Common houseplants cure sick building syndrome

Tightly sealed homes save both energy and money, but without proper ventilation, they can become cesspools of dust, chemicals and toxic vapors. These pollutants can cause "sick building syndrome"and pose a hazard to human health, particularly for those with allergies or respiratory conditions. Even in central cities, the air quality inside homes can be lower than the air quality outside. People with green thumbs, however, can rest easy. Not only are plants relaxing to look at, they provide a simple air cleaning service.

Last year, researchers from the University of Georgia tested 28 different indoor plants for their ability to remove toxic chemicals such as benzene, octane and toluene. These volatile organic compounds can be found in carpeting, electronics, furniture, pets and even tap water. High levels of these compounds were found in older homes in Athens, Georgia, which surprised the researchers as older homes are generally more drafty and less insulated than newer homes. Of the plants tested, the purple waffle plant did the best job of purifying the air, closely followed by English ivy and variegated wax plant. The researchers recommend having at least one plant per 100 square feet of living space.

NASA researchers have also found that plants improve indoor air quality. A two year study from 1989 concluded that plant leaves, roots and soil bacteria all work together to remove even trace levels of toxic vapors. Philodendrons, spider plants and golden pathos earned the highest ratings for removing formaldehyde, while flowering plants such as daisies were most effective at removing benzene. The chemical benzene can be found in common household items like detergents, paints and plastics, while formaldehyde can be found in grocery bags, paper towels, cigarette smoke and resins. Other plants effective at removing these chemicals and carbon monoxide include bamboo palm, Chinese evergreen, mother-in-law's tongue and peace lily. All of these plants require minimal care and survive in low light. Researchers noted that adding a fan to improve airflow increased the plants' ability to remove toxins.

Pollution is becoming an increasing concern in India, where burgeoning cities contribute to poor air quality. Researcher Kamal Meattle has found that you only need three basic plants to provide enough fresh air indoors: areca palm, mother-in-law's tongue and money plant. Areca palm removes carbon dioxide during the day while mother-in-law's tongue removes carbon dioxide during the night. Money plant removes formaldehyde and other volatile organic compounds. Meattle recommends growing several waist- or shoulder-high plants per person. With these three plants, you can have fresh air around the clock.

For those without green thumbs, simple lifestyle changes can still make a dramatic difference. Take off your shoes to keep dirt and dust outside, switch to environmentally-friendly cleaning products and definitely invest in a fan.