SMOKING PLANTS

Plants can pick up pollutants from the air and soil, including the nicotine from tobacco

Plants turn out to be secondhand smokers. They breathe in smoke, nicotine and other pollutants released by burning tobacco. And that can be a good thing for people. By sharing our environment with green plants, people may be able to breathe easier. But can plants that people eat also suck up pollutants? Yes, a new study finds. And that may explain why nicotine has been found in some herbal teas, its authors note.

A quarter-century ago, NASA scientists showed that houseplants could filter formaldehyde, benzene and other nasty pollutants from the air. As reported in Science News, a broad range of plants could do this — everything from spider plants and Gerbera daisies to mums and English ivy. So perhaps it’s not surprising that greenery also can remove smoking related pollutants such as nicotine.

Dirk Selmar works at the Technical University of Braunschweig, Germany. His research team recently decided to work with peppermint plants. They trapped pots of them with fumes from 11 smoked cigarettes. Within two hours, peppermint leaves had picked up a “tremendously” high amount of nicotine, the researchers now report.

Nicotine is the addictive chemical in tobacco that makes it so hard for smokers to give up their habit. Smokers inhale plenty of nicotine. They also exhale some. And as tobacco burns, it also releases nicotine into the air. Even eight days after the plants encountered the cigarette smoke, their leaves’ spike in nicotine had dropped by only half.

But air is not the only route by which plants can become exposed to nicotine. Roots can also take up the pollutant from soil. For instance, the researchers sprinkled 100 milligrams of tobacco — about an eighth to a tenth of what would be in a cigarette — onto the ground in which plants were growing. Nine days later, the plants’ older peppermint leaves had roughly five times as much nicotine as did those in untreated plants. “From a food safety point of view, there is no reason to panic,” Selmar says. He intended the research to help explain unexpected amounts of nicotine in some herbal teas and spices. Smoking farmers and processors could contribute, at least somewhat, to the bonus nicotine, he now concludes.

Neema Suresh

EVS Faculty

BenchMark International School