Tobacco cleans up toxic act

Tobacco could soon be used to treat cancer-causing pollutants thanks to a bizarre twist of science.

Companies still traditionally deal with the problem of contaminated land by removing the soil and transporting it elsewhere.

Now scientists are genetically engineering tobacco plants whose roots produce detergents that break down the toxins in the soil, leaving the land safe to be reused.

Clayton Rugh, an assistant professor of crop and soil sciences at Michigan State University in the US, described his team's "mop and glow" tobacco plants as a "beautiful irony".

The technology, one of the latest developments in an area known as "phytoremediation", was unveiled at the Association for the Advancement of Science meeting in Washington last week.

It is designed to deal with hazardous chemicals such as pesticides, PCBs (polychlorinated biphenyls) and dioxins that cling tightly to the soil.

These pollutants, which cannot be absorbed in water, are dangerous in small concentrations and notoriously difficult to remove.

Professor Rugh said: "If companies want to develop a contaminated brownfield site, they usually want waste removed as fast as possible in trucks.

"But phytoremediation is cheaper than lawyers, so they should be inclined to use it."

Professor Rugh, who is collaborating with York University and the Sainsbury Laboratory in Norwich, as well as with scientists in Belarus, insisted that there was no risk of cross-breeding between these genetically engineered tobacco plants and food-related plants.

This meant that there would be no risk of the contaminants entering the food chain, he added.