Even after they've been cleaned and repainted, homes where smokers once lived can contain cigarette smells and toxins for months afterward.

Afternoon smokeGeorg E. Matt, a San Diego State psychology professor and the first to examine smokers' residences after they left, found that "Third-hand smoke is trapped on surfaces like walls and ceilings, and in household dust and carpets left over by previous residents."

So, how do you clean cigarette smells out of a home? It may come as a surprise but the most effective and natural way to get rid of tobacco smoke odors and pollutants is with plants. How does it work? Plants emit a water vapor, which creates a pumping action that pulls in contaminated air and converts it into food for the plant. It's an incredible win-win situation provided by Mother Nature: The air is cleaned and the plants are fed. In addition, the humans don't have to lift a finger to make it happen.

This can be particularly important if you have small children. Residue and particles left behind by smokers contain heavy metals, carcinogens, and even radioactive materials. The toxins in lingering cigarette smoke include toluene, formaldehyde, acetone and ammonia.

The discovery of plants as environmental cleaners

Around the time of the U.S. energy crisis in the '70s, scientist B.C. Wolverton was studying ways the environment cleans itself naturally.

As builders created indoor environments that were sealed tight to prevent energy leakage, an occurrence dubbed the Sick Building Syndrome became prevalent, with symptoms that included burning eyes and respiratory difficulties.

The syndrome was caused by the synthetic materials and volatile organic compounds (VOC) used in the building process, and the lack of circulation or a natural cleansing process brought about by the earth's incredible ecosystem.

Wolverton's work with plants

Wolverton's first success was finding that swamp plants naturally removed Agent Orange that had leaked into local waters near a NASA test center. Wolverton then turned his attention to cleaning the air. In a 1989 report, he advised, "If man is to move into closed environments, on Earth or in space, he must take along nature’s life support system." This support system referred to plants.

In his highly-popular book, "How to Grow Fresh Air: 50 Houseplants That Purify Your Home or Office," Wolverton details which plants remove the most toxins, and the level of maintenance required for each type of plant.

Powerful air-cleaning plants

Peace LilyThe best plants for improving indoor air quality include the philodendron, spider plant, English ivy, peace lily, Chinese evergreen, bamboo palm and golden pothos. Some of the more effective plants to clear out formaldehyde include the Boston fern, dwarf date palm, bamboo palm, English ivy, weeping fig and lady palm.

Gerbera daisies and English ivy have been shown to remove benzene, another toxin in cigarette smoke, while the daisies also get rid of trichloroethylene, which is found in inks, solvents and paint. Chrysanthemums are helpful in removing carbon monoxide from the air, and add a cheerful spot of color to the decor.

Cost effective

Compared to costly manufactured air purifiers, nature's version of cleaning cigarette smells and toxins is inexpensive, requires no electricity, and adds beauty to your home.

Most of the plants listed require minimal care, and can provide years of purifying action with just a bit of watering, leaf-dusting and pruning. Research also suggests that plants add a psychological perk to a home or office, and that individuals recovering from illness do so faster in the presence of plants.

Know of other ways to clean cigarette smells with plants? Leave us a note in the comments below.

Photos: Armando Maynez/Flickr; pizzodisevo (therapy - terapia - Therapie )/Flickr