Thirty of America\'s 50 largest cities are now covered by laws that prohibit smoking in all indoor areas of private workplaces, restaurants, and bars, according to a study released Thursday from the Centers for Disease Control and Prevention. By late 2000, only one of the 50 largest U.S. cities -- San Jose, California -- was covered by such a law. As of Oct. 5, 2012, 16 of the 50 largest cities were covered by local comprehensive smoke-free laws, and 14 more were covered by state comprehensive smoke-free laws. According to the study, almost half Americans are protected by state or local laws of this kind, compared to less than three percent in 2000. Scientific studies have found that smoke-free laws reduce exposure to secondhand smoke, reduce smoking, and improve health, including reducing heart attacks. \"Communities have made tremendous progress eliminating smoking from worksites and public places in 60 percent of big cities in the United States. Smoke-free laws save lives and don\'t hurt business,\" said CDC Director Thomas Frieden in a statement. \"If we can protect workers and the public in the remaining 20 largest cities, 16 million people would be better protected from cancer and heart disease caused by secondhand smoke.\"