Some researchers have found a good use for those billions of cigarette butts that line our streets and generally foul our environment.

They can be recycled into an anti-corrosive agent for steel, according to the researchers in the American Chemical Society's March issue of Industrial & Engineering Chemistry Research.

"Cigarette butts, one of the most ubiquitous forms of garbage in the world, have been found to be toxic to saltwater and freshwater fish," the researchers write. "Still, humans are inadvertently carpeting the planet in cigarette butts. That is billions of cigarettes flicked, one at a time, on our sidewalks, beaches, nature trails, gardens, and other public places every single day."

The article says one estimate is that 4.5 trillion cigarette butts are cast off into the environment every year. And while some states and cities have moved to ban smoking on beaches, there doesn't seem to be much impact and there haven't been reports about how to reuse them.

The researchers took discarded butts from cigarettes made in Virginia, ran some water through them and mixed what was extracted with hydrochloric acid in different concentrations until they found the best anti-corrosive agent.

With all the smoking bans in effect across the nation, they would need only go outside any bar to find a ready supply of material.

(By Meredith Cohn, The Baltimore Sun, 19/05/2010)