Tabacco smoke is made up of thousands of harmful chemicals. Some of these leading to cause cancer. This can lead to lung and heart diease which is deadly. Some of the chemicals found in cigarettes are: Cyanide, Benzene, Methanol, Acetylene, and Ammonia. Cigarettes not only contain these harmful chemicals but they also contain tar and poisonous gases. Millions of Americans and people around the world are addicted to smoking. In the United States smoking is responsible for 30% of cancer deaths. Stop smoking. It is a very unhealthy habit.