Tobacco companies are confirming the presence of cadmium, ammonia, lead, formeldehyde, and arsenic in most cigarettes. In compliance with a new Minnesota law, 65 companies have filed information with the state health department on over seven-hundred brands of cigarettes. The vast majority contain at least trace amounts of these toxic substances in their lit cigarettes. Health researchers say its well-known that cigarettes contain harmful chemicals. Dr. Harry Lando, a professor of epidemiology at the University of Minnesota, says the public disclosure may just make some smokers more aware of what they're inhaling.