House plants aren't just about decoration. They provide very real health benefits in both your home and workplace.

Plants can deter illness. Ten percent of the moisture in the atmosphere is the result of transpiration – the process whereby plant roots tap the groundwater table for water which then evaporates through its leaves. Hopefully you have no groundwater in your home, but your house plants are still transpiring, generating humidity, and that's a good thing. Moist air protects against colds, dry skin, sore throats and dry coughs. Higher absolute humidity also inhibits thesurvival and transmission of the flu virus.

When house plants are not preventing you from getting sick, they may be enhancing your healing processes. How do you think the tradition of bringing flowers to people in the hospital got started? One study indicated that “viewing plants during the recovery period had a positive influence linking directly to health outcomes of surgical patients” and that “patients in hospital rooms with plants and flowers had significantly more positive physiologic responses evidenced by lower systolic blood pressure, and lower ratings of pain, anxiety, and fatigue than patients in the control room.”

As you learned in grade school, plants “inhale” the carbon dioxide we exhale and release fresh oxygen. Less well-known is that when plants cease their photosynthesis at night, most of them switch gears and start taking in oxygen and belching out CO2. For this reason, be sure to adorn your bedrooms with orchids, succulents and epiphytic bromeliads; these are the among the few special plants which stick to the daytime program of releasing oxygen.

It should come as no surprise that NASA is no slouch when it comes to research on air quality within sealed environments, and the spacemen are very pro-plant. Up to 87 percent of volatile organic compounds (VOCs) are expunged every 24 hours by houseplants, according to NASA research. VOCs include substances like formaldehyde (present in rugs, vinyl, cigarette smoke and grocery bags), benzene and trichloroethylene (both found in man-made fibers, inks, solvents and paint). They cite how both plant leaves and roots are utilized in removing trace levels of toxic vapors from inside tightly sealed buildings.

NASA even made a little list of the top ten house plants for removing indoor pollutants:

• Peace lily
• Golden pothos
• English Ivy
• Chrysanthemum
• Gerbera daisy
• Mother-in-law's tongue
• Bamboo palm
• Azalea
• Red-edge dracaena
• Spider plant

You don't have to turn your home into an arboretum for your health to benefit from house plants. Experts at NASA suggest you use 15 to 18 plants in 6- to 8-inch diameter pots for an 1,800-square-foot house, or roughly one larger plant every 100 square feet.