Polystyrene — more commonly known by its Styrofoam brand name — is considered one of the more difficult materials to recycle. But Maryland's Carroll County recently became the second jurisdiction in the state to introduce a public recycling program for the substance. According to Steven L. Johnson, a professor at Temple's Fox School of Business who has studied social trends, participation in the new recycling program could be contagious. "Once people see their neighbors recycling Styrofoam," Johnson said, "they'll get on board."