Smoking is responsible for one in three preventable deaths in New York City, according to NYC figures. Secondhand smoke causes more cancer deaths than asbestos, benzene, arsenic, and pesticides combined. In addition to the dangers of breathing secondhand smoke, the act of smoking, especially in front of children, makes the practice seem normal and acceptable. Studies have shown that adolescents whose parents smoke are nearly three times as likely to start. Smoking is also a significant source of litter. Cigarette butts, made of plastic cellulose acetate, can take more than 18 months to decompose and are the primary source of beach litter. In fact, cigarette butts account for 75 percent of the litter found on New York City beaches.