The remedy for a sick building could be rooted in live plants.

A NASA study concludes that greenery naturally filters the air and can reduce nearly half the airborne illnesses that thrive in tight, energy-efficient buildings.

The study concluded that even a small planting of ivy can counteract toxins in the air, especially benzene, a carcinogen found in gasoline and some paints and glues. Other healthy favorites are chrysanthemums, peace lilies, parlor palms, dracaena and philodendron.

"It is incredibly soothing working around plants," said Kathleen Campiglia of Cooper Medical Services. "It's more pleasant and less stressful."

A Washington State University study found that workers' blood pressure dropped slightly when plants were brought into offices. But the results were negligible, with systolic readings declining between two and four units.

However, plants did make a significant improvement in productivity. Worker output at computers increased 12 percent after their offices went green, the study said.

Four out of five -- 81 percent -- said they enjoyed having plants in their workspaces. Greenery was especially important to people who work in areas without windows.

Reach Eileen Smith at (856) 486-2444 or esmith@courierpostonline.com