<http://schema.org/about>
"Throwing out gum isn't much better for the environment than swallowing it is for your stomach. That's because conventional gum doesn't biodegrade. At all. And Americans chew around 100 million pounds of the stuff every year."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/green-food/new-gum-is-degradable-and-easily-removed-from-desks-and-sidewalks.html>