you can,” says Nicole Bijsma. “A healthy home smells like fresh air.” Another option is to have “trickle vents” installed, filtered ventilation that fits in your window (make sure to have two fitted for effective cross ventilation. You can also have a HEPA filter installed in your air conditioner, if you use one.
- Wet mop, and seal crevices and cracks where dust can collect.
Leave the pollution outside
Of course we can’t get away from pollution completely. One of the reasons I called my recently released book Less Toxic Living, and not Non-toxic Living, is because there is really no such thing as the latter anymore. But we can reduce our exposure.
All the suggestions above will help clean your air. You can also reduce the amount of contaminants that enter your house, by paying attention to what comes in. This is a whole article (or book) on its own, but you can start by
- avoiding anything that is artificially fragranced or has the word “fragrance” listed in the ingredients, from cleaning and personal care products, air fresheners to scented toys; using only phthalate free plastics (ideally choose plastics labelled #2, #4 or #5, or no plastics at all);
- allowing dry cleaned clothes to hang outside on the line for a period before bringing them into your home;
- cleaning with non-toxic DIY options like bicarb soda (baking soda), washing soda and vinegar, and
- taking off your shoes at the door.
This post was shared over at Essentially Jess.
Over to you: Do you have house plants? What else do you do to keep your indoor air clean?