Houseplants add a touch of decoration indoors, but they also have a practical use. Most people know plants add oxygen to the air, but many do not know that some plants also clean the air. Although smoking should always be done away from children, sometimes residual smoke is unavoidable. Place a few plants in the area where smoke is a problem to help rid the air of unpleasant scents and unhealthy toxins.
In the early 1970s, NASA became concerned by the amount of pollution in the air in the Skylab space station. After all, the astronauts in the Skylab couldn't simply open a window to let in some fresh air. NASA needed a sustainable way to clean and freshen the air in the space station. To that end, NASA contacted and eventually hired Bill Wolverton, an environmental scientist who worked for the U.S. military and had become famous for his work in using plants to filter pollutants. Throughout the 1980s and 1990s, Wolverton published dozens of papers detailing his findings on how plants can be used to remove contaminants in the air.
Wolverton's studies did not specifically focus on tobacco smoke. But the studies did find that several common houseplants are effective at ridding the air of formaldehyde, benzene and carbon monoxide, among other toxins. These are all chemicals in cigarette smoke. Of the thousands of other chemicals in cigarette smoke, more than 70 of them are known to cause cancer. This is especially concerning when it comes to children and secondhand or even thirdhand smoke. Georg E. Matt, a professor at San Diego State University, in a study published in January 2011 in the journal "Tobacco Control," found that smoke becomes trapped on surfaces, such as carpets, walls and ceilings, even long after smokers have left the residence. Even if you don't smoke, your children could be exposed to the toxins in tobacco smoke left in the home.
The best air-cleaning plants are broad-leaved foliage plants. Topping the list is English ivy (Hedera helix), which makes an attractive houseplant and also thrives outdoors in U.S. Department of Agriculture plant hardiness zones 4 through 9. Another top-performing plant is golden pothos (Epipiremnum aureum), which is also a vine. The plant, which features golden markings on the leaves, is most often grown indoors, as it is only hardy in USDA zones 10 through 12. Philodendrons, and the heartleaf philodendron in particular (Philodendron scandens) were also found to be highly effective. The heartleaf philodendron grows outdoors in USDA zones 11 and 12 but is usually grown as a houseplant.
No plant or combination of plants can filter all toxins from cigarette smoke out of the air. If you have children who are exposed to tobacco smoke, consider buying a HEPA-rated air purifier. If you do want to use plants to filter at least some of the chemicals, make sure you use enough of them: Wolverton's study found that at minimum, it takes one plant for every 100 square feet to show a significant change in air quality.