The people who clean up public floors and surfaces worldwide are getting fed up with trying to scrape up chewing gum. Pressure is mounting on gum makers to invent non-sticky gum. In China, discarded gum is a menace in Tiananmen Square. Chinese authorities are trying to develop a chemical strong enough to dissolve the gum. In Singapore, the chewing gum ban of 1991 is still in place, except for those who need to chew for medical reasons. In the U.K., local governments want to tax chewing gum to pay for the cost of removing it. Cigarettes are already taxed in many countries, in order to pay for the health problems they cause. One official says, “It’s a serious filth that threatens the more